JP4793208B2 - Sublimation type thermal transfer sheet - Google Patents

Description

The present invention relates to a sublimation thermal transfer sheet.

As a thermal transfer sheet in an image forming method using thermal transfer, a sublimation type thermal transfer sheet provided with a sublimation transfer type ink layer composed of a sublimation dye and a binder as a color material layer on one surface of a base film, or the sublimation There is known a heat melting type thermal transfer sheet provided with a heat melting transfer type ink layer made of pigment and wax in place of the transfer type ink layer.
The sublimation thermal transfer method generally performs full-color expression by sequentially superimposing three primary colors (three colors of yellow, magenta, and cyan. Black may be added as necessary) and sequentially printing gradations.

The image obtained by such a heat-sensitive sublimation transfer method can form a high-quality image similar to a silver salt photograph, and accordingly, image quality deterioration prevention due to factors such as light, heat, and humidity of the image can be prevented. The demand is getting very high.
Conventionally, new dyes have been developed, but none of them can sufficiently satisfy the cost, storage stability, print density, and hue. Furthermore, when an image is formed using a single dye, there is a problem that the light resistance is inferior when combined with other dyes on the printed matter even if the light resistance is sufficient. . For example, when comparing the light resistance of magenta, yellow, and red (comprising a mixture of magenta and yellow), the magenta and yellow components in red may be significantly worse than the light resistance levels of magenta and yellow. is there.

In Patent Document 1, in a thermal transfer sheet in which dye layers of at least three colors of yellow, magenta, and cyan are provided on one surface of a base sheet in a surface sequential manner, a yellow dye, a magenta dye, and a cyan having a specific chemical structure, respectively. A thermal transfer sheet using a dye is disclosed. However, although this thermal transfer sheet has a sufficient printing density, it has not been able to achieve a sufficient balance with light resistance.

In Patent Document 2, for sublimation color thermal transfer, at least three ink layers of cyan, magenta, and yellow, or four ink layers obtained by adding black to these hues are sequentially coated on one side of a substrate. The basic molecular skeleton of the dye constituting the cyan ink layer is an anthraquinone, and the basic molecular skeleton of the sublimation paint constituting the magenta ink layer is an anthraquinone, and a yellow ink. A thermal transfer sheet is disclosed in which the molecular basic skeleton of the sublimation paint constituting the layer is anthraquinone, quinophthalone, acrid, nitro, pyridone, or pyrazolone. However, although this heat transfer sheet has sufficient light resistance, the print density is insufficient.

Patent Document 3 discloses a thermal transfer sheet in which a yellow dye layer contains a specific dye and a cyan dye layer contains a specific dye. Even in the combination of the thermal transfer sheet, either the light resistance or the print density is insufficient.

As described above, it is difficult for the conventional thermal transfer sheet to achieve both excellent light resistance and a suitable printing density.
JP-A-5-262056 JP-A-6-92039 Japanese Patent Application Laid-Open No. 7-232481

The present invention provides a sublimation type thermal transfer sheet that is excellent in various fastness properties such as light resistance and can form a printed matter having a good density residual ratio when red is formed from yellow and magenta. The purpose is to do.

The present invention is a thermal transfer sheet in which at least a yellow dye layer and a magenta dye layer are formed on a base sheet as a dye layer composed of a dye and a binder resin,
The yellow dye layer has the following general formula (A)

(In the formula, R ¹ represents an alkyl group containing two or more oxygen atoms in the form of an ether bond.)
A yellow dye composed of a quinophthalone compound represented by
The magenta dye layer has the following general formula (B)

(Wherein R ² represents an alkyl group, R ³ and R ⁴ each independently represents an alkyl group having 2 or more carbon atoms, and X represents a halogen atom.)
A sublimation type thermal transfer sheet comprising a magenta dye comprising an azo compound represented by the formula:

The yellow dye is represented by the following formula (Y-1)

It is preferable that it is a compound represented by these.
The magenta dye is represented by the following formula (M-1)

It is preferable that it is a compound represented by these.
The magenta dye layer further comprises the following general formula (C)

Wherein R ⁵ is a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted alkylaminocarbonyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkyl Represents a group, a substituted or unsubstituted cycloalkyl group, a heterocyclic group or a halogen atom, R ⁶ represents an amino group or a hydroxyl group, and n represents an integer of 2 or less.)
It is preferable to contain the compound represented by these.
The compound represented by the general formula (C) is represented by the following formula (M-2)

And / or the following formula (M-3)

It is preferable that it is a compound represented by these.
The yellow dye layer further comprises the following formula (Y-2)

A compound represented by formula (Y-3):

And a compound represented by formula (Y-4):

It is preferable to contain at least one compound selected from the group consisting of compounds represented by:
Hereinafter, the present invention will be described in detail.

First, it explains in full detail for every layer which comprises the sublimation type thermal transfer sheet of this invention.
(Substrate sheet)
The substrate sheet in the present invention may be any sheet having a certain level of heat resistance and strength known in the art, such as polyethylene terephthalate film, 1,4-polycyclohexylenedimethylene terephthalate film, polyethylene naphthalate. Phthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose derivatives such as cellulose acetate, polyethylene film, polyvinyl chloride film, nylon film, polyimide film, Resin films such as ionomer films; papers such as condenser paper, paraffin paper, and synthetic paper; non-woven fabrics; Body; and the like.
The substrate sheet generally has a thickness of about 0.5 to 50 μm, preferably about 3 to 10 μm.
The base material sheet may be subjected to an adhesion treatment on one side or both sides as necessary.
When the dye ink for forming the dye layer is applied on the base sheet, the wettability and adhesiveness of the dye ink are likely to be insufficient.
Examples of the above-mentioned adhesion treatment include corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, plasma treatment, low temperature plasma treatment, primer treatment, grafting treatment, etc. The reforming technique can be applied as it is. Two or more of these treatments can be used in combination.

Furthermore, it is also possible to apply and form an adhesive layer on the base material sheet as the base material adhesive treatment.
The said adhesive layer can be formed from the following organic materials and inorganic materials, for example. Examples of the organic material include polyester resins, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylamide resins, polyamide resins, polyether resins, polystyrene resins, Examples thereof include polyethylene resins, polypropylene resins, polyvinyl chloride resins and polyvinyl alcohol resins, vinyl resins such as polyvinyl pyrrolidone and modified products thereof, and polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral.
Examples of the inorganic material include silica (colloidal silica), alumina or alumina hydrate (alumina sol, colloidal alumina, cationic aluminum oxide or hydrate, suspicion bakumaite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, oxidation Examples include colloidal inorganic pigment ultrafine particles such as magnesium and titanium oxide.
The primer treatment can be performed by applying a primer solution to an unstretched film and then stretching the plastic film when the plastic film is produced by stretching.

(Dye layer)
The sublimation type thermal transfer sheet of the present invention is one in which at least a yellow dye layer and a magenta dye layer are formed as a dye layer.
The above-mentioned thermal transfer sheet further comprises a conventionally known cyan dye layer and a yellow, magenta, and cyan dye layer repeatedly provided in a surface sequential manner, and further a black ink layer and a plurality of dye layers such as yellow, magenta, cyan, and black. May be repeatedly provided in the surface order.
Alternatively, a transfer protective layer provided in the surface order in addition to the plurality of dye layers may be used. Note that black may be a heat-meltable ink layer or a dye layer, or may be one in which a dye layer and a heat-meltable ink layer are provided in the surface order.

The yellow dye layer has the following general formula (A)

(In the formula, R ¹ represents an alkyl group containing two or more oxygen atoms in the form of an ether bond.)
The yellow dye which consists of a quinophthalone compound represented by these is included.

In the above general formula (A), R ¹ represents an ether oxygen-containing alkyl group containing two or more oxygen atoms in the form of an ether bond.
The number of oxygen as an ether bond contained in R ¹ is preferably 2 to 5, more preferably 2 to 4.
R ¹ is preferably a linear, branched or cyclic alkyl group having 3 to 16 carbon atoms, more preferably 4 to 14 carbon atoms, and in particular, the following general formula (a-1)

(Wherein R ⁷ represents an alkylene group having 1 to 6 carbon atoms which may contain one or more oxygen atoms in the form of an ether bond, and ring A represents one or more oxygen atoms of an ether bond. And represents a 5- to 7-membered cyclic ether contained in the form, and R ⁸ and R ⁹ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxyalkyl group having 2 to 8 carbon atoms.) Those having a cyclic ether moiety such as an alkyl group represented by

In the general formula (a-1), R ⁷ is preferably an alkylene group having 1 to 4 carbon atoms which may contain 1 to 2 oxygen atoms in the form of an ether bond, and the ring A is preferably 1 It is a 5- to 6-membered cyclic ether containing 3 oxygen atoms in the form of an ether bond.
R ⁸ and R ⁹ are preferably each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms in total.

Specific examples of R ¹ include a methoxymethoxymethyl group, a methoxymethoxyethyl group, a methoxyethoxyethyl group, an ethoxyethoxyethyl group, a methoxyethoxyethoxyethyl group, an ethoxyethoxyethoxyethyl group,

Etc.

Especially, as said quinophthalone compound, following formula (Y-1)

It is preferable that it is a compound represented by these.
When the quinophthalone compound represented by the general formula (A) is contained in a dye ink, it can form a tautomer thereof. The invention also includes those containing such tautomers.

(Method for producing quinophthalone compound)
A method for producing the quinophthalone compound represented by the general formula (A) will be described below.
As a typical production method of the quinophthalone compound, the following general formula (a-2):

In the presence of an alkali compound in an organic solvent, the following general formula (a-3):
HS-R ¹ (a-3)
(In the formula, R ¹ represents the same as in the general formula (1)).
Is reacted at 20 to 120 ° C., preferably 80 to 100 ° C. for 1 to 48 hours, preferably 4 to 24 hours.

As the organic solvent in the above production method, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone [DMI], sulfolane, N, N-dimethylformamide [DMF], N, N-dimethylacetamide [DMAC] , Toluene, ethyl acetate, and mixtures thereof.
The amount of the organic solvent to be used varies depending on the type. For example, in the case of DMI, the weight ratio is 2 to 50 times, preferably 5 to 20 times with respect to 1 mol of the compound of the general formula (a-2).

As the alkali compound in the above production method, potassium carbonate, calcium carbonate, sodium hydroxide, potassium hydroxide or the like is used. The usage-amount of this alkali compound is 1-16 mol with respect to 1 mol of compounds of the said general formula (a-2), Preferably it is 1-4 mol.

After the above reaction, the reaction solution is discharged into water, extracted with an organic solvent such as toluene and ethyl acetate, washed with water, concentrated, and then added with methanol, n-heptane, etc. to precipitate product crystals. Furthermore, the target quinophthalone compound of the general formula (A) can be obtained by purifying the product by column chromatography as necessary.

Further, when R ¹ quinophthalone compound of the general formula (A) is a compound having a cyclic ether moiety, it can be prepared for example by the following method.
The compound of the above general formula (a-2) and the following general formula (a-4):
HS-R ¹⁰ (a-4)
(In the formula, R ¹⁰ represents an alkyl group having two hydroxyl groups.)
In the following general formula (a-5):

^{(Wherein, R 10} represents the same as in formula (a-4).)
A quinophthalone compound as an intermediate represented by the formula:
Next, the compound of the general formula (a-5) and the following general formula (a-6):

(Wherein R ⁸ and R ⁹ are the same as those in the above general formula (a-1).) By refluxing in an organic solvent while dehydrating in the presence of an acid catalyst. The intended quinophthalone compound of the general formula (A) can be obtained.

As the acid catalyst used for the reflux, p-toluenesulfonic acid, sulfuric acid, benzoic acid and the like can be used.
As the organic solvent used for the reflux, the same organic solvent as used for the reaction of the compound of the general formula (a-2) and the compound of the general formula (a-3) can be used.
The refluxing time is 6 to 72 hours, preferably 12 to 48 hours, and the reaction temperature is preferably 100 to 115 ° C., although it depends on the type of organic solvent used.
After the completion of the reflux, the reaction solution is subjected to the same operation as the above-described post-treatment method, whereby the target quinophthalone compound of the general formula (A) can be obtained.

In the present invention, the yellow dye layer containing the quinophthalone compound of the general formula (A) as a yellow dye may contain only one kind of the quinophthalone compound of the general formula (A) as a dye, or two kinds The above may be included. Further, in addition to the quinophthalone compound, a dye compound having a structure other than the general formula (A) may be included.

The dye comprising a compound having a structure other than the general formula (A) is a dye that can be used for a conventionally known sublimation transfer type thermal transfer sheet, and is not particularly limited as long as it undergoes sublimation transfer by heat. It can be appropriately selected in consideration of printing sensitivity, light resistance, storage stability, solubility in a binder, and the like.
Examples of the dye having a structure other than the general formula (A) include a diarylmethane dye; a triarylmethane dye; a thiazole dye; a merocyanine dye; a methine dye such as pyrazolone methine; an indoaniline dye; Azomethine dyes represented by azomethine, pyrazoloazomethine, imidazolazomethine, imidazoazomethine, pyridoneazomethine; xanthene dyes; oxazine dyes; cyanostyrene dyes represented by dicyanostyrene and tricyanostyrene; thiazine dyes; Azine dyes; acridine dyes; benzeneazo dyes; general formulas such as pyridoneazo, thiophenazo, isothiazoleazo, pyrroleazo, pyralazo, imidazoleazo, thiadiazoleazo, triazoleazo, diazo I) other than the azo dye; spiropyran dyes; Indian Linus Piropi run based dyes; fluoran dyes; rhodamine lactam-based dyes; naphthoquinone dyes; anthraquinone dyes; quinophthalone dyes; and the like.

The yellow dye layer further comprises the following formula (Y-2)

A compound represented by the following formula (Y-3)

And a compound represented by the following formula (Y-4):

It is preferable to contain at least one compound selected from the group consisting of compounds represented by: As the yellow dye, not only the compound represented by the general formula (A) but also at least one of the compounds represented by the formula (Y-2), the formula (Y-3) and the formula (Y-4). By containing the seed, it is possible to adjust the density and hue while maintaining the same light resistance.

In addition to the quinophthalone compound represented by the above general formula (A), the yellow dye is a compound represented by the above formula (Y-2), a compound represented by the above formula (Y-3), and the above formula. When the compound represented by (Y-4) includes at least one compound, the ratio of each compound includes the compound represented by the above formula (Y-2), when the above quinophthalone compound / the above formula ( The compound represented by the compound represented by Y-2) is preferably 1/0 to 1/3, and more preferably 1/0 to 1/2.
When the compound represented by the above formula (Y-3) is included, the above quinophthalone compound / the compound represented by the above formula (Y-3) is preferably 1/0 to 1/1, More preferably, it is 0-2 / 1.
When the compound represented by the formula (Y-4) is included, the mass ratio of the compound represented by the quinophthalone compound / the compound represented by the formula (Y-4) is 1/0 to 1 / 3 is preferable, and 1/0 to 1/2 is more preferable.
The mass ratio of the above quinophthalone compound / the compound represented by the above formula (Y-2) / the above formula (Y-3) / the above formula (Y-4) is 1/0/0/0. It is preferably ˜2 / 5/1/5, more preferably 1/0/0/0 to 2/3/1/3.

The yellow dye preferably has an extinction coefficient in toluene of 10,000 to 150,000 ml / g · cm in terms of color developability.
In the present specification, the extinction coefficient is a value obtained by preparing a toluene solution containing 0.0002 wt% dye and measuring the extinction coefficient at the maximum absorption wavelength λmax with Shimadzu Corporation UV-3100PC.

The sublimation type thermal transfer sheet of the present invention has a magenta dye layer formed thereon.
The magenta dye layer has the following general formula (B)

(In the formula, R ² represents an alkyl group, R ³ and R ⁴ each independently represents an alkyl group having 2 or more carbon atoms, and X represents a halogen atom.) It contains a dye.
In the above general formula (B), R ² represents an alkyl group.
Examples of the alkyl group for R ² include linear alkyl groups such as methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, and n-octyl group. Group, iso-propyl group, iso-butyl group, sec-butyl group, tert-butyl group, 3-methylbutyl group, 2-methylbutyl group, 1-methylbutyl group, 2,2-dimethylpropyl group, 1,2-dimethyl group Propyl group, 1,1-dimethylpropyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 3,2-dimethylbutyl group 3,1-dimethylbutyl group, 2,2-dimethylbutyl group, 2,1-dimethylbutyl group, 1,1-dimethylbutyl group, 2,2,1-trimethylpropyl group, 2,1 And branched alkyl groups such as 1-trimethylpropyl group.
R ² is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, particularly preferably a linear or branched alkyl group having 1 to 3 carbon atoms.

In the general formula (B), R ³ and R ⁴ each independently represents an alkyl group having 2 or more carbon atoms.
Examples of the alkyl group having 2 or more carbon atoms include linear groups such as an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. Alkyl group; iso-propyl group, iso-butyl group, sec-butyl group, tert-butyl group, 3-methylbutyl group, 2-methylbutyl group, 1-methylbutyl group, 2,2-dimethylpropyl group, 1,2- Dimethylpropyl group, 1,1-dimethylpropyl group, 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 3,2-dimethylbutyl Group, 3,1-dimethylbutyl group, 2,2-dimethylbutyl group, 2,1-dimethylbutyl group, 1,1-dimethylbutyl group, 2,2,1-trimethylpropyl group, 2, , Branched alkyl groups such as 1-trimethyl propyl group, and the like.

R ³ and R ⁴ are each preferably a linear or branched alkyl group having 2 to 8 carbon atoms, particularly a linear or branched alkyl group having 3 to 5 carbon atoms, particularly a branched alkyl group having 3 to 5 carbon atoms. preferable.

In the general formula (B), X represents a halogen atom.
Examples of the halogen atom for X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
As said X, a chlorine atom or a bromine atom is preferable, and a chlorine atom is especially preferable.

In the sublimation thermal transfer sheet of the present invention, in the azo compound represented by the general formula (B), R ² is an alkyl group having 1 to 5 carbon atoms, and R ³ and R ⁴ have 2 to 8 carbon atoms. More preferably, it is an alkyl group, and X is a chlorine atom or a bromine atom.

The example of the manufacturing method of the azo compound represented by the said general formula (B) is demonstrated below.
First, the following general formula (b-1):

(In the formula, X is the same as defined above.)
Is dissolved in an acid solvent, nitrosylsulfuric acid is added dropwise, and diazotization is performed to obtain a diazo solution.
As the acid solvent, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, propionic acid, a mixture of these acids, or the like can be used.
The amount of the acid solvent used is the same amount to 10 times the weight, preferably the same amount to 5 times the weight of the aniline.

The usage-amount of the said nitrosyl sulfuric acid is 0.8-1.2 times mole with respect to the molar amount of the anilines shown by the said general formula (b-1), Preferably it is 0.95-1.1 times mole.
In the diazotization of the anilines, the dropping temperature and the reaction temperature are generally −10 to 30 ° C., preferably −5 to 10 ° C., and the reaction time is generally 0.5 to 10 hours, preferably 1 to 5 hours. It is.

Next, the obtained diazo liquid is converted into the following general formula (b-2)

(Wherein R ² , R ³ and R ⁴ are the same as defined above)
A coupling reaction is carried out with a compound represented by

The coupling reaction is usually performed in an aqueous solvent under acidic conditions.
The coupling reaction involves dissolving or dispersing the compound represented by the general formula (b-2) in an aqueous solvent containing, for example, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, propionic acid, or a mixture of these acids. , By mixing the diazo liquid.
The amount of the compound represented by the general formula (b-2) to be used is generally 0.9 to 1.3 times mol, preferably 1. with respect to the molar amount of the anilines represented by the general formula (b-1). It is 0-1.2 times mole.

In the coupling reaction, the dropping temperature and reaction temperature of the diazo liquid are generally −10 to 30 ° C., preferably −5 to 10 ° C., and the reaction time is 0.5 to 10 hours, preferably 1 to 5 hours. It is.

Further, an alkaline aqueous solution, for example, an aqueous solution of sodium acetate, potassium acetate, sodium hydroxide, potassium hydroxide, or the like is added to the obtained coupling reaction solution, and the precipitate is collected by filtration, washed with water, dried, and the following general formula (b -3)

(Wherein R ² , R ³ , R ⁴ and X are the same as defined above)
Is obtained.

Finally, the intended azo compound of the general formula (B) can be obtained by cyanating the bromine atom of the azo compound of the general formula (b-3).
The cyanation reaction is performed by reacting copper (I) cyanide in a polar solvent.
As the polar solvent, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, sulfolane and the like can be used.
The amount of copper (I) cyanide used is generally 2.0 to 2.5 times the molar amount of the azo compound represented by the general formula (b-3).
In the above cyanation reaction, the reaction temperature is generally 50 to 150 ° C., preferably 70 to 90 ° C., and the reaction time is generally 1 to 5 hours.

Further, the cyanation reaction solution is discharged into water, and the precipitate is collected by filtration, washed with water, extracted with an organic solvent such as toluene, and then the extract is filtered to remove the metal component, and the organic layer is concentrated. By subjecting it to a dispersion treatment with aliphatic hydrocarbons such as n-heptane, the desired azo compound represented by the above general formula (B) can be purified and recovered.

Specific examples of the azo compound represented by the general formula (B) are shown in Tables 1 and 2. These specific examples do not limit the scope of the present application.

Especially, as said azo compound, following formula (M-1)

It is preferable that it is a compound represented by these.

The magenta dye layer contains the azo compound represented by the general formula (B), but may contain only one kind of the azo compound, or may contain two or more kinds. Good. In addition to the azo compound, a dye compound having a structure other than the general formula (B) may be included.

The dye compound having a structure other than the above general formula (B) is not particularly limited as long as it is a dye that can be used in a conventionally known sublimation type thermal transfer sheet and can be sublimated by heat. Hue, printing sensitivity The light resistance, storage stability, solubility in the binder, etc. can be selected as appropriate.
Examples of the dye having a structure other than the general formula (B) include the same dyes as those described for the yellow dye layer.

The magenta dye layer further comprises the following general formula (C)

(R ⁵ represents a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted alkylaminocarbonyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkyl group, substituted Or an unsubstituted cycloalkyl group, a heterocyclic group or a halogen atom, R ⁶ represents an amino group or a hydroxyl group, and n represents an integer of 2 or less. Preferably there is.
In the magenta dye layer, in addition to the azo compound represented by the general formula (B), the hue may be adjusted while maintaining light resistance by further including the compound represented by the general formula (C). Can do.

In the general formula (C), the alkoxycarbonyl group, alkylaminocarbonyl group, alkoxyl group, aryloxy group, alkyl group and cycloalkyl group as R ⁵ preferably have 1 to 6 carbon atoms.
The anthraquinone compound represented by the general formula (C) may be an anthraquinone compound represented by the following formula (M-2) and / or an anthraquinone compound represented by the following formula (M-3). preferable.

The magenta dye includes an azo compound represented by the general formula (B), an anthraquinone compound represented by the formula (M-2) and / or an anthraquinone represented by the formula (M-3). The azo compound represented by the general formula (B), the anthraquinone compound represented by the formula (M-2), and the formula (M-3) are preferable. It is more preferable that it contains the anthraquinone type compound represented by these.
When each anthraquinone compound represented by the above formula (M-2) and the above formula (M-3) is contained, the light resistance can be improved, but the specific magenta dye is represented by the general formula (B). When it contains at least one of the azo compounds represented and at least one of the anthraquinone compounds represented by formula (M-2) or formula (M-3), the light resistance can be improved. Conceivable.

The specific magenta dye has a mass ratio of the azo compound represented by the general formula (B) to the anthraquinone compound represented by the general formula (C). The ratio of the azo compound is preferably higher than the anthraquinone compound of the general formula (C) = 1/4, and more preferably the ratio of the azo compound is higher than 2/5. If it is less than this, a sufficient density may not be obtained at the time of printing.

Examples of the compound represented by the above formula (M-2) include anthraquinone dyes such as Disperse Violet 26, and examples of the compound represented by the above formula (M-3) include anthraquinone dyes such as Disperse Red60. It is done.

When the magenta dye layer contains both the anthraquinone compounds represented by the formula (M-2) or the formula (M-3) as the anthraquinone compounds represented by the general formula (C), the inclusion of both The ratio can be arbitrarily determined according to the target hue.

The magenta dye preferably has an extinction coefficient in toluene of 10,000 to 100,000 ml / g · cm in terms of color developability.
In the present specification, the extinction coefficient is a value obtained by preparing a toluene solution containing 0.0002% by mass of a dye and measuring the extinction coefficient at the maximum absorption wavelength λmax with UV-3100PC manufactured by Shimadzu Corporation.

The content of various dyes in the present invention depends on the combination of the base material and the primer, but contains a dye that can provide a sufficient density (yellow, magenta reflection density 1.8 or higher: ISO status A density) as an image. An amount is preferred. The content range will be described later.

Each of the dye layers contains a binder resin in addition to the specific dye.
The binder resin is not particularly limited, and conventionally known binder resins can be used. For example, cellulose resins such as methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, and cellulose butyrate; polyvinyl Examples thereof include vinyl resins such as alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, and polyacrylamide; polyester resins; phenoxy resins;

Examples of the binder resin further include a releasable graft copolymer. The releasable graft copolymer can be blended as a release agent.
The releasable graft copolymer comprises at least one releasable segment selected from a polysiloxane segment, a fluorocarbon segment, a fluorinated hydrocarbon segment, and a long-chain alkyl segment. It is obtained by graft polymerization on the chain.
Among these, the releasable graft copolymer is preferably a graft copolymer obtained by grafting a polysiloxane segment to a main chain composed of polyvinyl acetal.

The dye layer may use additives such as a release agent, inorganic fine particles, and organic fine particles as desired.
Examples of the release agent include the above-described releasable graft copolymer, silicone oil, and phosphate ester.
Examples of the inorganic fine particles include carbon black, aluminum, and molybdenum disulfide.
Examples of the organic fine particles include polyethylene wax.

Each of the above-described dye layers is formed from a dye ink containing a specific dye, a binder resin, an additive to be added as required, and a solvent.
The solvent is not particularly limited as long as it is a conventionally known dye ink material. For example, acetone, methanol, water, methyl ethyl ketone, toluene, ethanol, isopropyl alcohol, cyclohexanone, dimethylformamide [DMF], ethyl acetate, A mixed solvent of these solvents can be used, and among them, a mixed solvent of methyl ethyl ketone and toluene is preferable.

In the dye ink containing the yellow dye, the yellow dye is preferably 50 to 300 parts by mass, and more preferably 85 to 250 parts by mass with respect to 100 parts by mass of the binder resin.

The yellow dye ink generally has a yellow dye content of 1% by mass or more, and may be about 20% by mass or less as long as it is within the above range.
The yellow dye content is preferably a lower limit of 1% by mass and an upper limit of 15% by mass.
The yellow dye ink has a total amount of a dye such as a yellow dye and a binder resin, that is, a solid content of preferably 2 to 30% by mass, and more preferably 5 to 15% by mass.
In the present specification, when the yellow dye ink contains two or more dye compounds, the yellow dye content and the solid content each represent a range relating to the total of the respective dye compounds.

In the dye ink containing the magenta dye, the content of the magenta dye is preferably 50 to 300 parts by mass, more preferably 85 to 250 parts by mass with respect to 100 parts by mass of the binder resin solid content. . In addition, when the said magenta dye contains 2 or more types of dye compounds, both content and solid content of the said magenta dye represent the range regarding the sum total of each dye compound.

The azo compound of the general formula (B) has high solubility regardless of the type of organic solvent commonly used for dye inks such as toluene, methyl ethyl ketone, methyl lactate, etc. / Resin ratio dye-supporting layer. In this respect, the sublimation type thermal transfer sheet of the present invention has a dye-carrying layer having a high dye / resin ratio by using the azo compound of the general formula (B) as a dye. Excellent concentration.

The above dye inks are, for example, paint shakers, propeller type stirrers, dissolvers, homomixers, ball mills, bead mills, sand mills, two roll mills, three roll mills, ultrasonic dispersers, kneaders, line mixers, twin screw extruders, etc. It can prepare using a conventionally well-known manufacturing method.

Each said dye layer is formed by applying each said dye ink to the said base material sheet by conventionally well-known methods, such as a reverse roll coating method using a wire bar coating, a gravure printing method, and a gravure plate, for example. be able to.
As the coating method, gravure coating is preferred.
Although it does not specifically limit in the said coating, It is preferable to dry for about 1 second-5 minutes at the temperature of 60-120 degreeC.
If the above-mentioned dye inks are not sufficiently dried, the dye ink will turn over when it is soiled or wound, and then retransferred to the dye layer that has a different hue when the turned-off dye ink is turned over. So-called kickback may occur.
The above dye inks may be applied so that the dry coating amount is preferably about 0.2 to 3.0 g / m ² , more preferably about 0.4 to 1.0 g / m ² .

The sublimation type thermal transfer sheet of the present invention has, as dyes, a yellow dye layer containing the above-mentioned specific yellow dye and a magenta dye layer containing the above-mentioned specific magenta dye. Even when printing is performed, it is possible to obtain a printed matter having a good density remaining ratio when red is formed from yellow and magenta.

(Other layers)
1. Heat-resistant slip layer The sublimation thermal transfer sheet of the present invention may further be provided with a heat-resistant slip layer on the substrate sheet surface opposite to the surface on which the dye layer is formed.
The heat resistant slipping layer is provided to prevent problems caused by heat of the thermal head during thermal transfer, such as sticking and printing wrinkles.

The heat-resistant slip layer is mainly composed of a heat-resistant resin.
The heat-resistant resin is not particularly limited. For example, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer resin, polyether resin, polybutadiene resin, styrene-butadiene copolymer resin. , Acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetate propionate resin, cellulose acetate butyrate resin, cellulose acetate-hydro Diene phthalate resin, cellulose acetate resin, aromatic polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, Fluorinated polyolefin resins.

The heat-resistant slip layer may be formed by blending additives such as a slipperiness-imparting agent, a crosslinking agent, a release agent, an organic powder, and an inorganic powder in addition to the heat-resistant resin.

In general, the heat-resistant slipping layer is coated with the heat-resistant slipping layer by adding the above-mentioned heat-resistant resin, and optionally adding the slipperiness-imparting agent and additives to the solvent and dissolving or dispersing each component. After preparing the liquid, the heat resistant slipping layer coating liquid can be applied on a substrate and dried.
As the solvent in the heat resistant slipping layer coating solution, the same solvent as that in the dye ink can be used.
Examples of the coating method of the heat resistant slipping layer coating solution include wire bar coating, gravure printing, screen printing, reverse roll coating using a gravure plate, and gravure coating is particularly preferable.
The heat-resistant slip layer coating solution, dry coating amount is preferably 0.1 to 3 g / ^{m 2,} more preferably may be applied so as to be 1.5 g / ^{m 2} or less.

2. If the sublimation type thermal transfer sheet of the present invention has the above-mentioned dye layer on the base sheet, an undercoat layer is provided between the base sheet and the dye layer. There may be.
In the present invention, the undercoat layer is not particularly limited, and a composition that improves the adhesion between the substrate and the dye layer can be appropriately selected and provided.

The sublimation type thermal transfer sheet of the present invention may be one in which a transfer protective layer is further formed in the surface order with the above-mentioned dye layer so that a protective layer for protecting the image surface can be transferred after image formation.
The configuration and preparation of the transfer protective layer are not particularly limited, and can be selected from conventionally known techniques depending on the characteristics of the base material sheet, the dye layer, and the like to be used.
When the base film is not releasable, the transfer protective layer is preferably provided with a release layer between the base film and the transfer protective layer to improve the transfer property of the transfer protective layer.

The sublimation type thermal transfer sheet of the present invention heats and pressurizes a predetermined portion with a thermal head or the like on the side opposite to the dye layer of the above-mentioned base film, and uses the dye corresponding to the printing portion of the dye layer as a transfer material. Can be transferred and printed.
A thermal transfer image receiving sheet or the like can be used as the transfer material.
The thermal transfer image-receiving sheet is not particularly limited as long as the recording surface has dye acceptability. For example, a dye-receiving layer is formed on at least one surface of a substrate such as paper, metal, glass, or synthetic resin. Things can be mentioned.
The printer used for performing the thermal transfer is not particularly limited, and a known thermal transfer printer can be used.

Since the sublimation type thermal transfer sheet of the present invention has the above-described configuration, it is possible to obtain a printed matter having excellent light resistance and density residual ratio when red is formed from yellow and magenta.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.

(Example)
The following heat resistant slipping layer coating solution 1.0 g / m ² (dry coating amount) is applied to a 4.5 μm thick polyethylene terephthalate film [PET] and dried to form a heat resistant slipping layer. On the surface opposite to the slipping layer, a dye ink having the following composition was applied by gravure coating to a dry coating amount of 0.6 g / m ² and dried at 80 ° C. for 2 minutes to form a dye layer. .

<Heat resistant slipping layer coating solution>
Polyvinyl butyral resin (ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) 13.6 parts Polyisocyanate curing agent (Takenate D218, manufactured by Takeda Pharmaceutical Co., Ltd.) 0.6 parts Phosphate ester (Plysurf A208S, No. 1) Manufactured by Ichi Kogyo Seiyaku Co., Ltd.) 0.8 parts methyl ethyl ketone [MEK] 42.5 parts toluene 42.5 parts

<Dye ink>

The chemical formulas of dye Y-1, dye Y-2, dye Y-3, dye Y-4, dye M-1, dye M-2, and dye M-3 in the table are as follows.

(Comparative example)
A thermal transfer sheet was produced in the same manner as in Example except that the dye in the dye ink was replaced with that in Table 4 described later.

The chemical formula of the dye M-11 in the table is as follows.

(Test example)
The following tests were conducted on the dyes used in each Example and each Comparative Example, and the thermal transfer sheets obtained from each Example and each Comparative Example. The results are shown in Table 5.
Thermal transfer recording test (color density)
Olympus Co., Ltd., A4 size standard paper for digital color printer P-400 is used as the transfer target, and Olympus Co., Ltd., digital ribbon printer-printed ink ribbon pack transfer protective layer is used as the transfer protective layer. The thermal transfer sheet is subjected to thermal transfer with a thermal head under the condition of a head applied energy of 0 to 0.15 mJ / dot from the back surface of the thermal transfer sheet with the dye layer and the dye receiving surface of each thermal transfer sheet facing each other. A print was prepared and the color density (ISO status A density) was measured.
(Evaluation criteria)
Under conditions (applied energy) of 0.15 mJ / dot: ○: Both yellow and magenta color densities are 1.8 or more x: Yellow or magenta color density is 1.8 or less

Light resistance test The image obtained in the thermal transfer recording test was irradiated for 90 hours with Xenon Weatherweather (Atlas, Ci4000: Black panel temperature 45 ° C, filter CIRA, soda lime) before irradiation. The density residual ratio after irradiation of the printed material having a density of 1 was calculated, and the change in density before and after irradiation was evaluated according to the following criteria.
(Evaluation criteria)
○: Concentration residual ratio of yellow and magenta is both 70% or more ×: Concentration residual ratio of yellow or magenta is 70% or less

Measurement of density hue The density was measured using a spectrophotometer SpectroLino manufactured by Gretag Macbeth (measuring condition, density: ISO status A density (ANSI Status A)).

In the examples, when the red color was formed from yellow and magenta as compared with the comparative example, the respective density residual ratios were good.

Since the sublimation type thermal transfer sheet of the present invention has the above-described configuration, it is excellent in various fastnesses such as light resistance, and a printed matter having a good density remaining ratio when red is formed from yellow and magenta. Obtainable.

Claims (6)

A thermal transfer sheet in which at least a yellow dye layer and a magenta dye layer are formed as a dye layer composed of a dye and a binder resin on a base sheet,
The yellow dye layer has the following general formula (A)

(In the formula, R ¹ represents an alkyl group containing two or more oxygen atoms in the form of an ether bond.)
Containing a yellow dye consisting of a quinophthalone compound represented by
The magenta dye layer has the following general formula (B)

(Wherein R ² represents an alkyl group, R ³ and R ⁴ each independently represents an alkyl group having 2 or more carbon atoms, and X represents a halogen atom.)
A sublimation type thermal transfer sheet comprising a magenta dye comprising an azo compound represented by the formula: The yellow dye is represented by the following formula (Y-1)

The sublimation type thermal transfer sheet according to claim 1, which is a compound represented by the formula: The magenta dye is represented by the following formula (M-1)

The sublimation thermal transfer sheet according to claim 1, wherein the sublimation thermal transfer sheet is a compound represented by the formula: The magenta dye layer further comprises the following general formula (C)

Wherein R ⁵ is a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted alkylaminocarbonyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkyl Represents a group, a substituted or unsubstituted cycloalkyl group, a heterocyclic group or a halogen atom, R ⁶ represents an amino group or a hydroxyl group, and n represents an integer of 2 or less.)
The sublimation type thermal transfer sheet according to claim 1, comprising an anthraquinone compound represented by the formula: An anthraquinone compound represented by the general formula (C) is represented by the following formula (M-2)

And / or the following formula (M-3)

The sublimation type thermal transfer sheet according to claim 1, 2, 3, or 4. The yellow dye layer further comprises the following formula (Y-2)

A compound represented by the following formula (Y-3)

And a compound represented by the following formula (Y-4):

The sublimation type thermal transfer sheet according to claim 1, 2, 3, 4, or 5, which contains at least one compound selected from the group consisting of compounds represented by: