Ink and sheet for thermal transfer recording

Abstract

To provide an ink having excellent storage stability and high light fastness.SOLUTION: Provided is an ink including a medium and carrier particles dyed with an anthraquinone compound as a cyan colorant, a monoazo compound as a magenta colorant, and a pyrazoline compound as a yellow colorant.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an ink and a thermal transfer recording sheet. [Background technology]

[0002] In the apparel industry, the large amount of industrial wastewater generated during the dyeing process of various fabrics is considered a problem from the viewpoint of environmental impact. Therefore, digital textile printing methods using inkjet printing or electrophotography have been actively developed in recent years as a method for providing printed products with low energy and low cost. For example, there are methods using ink containing pigments, methods using ink containing dye-dyed resin particles, and methods using ink containing sublimation dyes.

[0003] Water-based inks containing pigments (water-based pigment inks) have excellent lightfastness, but they tend to have poor color development. Ink containing dye-dyed resin particles also has difficulty achieving both lightfastness and color development.

[0004] For example, inkjet inks using resin particles colored with an anthraquinone dye, an azo dye, or a methine dye as a colorant have been reported, but the inventors' investigations have revealed that further improvement is required in terms of lightfastness.

[0005] Additionally, in the field of writing instruments (particularly ballpoint pens), there is growing demand for inks and functions that meet user requirements such as writing feel, initial writing performance, and consistent writing. Ballpoint pens come in a variety of colors, including oil-based ballpoint pens, water-based ballpoint pens, and gel ink ballpoint pens, as well as black, red, blue, yellow, pink, green, and orange. Dyes, pigments, and mixtures thereof are used as colorants in inks. For example, oil-based inks using pigments have excellent writing durability, but suffer from storage stability issues due to the tendency of pigments to aggregate and settle in the ink. Using oil-based inks with aggregated or settled pigments can result in poor writing results. In contrast, oil-based inks using dyes, which are characterized by their ease of dissolving in solvents, are less prone to aggregation and settling than pigments and have excellent storage stability, but tend to have poor lightfastness. For example, Patent Document 1 reports a ballpoint pen paste (ink for writing instruments) that uses an anthraquinone dye, an azo dye, or a methine dye as a colorant.

[0006] In addition, in image recording methods using a sublimation transfer system that uses ink containing sublimation dyes, not only are images with high optical density required, but also suppression of color blur due to heat press temperatures is required to ensure color tone stability when repeatedly recording images. Furthermore, with the expansion of applications to sports apparel, etc., there is also an increasing demand for lightfastness. For example, Patent Document 2 reports an example of using a black ink containing multiple colors of sublimation dyes.

[0007] Furthermore, sublimation dyes can also be used in image recording methods using a thermal transfer recording system that uses a thermal transfer recording sheet having a colorant layer containing a sublimation dye, allowing printing by a dry process. In thermal transfer recording systems, each colorant layer is typically formed by mixing two or three compounds. This poses the problem of color fading due to color mixing between the compounds during image recording. Therefore, efforts have been made to suppress this fading in thermal transfer recording sheets. For example, Patent Document 3 proposes a solution by incorporating an anti-fading agent into the colorant layer. Patent Document 4 also reports a combination of yellow, magenta, and cyan colorants to produce black. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 8-20669 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-132756 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-158879 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-193545 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the inventors' investigations revealed that the inks described in Patent Documents 1 to 4 all had issues that needed to be improved. Specifically, the ink described in Patent Document 1 needed further improvement in terms of lightfastness. Furthermore, the ink described in Patent Document 2 needed further improvement in terms of the stability of the image density due to differences in black image density and heat press temperature (hereinafter also referred to as color development stability), and in terms of lightfastness. Furthermore, the inks described in Patent Documents 3 and 4 needed further improvement in terms of color fading due to color mixing (hereinafter also referred to as color mixing fading).

[0010] Therefore, an object of the present invention is to provide an ink having good storage stability and high lightfastness. Another object of the present invention is to provide an ink having high optical density and excellent color development stability and lightfastness during heat pressing. Still another object of the present invention is to provide a thermal transfer recording sheet that can suppress fading due to color mixing when blending three types of yellow, magenta, and cyan colorants used in the black colorant layer of the thermal transfer recording sheet. [Means for solving the problem]

[0011] According to one aspect of the present invention, there is provided an ink comprising a medium and carrier particles dyed with a compound represented by the following general formula (1), a compound represented by the following general formula (2), and a compound represented by the following general formula (3):

[0012] [ka]

[0013] [In general formula (1), R1 to R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group.

[0014] [ka]

[0015] [In general formula (2), R5 and R6 each independently represent an alkyl group; R7 represents an alkyl group or an -NH2 group; R8 represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group;

[0016] [ka]

[0017] [In general formula (3), R9 and R 10 each independently represents an alkyl group, R 11 represents an alkyl group, an aryl group, or an alkoxy group; R 12 represents an alkyl group or an aryl group.

[0018] According to another aspect of the present invention, there is provided an ink comprising an aqueous medium, a dispersant, a compound represented by the following general formula (1), a compound represented by the following general formula (2), and a compound represented by the following general formula (3):

[0019] [ka]

[0020] [In general formula (1), R1 to R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group.

[0021] [ka]

[0022] [In general formula (2), R5 and R6 each independently represent an alkyl group; R7 represents an alkyl group or an -NH2 group; R8 represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group;

[0023] [ka]

[0024] [In general formula (3), R9 and R 10 each independently represents an alkyl group, R 11 represents an alkyl group, an aryl group, or an alkoxy group; R 12 represents an alkyl group or an aryl group.

[0025] Furthermore, according to another aspect of the present invention, there is provided a thermal transfer recording sheet having a substrate and a black colorant layer formed on the substrate, characterized in that the black colorant layer contains a compound represented by the following general formula (1), a compound represented by the following general formula (2), and a compound represented by the following general formula (3).

[0026] [ka]

[0027] [In general formula (1), R1 to R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group.]

[0028] [ka]

[0029] [In general formula (2), R5 and R6 each independently represent an alkyl group; R7 represents an alkyl group or an -NH2 group; R8 represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group;

[0030] [ka]

[0031] [In general formula (3), R9 and R 10 each independently represents an alkyl group, R 11 represents an alkyl group, an aryl group, or an alkoxy group; R 12 represents an alkyl group or an aryl group. [Effects of the Invention]

[0032] According to one aspect of the present invention, an ink having good storage stability and high lightfastness can be provided. According to another aspect of the present invention, an ink having high optical density and excellent color development stability and lightfastness during heat pressing can be provided. According to yet another aspect of the present invention, a thermal transfer recording sheet can be provided that can suppress fading due to color mixing in the yellow, magenta, and cyan color materials used in the black color material layer of the thermal transfer recording sheet. DETAILED DESCRIPTION OF THE INVENTION

[0033] The present invention will be described in detail below.

[0034] First Embodiment As a result of extensive research to solve the above problems, the present inventors have found that by using a medium and carrier particles dyed with compounds represented by general formulas (1), (2), and (3), it is possible to provide an ink having good storage stability and high light resistance.

[0035] Conventionally, inks using carrier particles dyed solely with the compounds represented by general formulas (1), (2), and (3) have been prone to aggregation and have had problems with storage stability or light resistance.

[0036] The inventors' investigations have revealed that when carrier particles dyed with compounds represented by general formulas (1), (2), and (3), which each have problems when used alone as coloring materials, are used, inks with good storage stability and high lightfastness are obtained. The mechanism by which the above-mentioned effects are achieved by mixing these compounds represented by general formulas (1), (2), and (3) is not clearly understood, but the inventors speculate as follows.

[0037] The compounds represented by general formulas (1), (2), and (3) are structurally similar in size, and the three compounds overlap due to π-π stacking interactions or hydrogen bonds between the benzene rings of each compound. This overlapping stabilizes the three compounds, which is thought to result in the aforementioned effects.

[0038] The composition of the ink according to this embodiment will be described in detail below.

[0039] The ink according to this embodiment contains a medium and carrier particles dyed with compounds represented by general formulas (1), (2), and (3). The ink according to this embodiment is suitable as an ink because it has good storage stability and high light resistance due to the use of carrier particles dyed with three specific compounds.

[0040] [Coloring agent] (Compound represented by general formula (1)) First, the compound represented by the following general formula (1), which is a cyan coloring material, will be described.

[0041] [ka]

[0042] [In general formula (1), R1 to R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group.]

[0043] In general formula (1), the alkyl groups represented by R1 to R4 are not particularly limited. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, octyl, dodecyl, nonadecyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, 2-ethylpropyl, and 2-ethylhexyl groups. Among these, linear, branched, or cyclic primary, secondary, or tertiary alkyl groups having 1 to 20 carbon atoms are preferred. A methyl or ethyl group is more preferred, as this facilitates the production of an ink with good storage stability and high lightfastness.

[0044] In general formula (1), the aryl group in R1 to R4 is not particularly limited, but specific examples include a phenyl group and a naphthyl group. In particular, a phenyl group is preferred because it makes it easier to obtain an ink with good storage stability and high light resistance.

[0045] Preferred examples of the compound represented by general formula (1) include compounds (1-1) to (1-14) shown below, but are not limited to these compounds.

[0046] [ka]

[0047] The compound represented by the general formula (1) may be used alone, or two or more may be used in combination to adjust the color tone, etc., depending on the application. Furthermore, the compound may be used in combination with a known pigment or dye within a range that does not impair the effects of the present invention. The known pigment or dye to be combined may be one type alone or two or more types.

[0048] Among these, compounds represented by general formula (1) in which R1 and R3 are each independently a hydrogen atom, R2 is an alkyl group having 1 to 4 carbon atoms, and R4 is a phenyl group or a methylphenyl group are preferred. Compounds (1-6), (1-7), (1-8), and (1-9) are particularly preferred. Use of any of these compounds makes it easier to obtain an ink with good storage stability and high lightfastness.

[0049] The compound represented by general formula (1) can be synthesized by a known method, but is also available as a commercially available product.

[0050] (Compound represented by general formula (2)) Next, the compound represented by the following general formula (2), which is a magenta coloring material, will be described.

[0051] [ka]

[0052] [In general formula (2), R5 and R6 each independently represent an alkyl group; R7 represents an alkyl group or an -NH2 group; R8 represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group.

[0053] In general formula (2), the alkyl groups for R5 and R6 are not particularly limited, but specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these, a linear or branched alkyl group having 1 to 4 carbon atoms is preferred. An ethyl group or an isobutyl group is more preferred, as this makes it easier to obtain an ink with good storage stability and high lightfastness.

[0054] In general formula (2), the alkyl group for R7 is not particularly limited, but specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a sec-butyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these, a linear or branched alkyl group having 1 to 4 carbon atoms is preferred. An ethyl group or an isobutyl group is more preferred, as this makes it easier to obtain an ink with good storage stability and high lightfastness.

[0055] In general formula (2), the alkyl group for R8 is not particularly limited, but specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these, a linear or branched alkyl group having 1 to 4 carbon atoms is preferred. A methyl group is more preferred because it makes it easier to obtain an ink with good storage stability and high lightfastness.

[0056] In general formula (2), the halogen atom for R8 is not particularly limited, but specific examples include a chlorine atom, a bromine atom, a fluorine atom, etc. Among these, a chlorine atom is preferred because it makes it easier to obtain an ink that has good storage stability and high lightfastness.

[0057] The compound represented by general formula (2) has an azo-hydrazo tautomer, which is within the scope of the present invention. The chemical formulas described in this paragraph and subsequent paragraphs will only depict structures similar to general formula (2), but they also include both azo-hydrazo tautomers. Furthermore, the compound represented by general formula (2) may be a mixture of these tautomers.

[0058] Preferred examples of the compound represented by general formula (2) include compounds (2-1) to (2-9) shown below, but are not limited to these compounds.

[0059] [ka]

[0060] The compound represented by the general formula (2) may be used alone, or two or more may be used in combination to adjust the color tone, etc., depending on the application. Furthermore, the compound may be used in combination with a known pigment or dye within a range that does not impair the effects of the present invention. The known pigment or dye to be combined may be one type alone or two or more types.

[0061] Among these, compounds represented by general formula (2) are preferred in which R5 to R7 are each independently an alkyl group having 1 to 4 carbon atoms and the same number of carbon atoms, and R8 is a hydrogen atom. Compounds (2-1), (2-2), (2-3), and (2-4) are particularly preferred. Use of any of these compounds makes it easier to obtain an ink with good storage stability and high lightfastness.

[0062] The compound represented by formula (2) can be synthesized by a known method, but is also available as a commercially available product.

[0063] (Compound represented by general formula (3)) Next, the compound represented by the following general formula (3), which is a yellow coloring material, will be described.

[0064] [ka]

[0065] [In general formula (3), R9 and R 10 each independently represents an alkyl group, R 11 represents an alkyl group, an aryl group, or an alkoxy group; R 12 represents an alkyl group or an aryl group.

[0066] In general formula (3), R9~R 12The alkyl group in is not particularly limited, but specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Among these, a linear or branched alkyl group having 1 to 4 carbon atoms is preferred. In particular, a methyl group or an ethyl group is preferred, and an ethyl group is particularly preferred, as this makes it easier to obtain an ink that has good storage stability and high lightfastness.

[0067] In general formula (3), R 11 and R 12 The aryl group in is not particularly limited. Examples of the substituent include an alkyl group, an alkoxy group, a carboxamide group, or a sulfonate salt group such as sodium sulfonate. Specific examples of the aryl group include a phenyl group, a naphthyl group, a methylphenyl group, a methoxyphenyl group, or a benzenecarboxamide group (aminocarbonylphenyl group). In particular, a phenyl group is more preferred because it makes it easier to obtain an ink with good storage stability and high light resistance.

[0068] In general formula (3), R 11 The alkoxy group in is not particularly limited, but examples include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Among these, an alkoxy group having 1 to 4 carbon atoms is preferred. In particular, a methoxy group or an ethoxy group is more preferred, as this makes it easier to obtain an ink with good storage stability and high light resistance.

[0069] As shown in the reaction formula below, the compound represented by general formula (3) has a cis-trans structural isomer represented by the following general formula (3). Therefore, the compound represented by general formula (4) may be contained together with general formula (3) within a range that does not impair the effects of the present invention.

[0070] [ka]

[0071] Preferred examples of the compound represented by general formula (3) include compounds (3-1) to (3-5) shown below, but are not limited to these compounds.

[0072] [ka]

[0073] The compound represented by the general formula (3) may be used alone, or two or more may be used in combination to adjust the color tone, etc., depending on the application. Furthermore, the compound may be used in combination with a known pigment or dye as long as the effect of the present invention is not impaired. The known pigment or dye to be combined may be one or two or more.

[0074] Among these, in general formula (3), R9 and R 10 are each independently an alkyl group having 1 to 4 carbon atoms, and R 11 is preferably an alkoxy group having 1 to 4 carbon atoms. 10 are each independently an alkyl group having 1 to 4 carbon atoms, and R 11 is an alkoxy group having 1 to 4 carbon atoms, and R 12 is more preferably an aryl group. In particular, compounds (3-2), (3-4), or (3-5) are preferred, and compounds (3-2) or (3-5) are more preferred. Use of any of these compounds makes it easier to obtain an ink with good storage stability and high lightfastness.

[0075] The compound represented by the general formula (3) can be synthesized by a known method, but is also available as a commercially available product.

[0076] In the ink of this embodiment, the total amount of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is not particularly limited. Preferably, it is 0.5% by mass or more and 10.0% by mass or less, and more preferably 1.0% by mass or more and 7.0% by mass or less, based on the total mass of the ink. Furthermore, the blending ratio of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is not particularly limited. Preferably, the blending ratio (mass ratio) of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is as follows: For 10 parts by mass of the compound represented by general formula (1), it is preferred that the compound represented by general formula (2) is 3 parts by mass or more and 9 parts by mass or less, and the compound represented by general formula (3) is 1 part by mass or more and 6 parts by mass or less. In particular, it is more preferable that the compound represented by general formula (2) is 4 parts by mass or more and 8 parts by mass or less, and the compound represented by general formula (3) is 2 parts by mass or more and 5 parts by mass or less. Also, it is even more preferable that the compound represented by general formula (2) is 4 parts by mass or more and 6 parts by mass or less, and the compound represented by general formula (3) is 2 parts by mass or more and 4 parts by mass or less. By using carrier particles dyed with a colorant within such ranges, it is easy to obtain an ink with good storage stability and high light resistance.

[0077] As described above, the ink of this embodiment uses a combination of at least one compound represented by general formula (1), (2), and (3) as a colorant, but may also use a known colorant in combination within a range that does not impair solubility or dispersibility in a medium. Examples of such colorants include, but are not limited to, condensed azo compounds, azo metal complexes, and methine compounds.

[0078] In the ink of this embodiment, the content of the colorant is not particularly limited and is set appropriately depending on the application. Preferably, the total content, including any known colorant, is 1.0 to 30.0 parts by mass, more preferably 2.0 to 20.0 parts by mass, and even more preferably 3.0 to 15.0 parts by mass, based on 100 parts by mass of the medium. If it is within the above range, sufficient coloring power is obtained and the dispersibility of the colorant is also good.

[0079] [Carrier particles] In this specification, "carrier particles" refers to carriers that can be dispersed in a medium and exist in the medium in a state of particle size. The carrier particles exist in a dispersed state in the ink. When the medium is an aqueous medium, the carrier particles exist in a dispersed state in the aqueous medium, i.e., in the state of a carrier emulsion. The carrier particles dyed with the colorant exist in a state in which the colorant is dispersed or colored in the carrier particles.

[0080] The carrier particles preferably have a cumulative 50% particle diameter (D50) of a volume-based particle size distribution of 140 nm or more and 300 nm or less. When D50 is 140 nm or more, a decrease in the lightfastness of the image can be suppressed. On the other hand, when D50 is 300 nm or less, a decrease in the ink ejection stability can be suppressed.

[0081] When the compounds represented by general formulas (1), (2), and (3) are dyed onto carrier particles, the compounding ratio (mass ratio) of the compounds represented by general formulas (1), (2), and (3) to the carrier particles is not particularly limited. On a mass basis, the total amount of the compounds represented by general formulas (1), (2), and (3) is preferably 0.5 parts by mass or more and 20 parts by mass or less, and more preferably 1 part by mass or more and 10 parts by mass or less, per 100 parts by mass of the carrier particles.

[0082] The content of dyed carrier particles is preferably 1% by mass or more and 10% by mass or less, and more preferably 3% by mass or more and 6% by mass or less, based on the total amount of ink.

[0083] Examples of carrier particles include resins and cellulose nanofibers. Examples of resin types include styrene polymers, acrylic acid polymers, methacrylic acid polymers, polyester resins, polyvinyl ether resins, polyvinyl methyl ether resins, polyvinyl alcohol resins, polyvinyl butyral resins, polyurethane resins, and polypeptide resins. One of these resins may be used alone, or two or more may be used in combination as needed. When the carrier particles are made of resin, they may also be referred to as "resin particles." From the viewpoint of ease of dyeing with a colorant, the carrier particles are preferably resin particles.

[0084] The cellulose nanofibers are selected depending on the intended use. For example, they are obtained by chemically and / or mechanically defibrating plant fibers, and are ultrafine fibers with an average width of about several nm to 20 nm and an average length of about 0.5 μm to several μm. The size (fiber diameter) of these cellulose nanofibers varies depending on the type of cellulose nanofiber. Furthermore, a fiber diameter is selected within a range that does not impair the properties required for various applications, taking into account factors such as thickening effect, stability over time, and color development.

[0085] Materials containing cellulose fibers that can be used include plants such as wood, bamboo, kenaf, hemp, jute, wood pulp, waste paper, crystalline cellulose, agricultural waste, and recycled pulp, animals such as sea squirts, algae, and microorganisms.

[0086] Cellulose nanofibers are commercially available and can also be used. Examples of commercially available products include those sold under the trade names "Leocrysta I-2AX," "CNF 03," and "CNF 04" (all manufactured by Daiichi Chemical Industry Co., Ltd.), "ELLEX-S" (manufactured by Daio Paper Co., Ltd.), and "na noforest-S" (manufactured by Chuetsu Pulp Industry Co., Ltd.).

[0087] [Method for producing dyed carrier particles] When resin particles are used as carrier particles, the resin particles can be produced by a conventionally known method, such as emulsion polymerization, mini-emulsion polymerization, seed polymerization, phase inversion emulsification, etc. Examples of methods for dyeing resin particles include a method of forming resin particles by polymerizing a monomer mixture in which compounds represented by general formulas (1), (2), and (3) are dissolved, and a method of adding compounds represented by general formulas (1), (2), and (3) to resin particles and heating them.

[0088] When cellulose nanofibers are used as carrier particles, the cellulose nanofibers can be dyed, for example, by contacting the cellulose nanofibers with compounds represented by general formulas (1), (2), and (3) in an aqueous medium, followed by heating or oxidation treatment as necessary, and then distilling off the medium to obtain dyed cellulose nanofibers.

[0089] [Medium] In this embodiment, the term "medium" refers to, but is not limited to, water or an organic solvent, and is selected depending on the application and purpose of the ink. When an organic solvent is used as the medium, the type of organic solvent is selected depending on the application and purpose of the ink, and is not limited to the type of organic solvent.

[0090] Examples of organic solvents include alcohols such as methanol, ethanol, isopropanol, butanol, 2-methyl-2-butanol, 3-pentanol, benzyl alcohol, and cyclohexanol; glycols such as methyl cellosolve, diethylene glycol, and diethylene glycol monobutyl ether; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, and cellosolve acetate; aliphatic hydrocarbons such as octane, petroleum ether, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; ethers such as diethyl ether, dimethyl glycol, trioxane, and tetrahydrofuran; acetals such as diethyl acetal; organic acids such as formic acid, acetic acid, and propionic acid; and sulfur- or nitrogen-containing organic compounds such as monoethanolamine, pyridine, dimethyl sulfoxide, and dimethylformamide.

[0091] Furthermore, a polymerizable monomer can also be used as the organic solvent. Examples of the polymerizable monomer include addition polymerizable monomers and condensation polymerizable monomers, and addition polymerizable monomers are preferred. Specific examples of the polymerizable monomer include styrene-based monomers such as styrene, methylstyrene, and ethylstyrene; acrylate-based monomers such as methyl acrylate, ethyl acrylate, behenyl acrylate, 2-ethylhexyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, acrylonitrile, and acrylic acid amide; methacrylate-based monomers such as methyl methacrylate, ethyl methacrylate, diethylaminoethyl methacrylate, methacrylonitrile, and methacrylic acid amide; ethylene, propanol, and the like. Examples of the monomers include olefin monomers such as propylene, butylene, butadiene, isoprene, isobutylene, and cyclohexene; halogenated vinyl monomers such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl iodide; vinyl ester monomers such as vinyl acetate, vinyl propionate, and vinyl benzoate; vinyl ether monomers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; and vinyl ketone monomers such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone. These monomers may be used alone or in combination of two or more, as necessary.

[0092] The content of the medium in the ink is selected depending on the purpose and use of the ink, and is not particularly limited.

[0093] The medium is preferably an aqueous medium containing at least water. The aqueous medium may further contain a water-soluble organic solvent in addition to water. The water used is preferably deionized water or ion-exchanged water.

[0094] The content of water in the ink is preferably 50.0% by mass or more and 95.0% by mass or less, based on the total mass of the ink. Furthermore, the content of water-soluble organic solvent in the ink is preferably 2.0% by mass or more and 40.0% by mass or less, based on the total mass of the ink. As the water-soluble organic solvent, those generally used in inks can be used. Examples include alcohols, (poly)alkylene glycols, glycol ethers, nitrogen-containing compounds, and sulfur-containing compounds. The content of the water-soluble organic solvent in the ink is appropriately selected and is not particularly limited. One type of water-soluble organic solvent may be used alone, or two or more types may be used in combination.

[0095] [Dispersant] When an aqueous medium is used as the medium, it is preferable to use a dispersant to obtain good dispersion stability in the aqueous medium of the carrier particles dyed with the compounds represented by general formulas (1), (2), and (3). The dispersant is not particularly limited, but may be an ionic surfactant, a nonionic surfactant, a polymer surfactant, or the like.

[0096] Examples of ionic surfactants include aliphatic monocarboxylates, polyoxyethylene alkyl ether carboxylates; N-acylsarcosinates, N-acylglutamates, dialkyl sulfosuccinates; alkanesulfonates, alpha-olefin sulfonates, linear or branched alkylbenzene sulfonates, naphthalene sulfonate formaldehyde condensates, alkylnaphthalene sulfonates; N-methyl-N-acyltaurates; alkyl sulfates, polyoxyethylene alkyl ether sulfates, fat and oil sulfate esters; alkyl phosphates, polyoxyethylene alkyl ethers anionic surfactants such as alkyl phosphates and polyoxyethylene alkyl phenyl ether phosphates; cationic surfactants such as alkylamine salts, alkyltrimethylammonium chloride, bromide or iodide, dialkyldimethylammonium chloride, bromide or iodide, alkylbenzalkonium chloride, and alkylpyridinium chloride; and amphoteric surfactants such as alkyl betaine, fatty acid amidopropyl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, alkyl or dialkyldiethylenetriaminoacetic acid, and alkylamine oxide.

[0097] Examples of nonionic surfactants include glycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters; polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polyoxypropylene glycols; fatty acid polyethylene glycols, fatty acid polyoxyethylene sorbitan, and fatty acid alkanolamides.

[0098] Examples of polymer surfactants include anionic polymers such as polyacrylates, styrene-acrylic acid copolymer salts, vinylnaphthalene-acrylic acid copolymer salts, styrene-maleic acid copolymer salts, vinylnaphthalene-maleic acid copolymer salts, and polyphosphoric acid; and nonionic polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyalkylene glycol.

[0099] Examples of commercially available dispersants include styrene-based resin dispersants such as X-200, X-1, X-205, and X-220 (manufactured by Seiko PMC Co., Ltd.) and Nopcosperse 6100 (manufactured by San Nopco Ltd.), acrylic-based resin dispersants such as BYK-190, BYK-187, BYK-191, BYK-194N, BYK-199, and BYKJET-9171 (manufactured by BYK-Chemie Co., Ltd.) and Aron A-6114 (manufactured by Toa Gosei Co., Ltd.), and urethane-based resin dispersants such as BYK-184, BYK-182, BYK-183, and BYK-185 (manufactured by BYK-Chemie Co., Ltd.) and TEGO Disperse 710 (manufactured by Evonic Tego Chemi).

[0100] Among these, BYK-190, BYK-187, BYK-191, BYK-194N, BYK-199, and BYKJET-9171 are preferred, and BYK-190 and BYKJET-9171 are more preferred.

[0101] The content of the dispersant in the ink is not particularly limited and may be selected appropriately. The content (mass %) of the dispersant in the ink is preferably 0.1% by mass or more and 20.0% by mass or less, and more preferably 0.5% by mass or more and 15.0% by mass or less, based on the total mass of the ink.

[0102] [Additives] The following additives may be added to the ink as appropriate, provided they do not impair the properties for various applications: polyhydric alcohols such as trimethylolpropane and trimethylolethane; urea derivatives such as urea and ethyleneurea; water-soluble resins, undyed resin particles; pH adjusters, rust inhibitors, preservatives, antifungal agents, antioxidants, antireducing agents, evaporation accelerators, lubricants, wetting agents, UV absorbers, antifoaming agents, leveling agents, chelating agents, and cellulose nanofibers.

[0103] Examples of ultraviolet absorbers include benzophenone-based, benzotriazole-based, cyanoacrylate-based, and triazine-based ones.

[0104] Examples of commercially available ultraviolet absorbers include Tinuvin P, Tinuvin 326, Tinuvin 571, and Tinuvin 360 (all manufactured by BASF), and Adeka STAB LA-24, LA-29, LA-31RG, LA-32, LA-36, LA-46, LA-F70, and 1413 (all manufactured by ADEKA Corporation). Among these, Adeka STAB LA-29, LA-32, LA-36, and LA-46 are preferred, and Adeka STAB LA-29, LA-32, and LA-36 are particularly preferred.

[0105] The antioxidant may include a phenolic compound.

[0106] Commercially available antioxidants include, for example, Adeka STAB AO-20, AO-30, AO-40, AO-50, AO-50F, AO-60, AO-60G, AO-80, and AO-330 (all manufactured by ADEKA Corporation).

[0107] [Ink properties] It is preferable to use an ink whose surface tension and viscosity are appropriately controlled depending on the application. For example, when used as an inkjet ink, the following are preferable.

[0108] The surface tension of the ink at 25° C. is preferably 10 mN / m or more and 60 mN / m or less, more preferably 20 mN / m or more and 60 mN / m or less, and particularly preferably 30 mN / m or more and 50 mN / m or less.

[0109] The viscosity of the ink at 25° C. is preferably 1.0 mPa·s or more and 10 mPa·s or less, and more preferably 1.0 mPa·s or more and 5 mPa·s or less.

[0110] [Ink production method] The ink according to this embodiment can be prepared as follows.

[0111] Carrier particles dyed with the compounds represented by general formulas (1), (2), and (3) are prepared according to the method described above. The prepared carrier particles dyed with the compounds represented by general formulas (1), (2), and (3), along with other colorants, emulsifiers, resins, etc., as needed, are gradually added to a medium selected according to the intended use while stirring, and thoroughly blended into the medium. Further, mechanical shear force is applied using a disperser to stably dissolve or finely disperse the carrier particles, thereby obtaining the ink of the present invention.

[0112] [Dispersion machine] The disperser for dispersing each component in the medium is not particularly limited, but media-type dispersers such as a rotary shear homogenizer, a ball mill, a sand mill, and an attritor, and a high-pressure counter-collision type disperser can be used.

[0113] [Ink use] The ink according to this embodiment is also suitable as an ink for oil-based writing instruments, an ink for water-based writing instruments, an ink for inkjet printing, an ink for textile printing, and an ink for paints. Among these, it is preferable to use it as an ink for oil-based writing instruments, an ink for water-based writing instruments, or an inkjet ink. Specific examples of application of the ink according to this embodiment will be described below. Note that for items not specifically described, the same description of the ink according to this embodiment applies as is.

[0114] [Oil-based writing ink] The ink for oil-based writing instruments contains carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) described above, and an oil-based medium. The oil-based medium can be an organic solvent from among the above-mentioned media. Among them, the oil-based medium preferably contains alcohol or glycol ether. It is also preferable that the medium does not contain water. In addition to these, the ink for oil-based writing instruments preferably contains a resin dissolved in the medium. The content of the carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) is appropriately selected depending on the application and is not particularly limited.

[0115] [Medium containing alcohol or glycol ether] Examples of alcohols include unsubstituted alkyl monoalcohols such as ethanol, isopropanol, n-butanol, isobutanol, tert-butanol, sec-butanol, 2-methyl-2-butanol, 3-pentanol, octanol, and cyclohexanol; substituted alkyl monoalcohols such as 2-phenoxyethanol and 3-methyl-3-methoxy-1-butanol; alkyl polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, 3-methyl-1,3-butanediol, and 1,3-butanediol; and aromatic alcohols such as benzyl alcohol. Examples of the substituents in substituted alkyl monoalcohols include alkoxy groups and aryloxy groups.

[0116] Glycol ethers also include monoalcohol monoethers, but these are described as alcohols. Examples of diethers include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, and diethylene glycol dipropyl ether.

[0117] The medium may contain, in addition to alcohol or glycol ether, water; or an ester solvent such as 3-methyl-3-methoxybutyl acetate, butyl acetate, or methyl propionate.

[0118] The amount of the medium used is not particularly limited and may be appropriately selected depending on the type of writing implement, such as a ballpoint pen, a felt-tip pen, or a marking pen.

[0119] [Resin dissolved in the medium] In order to adjust the viscosity of the ink and improve the scratch resistance, it is preferable that the ink contains a resin that exists in a dissolved state in the medium.

[0120] The resin is determined depending on the purpose and application of the ink, and is not particularly limited. Examples of the resin include butyral resin, ketone resin, polyvinylpyrrolidone resin, styrene resin, styrene-acrylic resin, styrene-maleic acid resin, terpene resin, acrylic resin, polyvinyl acetal resin, polyvinyl butyral resin, terpene phenol resin, rosin-modified maleic resin, rosin phenol resin, maleic acid resin, phenol resin, xylene resin, urea resin, polyamide resin, phenoxy resin, and cellulose-based resin. Of these, butyral resin and ketone resin are preferably used to achieve a writing feel that does not cause smearing.

[0121] The butyral resin and the ketone resin may be commercially available products. Examples of commercially available ketone resins include low-polymerization types under the trade names "S-LEC BL-1," "BL-2," and "BL-10," and high-polymerization types under the trade names "BH-3," "BH-6," "BX-1," "BX-5," and "BH-S" (all manufactured by Sekisui Chemical Co., Ltd.).

[0122] Commercially available ketone resins include, for example, those under the trade name "Ketone Resin K-90" (manufactured by Arakawa Chemical Industries, Ltd.), and those under the trade names "Hilac 901," "Hilac 110H," and "Hilac 111" (all manufactured by Hitachi Chemical Co., Ltd.).

[0123] By incorporating these resins into the ink, viscosity adjustment is easy, wear on the pen tip can be prevented, and a stable and good writing feel can be achieved. Furthermore, because film-forming properties can be moderately suppressed, ink solidification can be suppressed even if the pen tip is exposed to the air for a long period of time, and the "blurring phenomenon" when starting to write can be suppressed.

[0124] The content of these resins is appropriately selected and is not particularly limited.

[0125] [Water-based writing ink] The aqueous writing ink contains carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) and an aqueous medium. The aqueous writing ink preferably further contains a dispersant. The aqueous writing ink may also contain a water-soluble resin as needed. The content of the carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) is not particularly limited and can be selected appropriately depending on the application.

[0126] [Inkjet ink] The inkjet ink contains carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) and a medium. The medium is preferably an aqueous medium. The inkjet ink preferably further contains a dispersant. The amount of the carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) is not particularly limited and can be appropriately selected depending on the application.

[0127] [Inkjet recording method] The inkjet ink according to this embodiment can be applied to an inkjet recording method in which ink is ejected from an inkjet recording head to record an image on a recording medium. Methods for ejecting ink include a method of applying mechanical energy to the ink and a method of applying thermal energy to the ink. Other than using the ink according to this embodiment, the steps of the inkjet recording method may be any known method.

[0128] Any recording medium may be used for recording using the inkjet ink according to this embodiment. Recording media with ink absorption properties, such as recording media without a coating layer, such as plain paper, and recording media with a coating layer, such as glossy paper or matte paper, may be used. Recording media with low or no ink absorption properties, such as printing paper, coated paper, resin sheets, and resin films, may also be used.

[0129] [Textile printing ink] The textile printing ink contains carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) described above, and a medium. The medium is preferably an aqueous medium among the above-mentioned media. The textile printing ink preferably further contains a dispersant. The content of the carrier particles dyed with the compounds represented by the general formulas (1), (2), and (3) is not particularly limited and can be appropriately selected depending on the application.

[0130] [Printing method] The textile printing ink according to this embodiment can be applied to known textile printing methods, and in particular, to direct printing recording methods.

[0131] Hereinafter, a direct printing method will be described as an example of a recording method using the textile printing ink according to this embodiment, but the method is not limited to this method.

[0132] The direct printing recording method is a recording method that includes a step of applying ink directly to a fabric by an ink jet method without using an intermediate transfer medium to record an image.

[0133] As a print head that can be used in the ink jet method, a piezo type or a thermal type print head can be used.

[0134] The fabric to which the ink has been applied is subjected to a heating and pressurizing treatment, thereby fixing the image to the fabric. The heating and pressurizing treatment time is preferably 30 seconds or more and 180 seconds or less. The heating temperature in this step is not particularly limited, but is preferably 180°C or more and 220°C or less, more preferably 185°C or more and 205°C or less, and particularly preferably 190°C or more and 200°C or less.

[0135] When the ink according to this embodiment is used as a textile printing ink, the type of fabric that can be used for textile printing is not particularly limited as long as it can be dyed, and examples include fabrics made of fibers containing polyester, acetate, or triacetate. The fabric may be in any form, such as woven fabric, knitted fabric, or nonwoven fabric. Fabrics made of cotton, silk, linen, polyurethane, acrylic, nylon, wool, or rayon fibers, or fabrics made of a combination of two or more of these fibers, can also be used. Other objects that have a three-dimensional shape, such as a sheet, sphere, or rectangular parallelepiped, such as a polyester-coated mug, may also be used.

[0136] The thickness of the threads constituting the fabric is preferably in the range of 10 denier to 100 denier. The thickness of the fibers constituting the threads is not particularly limited, but is preferably 1 denier or less.

[0137] Second Embodiment As a result of extensive research aimed at solving the above problems, the present inventors have found that the following configuration can provide an ink that has high optical density, excellent color development stability during heat pressing, and excellent light resistance.

[0138] The ink according to this embodiment contains an aqueous medium, a dispersant, a compound represented by general formula (1), a compound represented by general formula (2), and a compound represented by general formula (3).

[0139] When the compounds represented by the above general formulas (1), (2), and (3) are used, inks having high optical density and excellent color stability and lightfastness during heat pressing can be obtained. The mechanism contributing to the color stability is not clearly understood, but the present inventors speculate as follows.

[0140] The compounds represented by general formulas (1), (2), and (3) are structurally similar in size, and overlap occurs due to π-π stacking interactions or hydrogen bonds between the benzene rings of each compound. This overlapping stabilizes the three compounds, which is thought to be the reason for the aforementioned effects.

[0141] The ink according to this embodiment can be used in textile applications that have been expanding in recent years, such as dyeing polyester fibers, sports apparel in which polyester is woven with polyurethane or the like, and high-quality one-piece dresses in which the shape of the fibers is processed.

[0142] Each component of the ink according to this embodiment will be described in detail. The compounds represented by general formulas (1), (2), and (3), the additives, and the disperser for dispersing each component in the aqueous medium can be the same as those described in the first embodiment, and therefore a description thereof will be omitted. Furthermore, the ink according to this embodiment can be used as an inkjet ink containing an aqueous medium (aqueous ink). The composition, ink properties, and ink preparation method of the inkjet ink containing an aqueous medium can also be adjusted in the same manner as those described in the first embodiment, and therefore a description thereof will be omitted.

[0143] [Dispersant] In the ink according to this embodiment, a dispersant is used to obtain good dispersion stability in an aqueous medium of the compounds represented by general formulas (1), (2), and (3). The dispersant is not particularly limited, but the same dispersants as those described in the first embodiment above can be used.

[0144] [Aqueous medium] The ink according to this embodiment is an aqueous ink containing at least water as an aqueous medium. The aqueous medium is not particularly limited, but the same medium as that described in the first embodiment can be used.

[0145] [Recording method] The ink according to this embodiment can be applied to a sublimation transfer method or a direct printing method.

[0146] Below, a sublimation transfer method will be described as an example of a recording method using the ink according to this embodiment, but the method is not limited to this method.

[0147] The sublimation transfer recording method includes (1) a step of applying ink to an intermediate transfer medium to record an image, and (2) a transfer step of transferring the image from the intermediate transfer medium to a fabric.

[0148] (Process for recording an image on an intermediate transfer medium) In the process of recording an image on transfer paper, the ink according to the present embodiment is applied to transfer paper, which is an intermediate transfer medium, by an inkjet method. The transfer paper is not particularly limited, but it is preferable to use sublimation transfer printing paper.

[0149] The print head that can be used in the ink jet method may be a piezo type or a thermal type print head.

[0150] (The process of transferring an image onto fabric) The transfer paper on which the image has been recorded through the image recording process is overlapped with a fabric serving as a recording medium, and then subjected to a heat and pressure treatment using a heat and pressure device such as a heat press. This transfers the image to the fabric, allowing the image to be recorded on the fabric. The fabric can be the same as that described in the first embodiment. In particular, with polyester and polyurethane blend materials, which have become popular in recent years for sportswear and the like, conventional sublimation dyes have tended to exhibit color variations depending on the heat press temperature. However, the ink according to this embodiment allows for the production of dyed products with excellent color stability during heat pressing. The heat and pressure treatment time is preferably 30 seconds or more and 180 seconds or less. The lower limit of the heating temperature in this process is not particularly limited, but is preferably 180°C or more and 220°C or less, more preferably 185°C or more and 205°C or less, and particularly preferably 190°C or more and 200°C or less.

[0151] The heat pressing pressure in this step is not particularly limited, but is preferably 30 PSI or more and 120 PSI or less, and particularly preferably 40 PSI or more and 90 PSI or less.

[0152] Instead of a heat press, a sublimation transfer machine (for example, trade name "PSH-4230" manufactured by Europort Co., Ltd.) that transfers at low temperatures under vacuum can also be used.

[0153] <Third embodiment> As a result of extensive research into solving the above problems, the present inventors have found that color mixing and fading can be suppressed by the following configuration.

[0154] The thermal transfer recording sheet according to this embodiment includes a substrate and a black colorant layer formed on the substrate, and the black colorant layer contains a compound represented by general formula (1), a compound represented by general formula (2), and a compound represented by general formula (3).

[0155] As a result of investigations, the present inventors have found that color mixing and fading can be suppressed by using a combination of compounds represented by general formulas (1), (2), and (3) as black colorants, each of which has problems when used alone.

[0156] The mechanism by which the effect of suppressing color mixing and fading caused by mixing compounds of different colors with different structures as a black coloring material is achieved is not clearly understood, but the inventors speculate as follows.

[0157] The compounds represented by general formulas (1), (2), and (3) are structurally similar in size, and overlap occurs between the compounds due to π-π stacking interactions or hydrogen bonds between the benzene rings of each compound. It is believed that this overlapping stabilization results in the aforementioned effects. Color mixing and fading can be evaluated by measuring the lightfastness of the image recording. For example, the presence or absence of color mixing and fading can be evaluated by a lightfastness test using a xenon tester to irradiate the image recording with light and calculate the color difference ΔE before and after exposure.

[0158] The structure of the thermal transfer recording sheet will be described in detail below. Note that the compounds represented by the general formulas (1), (2), and (3) used in the thermal transfer recording sheet are the same as those described in the first embodiment, and therefore further description will be omitted.

[0159] The thermal transfer recording sheet preferably further comprises a yellow colorant layer, a magenta colorant layer, and a cyan colorant layer in addition to the black colorant layer, and more preferably the yellow colorant layer, the magenta colorant layer, the cyan colorant layer, and the black colorant layer are formed in face order on the base material.

[0160] [Base material] The substrate of the thermal transfer recording sheet is preferably one that supports at least the four colorant layers described above. The substrate is not particularly limited, and any substrate that has been conventionally known in the field of thermal transfer recording sheets and has appropriate heat resistance and strength can be used.

[0161] ·Material of the base material Examples of the substrate include polyethylene terephthalate film, polyethylene naphthalate film, polycarbonate film, polyimide film, polyamide film, aramid film, polystyrene film, 1,4-polycyclohexylene dimethylene terephthalate film, polysulfone film, polypropylene film, polyphenylene sulfide film, polyvinyl alcohol film, cellophane film, cellulose derivative film, polyethylene film, polyvinyl chloride film, nylon film, condenser paper, and paraffin paper. Among these, polyethylene terephthalate film is preferred as the substrate from the viewpoints of mechanical strength, solvent resistance, and economy.

[0162] ·Base material thickness The thickness of the substrate can be set to 0.5 μm or more and 50 μm or less, and from the viewpoint of transferability, it is preferably set to 3 μm or more and 10 μm or less.

[0163] Adhesion treatment When a colorant composition (ink) containing a dye is applied to a substrate to form each colorant layer, the coating liquid (colorant composition) may lack wettability, adhesiveness, etc. Therefore, it is preferable to subject the substrate to an adhesion treatment on the coated surface as needed.

[0164] The adhesive treatment is not particularly limited, and any method known in the field of thermal transfer recording sheets can be used. Examples of adhesive treatments include ozone treatment, corona discharge treatment, ultraviolet treatment, plasma treatment, low-temperature plasma treatment, primer treatment, and chemical treatment. Two or more of these treatments may also be combined.

[0165] The adhesive treatment of the substrate may also be carried out by coating an adhesive layer on the substrate. The adhesive layer is not particularly limited, and any adhesive layer known in the field of thermal transfer recording sheets may be used. Examples of materials used for the adhesive layer include organic materials such as polyester resin, polystyrene resin, polyacrylic ester resin, polyamide resin, polyether resin, polyvinyl acetate resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinyl alcohol resin, and polyvinyl butyral resin, and inorganic fine particles such as silica, alumina, magnesium carbonate, magnesium oxide, and titanium oxide.

[0166] [Heat-resistant slipping layer] In order to improve heat resistance and the running property of a thermal head, the thermal transfer recording sheet preferably has a heat-resistant slip layer on the surface of the substrate opposite to the surface on which the coloring material layer is formed.

[0167] The heat-resistant slip layer is composed of a layer containing a heat-resistant resin. The heat-resistant resin is not particularly limited, and the following resins can be used, for example: polyvinyl butyral resin, polyvinyl acetal resin, polyester resin, polyether resin, polybutadiene resin, vinyl chloride-vinyl acetate copolymer resin, styrene-butadiene copolymer resin, polyurethane acrylate, polyester acrylate, polyimide resin, polycarbonate resin, etc.

[0168] The heat-resistant slip layer may also contain additives such as a crosslinking agent, a release agent, a lubricant, and a slip-imparting agent. Examples of the lubricant include amino-modified silicone compounds and carboxy-modified silicone compounds. Examples of the slip-imparting agent include heat-resistant fine particles such as silica.

[0169] The heat-resistant slipping layer can be formed by applying a heat-resistant slipping layer coating liquid, which is prepared by adding the above-mentioned heat-resistant resin and additives to a solvent, dissolving or dispersing the heat-resistant resin and additives, to a substrate, and then drying the liquid. The method for applying the heat-resistant slipping layer coating liquid is not particularly limited, and for example, methods using a bar coater, gravure coater, reverse roll coater, rod coater, or air doctor coater can be used. Among these, the coating method using a gravure coater is preferred, as it is easy to adjust the film thickness.

[0170] The amount of the heat-resistant slip layer coating solution applied to the substrate is preferably such that the thickness of the heat-resistant slip layer after drying is in the range of 0.1 μm to 5 μm, from the viewpoint of transferability.

[0171] [Protective layer] The thermal transfer recording sheet may have one or two transferable protective layers on a substrate to protect the image surface after image formation, in face order with the colorant layer described below. This protective layer may also be formed on a sheet (substrate) different from the colorant layer. In this case, the thermal transfer recording sheet according to this embodiment includes a sheet having a substrate and a colorant layer (colorant layer sheet) and a sheet having a substrate and a protective layer (protective layer sheet).

[0172] The protective layer can be formed by applying the composition for each layer to the substrate and drying it. The method for applying the composition for each layer to the substrate is not particularly limited, and examples thereof include methods using a bar coater, gravure coater, reverse roll coater, rod coater, air doctor coater, etc. Among these, the application method using a gravure coater is preferred because it is easy to adjust the film thickness.

[0173] Furthermore, the drying conditions after coating the composition for each layer are not particularly limited as long as sufficient drying is achieved. For example, drying can be performed at a temperature range of 50°C or higher and 120°C or lower for 1 second or longer and 5 minutes or shorter.

[0174] The binder resin used in the protective layer is not particularly limited, but suitable examples include acrylic resins such as polystyrene, polymethyl methacrylate, and polyethyl acrylate; styrene resins such as poly-α-methylstyrene; vinyl resins such as polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, and polyvinyl acetal; and synthetic resins such as polyamide resin, epoxy resin, polyurethane resin, petroleum resin, ionomer, ethylene-acrylic acid copolymer, and ethylene-acrylic acid ester copolymer.

[0175] The thickness of the protective layer is preferably in the range of 0.1 μm to 5 μm.

[0176] It is more preferable that a release layer containing an acrylic resin such as polymethyl methacrylate or polyethyl acrylate and having a thickness of 0.1 μm to 1.5 μm be provided under the black color material layer containing the above-mentioned compound to facilitate peeling from the sheet.

[0177] The release layer is formed on the substrate.

[0178] [Color layer] In the thermal transfer recording sheet, the black colorant layer contains the compounds represented by the above-mentioned general formulas (1), (2), and (3) as black colorants.

[0179] The above-mentioned three types of compounds can be used in combination with other yellow, magenta, and cyan coloring materials as long as the effects of this embodiment are not impaired. The other yellow, magenta, and cyan coloring materials are those used in the field of thermal transfer recording sheets and can be used without any particular limitation as long as they are thermally transferred.

[0180] From the viewpoint of transferability and storage stability, the melting points of the compounds represented by formulas (1), (2), and (3) are preferably 40° C. or higher and 200° C. or lower, more preferably 50° C. or higher and 180° C. or lower, and particularly preferably 60° C. or higher and 150° C. or lower.

[0181] The compounding ratio of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is not particularly limited. Preferably, the compounding ratio (mass ratio) of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is as follows: For 10 parts by mass of the compound represented by general formula (1), the compound represented by general formula (2) is preferably 3 to 9 parts by mass and the compound represented by general formula (3) is preferably 1 to 6 parts by mass. In particular, it is more preferable that the compound represented by general formula (2) is 4 to 8 parts by mass and the compound represented by general formula (3) is 2 to 5 parts by mass. Furthermore, it is even more preferable that the compound represented by general formula (2) is 4 to 6 parts by mass and the compound represented by general formula (3) is 2 to 4 parts by mass. Within this range, a thermal transfer recording sheet in which color mixing and fading are suppressed in the blend of the three types of yellow, magenta, and cyan color materials used in the black color material layer is easily obtained.

[0182] (Components contained in the colorant layer) The components contained in the colorant layer other than the above-mentioned three types of compounds will be described below.

[0183] (i) Other coloring compounds The yellow colorant used in the yellow colorant layer, the magenta colorant used in the magenta colorant layer, and the cyan colorant used in the cyan colorant layer are not particularly limited as long as they are used in the field of thermal transfer recording sheets and are thermally transferable. Furthermore, each colorant compound can be used alone or in combination of two or more types.

[0184] (ii) Binder resin The binder resin that can be used in each colorant layer of the thermal transfer recording sheet is not particularly limited, and various resins can be used. Among them, the following water-soluble resins and organic solvent-soluble resins are preferably used. Water-soluble resins: cellulose resins, polyacrylic resins, starch resins, and epoxy resins. Organic solvent-soluble resins: polyacrylate resin, polymethacrylate resin, polystyrene resin, polycarbonate resin, polyethersulfone resin, polyvinyl butyral resin, ethyl cellulose resin, acetyl cellulose resin, polyester resin, AS resin, and phenoxy resin.

[0185] These binder resins may be used alone or in combination of two or more types as required.

[0186] (iii) surfactants A surfactant may be added to each colorant layer of the thermal transfer recording sheet to provide sufficient lubricity during heating with a thermal head (during image recording). Examples of surfactants that can be added to each colorant layer include cationic surfactants, anionic surfactants, and nonionic surfactants.

[0187] Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, and hexadecyl trimethyl ammonium bromide.

[0188] Examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzene sulfate, and sodium lauryl sulfate.

[0189] Examples of the nonionic surfactant include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, nonylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, and monodecanoyl sucrose.

[0190] (iv) Wax Wax may be added to each color material layer of the thermal transfer recording sheet to provide sufficient lubricity when the thermal head is not heated. Examples of wax that can be added to each color material layer include, but are not limited to, polyethylene wax, paraffin wax, and fatty acid ester wax.

[0191] (v) Other additives In addition to the above-mentioned components, ultraviolet absorbers, preservatives, antioxidants, antistatic agents, viscosity adjusters, etc. may be added to each colorant layer of the thermal transfer recording sheet, if necessary.

[0192] Examples of ultraviolet absorbers include benzophenone-based, benzotriazole-based, cyanoacrylate-based, and triazine-based ones.

[0193] Examples of commercially available ultraviolet absorbers include Tinuvin P, Tinuvin 326, Tinuvin 571, and Tinuvin 360 (all manufactured by BASF), and Adeka STAB LA-24, LA-29, LA-31RG, LA-32, LA-36, LA-46, LA-F70, and 1413 (all manufactured by ADEKA Corporation).

[0194] Preferred are ADK STAB LA-29, LA-32, LA-36, and LA-46, and particularly preferred are ADK STAB LA-29, LA-32, and LA-36.

[0195] The antioxidant may include a phenolic compound.

[0196] Commercially available antioxidants include, for example, ADK STAB AO-20, AO-30, AO-40, AO-50, AO-50F, AO-60, AO-60G, AO-80, and AO-330 (all manufactured by ADEKA Corporation).

[0197] (vi) Medium The medium that can be used to prepare each colorant composition for the thermal transfer recording sheet is not particularly limited, but examples include water and organic solvents. The following organic solvents are preferred: alcohols such as methanol, ethanol, isopropanol, and isobutanol; cellosolves such as methyl cellosolve and ethyl cellosolve; aromatic hydrocarbons such as toluene, xylene, and chlorobenzene; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; halogenated hydrocarbons such as methylene chloride, chloroform, and trichloroethylene; ethers such as tetrahydrofuran and dioxane; N,N-dimethylformamide, N-methylpyrrolidone, and the like. These organic solvents may be used alone or in combination of two or more types as needed. Water and organic solvents can also be used in combination.

[0198] (Composition of Colorant Composition for Forming Colorant Layer) Colorant content (amount used) From the viewpoint of sheet storage stability, the amount of each colorant (yellow colorant, magenta colorant, cyan colorant, or black colorant) used in each colorant composition is preferably 1 part by mass or more and 200 parts by mass or less relative to 100 parts by mass of binder resin. From the viewpoint of colorant dispersion, it is more preferably 50 parts by mass or more and 180 parts by mass or less relative to 100 parts by mass of binder resin. Note that when two or more types of colorant are used in combination, the amount of the colorant used refers to the total amount of the parts by mass of each colorant. For example, even when the compounds of the above general formulas (1), (2), and (3) are used in combination with an existing colorant as a black colorant, the amount of the colorant used refers to the total number of parts by mass of these colorants.

[0199] Other ingredient content (amount used) The amounts of other components (additives) used can be set appropriately and are not particularly limited.

[0200] [Method for producing a thermal transfer recording sheet] The method for producing the thermal transfer recording sheet is not particularly limited, but it can be produced, for example, as follows: As an example, the black colorant layer will be described.

[0201] First, the compounds (colorants) represented by the general formulas (1), (2), and (3), and optionally a binder resin, a surfactant, and a wax are gradually added to a medium (e.g., an organic solvent) while stirring, and are thoroughly mixed into the medium.

[0202] In this process, mechanical shear force is applied using a disperser to stably dissolve or disperse these components in the medium into fine particles to produce a colorant composition (ink).The colorant composition is applied to a base film, which is a substrate, and then dried to produce the desired colorant layer.

[0203] The dispersing machine used in preparing the colorant composition is not particularly limited, but for example, a media type dispersing machine such as a rotary shear type homogenizer, a ball mill, a sand mill, or an attritor, as well as a high-pressure counter-collision type dispersing machine, etc. can be used.

[0204] In a thermal transfer recording sheet, each color material layer is formed in face order on a substrate. For example, a yellow color material layer, a magenta color material layer, a cyan color material layer, a black color material layer, and a protective layer can be repeatedly formed on a substrate (substrate sheet) along the direction of movement of the substrate. When a thermal transfer sheet having color material layers in this order is used, a yellow image is formed first, followed by a magenta image, a cyan image, and then a black image, forming a series of images in this order to form a full-color image. Finally, a protective layer is formed, and this series of image formation is repeated.

[0205] The colorant layers can be formed by applying a colorant composition for forming each colorant layer to the substrate and drying it. The method for applying the colorant composition for forming the colorant layer to the substrate is not particularly limited, and examples thereof include methods using a bar coater, gravure coater, reverse roll coater, rod coater, air doctor coater, etc. Among these, the application method using a gravure coater is preferred because it is easy to adjust the thickness of the colorant layer.

[0206] Furthermore, the drying conditions after applying the colorant composition for forming each colorant layer are not particularly limited as long as sufficient drying is possible. For example, drying can be performed at a temperature of 50°C or higher and 120°C or lower for 1 second or longer and 5 minutes or shorter.

[0207] By thoroughly drying each colorant composition, it is easy to prevent background smearing and the transfer of the colorant composition to the back surface when winding, and further it is easy to prevent the transferred colorant composition from being transferred again to a colorant layer of a different hue when rewinding.

[0208] The amount of the colorant composition to be applied is preferably such that the thickness of the colorant layer after drying is in the range of 0.1 μm to 5 μm, from the viewpoint of transferability.

[0209] [Method for recording images on a thermal transfer recording sheet] A thermal transfer recording sheet is superimposed on a transferee, for example, an image receiving sheet having a colorant-receiving layer on its surface, and the thermal transfer recording sheet is heated using a heating method such as a thermal head, thereby transferring the colorant in the sheet to the image receiving sheet, thereby recording an image. If the thermal transfer recording sheet has the transferable protective layer described above, the sheet with this protective layer portion is superimposed on the image formed on the image receiving sheet. Then, by heating using a heating method such as a thermal head, the protective layer can be transferred (formed) on the image.

[0210] The means for heating the thermal transfer recording sheet for image recording is not particularly limited, and not only the usual method using a thermal head but also infrared rays or laser light can be used. Also, the sheet can be used as an electrically conductive dye transfer sheet by using an electrically conductive heat-generating film that generates heat by passing electricity through the base film itself of the substrate. [Example]

[0211] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the text, "parts" are by mass unless otherwise specified.

[0212] <<Example of the First Embodiment>> <Preparation and Evaluation of Inkjet Inks> Examples 1-1 to 1-14 and Comparative Examples 1-1 to 1-8 [Compounds represented by general formulas (1), (2), and (3)] The compounds represented by the general formulas (1), (2), and (3) were synthesized by known methods. The compounds represented by the general formulas (1), (2), and (3) used in this example are listed in Table 1-1.

[0213] The identification of the obtained compound was carried out as follows: 1 H nuclear magnetic resonance spectroscopy ( 1 The measurements were carried out using a H-NMR instrument (trade name "AVANCE-600 NMR spectrometer", manufactured by BRUKER) and a MALDI-TOF / MS instrument (trade name "MALDI-TOF / MS ultraFleXtreme", manufactured by BRUKER).

[0214] [Comparative compounds] As comparative compounds, the following magenta comparative compounds (1) and (3) and cyan comparative compound (2) were used.

[0215] [ka]

[0216] [Preparation of aqueous dispersion of resin particles (A)] A reaction vessel was charged with 1,178 parts of water at 70°C, and 466 parts of monomer (50% styrene, 47% acrylonitrile, 3% methacrylic acid) was mixed, followed by dropwise addition of a polymerization initiator (1.9 parts potassium persulfate in 659 parts water) over 60 minutes. The mixture was stirred at 70°C for an additional 30 minutes to obtain an aqueous dispersion of core resin particles.

[0217] Next, the temperature of the aqueous dispersion of the core resin particles was raised to 80°C, and 80 parts of a monomer mixture (85% styrene, 15% methacrylic acid) and a polymerization initiator (aqueous solution prepared by adding 0.1 parts of potassium persulfate to 133 parts of water) were added dropwise over 10 minutes. Stirring was continued for a further 120 minutes to synthesize resin particles (A) that would form a shell film (core-shell structure) on the core resin.

[0218] Next, an appropriate amount of 8 mol / L potassium hydroxide aqueous solution was added to the reaction vessel, and the pH of the liquid was adjusted to 8.5. Furthermore, a total of 29 parts (5% of the resin particles) of powder of the compounds shown in Table 1-1 (the compounding ratio of each compound is as shown in Table 1-1) and 29 parts of ethanol / butanol (8 / 2) were added, and the temperature was raised to 80°C. Thereafter, the mixture was stirred for 2 hours. After the solvent was distilled off under reduced pressure, an appropriate amount of 8 mol / L potassium hydroxide aqueous solution was added to the reaction vessel, and the pH of the liquid was adjusted to 8.5. Water was added so that the resin particle content was 20%, and an aqueous dispersion of resin particles (A) was obtained.

[0219] [Preparation of aqueous dispersion of resin particles (B)] Under a nitrogen atmosphere, 100 parts of monomer were added to 100 parts of methyl ethyl ketone at 78°C in a reaction vessel and mixed, and a polymerization initiator (a mixture of 1 part azobisisobutyronitrile and 20 parts of methyl ethyl ketone) was added dropwise over 2 hours. The monomer contained 30% styrene, 30% n-butyl acrylate, and 40% methacrylic acid. After reacting for another 2 hours, the mixture was cooled to 30°C, and 100 parts of dimethylethanolamine and 100 parts of water were added. The solvent was then removed by vacuum concentration to obtain resin particle solution (B).

[0220] Meanwhile, under a nitrogen atmosphere, an aqueous solution prepared by adding 1 part sodium bicarbonate and 1 part sodium lauryl sulfate to 178 parts water was heated to 80°C, and 1 part potassium persulfate was added. To this solution, a solution prepared by adding 200 parts methyl methacrylate, 140 parts butyl acrylate, 5 parts glycidyl methacrylate, a total of 5 parts of the compounds shown in Table 1-1, and 6 parts sodium lauryl sulfate to 178 parts water was added dropwise over 2 hours. The compounding ratios of each compound shown in Table 1-1 are as shown in Table 1-1. Subsequently, 119 parts of the resin particle solution (B) obtained above were added dropwise over 30 minutes, followed by the dropwise addition of 35 parts of a 1% aqueous ammonium persulfate solution over 30 minutes. The mixture was allowed to react at 80°C for 2 hours to obtain an aqueous dispersion (B) of resin particles with a solids concentration of 40%.

[0221] [Preparation of aqueous dispersion of resin particles (C)] In preparing the above aqueous dispersion of resin particles (B), the compounds were changed as shown in Table 1-1, and 10 parts of an ultraviolet absorber, ADK STAB LA-36 (manufactured by ADEKA CORPORATION), was further added to change the solution to 168 parts of water. Except for this, an aqueous dispersion of resin particles (C) with a solids concentration of 40% was obtained in the same manner as in the aqueous dispersion of resin particles (B).

[0222] [Ink preparation] 50 parts of aqueous dispersion of resin particles (A), (B), or (C), 10 parts of glycerin, 10 parts of triethylene glycol, 1 part of Acetylenol E100 (Kawaken Fine Chemicals), and 35 parts of water were mixed and stirred. The mixture was then pressure filtered through a 3.0 μm pore size microfilter (Fujifilm) to prepare each of the inks listed in Table 1-1. The pH of each ink prepared was in the range of 8.5 to 9.0.

[0223] [Evaluation of ink storage stability] The inks used in the examples and comparative examples were each placed in a 100 mL sample bottle, sealed, and stored at 10°C for one month. The presence or absence of aggregates and precipitates after storage was visually inspected and evaluated. The evaluation results are shown in Table 1-1. The evaluation criteria were as follows. In the evaluation, the storage stability was judged to be good if "almost no aggregates and precipitates of the compound were observed" or "a small amount of aggregates and precipitates of the compound were observed."

[0224] (Evaluation criteria) A: Almost no compound aggregates or precipitates were observed B: A small amount of compound aggregates and precipitates were observed. C: Significant amounts of compound aggregates and precipitates are observed.

[0225] [Creating image samples] Each ink was filled into an ink cartridge, and a 100% duty solid image was recorded on a recording medium using an inkjet recording device (product name "PIXUS Pro-10", manufactured by Canon) to obtain a black image sample (image recording material). The recording medium used was photo paper (product name "Canon Photo Paper Glossy Pro [Platinum Grade] (model number: PT-201), manufactured by Canon).

[0226] [Evaluation of lightfastness of printed matter (image recording matter)] Each of the obtained black image samples was placed in a xenon test device (trade name "Atlas Weatherometer Ci4000", manufactured by Toyo Seiki Seisakusho Co., Ltd.) and subjected to illuminance of 0.28 W / m at 340 nm. 2 The samples were exposed to the conditions of a temperature of 40°C and a relative humidity of 50% for 24 hours.

[0227] The reflection density of the black image sample before and after exposure was measured using a reflection densitometer (product name "FD-7", manufactured by Konica Minolta, Inc.).

[0228] The initial chromaticity before exposure is a0 * , b0 * , L0 * and the chromaticity after exposure is a* , b * , L * Then, the color difference ΔE was defined and calculated as follows:

[0229]

number

[0230] The evaluation was based on the ΔE. The evaluation criteria were as follows: If the ΔE after 24 hours was less than 7.00, the lightfastness was judged to be good.

[0231] (Evaluation criteria) A: ΔE<5.00 B: 5.00≦ΔE<7.00 C:7.00≦ΔE

[0232] [Table 1-1]

[0233] As is clear from Table 1-1 above, the inks using resin particles dyed with a combination of the compounds of general formulas (1), (2), and (3) described in the examples had good storage stability and improved lightfastness of the printed matter. In contrast, the comparative inks using resin particles dyed with comparative compounds having structures different from those of general formulas (1), (2), and (3) had poor storage stability or lightfastness.

[0234] <Preparation and evaluation of ink for oil-based writing implements> Examples 1-15 To a mixed solution of 78 parts 1-phenoxy-2-propanol and 22 parts benzyl alcohol, 9 parts of Elec BL-1 (manufactured by Sekisui Chemical Co., Ltd.) as a resin and 1 part of polyvinylpyrrolidone resin K-90 (manufactured by Nippon Shokubai Co., Ltd.) were added and heated to 70°C to dissolve. The mixture was then cooled to room temperature, and 8 parts of compound (1-6) represented by general formula (1), 4 parts of compound (2-3) represented by general formula (2), 3 parts of compound (3-2) represented by general formula (3), and 3 parts of Plysurf A208N were added as colorants. The mixed solution was dispersed for 3 hours using an Attritor (manufactured by Mitsui Mining Co., Ltd.) to prepare ink (1-1) for oil-based writing instruments.

[0235] Comparative Examples 1-9 A comparative oil-based ink for a writing instrument (1-1) was prepared in the same manner as in Example 1-15, except that the colorant in Example 1-15 was changed to 8 parts of the compound (1-6) represented by general formula (1), 4 parts of the comparative compound (1), and 3 parts of the compound (3-2) represented by general formula (3).

[0236] [Evaluation of storage stability of ink for oil-based writing instruments] 20 mL of each of the oil-based writing inks obtained above was added to a 50 mL sample bottle, sealed, and left at 60°C for one month. After leaving the bottle, the surface condition was observed at 20x magnification using a phase-contrast microscope (trade name "BX53", manufactured by OLYMPUS Corporation). As a result of the observation, particle aggregation was observed in Comparative Example 1-9, which did not contain any of the compounds represented by general formulas (1), (2), and (3). On the other hand, no aggregation was observed in Example 1-15, which contained all of the compounds represented by general formulas (1), (2), and (3). This confirmed the improvement in storage stability due to the use of all of the compounds represented by general formulas (1), (2), and (3).

[0237] [Preparation of oil-based writing implements and evaluation of lightfastness] Each of the oil-based inks for writing instruments obtained above was filled into a polypropylene ink reservoir tube with an inner diameter of 1.2 mm and a length of 140 mm. A ballpoint pen for evaluation testing was prepared using this ink reservoir tube and a phosphor bronze tip (ball diameter: 0.7 mm). Using this ballpoint pen, a 2 cm square image sample was created on a recording medium with a constant writing pressure. Photo paper (product name "Canon Photo Paper Glossy Pro [Platinum Grade] (Model: PT-201)" manufactured by Canon) was used as the recording medium.

[0238] The obtained image sample was placed in a xenon test device (trade name "Atlas Weather-O-Meter Ci4000", manufactured by Toyo Seiki Seisakusho Co., Ltd.). After placement, the illuminance was 0.28 W / m at 340 nm. 2 The sample was exposed for 10 hours under conditions of a black panel temperature of 40°C and a relative humidity of 50%. Compared with Comparative Example 1-9, which did not use any of the compounds represented by general formulas (1) to (3), Example 1-15, which used all of the compounds represented by general formulas (1) to (3), had an OD residual rate (%) that was 11% higher, confirming improved light resistance.

[0239] The OD remaining rate (%) is the rate of change in black OD between the initial state and after 10 hours, measured using an image sample reflection densitometer (product name "FD-7", manufactured by Konica Minolta).

[0240] <Preparation and evaluation of ink for water-based writing instruments> Examples 1-16 As colorants, 8 parts of compound (1-6) represented by general formula (1), 4 parts of compound (2-3) represented by general formula (2), and 3 parts of compound (3-2) represented by general formula (3) were used. To these colorants, 0.6 parts of Plysurf A208N (Dai-ichi Kogyo Seiyaku Co., Ltd.), 1 part of methanol, and 0.5 parts of cellulose nanofiber Leocrysta I-2AX (Dai-ichi Kogyo Seiyaku Co., Ltd.) were added. Then, 99 parts of ion-exchanged water was added to this mixture. The mixture was heated to an internal temperature of 80°C and stirred for 2 hours while removing the methanol. After cooling to room temperature, the mixture was dispersed in a homogenizer for 5 minutes to prepare aqueous ink for writing instruments (1-2).

[0241] Comparative Examples 1-10 A comparative water-based ink for a writing instrument (1-2) was prepared in the same manner as in Example 1-16, except that in Example 1-16, the colorant was changed to 8 parts of the compound (1-6) represented by the general formula (1), 4 parts of the comparative compound (1), and 3 parts of the compound (3-2) represented by the general formula (3).

[0242] [Evaluation of storage stability of ink for water-based writing instruments] 20 mL of each of the obtained aqueous writing inks was added to a 50 mL sample bottle, sealed, and left at 60°C for one month. After leaving the bottle, the surface condition was observed at 20x magnification using a phase-contrast microscope (trade name "BX53", manufactured by OLYMPUS Corporation). As a result of the observation, particle aggregation was observed in Comparative Example 1-10, which did not contain any of the compounds represented by general formulas (1), (2), and (3). On the other hand, no aggregation was observed in Example 1-16, which contained all of the compounds represented by general formulas (1), (2), and (3). This confirmed the improvement in storage stability due to the use of all of the compounds represented by general formulas (1), (2), and (3).

[0243] [Preparation of water-based writing implements and evaluation of lightfastness] The resulting water-based writing ink was filled into a polypropylene ink reservoir tube with an inner diameter of 1.2 mm and a length of 140 mm. A ballpoint pen for evaluation testing was prepared using this ink reservoir tube and a phosphor bronze tip (ball diameter: 0.7 mm). Using this ballpoint pen, a 2 cm square image sample was created on a recording medium with a constant writing pressure. Photo paper (product name "Canon Photo Paper Glossy Pro [Platinum Grade] (Model: PT-201)" manufactured by Canon) was used as the recording medium.

[0244] The obtained image sample was placed in a xenon test device (trade name "Atlas Weather-O-Meter Ci4000", manufactured by Toyo Seiki Seisakusho Co., Ltd.). After placement, the illuminance was 0.28 W / m at 340 nm. 2The samples were exposed for 10 hours under conditions of a black panel temperature of 40°C and a relative humidity of 50%. Compared with Comparative Example 1-10, which did not use any of the compounds represented by general formulas (1) to (3), Example 1-16, which used all of the compounds represented by general formulas (1) to (3), had an OD residual rate (%) that was 8.8% higher, confirming improved light resistance.

[0245] The OD residual rate (%) was determined in the same manner as in Example 1-15.

[0246] <<Example of the second embodiment>> <Preparation and evaluation of sublimation transfer ink> Examples 2-1 to 2-13 and Comparative Examples 2-1 to 2-8 [Compounds represented by general formulas (1), (2), and (3)] The compounds represented by the general formulas (1), (2), and (3) were synthesized by known methods. The compounds represented by the general formulas (1), (2), and (3) used in this example are listed in Table 2-1.

[0247] The identification of the obtained compound was carried out as follows: 1 H nuclear magnetic resonance spectroscopy ( 1 The measurements were carried out using a H-NMR instrument (trade name "AVANCE-600 NMR spectrometer", manufactured by BRUKER) and a MALDI-TOF / MS instrument (trade name "MALDI-TOF / MS ultraFleXtreme", manufactured by BRUKER).

[0248] [Comparative compounds] As comparative compounds, the following magenta comparative compounds (1) and (3) and cyan comparative compound (2) were used.

[0249] [ka]

[0250] [Ink preparation] A total of 3 parts of the compounds shown in Table 2-1, 16 parts of water, 1.2 parts of a dispersant (trade name "DisperBYK190", manufactured by BYK-Chemie), and 80 parts of 0.2 mm diameter zirconia beads were placed in a zirconia grinding container. The compounding ratios of the compounds shown in Table 2-1 are as shown in Table 2-1. The mixture was then dispersed at 300 rpm for 4 hours using a planetary ball mill (trade name "P-7 classic line", manufactured by Fritsch). The dispersion was diluted with a 15% aqueous glycerin solution to a solids concentration of 7%, and then filtered through a 0.5 μm filter to obtain an ink.

[0251] [Printing process onto transfer paper] Fill ink into a modified Canon printer equipped with a piezo system and print it on sublimation paper ( A solid image with 100% duty was printed on a printer (trade name "LUCY" manufactured by Dairyoku Co., Ltd.).

[0252] [Transfer process to fabric] After the obtained solid image was dried, it was transferred to a polyester fabric recording medium using a heat press machine at a heat press pressure of 60 SPI and the heat press temperature shown in Table 2-1 to obtain an image sample (image recorded material). Here, the heat press machine used was "AIR FUSION" manufactured by STAHLS, and the polyester fabric was "Polyester Amunzen" manufactured by Tajimaya.

[0253] [Black optical density evaluation] The optical density (OD) of black of the image samples prepared at a heat press temperature of 200° C. in the examples and comparative examples was measured using a reflection densitometer (product name "FD-7", manufactured by Konica Minolta, Inc.).

[0254] The measurement results were evaluated for density according to the following evaluation criteria. The evaluation results are shown in the "Optical Density" column in Table 2-1. In the evaluation, if the black OD was 1.50 or higher, it was determined that the optical density was high.

[0255] (Evaluation criteria) A: The black OD is 1.70 or higher. B: Black OD is 1.50 or more and less than 1.70 C: Black OD is less than 1.50

[0256] [Evaluation of heat press color stability] The color stability during heat pressing was calculated using the following formula: The method for measuring the black optical density (OD) of the image at each heat pressing temperature was the same as the method for evaluating the black optical density described above, except that the heat pressing temperatures were different. Color stability (%) when heat pressed at 180℃~210℃= |Black OD when heat pressed at 210°C - Black OD when heat pressed at 180°C| (absolute value) Color stability (%) when heat pressed at 190℃~200℃= |Black OD when heat pressed at 200°C - Black OD when heat pressed at 190°C| (absolute value)

[0257] The obtained results were evaluated according to the following criteria: In the evaluation, if the OD difference (absolute value) of black was less than 0.50, it was determined that the color development stability was good.

[0258] (Evaluation criteria) A: The OD difference (absolute value) of black is less than 0.30 B: The OD difference (absolute value) of black is 0.30 or more and less than 0.50 C: Black OD difference (absolute value) is 0.50 or more

[0259] [Evaluation of lightfastness of printed matter (image recording matter)] Each of the obtained black image samples was placed in a xenon test device (trade name "Atlas Weatherometer Ci4000", manufactured by Toyo Seiki Seisakusho Co., Ltd.) and subjected to illuminance of 0.28 W / m at 340 nm. 2 The samples were exposed to the conditions of a temperature of 40°C and a relative humidity of 50% for 24 hours.

[0260] The reflection density of the black image sample before and after exposure was measured using a reflection densitometer (product name "FD-7", manufactured by Konica Minolta, Inc.).

[0261] The initial chromaticity before exposure is a0 * , b0 * , L0 * and the chromaticity after exposure is a * , b * , L * Then, the color difference ΔE was defined and calculated as follows:

[0262]

number

[0263] The evaluation was based on the ΔE. The evaluation criteria were as follows: If the ΔE after 24 hours was less than 7.00, it was determined that the lightfastness was good.

[0264] (Evaluation criteria) A: ΔE<5.00 B: 5.00≦ΔE<7.00 C:7.00≦ΔE

[0265] [Table 2-1]

[0266] As is clear from Table 2-1 above, by using inks containing the compounds represented by general formulas (1), (2), and (3), it was possible to obtain image recordings with high optical density, excellent color development stability, and excellent light resistance.

[0267] Example 2-14 A total of 2 parts of the compounds of general formulas (1) to (3) used in Example 2-11, 1 part of ADK STAB LA-36 (manufactured by ADEKA CORPORATION), 15 parts of water, 0.8 parts of a dispersant, and 80 parts of 0.2 mm diameter zirconia beads were placed in a zirconia grinding container. The compounding ratios of the compounds of general formulas (1) to (3) were the same as in Example 2-11. The dispersant used was "DisperBYK190" manufactured by BYK-Chemie. The mixture was then dispersed at 300 rpm for 4 hours in a planetary ball mill ("P-7 classic line" manufactured by Fritsch GmbH). The dispersion was diluted with a 15% aqueous glycerin solution to a solids concentration of 5%, and then filtered through a 0.5 μm filter to obtain an ink.

[0268] This ink was evaluated for black optical density, heat press color stability, and lightfastness in the same manner as in Example 2-11. The evaluation results are shown in Table 2-2 below. As shown in Table 2-2, Example 2-14 showed even greater improvements in heat press color stability and lightfastness than Example 2-11.

[0269] [Table 2-2]

[0270] <<Example of the third embodiment>> <Preparation and Evaluation of Thermal Transfer Recording Sheets> Examples 3-1 to 3-13 and Comparative Examples 3-1 to 3-8 [Compounds represented by general formulas (1), (2), and (3)] The compounds represented by the general formulas (1), (2), and (3) were synthesized by known methods. The compounds represented by the general formulas (1), (2), and (3) used in this example are listed in Table 3-1.

[0271] The identification of the obtained compound was carried out as follows: 1 H nuclear magnetic resonance spectroscopy ( 1The measurements were carried out using a H-NMR instrument (trade name "AVANCE-600 NMR spectrometer", manufactured by BRUKER) and a MALDI-TOF / MS instrument (trade name "MALDI-TOF / MS ultraFleXtreme", manufactured by BRUKER).

[0272] [Comparative compounds] As comparative compounds, the following magenta comparative compounds (1) and (3) and cyan comparative compound (2) were used.

[0273] [ka]

[0274] [Preparation of Colorant Composition] Five parts of polyvinyl butyral resin (product name "KS-3", manufactured by Sekisui Chemical Co., Ltd.) was gradually added and dissolved in a mixed solution of 45 parts of methyl ethyl ketone and 45 parts of toluene. Five parts of a compound of the type shown in Table 3-1 below was added and dissolved in this solution to obtain a black colorant composition.

[0275] [Preparation of thermal transfer recording sheet] A 4.5 μm thick polyethylene terephthalate film (trade name "Lumirror", manufactured by Toray Industries, Inc.) was used as the substrate. The colorant composition was applied onto this substrate and then dried to produce a thermal transfer recording sheet having a black colorant layer with a thickness of 1.0 μm after drying.

[0276] [Creating image samples] Using the thermal transfer recording sheet having the prepared black colorant layer, a black image was transferred to a recording medium using a modified machine (trade name "Selphy CP1300, manufactured by Canon) to prepare an image sample (image recording). Paper from a color ink / paper set (trade name "KL-36IP (L size)", manufactured by Canon) specifically for Selphy was used as the recording medium. Here, the image samples prepared using colorant compositions (3-1) to (3-13) are referred to as image samples (3-1) to (3-13), respectively. Furthermore, the image samples prepared using comparative colorant compositions (3-1) to (3-8) are referred to as comparative image samples (3-1) to (3-8), respectively. In this modified machine, the amount of heat supplied for thermal transfer was reduced to approximately 80%.

[0277] The color of the image sample was measured using a reflection densitometer (product name "FD-7", manufactured by Konica Minolta, Inc.).

[0278] [Evaluation of storage stability of colorant composition (ink)] The colorant compositions used in the Examples and Comparative Examples were each placed in a 100 mL sample bottle, sealed, and stored at 10°C for one month. After storage, the presence or absence of aggregates and precipitates was visually confirmed and evaluated. The evaluation results are shown in Table 3-1. The evaluation criteria were as follows. In the evaluation, the storage stability was determined to be good if "almost no aggregates and precipitates of the compound were observed" or "a small amount of aggregates and precipitates of the compound were observed."

[0279] (Evaluation criteria) A: Almost no compound aggregates or precipitates were observed B: A small amount of compound aggregates and precipitates were observed. C: Significant amounts of compound aggregates and precipitates are observed.

[0280] [Evaluation of lightfastness of printed matter (image recording matter)] Each of the obtained black image samples was placed in a xenon test device (trade name "Atlas Weather-O-Meter Ci4000", manufactured by Toyo Seiki Seisakusho Co., Ltd.). The illuminance was 0.28 W / m at 340 nm.2 The sample was exposed for 20 hours under conditions of a temperature of 40°C and a relative humidity of 50%. The reflection density of the black image sample was measured before and after exposure using a reflection densitometer (product name "FD-7", manufactured by Konica Minolta).

[0281] The initial chromaticity before exposure is a0 * , b0 * , L0 * and the chromaticity after exposure is a * , b * , L * Then, the color difference ΔE was defined and calculated as follows:

[0282]

number

[0283] The evaluation was based on the ΔE. The evaluation criteria were as follows: If the ΔE after 20 hours was less than 7.00, the lightfastness was judged to be good.

[0284] (Evaluation criteria) A: ΔE<5.00 B: 5.00≦ΔE<7.00 C:7.00≦ΔE

[0285] [Table 3-1]

[0286] As is clear from Table 3-1 above, the storage stability of the colorant composition used to form the cyan colorant layer of the thermal transfer recording sheet described in the Examples was good, and the light resistance of the image sample recorded using the thermal transfer recording sheet described in the Examples was also high. That is, in the thermal transfer recording sheet described in the Examples, the blending of the three types of colorants, yellow, magenta, and cyan, used in the black colorant layer was able to suppress color mixing and fading.

[0287] The present disclosure includes the following configurations.

[0288] [Configuration 1] The medium and Carrier particles dyed with a compound represented by the following general formula (1), a compound represented by the following general formula (2), and a compound represented by the following general formula (3), An ink characterized in that it comprises:

[0289] [ka]

[0290] [In general formula (1), R1 to R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group.

[0291] [ka]

[0292] [In general formula (2), R5 and R6 each independently represent an alkyl group; R7 represents an alkyl group or an -NH2 group; R8 represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group;

[0293] [ka]

[0294] [In general formula (3), R9 and R 10 each independently represents an alkyl group, R 11 represents an alkyl group, an aryl group, or an alkoxy group; R 12 represents an alkyl group or an aryl group.

[0295] [Configuration 2] The ink according to [Configuration 1], wherein in the general formula (1), R1 and R3 are each independently a hydrogen atom, R2 is an alkyl group having 1 to 4 carbon atoms, and R4 is a phenyl group or a methylphenyl group.

[0296] [Configuration 3] The ink according to [Configuration 1] or [Configuration 2], wherein in the general formula (2), R5 to R7 are each independently alkyl groups having 1 to 4 carbon atoms and the same number of carbon atoms, and R8 is a hydrogen atom.

[0297] [Configuration 4] In the general formula (3), R9 and R 10 are each independently an alkyl group having 1 to 4 carbon atoms, and R 11 The ink according to any one of [Configuration 1] to [Configuration 3], wherein is an alkoxy group having 1 to 4 carbon atoms.

[0298] [Configuration 5] The ink according to any one of [Configuration 1] to [Configuration 4], wherein the mass ratio of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is such that, relative to 10 parts by mass of the compound represented by general formula (1), the compound represented by general formula (2) is 3 parts by mass or more and 9 parts by mass or less, and the compound represented by general formula (3) is 1 part by mass or more and 6 parts by mass or less.

[0299] [Configuration 6] The ink according to any one of [Configuration 1] to [Configuration 5], which contains a dispersant.

[0300] [Configuration 7] The ink according to any one of [Configuration 1] to [Configuration 6], further comprising a resin present in a dissolved state in the medium.

[0301] [Configuration 8] The ink according to any one of [Configuration 1] to [Configuration 7], which is for use with an oil-based writing instrument, a water-based writing instrument, or an inkjet printer.

[0302] [Configuration 9] an aqueous medium; a dispersant; and A compound represented by the following general formula (1), A compound represented by the following general formula (2), A compound represented by the following general formula (3), An ink characterized in that it comprises:

[0303] [ka]

[0304] [In general formula (1), R1 to R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group.

[0305] [ka]

[0306] [In general formula (2), R5 and R6 each independently represent an alkyl group; R7 represents an alkyl group or an -NH2 group; R8 is a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group;

[0307] [ka]

[0308] [In general formula (3), R9 and R 10 each independently represents an alkyl group, R 11 represents an alkyl group, an aryl group, or an alkoxy group; R 12 represents an alkyl group or an aryl group.

[0309] [Configuration 10] The ink according to [Configuration 9], wherein in the general formula (1), R1 and R3 are each independently a hydrogen atom, R2 is an alkyl group having 1 to 4 carbon atoms, and R4 is a phenyl group or a methylphenyl group.

[0310] [Configuration 11] The ink according to [Configuration 9] or [Configuration 10], wherein in the general formula (2), R5 and R7 are each independently alkyl groups having 1 to 4 carbon atoms and the same number of carbon atoms, and R8 is a hydrogen atom.

[0311] [Configuration 12] In the general formula (3), R9 and R 10 , an alkyl group having 1 to 4 carbon atoms, and R 11 The ink according to any one of [Configuration 9] to [Configuration 11], wherein is an alkoxy group having 1 to 4 carbon atoms.

[0312] [Configuration 13] The ink according to any one of [Configuration 9] to [Configuration 12], wherein the mass ratio of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is such that, relative to 10 parts by mass of the compound represented by general formula (1), the compound represented by general formula (2) is 3 parts by mass or more and 9 parts by mass or less, and the compound represented by general formula (3) is 1 part by mass or more and 6 parts by mass or less.

[0313] [Configuration 14] A thermal transfer recording sheet having a substrate and a black colorant layer formed on the substrate, The black colorant layer is A compound represented by the following general formula (1), A compound represented by the following general formula (2), A compound represented by the following general formula (3), A thermal transfer recording sheet comprising:

[0314] [ka]

[0315] [In general formula (1), R1 to R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group.

[0316] [ka]

[0317] [In general formula (2), R5 and R6 each independently represent an alkyl group; R7 represents an alkyl group or an -NH2 group; R8 represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group;

[0318] [ka]

[0319] [In general formula (3), R9 and R 10 each independently represents an alkyl group, R 11 represents an alkyl group, an aryl group, or an alkoxy group; R 12 represents an alkyl group or an aryl group.

[0320] [Configuration 15] A thermal transfer recording sheet according to [Structure 14], wherein in the general formula (1), R1 and R3 are each independently a hydrogen atom, R2 is an alkyl group having 1 to 4 carbon atoms, and R4 is a phenyl group or a methylphenyl group.

[0321] [Configuration 16] A thermal transfer recording sheet according to [Structure 14] or [Structure 15], wherein in the general formula (2), R5 to R7 are each independently alkyl groups having 1 to 4 carbon atoms and the same number of carbon atoms, and R8 is a hydrogen atom.

[0322] [Configuration 17] In the general formula (3), R9 and R 10 are each independently an alkyl group having 1 to 4 carbon atoms, and R 11 The thermal transfer recording sheet according to any one of [Configuration 14] to [Configuration 16], wherein is an alkoxy group having 1 to 4 carbon atoms.

[0323] [Configuration 18] A thermal transfer recording sheet according to any one of [Structure 14] to [Structure 17], wherein the mass ratio of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is such that, relative to 10 parts by mass of the compound represented by general formula (1), the compound represented by general formula (2) is 3 parts by mass or more and 9 parts by mass or less, and the compound represented by general formula (3) is 1 part by mass or more and 6 parts by mass or less.

[0324] [Configuration 19] The thermal transfer recording sheet according to any one of [Configuration 14] to [Configuration 18] further comprises a yellow colorant layer, a magenta colorant layer, and a cyan colorant layer, and the yellow colorant layer, the magenta colorant layer, the cyan colorant layer, and the black colorant layer are formed in face order on the base material.

Claims

1. The medium and Carrier particles dyed with a compound represented by the following general formula (1), a compound represented by the following general formula (2), and a compound represented by the following general formula (3), An ink characterized in that it comprises: 【Chemistry 1】 [In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, or an aryl group; 【Chemistry 2】 [In general formula (2), R ５ and R ６ each independently represents an alkyl group, R ７ is an alkyl group or —NH ２ represents a group, R ８ represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group; 【Transformation 3】 [In general formula (3), R ９ and R １０ each independently represents an alkyl group, R １１ represents an alkyl group, an aryl group, or an alkoxy group; R １２ represents an alkyl group or an aryl group.

2. In the general formula (1), R １ and R ３ are each independently a hydrogen atom, and R ２ is an alkyl group having 1 to 4 carbon atoms, and R ４ 2. The ink according to claim 1, wherein is a phenyl group or a methylphenyl group.

3. In the general formula (2), R ５ ~R ７ each independently has 1 to 4 carbon atoms, and R ８ The ink according to claim 1, wherein is a hydrogen atom.

4. In the general formula (3), R ９ and R １０ are each independently an alkyl group having 1 to 4 carbon atoms, and R １１ 2. The ink according to claim 1, wherein is an alkoxy group having 1 to 4 carbon atoms.

5. 2. The ink according to claim 1, wherein the mass ratio of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is such that, relative to 10 parts by mass of the compound represented by general formula (1), the compound represented by general formula (2) is 3 parts by mass or more and 9 parts by mass or less, and the compound represented by general formula (3) is 1 part by mass or more and 6 parts by mass or less.

6. 10. The ink of claim 1, further comprising a dispersant.

7. 10. The ink of claim 1, further comprising a resin present in a dissolved state in said medium.

8. 2. The ink according to claim 1, which is for use in an oil-based writing instrument, a water-based writing instrument, or an ink-jet writing instrument.

9. an aqueous medium; a dispersant; and A compound represented by the following general formula (1), A compound represented by the following general formula (2), A compound represented by the following general formula (3), An ink characterized in that it comprises: 【Chemistry 4】 [In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, or an aryl group; 【Transformation 5】 [In general formula (2), R ５ and R ６ each independently represents an alkyl group, R ７ is an alkyl group or -NH ２ represents a group, R ８ represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group; 【Transformation 6】 [In general formula (3), R ９ and R １０ each independently represents an alkyl group, R １１ represents an alkyl group, an aryl group, or an alkoxy group; R １２ represents an alkyl group or an aryl group.

10. In the general formula (1), R １ and R ３ are each independently a hydrogen atom, and R ２ is an alkyl group having 1 to 4 carbon atoms, and R ４ The ink according to claim 9, wherein is a phenyl group or a methylphenyl group.

11. In the general formula (2), R ５ and R ７ are each independently an alkyl group having 1 to 4 carbon atoms and the same number of carbon atoms; R ８ The ink according to claim 9, wherein is a hydrogen atom.

12. In the general formula (3), R ９ and R １０ , an alkyl group having 1 to 4 carbon atoms, and R １１ The ink according to claim 9, wherein is an alkoxy group having 1 to 4 carbon atoms.

13. 10. The ink according to claim 9, wherein the mass ratio of the compound represented by general formula (1), the compound represented by general formula (2), and the compound represented by general formula (3) is such that, relative to 10 parts by mass of the compound represented by general formula (1), the compound represented by general formula (2) is 3 parts by mass or more and 9 parts by mass or less, and the compound represented by general formula (3) is 1 part by mass or more and 6 parts by mass or less.

14. A thermal transfer recording sheet having a substrate and a black colorant layer formed on the substrate, The black colorant layer is A compound represented by the following general formula (1), A compound represented by the following general formula (2), A compound represented by the following general formula (3), A thermal transfer recording sheet comprising: 【Transformation 7】 [In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, an alkyl group, or an aryl group; 【Transformation 8】 [In general formula (2), R ５ and R ６ each independently represents an alkyl group, R ７ is an alkyl group or -NH ２ represents a group, R ８ represents a hydrogen atom, an alkyl group, a halogen atom, or an acetylamide group; 【Chemistry 9】 [In general formula (3), R ９ and R １０ each independently represents an alkyl group, R １１ represents an alkyl group, an aryl group, or an alkoxy group; R １２ represents an alkyl group or an aryl group.

15. In the general formula (1), R １ and R ３ are each independently a hydrogen atom, and R ２ is an alkyl group having 1 to 4 carbon atoms, and R ４ 15. The thermal transfer recording sheet according to claim 14, wherein is a phenyl group or a methylphenyl group.

16. In the general formula (2), R ５ ~R ７ each independently has 1 to 4 carbon atoms, and R ８ 15. The thermal transfer recording sheet according to claim 14, wherein is a hydrogen atom.

17. In the general formula (3), R ９ and R １０ are each independently an alkyl group having 1 to 4 carbon atoms, and R １１ The thermal transfer recording sheet according to claim 14, wherein is an alkoxy group having 1 to 4 carbon atoms.

18. 15. The thermal transfer recording sheet according to claim 14, wherein the mass ratio of the compound represented by the general formula (1), the compound represented by the general formula (2), and the compound represented by the general formula (3) is such that, relative to 10 parts by mass of the compound represented by the general formula (1), the compound represented by the general formula (2) is 3 parts by mass or more and 9 parts by mass or less, and the compound represented by the general formula (3) is 1 part by mass or more and 6 parts by mass or less.

19. 15. The thermal transfer recording sheet according to claim 14, further comprising a yellow colorant layer, a magenta colorant layer, and a cyan colorant layer, the yellow colorant layer, the magenta colorant layer, the cyan colorant layer, and the black colorant layer being formed in face order on the base material.

Images