WO2019107263A1

WO2019107263A1 - Pigment compound and thermosensitive transfer recording sheet

Info

Publication number: WO2019107263A1
Application number: PCT/JP2018/043108
Authority: WO
Inventors: 愛早川; 真範関; 城田　衣; 元牟田; 太一新藤; 三東　剛
Original assignee: キヤノン株式会社
Priority date: 2017-11-29
Filing date: 2018-11-22
Publication date: 2019-06-06

Abstract

The present invention uses a triphenylmethane-based compound having a specific substituent.

Description

Dye compound and sheet for thermal transfer recording

The present invention relates to a dye compound and a thermal transfer recording sheet.

In recent years, with the spread of portable color display devices, there has been a sharp increase in demand for easy color printing of photographs and documents taken or produced by the devices. As a color printing method corresponding to these, an electrophotographic method, an inkjet method, a thermal transfer recording method, etc. may be mentioned. Among them, the thermal transfer recording method is excellent in that printing can be performed by a dry process, miniaturization is possible, and portability of the printer is excellent, and printing can be performed easily regardless of the surrounding environment. In addition, since a dye is used as a color material, the density of the image can be expressed by the density gradation of the color material, so that the sharpness and the color reproducibility of the image are excellent.

In the thermal transfer recording method, an image is recorded by transferring a dye in the thermal transfer recording sheet to the image receiving sheet by superposing the thermal transfer recording sheet on the image receiving sheet and heating the thermal transfer recording sheet. It is a formation method. The thermal transfer recording sheet has a color material layer containing a thermally transferable dye on a sheet-like substrate, and the image receiving sheet has a dye receiving layer on the surface. The colorant contained in the colorant layer is a very important material because it affects the speed of transfer recording, the image quality of the recorded matter, and the storage stability. The colorant to be used is required to have excellent light fastness and dispersibility (at the time of ink sheet preparation), and therefore it is required to be excellent in light fastness and dispersibility as well as having high chroma. It was For example, as a cyan dye, anthraquinone compounds are known (Patent Document 1). However, the problem is that anthraquinone compounds have low saturation. In addition, it is generally known that triphenylmethane compounds have vivid color forming properties, and there is a proposal to use these in heat-meltable inks (also referred to as phase change inks and hot melt inks) (Patent Document 1) 2). However, the application of the triphenylmethane compound to a thermal transfer recording sheet has not been described.

JP 10-195318 A JP, 2008-189926, A

An object of the present invention is to provide a dye compound having high chroma, high light fastness and excellent dispersibility.

Another object of the present invention is to provide a thermal transfer recording sheet capable of obtaining an image having high saturation and high light resistance.

The present invention relates to a dye compound having a structure represented by the following formula (1-1) or (1-2).

[In the formula (1-1),
R ₁ and R ₂ each independently represent a substituted alkyl group or a non-substituted alkyl group,
R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having a substituent, an unsubstituted alkyl group, an aryl group having a substituent, or an unsubstituted aryl group,
R ₅ and R ₆ each independently represent a hydrogen atom or an unsubstituted alkyl group having 1 to 4 carbon atoms,
R ₇ and R ₈ each independently represent an unsubstituted alkyl group having 1 to 4 carbon atoms,
R ₉ represents a halogen atom, a nitro group, a sulfo group, a sulfonic acid ester group, a sulfonamide group, a sulfonic acid group, a benzenesulfonyl group, a trifluoromethylsulfonyl group or a perfluoroalkyl group,
R ₁₀ represents a hydrogen atom, a halogen atom, a nitro group, a sulfo group, a sulfonic acid ester group, a sulfonamide group, a sulfonic acid group, a benzenesulfonyl group, a trifluoromethylsulfonyl group, or a perfluoroalkyl group,
X ^- represents an anion. ]

[In the formula (1-2),
R ₁ ~ _{R 8} have the same meanings as _R 1 ~ _{R 8} in the formula (1-1).
R ₉ ′ represents a sulfonato group,
R ₁₀ ′ represents a hydrogen atom, a halogen atom, a nitro group, a sulfo group, a sulfonic acid ester group, a sulfonamide group, a sulfonic acid group, a benzenesulfonyl group, a trifluoromethylsulfonyl group, or a perfluoroalkyl group. ]

The present invention is also a thermal transfer recording sheet comprising a substrate and a coloring material layer on the substrate,
The colorant layer has at least a yellow dye layer containing a yellow dye, a magenta dye layer containing a magenta dye, and a cyan dye layer containing a cyan dye,
The present invention relates to a thermal transfer recording sheet, wherein the cyan dye is a dye compound having a structure represented by the above formula (1-1) or formula (1-2).

According to the present invention, it is possible to provide a dye compound having high chroma, excellent in light resistance, and high dispersibility.

In addition, by using the dye compound, it is possible to provide a thermal transfer recording sheet having high chroma and high light resistance.

FIG. 2 is a cross-sectional view showing an outline of a thermal transfer recording sheet used in Example 1;

Hereinafter, the present invention will be described in more detail.

<Color compound>
The present inventors have found that the compound represented by the following formula (1-1) or (1-2) has high chroma and high light resistance and is excellent in dispersibility.

The compound of the present invention has at least the substituents R ₇ and R ₈ and the substituents R ₁ and R ₂ bonded to the nitrogen atom, and due to the effects of these substituents, the steric twisted structure in the molecule is It is formed. Therefore, intramolecular or intermolecular interactions are suppressed by the effect of steric twist, and aggregation of the compound can be suppressed. Therefore, the high dispersion state is maintained and the high saturation is achieved. On the other hand, we believe that the three-dimensional twisted structure will be highly lightfast because it protects the carbon atoms in the center that are susceptible to attack. When all of R ₁ to R ₄ are hydrogen atoms, they are easily affected by light and are inferior in light resistance.

In Formula (1-1) and Formula (1-2), the unsubstituted alkyl group in R ₁ , R ₂ , R ₃ and R ₄ is not particularly limited, but it is linear or branched. Or a cyclic alkyl group having 1 to 20 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, tert-butyl group, octyl group, dodecyl group, nonadecyl group, cyclobutyl group, cyclopentyl group And cyclohexyl group, methylcyclohexyl group, 2-ethylpropyl group and 2-ethylhexyl group.

Among them, ethyl group, n-butyl group, sec-butyl group, dodecyl group, cyclohexyl group, methylcyclohexyl group, 2-ethylpropyl group, 2-ethylhexyl group and octyl group are preferable. More preferably, it is n-butyl group, 2-ethylhexyl group or octyl group. Further, it is preferable that R ₁ and R ₂ are the same alkyl group, and R ₃ and R ₄ are a hydrogen atom or the same alkyl group, because they are excellent in high chroma, high dispersion, and high light resistance.

The substituent of the alkyl group having a substituent in R ₁ , R ₂ , R ₃ and R ₄ in formulas (1-1) and (1-2) is not particularly limited, but is preferably a phenyl group , Cyano group, halogen atom (fluorine atom, chloro atom, etc.), nitro group, salt of sulfonic acid group (sulfonic acid sodium salt etc.), sulfo group (-SO ₃ H), sulfonic acid ester group (sulfonic acid methyl group etc.) And a perfluoroalkyl group (perfluoromethyl group, perfluoroethyl group etc.), an alkoxy group (methoxy group, ethoxy group etc.), a trifluoromethylsulfonyl group etc. In particular, a phenyl group or a cyano group is preferable because a compound having high chroma, high light resistance and excellent dispersibility can be obtained.

In the formulas (1-1) and (1-2), examples of the unsubstituted aryl group in R ₃ and R ₄ include, but not particularly limited to, a phenyl group and a naphthyl group.

The substituent of the aryl group having a substituent in R ₃ and R ₄ in formulas (1-1) and (1-2) is not particularly limited, and alkyl such as methyl group and ethyl group is not particularly limited. Groups, alkoxy groups such as methoxy group and ethoxy group, salts of sulfonic acid groups such as cyano group, sulfonic acid sodium salt, and sulfonic acid groups.

The alkyl group having 1 to 4 carbon atoms in R ₅ , R ₆ , R ₇ and R ₈ in the formulas (1-1) and (1-2) is not particularly limited, but a methyl group, Ethyl group, n-propyl group, iso-propyl group, n-butyl group and the like can be mentioned.

Among them, R ₅ , R ₆ , R ₇ and R ₈ are each independently preferably a methyl group or an ethyl group, and a methyl group is more preferable because it is excellent in high chroma, high dispersion, and high light resistance.

In the formula (1-1), the halogen atom for R ₉ and R ₁₀ is not particularly limited, and examples thereof include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Among them, a fluorine atom and a chlorine atom are more preferable because they are excellent in high chroma, high dispersion, and high light resistance.

In the formula (1-1), R ₉ and R _{10 each} represent a sulfo group; a sulfonic acid ester group such as a sulfonic acid methyl group or a sulfonic acid ethyl group; a sulfonamide group, an N-methyl sulfonamide group, N, N-dimethyl Sulfonamide group, N-ethyl sulfonamide group, N, N-diethyl sulfonamide group, N-propyl sulfonamide group, N, N-dipropyl sulfonamide group, N-butyl sulfonamide group, N, N-dibutyl sulfone group Amide group, N-pentyl sulfonamide group, N, N-dipentyl sulfonamide group, N-hexyl sulfonamide group, N, N- dihexyl sulfonamide group, N-octyl sulfonamide group, N, N- dioctyl sulfonamide group , N- (2-ethylhexyl) sulfonamide group, N, N-bis (2-ethylhexyl) sulfone Amide group, N- (1-methylhexyl) sulfonamide group, N- (1-methylheptyl) sulfonamide group, N-methyl-N-butyl sulfonamide group, N-methyl-N-pentyl sulfonamide group, N -Methyl-N-hexyl sulfonamide group, N-methyl-N-octyl sulfonamide group, N-phenyl sulfonamide group, N- (p-methylphenyl) sulfonamide group, N-pyrrolidinylsulfonyl group, N-piperidyl group Sulfonamide group such as sulfonyl group; Sulfonate group such as lithium sulfonate, sodium salt of sulfonic acid, potassium salt of sulfonic acid; benzenesulfonyl group, toluenesulfonyl group, nitrobenzenesulfonyl group, etc. Benzenesulfonyl group; trifluoromethylsulfonyl group etc. It is also good. Among them, a sulfo group and a sulfonic acid sodium salt are more preferable because they are excellent in high chroma, high dispersion, and high light resistance.

The perfluoroalkyl group for R ₉ and R ₁₀ in the formula (1-1) is not particularly limited, but a perfluoromethyl group, a perfluoroethyl group, a perfluoroisopropyl group, a perfluoro n-butyl group Groups, perfluorooctyl groups and the like. Among them, a perfluoromethyl group is more preferable because it is excellent in high chroma, high dispersion, and high light resistance.

In the case of the structures represented by the following formulas (4) to (6), the partial structure composed of R ₉ and R ₁₀ and the benzene ring to which they are bonded in formula (1-1) has high chroma, high dispersion, and high More preferable because of excellent light resistance.

Wherein (1-1), X ^- as the anion, but are not limited to, fluorine ion, chlorine ion, bromine ion, iodine ion, cyanide ion, nitrate ion, benzenesulfonate ion, p- Toluene sulfonate ion, methyl sulfate ion, ethyl sulfate ion, propyl sulfate ion, tetrafluoroborate ion, tetraphenylborate ion, benzenesulfinate ion, acetate ion, trifluoroacetate ion, propionacetate ion, benzoate ion, Oxalate ion, succinate ion, malonate ion, oleate ion, stearate ion, citrate ion, picolinate ion, monohydrogen diphosphate ion, dihydrogen diphosphate ion, pentafluoropropionate ion, chlorosulfone Acid ion, fluorosulfonic acid And perchlorate anion, trifluoromethanesulfonyl anion, bis (trifluoromethanesulfonyl) imide anion, naphthalene sulfonyl ion, naphthalene disulfonate ion, tris trifluoromethane sulfonyl methide anion, tetraaryl borate anion, sulfate anion and the like.

R ₉ ′ in the formula (1-2) is a sulfonato group (—SO ₃ ⁻ ).

R ₁₀ ′ in the formula (1-2) is a hydrogen atom, a halogen atom, a nitro group, a sulfo group, a sulfonic acid ester group, a sulfonamide group, a sulfonic acid group, a benzenesulfonyl group, a trifluoromethylsulfonyl group, or a perfluoro Represents an alkyl group.

In the case of the structure represented by the following formula (7), the partial structure composed of R ₉ ′ and R ₁₀ ′ and the benzene ring to which they are bonded in formula (1-2) has high chroma, high dispersion, and high light resistance It is more preferable because it is excellent in

Compounds (A1) to (A37) are shown below as preferable examples of the compound represented by the formula (1-1) or the formula (1-2), but the compounds are not limited to the following compounds.

Among these, compounds (A2), (A3), (A5), (A7), (A11), (A12), (A13), (A14), (A15), (A16), (A17), (A18), (A19), (A20), (A23), (A25), (A29), (A30), (A31), (A32), (A33), (A34), (A35), (A36) The compounds represented by (A37) and (A37) are preferred as cyan dyes. Furthermore, (A3), (A7), (A11), (A15), (A23), (A25), (A29), (A30), (A34) are excellent in high saturation, high dispersion, and high light resistance. , More preferred.

In the compound represented by the formula (1-1) or the formula (1-2), the cation may be present in a delocalized manner, and the cation site may be present at any position in the molecule, either of which is present. It is a category of invention. For example, in the case of the compound (A7) having an anionic substituent in the molecule, the structure changes as follows.

In the case of the compound (A25) having no anionic substituent in the molecule, the structure changes as follows.

The compounds represented by the general formula (1-1) or the formula (1-2) can be synthesized based on known methods. That is, the compound represented by the general formula (1-1) or the formula (1-2) is a condensation step of condensing the compounds (A), (B) and (C) to obtain the compound (D), and then It can synthesize | combine through the oxidation process which oxidizes a compound (D). The condensation step and the oxidation step can be carried out, if necessary, in the presence of a liquid medium, a condensing agent, an oxidizing agent and the like.

An example of a synthesis scheme is shown below, but is not limited to this synthesis method. Compounds in the synthesis scheme _{_{(A) ~ R 1 ~ R}} 10, R 9 in the (D) 'and _{R 10'} have the same meanings as _R 1 _{~ R 10} in the general formula (1-1). The compound represented by the general formula (1-1) or the formula (1-2) can be synthesized as a mixture of a plurality of isomers different in the kind, the number, and the position of the substituent, but in the present invention, for convenience. It describes as a "compound" also when it is a mixture. Although the compounds used in each synthesis scheme are shown as the free acid form, compounds in the salt form may be used.

When synthesizing a compound in which R ₁ and R ₂ , R ₃ and R ₄ , R ₅ and R ₆ , and R ₇ and R _{8 in the} general formula (1-1) are respectively the same substituent, The same compounds may be used as the compounds (A) and (B).

[Synthesis scheme 1]

(Condensation process)
First, the condensation step will be described. The condensation step can be carried out in the presence of a medium, a condensing agent, an oxidizing agent and the like, if necessary.

The condensation step can also be carried out without solvent, but it is preferred to use a medium.

The medium that can be used in the condensation step is not particularly limited, and, for example, water, methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, ethylene glycol, glycerin, tetrahydrofuran, N , N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethylsulfoxide, sulfolane, N, N'-dimethylpropyleneurea, chlorobenzene, 1 , 2-dichlorobenzene, nitrobenzene, ethyl acetate and the like can be used alone or in combination in any mixing ratio.

Particularly preferred are water, methanol, ethanol, N, N-dimethylformamide and the like. The amount of the reaction solvent used is preferably 0.1 to 1000% by mass, and more preferably 1.0 to 150% by mass, based on the aldehyde compound (C).

The condensing agent that can be used in the condensation step is not particularly limited, and examples thereof include sulfuric acid, hydrochloric acid, phosphoric acid, acetic acid, formic acid, aluminum chloride, zinc chloride, p-toluenesulfonic acid and the like. Particularly preferred are sulfuric acid, hydrochloric acid and acetic acid. The amount of the above-mentioned condensing agent used is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, with respect to the aldehyde compound (C).

The reaction temperature in the condensation step can be in the range of 0 to 160 ° C. In particular, the temperature is preferably 50 ° C. to 140 ° C., more preferably 60 ° C. to 120 ° C. This condensation reaction is usually completed within 24 hours, and after completion of the reaction, purification by column purification or crystallization can be performed.

(Oxidation process)
Next, the oxidation step will be described. The oxidation step can be carried out in the presence of a medium, an oxidant and the like, if necessary.

The oxidation step can be carried out without solvent, but it is preferred to use a medium.

The medium that can be used in the condensation step is not particularly limited, and, for example, water, methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, ethylene glycol, glycerin, tetrahydrofuran, N , N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethylsulfoxide, sulfolane, N, N'-dimethylpropyleneurea, chlorobenzene, 1 , 2-dichlorobenzene, nitrobenzene, ethyl acetate, chloroform and the like can be used alone or in combination in any mixing ratio.

Particularly preferred are 1,2-dichlorobenzene, ethyl acetate, chloroform and the like. The amount of the reaction solvent used is preferably 0.1 to 1000% by mass, and more preferably 1.0 to 200% by mass, based on the aldehyde compound (C).

The oxidizing agent that can be used in the oxidation step is not particularly limited, and examples thereof include zinc oxide, zinc oxide, iron oxide, manganese oxide, hydrogen peroxide, chloranil, oxygen and the like.

Preferred are manganese oxide and chloranil. The amount of the oxidizing agent used is preferably 0.01 to 20% by mass, and more preferably 0.1 to 5% by mass, based on the aldehyde compound (C).

The pH of the medium in the oxidation step is preferably pH 1-9, more preferably pH 2-8, especially pH 3-7.

The reaction temperature in the oxidation step can be in the range of 0 to 150 ° C. The temperature is preferably 10 ° C to 100 ° C, and particularly preferably 20 ° C to 80 ° C. The oxidation reaction is usually completed within 18 hours, and after completion of the reaction, purification by column purification or crystallization can be performed.

The compounds represented by the above general formulas (1-1) and (1-2) may be used alone or in combination of two or more in order to adjust the color tone or the like according to the application. You may use together. Furthermore, it can also be used in combination with known dyes. Two or more kinds of known dyes may be combined.

Although it does not specifically limit as an example of the dye used together, For example, the compound etc. which are selected from the compound group represented by following formula (2) and (3) are mentioned.

[In the formula (2), each of R ₁₁ to R ₁₅ independently represents an alkyl group, an aryl group having a substituent, or an unsubstituted aryl group. ]

Examples of the alkyl group in R ₁₁ to R ₁₅ in the formula (2) include the same groups as those exemplified as the alkyl group in R ₁ , R ₂ , R ₃ and R ₄ in the above formula (1-1). . In particular, when an alkyl group having 1 to 2 carbon atoms, such as a methyl group or an ethyl group, is used, it is preferable because it is excellent in high chroma, high dispersion, and high light resistance.

In Formula (2), the aryl group having a substituent in R ₁₁ to R ₁₅ or the unsubstituted aryl group is not particularly limited, but R ₃ and R _{4 in the} above Formula (1-1) may be used. And the same groups as those exemplified as the substituted or unsubstituted aryl group in the above.

Compounds (B1) to (B6) are shown below as preferable examples of the compound represented by the formula (2), but the compounds are not limited to the following compounds.

Among these, compounds (B1), (B2) and (B3) are preferable. Furthermore, from the viewpoint of the effect of the present invention, the compound (B2) is more preferable.

Next, the cyan dye represented by Formula (3) will be described.

[In Formula (3), R ₁₆ and R ₁₇ each independently represent an alkyl group, an aryl group having a substituent, or an unsubstituted aryl group. ]

Examples of the alkyl group in R ₁₆ and R ₁₇ in the formula (3) include the same groups as those exemplified as the alkyl group in R ₁ , R ₂ , R ₃ and R ₄ in the above formula (1-1). . In particular, when an alkyl group having 1 to 2 carbon atoms, such as a methyl group or an ethyl group, is used, it is preferable because it is excellent in high chroma, high dispersion, and high light resistance.

The aryl group having a substituent or the unsubstituted aryl group in R ₁₆ and R ₁₇ in the formula (3) is not particularly limited, and examples thereof include a phenyl group and a naphthyl group. In particular, when a phenyl group is used, it is preferable because it is excellent in high chroma, high dispersion, and high light resistance. Examples of the substituent of the substituted aryl group include an alkyl group and an alkoxy group.

Compounds (C1) to (C6) are shown below as preferable examples of the compound represented by the formula (3), but the present invention is not limited to the following compounds.

Among these, compounds (C3), (C4) and (C5) are preferred as cyan dyes. From the viewpoint of the effects of the present invention, the compound (C3) is further preferred.

<Thermal transfer recording sheet>
The thermal transfer recording sheet of the present invention has a substrate and a colorant layer on the substrate. The color material layer includes at least a yellow dye layer containing a yellow dye, a magenta dye layer containing a magenta dye, and a cyan dye layer containing a cyan dye.

Image formation using a thermal transfer recording sheet is performed as follows.

The thermal transfer recording sheet is placed on a heating means such as a thermal head by superposing the thermal transfer recording sheet and the image receiving sheet having the color material receiving layer on the surface, with the color material layer and the color material receiving layer facing each other. Use and heat. Thus, the color material in the thermal transfer recording sheet is sublimed and transferred to the image receiving sheet.

Hereinafter, the structure of the thermal transfer recording sheet of the present invention will be described.

<Base material>
The substrate constituting the heat-sensitive transfer recording sheet according to the present invention supports the later-described color material layer, and a known substrate can be used. The material is not particularly limited as long as it has a certain degree of heat resistance and strength, and examples thereof include the following. 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, cellulose derivative, polyethylene film, polyvinyl chloride film, nylon film, condenser paper, paraffin paper.

In particular, polyethylene terephthalate film is preferred in view of mechanical strength, solvent resistance and economy.

The thickness of the substrate is 0.5 μm to 50 μm, and preferably 3 μm to 10 μm from the viewpoint of transferability.

The substrate is preferably subjected to an adhesion treatment on one side or both sides as necessary. In the case of applying a dye ink to form a color material layer on a substrate, it is usually preferable to carry out an adhesion treatment, since the wettability, adhesion and the like of the coating liquid are likely to be insufficient.

The adhesion treatment is not particularly limited, and examples thereof include ozone treatment, corona discharge treatment, ultraviolet treatment, plasma treatment, low temperature plasma treatment, primer treatment, chemical treatment and the like. Also, two or more of these processes may be combined.

In the adhesion treatment of the substrate, an adhesion layer may be coated on the substrate.

Although it does not specifically limit as a material used for an adhesive layer, For example, the following are mentioned. 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, polyvinyl butyral resin. Inorganic fine particles such as silica, alumina, magnesium carbonate, magnesium oxide and titanium oxide.

<Color material layer>
The thermal transfer recording sheet has a colorant layer on a substrate. The color material layer has at least a yellow dye layer, a magenta dye layer and a cyan dye layer. A conventionally known black dye layer may be added as a dye layer to the thermal transfer recording sheet.

The thermal transfer recording sheet is not particularly limited, but the respective dye layers are formed face-sequentially (in a state of not being laminated, but side by side) on the substrate. For example, the yellow dye layer, the magenta dye layer, and the cyan dye layer are repeatedly formed on the base sheet along the moving direction of the base sheet. When this thermal transfer recording sheet is used, first, a yellow image is formed, and then a series of image formation is performed in the order of a magenta image and a cyan image to form one full-color image. . Then, this series of image formation is repeated. Furthermore, in addition to the plurality of dye layers, a transferable protective layer may be added surface-sequentially. Also, a heat melting black layer may be added.

In the present invention, a compound having a structure represented by the above formula (1-1) or formula (1-2) is used as the cyan dye to be contained in the cyan dye layer.

The dye is not particularly limited as long as it is a dye that is conventionally known and used for thermal transfer and is subjected to sublimation transfer by heat, and the hue, printing sensitivity, light resistance, storage stability, binding It can be appropriately selected and used in consideration of the solubility in the resin and the like.

Each dye layer contains each dye dye and a binder resin, and the method for forming each dye layer is not particularly limited, but it is usually produced as follows.

The above-mentioned specific dye, binder resin, surfactant, if necessary, and wax are gradually added to the medium with stirring, and the medium is sufficiently blended. Furthermore, the composition is stably dissolved or dispersed in the form of fine particles by applying mechanical shear force with a disperser to prepare an ink. Next, a dye layer can be produced on a base material by applying and drying the ink on a base film which is a base material. The application amount of the ink is preferably in the range of 0.1 μm to 5 μm after drying of the color material layer from the viewpoint of transferability.

Although it does not specifically limit as a medium which can be used for the said manufacturing method, For example, water or an organic solvent is mentioned. Organic solvents include 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 Preferred are 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-methyl pyrrolidone Used. The organic solvents may be used alone or in combination of two or more as needed.

The amount of each color dye used is 50 to 300 parts by mass, preferably 80 to 280 parts by mass, and further 85 to 250 parts by mass with respect to 100 parts by mass of the binder resin. Preferred. The amount used corresponds to the mass part of the total amount of the respective dyestuffs when two or more dyes are used in combination.

The binder resin includes various resins. Among them, water-soluble resins such as cellulose resin, polyacrylic acid resin, starch resin, and epoxy resin, and polyacrylate resin, polymethacrylate resin, polystyrene resin, polycarbonate resin, polyether sulfone resin, polyvinyl butyral resin, ethyl cellulose It is preferable that the resin is a resin soluble in an organic solvent such as a resin, an acetyl cellulose resin, a polyester resin, an AS resin, and a phenoxy resin. These resins may be used alone or in combination of two or more as needed.

<Other ingredients>
In addition, a surfactant may be contained in the heat-sensitive transfer recording sheet in order to provide sufficient lubricity at the time of heating the thermal head (during printing). Surfactants that can be added include cationic surfactants, anionic surfactants, and nonionic surfactants.

The following may be mentioned as cationic surfactants. Dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide.

Anionic surfactants include fatty acid soaps such as sodium stearate, sodium dodecanoate, sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium lauryl sulfate.

Examples of nonionic surfactants include the following. Dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, nonylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, monodecanoyl sucrose.

The thermal transfer recording sheet may contain a wax to have sufficient lubricity when the thermal head is not heated. Waxes that can be added include, but are not limited to, polyethylene wax, paraffin wax, fatty acid ester wax.

If necessary, an ultraviolet absorber, an antiseptic, an antioxidant, an antistatic agent, and a viscosity modifier may be added to the thermal transfer recording sheet in addition to the above-described additives.

The heat-sensitive transfer recording sheet has a heat-resistant slip layer on the surface opposite to the surface on which the coloring material layer is provided, for the purpose of improving heat resistance and runnability of the thermal head. Is preferably provided. The heat resistant slip layer is formed of a heat resistant resin. The heat-resistant resin is not particularly limited, and examples thereof include the following. 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.

A lubricant, a crosslinking agent, a mold release agent, heat resistant fine particles and the like may be further added to the heat resistant slip layer.

The lubricants include amino-modified silicone compounds and carboxy-modified silicone compounds. Further, as the heat resistant fine particles, fine particles such as silica may be mentioned, and as the binding agent, acrylic resin may be mentioned, however, it is not limited to these.

The heat-resistant slip layer is formed by applying a heat-resistant slip layer coating solution prepared by adding the above-mentioned resin and additive to a solvent and dissolving or dispersing it. Although it does not specifically limit as method to apply | coat a heat-resistant lubricating layer coating liquid, The method using a bar coater, a gravure coater, a reverse roll coater, a rod coater, an air doctor coater is mentioned. In particular, a method using a gravure coater is preferred. The coating amount of the heat resistant slipping layer coating solution is preferably such that the thickness of the color material layer after drying is in the range of 0.1 μm to 5 μm from the viewpoint of transferability.

In the coating, although not particularly limited, it is preferable to dry at a temperature of 50 to 120 ° C. for about 1 second to 5 minutes. If the drying is not sufficient, the dye back-off may occur during background staining or winding, or the back-out dye ink may retransfer to a dye layer of a different color when it is rewound. It will occur.
[Heating means]
The heating means for heating the thermal transfer recording sheet is not particularly limited, but not only a conventional method using a thermal head but also infrared rays or laser light can be used. Moreover, it can also heat by supplying electricity to base film itself. In this case, a conductive dye transfer sheet may be formed using a conductive heat generating film that generates heat.

Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not limited to these examples. In the following description, "part" is based on mass unless otherwise noted. Identification of the obtained compound includes ¹ H nuclear magnetic resonance spectroscopy ( ¹ H-NMR) apparatus (AVANCE-600 NMR spectrometer, manufactured by BRUKER), and MALDI-TOF / MS (MALDI-TOF / MS ultraFleXtreme, BRUKER) Company) equipment.

<Production Example of Compound Represented by Formula (1-1) or Formula (1-2)>
Production Example 1: Production of Compound (A3)
To a solution of N, N-dibutyl-2,6-dimethylaniline (2.32 g) in glacial acetic acid (20 mL) was added sodium 2-sulfobenzaldehyde (0.98 g) and heated at 100 ° C. for 12 hours. After completion of the reaction, the reaction solution was cooled to room temperature, diluted with water (50 mL) and extracted with chloroform (50 mL). After concentration under reduced pressure, the residue was dissolved in ethyl acetate (20 mL), chloranil (2.33 g) was added, and the mixture was heated at 80 ° C. for 4 hours. After completion of the reaction, the reaction solution was filtered and the obtained filtrate was washed three times with water. The residue was purified by column chromatography to obtain (A3) (1.96 g).

Identification of the compound was performed by [1] ¹ H-NMR analysis and [2] MALDI-TOF / MS analysis. The analysis results are shown below.
[1] ¹ H-NMR (600 MHz, DMSO-d6, room temperature 25 ° C.) results:
δ (ppm) = 7.78 (2H, m), 7.62 (1 H, dd), 7.45 (1 H, dd), 6.87 (12 H, s), 3.78 (8 H, m), 2.12 (12 H, s), 1.49 (8 H, m), 1.31 (8 H, m), 0.90 (12 H, m)
[2] MALDI-TOF / MS analysis results:
m / z = 633.20 (M + H) ⁺

(Production Examples 2 to 12: Production of Other Compounds)
The compounds shown in Table 1 were produced and identified in the same manner as in Production Example 1.

[Comparison compound]
The following compounds were used as comparative compounds.

<Cyan Ink Preparation Example 1>
To a mixed solution of 45 parts of methyl ethyl ketone and 45 parts of toluene, 5 parts of polyvinyl butyral resin (Denka 3000-K; manufactured by Denki Kagaku Kogyo Co., Ltd.) was gradually added and dissolved. Here, 5 parts of the compound (A3) was added and dissolved to obtain a cyan ink (C1) for preparing a cyan dye layer.

<Cyan Ink Preparation Examples 2 to 21>
Cyan ink (C2) to (C6) in the same manner as in Cyan ink preparation example 1 except that compound (A3) was changed to the cyan dye (the compound of the present invention and the comparative compound) shown in Table 1 I got C4).

Example 1
As a substrate, a polyethylene terephthalate film (Lumirror (registered trademark); manufactured by Toray Industries, Inc.) having a thickness of 4.5 μm is used. The cyan ink (C1) was applied onto the substrate so that the thickness after drying was 1 μm, and the cyan ink layer was formed by drying.

FIG. 1 is a cross-sectional view showing an outline of a thermal transfer recording sheet used in Example 1. As shown in FIG. The thermal transfer recording sheet 1 has a coloring material layer 3 and a protective layer 4 on a substrate 2. The color material layer 3 has a yellow dye layer Y, a magenta dye layer M, and a cyan dye layer C in a surface sequential manner.

As described above, the thermal transfer recording sheet having yellow dye layer Y, magenta dye layer M, cyan dye layer C, and protective layer 4 (color ink KL-36IP for compact photo printer SELPHY CP1200 manufactured by Canon Inc.) The cyan dye layer was cut out. Then, at the position where the cyan dye layer is cut out, a cyan dye layer formed using the above-mentioned cyan ink (C1) of the same size (width, length and thickness) as the cut-out cyan dye layer is stuck to obtain full color feeling. A thermal transfer recording sheet was formed. The obtained sheet for thermal transfer recording was transferred to a printing paper by a Selphy remodeler to prepare an image sample (1). As an image, the output was adjusted so that the optical density (OD) became 1.0, and cyan was printed in a single color.

The following evaluation was performed using the obtained image sample. The evaluation results are shown in Table 2.

[Examples 2-16, Comparative Examples 1-8]
A thermal transfer recording sheet having a cyan dye layer was produced in the same manner as in Example 1 except that the cyan ink used in Example 1 was changed as shown in Table 2.

Image samples (2) to (16) and comparative image samples (1) to (8) were prepared in the same manner as in Example 1 using each of the prepared thermal transfer recording sheets, and evaluations described later were performed. The The evaluation results are shown in Table 2.

(I) Saturation evaluation For each of the prepared image samples, chromaticity (L ^* , L ^* , L ^* , and L ^* in the L ^* a ^* b ^* color system using a spectral density system (Fluorescent spectral densitometer FD-7, manufactured by Konica Minolta Co., Ltd.) The a ^* and b ^* ) were measured, and the saturation (C ^* ) was calculated by the following equation.

The larger the saturation C ^{*, the} better the saturation expansion and the higher the saturation. The results are shown in Table 2.

The evaluation criteria are as follows.
A: C ^* is 45.0 or more B: C ^* is 35.0 or more and less than 45.0 C: C ^* is less than 35.0

(Ii) Evaluation of light fastness The above image sample is put into a xenon test apparatus (Atlas Weatherometer Ci4000, manufactured by Toyo Seiki Seisakusho Co., Ltd.) (illuminance: 0.28 W / m ^{2 at} 340 nm, black panel temperature: 40 ° C., relative) It exposed for 20 hours on the conditions of humidity: 50%. The initial optical density was OD ₀ and O.S. after 20 hours exposure. D. When OD is ₂₀ , O. D. The survival rate was defined as follows.
O. D. Residual ratio _{(%) = (OD 20 /} OD 0) × 100

Evaluation criteria are as follows.
A: 60 <O. D. Survival rate(%)
B: 50 <O. D. Residual rate (%) ≦ 60
C: O. D. Residual rate (%) ≦ 50

(Iii) Evaluation of Dispersibility of Cyan Dyes Each image sample is observed at 20 times magnification using a phase contrast microscope (trade name: BX53, manufactured by OLYMPUS Co., Ltd.) to evaluate the dispersibility of the compound. The

The evaluation criteria are as follows.
A: Almost no compound aggregates are observed B: Some compound aggregates are confirmed C: A lot of compound aggregates are confirmed

The present invention is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Accordingly, the following claims are attached to disclose the scope of the present invention.

The present application claims priority based on Japanese Patent Application No. 2017-229293 filed on Nov. 29, 2017 and Japanese Patent Application No. 2018-197292 filed on October 19, 2018, The entire contents of the description are incorporated herein.

Claims

A dye compound having a structure represented by the following formula (1-1) or (1-2):

[In the formula (1-1),
R 1 and R 2 each independently represent a substituted alkyl group or a non-substituted alkyl group,
R 3 and R 4 each independently represent a hydrogen atom, an alkyl group having a substituent, an unsubstituted alkyl group, an aryl group having a substituent, or an unsubstituted aryl group,
R 5 and R 6 each independently represent a hydrogen atom or an unsubstituted alkyl group having 1 to 4 carbon atoms,
R 7 and R 8 each independently represent an unsubstituted alkyl group having 1 to 4 carbon atoms,
R 9 represents a halogen atom, a nitro group, a sulfo group, a sulfonic acid ester group, a sulfonamide group, a sulfonic acid group, a benzenesulfonyl group, a trifluoromethylsulfonyl group, or a perfluoroalkyl group,
R 10 represents a hydrogen atom, a halogen atom, a nitro group, a sulfo group, a sulfonic acid ester group, a sulfonamide group, a sulfonic acid group, a benzenesulfonyl group, a trifluoromethylsulfonyl group, or a perfluoroalkyl group,
X - represents an anion. ]

[In the formula (1-2),
R 1 ~ R 8 have the same meanings as R 1 ~ R 8 in the formula (1-1).
R 9 ′ represents a sulfonato group,
R 10 ′ represents a hydrogen atom, a halogen atom, a nitro group, a sulfo group, a sulfonic acid ester group, a sulfonamide group, a sulfonic acid group, a benzenesulfonyl group, a trifluoromethylsulfonyl group, or a perfluoroalkyl group. ]
The dye compound according to claim 1, wherein in the formulas (1-1) and (1-2), R 1 and R 2 are the same alkyl group.
In Formula (1-1), a partial structure composed of R 9 and R 10 and a benzene ring to which they are bonded is any one of structures represented by the following Formulas (4) to (6): The pigment compound as described in 2.
The dye according to claim 1 or 2, wherein in the formula (1-2), a partial structure composed of R 9 'and R 10 ' and a benzene ring to which they are bonded is a structure represented by the following formula (7). Compound.
A thermal transfer recording sheet comprising a substrate and a colorant layer on the substrate, the sheet comprising
The colorant layer has at least a yellow dye layer containing a yellow dye, a magenta dye layer containing a magenta dye, and a cyan dye layer containing a cyan dye,
A sheet for thermal transfer recording, wherein the cyan dye comprises the dye compound according to any one of claims 1 to 4.
The thermal transfer recording sheet according to claim 5, wherein the cyan dye further contains at least one compound selected from the group of compounds represented by the following formulas (2) and (3).

[In the formula (2), R 11 to R 15 each independently represent an alkyl group, an aryl group having a substituent, or an unsubstituted aryl group. ]

[In Formula (3), R 16 and R 17 each independently represent an alkyl group, an aryl group having a substituent, or an unsubstituted aryl group. ]