JPH09100417A - Indoaniline pigment for heat-sensitive transfer and heat-sensitive transfer sheet using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an indoaniline pigment represented by a specific formula, having a highly concentrated brilliant cyan color in a low energy, capable of giving records good in light resistance and dark storage stability, and useful for sheets for heat-sensitive transfer records. SOLUTION: This pigment is expressed by formula I [X is H, methyl; R is a (substituted) alkyl, a cycloalkyl, an aryl, a (substituted) aryl; R<1> , R<2> are each (substituted) alkyl, an aryl]. The pigment is obtained by reacting 2- amino-4,6-dichloro-5-ethylphenol of formula II with a chloroformate ester of the formula: ClCOOR in the presence of an acid-removing agent in an inactive solvent and subsequently reacting the obtained compound of formula III with a p-phenylenediamine compound of formula IV in the presence of an oxidizing agent in an inactive solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indoaniline dye for heat transfer used in heat transfer recording, particularly dye transfer type heat transfer recording, and a heat transfer recording sheet using the same.

[0002]

2. Description of the Related Art A dye-transfer type heat-sensitive transfer recording is a heat-sensitive transfer sheet in which a heat-sensitive transfer sheet having a color material layer containing a heat transferable dye on a base film and an image-receiving sheet having a dye-receiving layer on the surface are superposed. Is a recording method in which recording is performed by transferring the dye in the heat-sensitive transfer sheet to the image-receiving sheet by heating. This recording method is applied to full-color image recording in video printers and the like, because the amount of dye transferred can be controlled by the amount of heating energy and gradation can be expressed.

In the dye transfer type thermal transfer recording, the dye used in the transfer sheet and the ink composition for the transfer sheet has a great influence on the transfer recording speed, the image quality of the recorded matter, the storage stability and the like. It is very important, and such a dye needs to satisfy the following conditions. Easy sublimation and / or heat diffusion under the operating conditions of the thermal recording head. Do not thermally decompose under the operating conditions of the thermal recording head. Having a favorable hue in color reproduction. Large molecular extinction coefficient. Stable against heat, light, moisture, chemicals, etc. Easy synthesis. Excellent ink suitability. There should be no safety issues.

As a cyan dye used in this recording method, the present inventors have the following general formula (II).

[0005]

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Although a compound represented by the formula (1) was previously proposed (see Japanese Patent Laid-Open No. 1-249860), these compounds have an excellent hue as a cyan color and have a good transfer sensitivity, but a transferred recorded matter. There was a problem that the storability in the dark was not sufficient.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a dye for thermal transfer recording of a dye transfer type, which has a high color density of the recorded matter, and is excellent in its light stability and storability in the dark, and as a cyan color. Indoaniline dyes with excellent hue,
And a heat-sensitive transfer sheet containing this dye in a color material layer.

[0008]

The present invention has the following general formula (I):

[0009]

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(Wherein X represents a hydrogen atom or a methyl group, R represents a substituted or unsubstituted alkyl group, a cycloalkyl group, an allyl group or a substituted or unsubstituted aryl group, and R ¹ and R ² are (Independently representing a substituted or non-substituted alkyl group or allyl group) for thermal transfer of an indoaniline dye, and a colorant layer containing the dye and a binder on a substrate. The heat transfer sheet is the gist.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The indoaniline dye represented by the general formula (I) according to the present invention is represented by the following general formula (III)

[0012]

Embedded image

2-amino-4,6-dichloro-5-ethylphenol represented by the following general formula (IV)

[0014]

Embedded image ClCOOR
(IV) (wherein R has the same meaning as in formula (I) above) is reacted with a chloroformate represented by the following formula (I) in an inert solvent in the presence of a deoxidizing agent. V)

[0015]

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(Wherein R has the same meaning as in the general formula (I) above) was prepared, and the compound represented by the following general formula (VI) was prepared.

[0017]

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(Wherein X, R ¹ and R ² are represented by the above general formula (I)
It has the same meaning as the above), and can be produced by reacting with p-phenylenediamines in the presence of an oxidizing agent in an inert solvent. As the inert solvent for producing this (V), ketone-based solvents such as acetone, methyl ethyl ketone and cyclohexanone, ester-based solvents such as ethyl acetate and butyl acetate, ether-based solvents such as diethyl ether, tetrahydrofuran and dioxane, and benzene. Aromatic solvents such as toluene, xylene, chlorobenzene and dichlorobenzene, aprotic polar solvents such as dimethylformamide and dimethylsulfoxide, and basic solvents such as pyridine, picoline and quinoline. Examples of the deoxidizing agent for producing (V) include inorganic salts such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate and potassium hydrogen carbonate, and organic amines such as pyridine, quinoline and triethylamine.

When (I) is prepared from (V) and (VI) in an inert solvent, the reaction in water is advantageous, but acetone, tetrahydrofuran, dioxane, dimethylformamide, which is miscible with water, is preferred. It is also possible to react in a mixed solvent of water, dimethylsulfoxide, pyridine, alcohols and the like. As the oxidizing agent used in this reaction, various oxidizing agents such as hydrogen peroxide, persulfates, ferricyanates, nitrates, etc. can be used, particularly sodium persulfate, potassium persulfate, ammonium persulfate. This can be advantageously carried out by using persulfates such as Further, this reaction is preferably carried out under neutral to alkaline conditions.

In the above reaction, the reaction of the next step can be carried out subsequently without isolating the compound (V). Since the compound (I) generally precipitates as crystals after the reaction, the crystals may be filtered and washed, but when the purity of the target product is low, rewashing, recrystallization, column chromatography, etc. It may be purified by. The dye represented by formula (I) relating to the invention will be specifically described.

In the alkyl group represented by R, R ¹ and R ² in the general formula (I), the unsubstituted alkyl group is a C ₁ -C ₈ linear or branched unsubstituted alkyl group. Groups, specifically methyl group, ethyl group, n
Examples include -propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, n-hexyl group, n-octyl group and 2-ethylhexyl group. Examples of the substituted alkyl group include a hydroxy group, an amino group, a halogen atom, a C _{1 to} C ₈ alkoxy group, and a C _{2 to} C ₈
Alkoxy alkoxy group, C _{2 to} C ₈ acyloxy group, C _{2 to} C ₁₀ alkoxycarbonyl group, C _{2 to} C ₁₀ alkoxycarbonyloxy group, C _{1 to} C ₈ substituted with a phenyl group or a heterocycle, etc. And a linear or branched alkyl group.

The cycloalkyl group represented by R is
Examples thereof include a cyclohexyl group and a cyclopentyl group. In the substituted or unsubstituted aryl group represented by R, the unsubstituted aryl group is a phenyl group, 1-
Examples thereof include a naphthyl group and a 2-naphthyl group. Examples of the substituted aryl group include a phenyl group having one or more substituents such as fluorine atom, chlorine atom, methyl group and methoxy group.

In the above, specific examples of the alkyl group substituted with a hydroxy group include a 2-hydroxyethyl group, a 3-hydroxypropyl group, a 2-hydroxypropyl group and a 4-hydroxybutyl group. In addition, specific examples of the alkyl group substituted with an amino group include a 2-aminoethyl group, a 2-methylaminoethyl group,
Examples thereof include 2-dimethylaminoethyl group.

Specific examples of the alkyl group substituted with a halogen atom include a 2-chloroethyl group, a 3-chloropropyl group, a 2-chloropropyl group and a 2,2,2-trifluoroethyl group. . In addition, specific examples of the alkyl group substituted with a phenyl group include a benzyl group and a 2-phenylethyl group.

Specific examples of the alkyl group substituted with a C ₁ -C ₈ alkoxy group include 2-methoxyethyl group, 2-ethoxyethyl group, 2-n-propoxyethyl group and 2-n-butoxy group. Ethyl group, 2-i-butoxyethyl group, 2-i-propoxyethyl group, 2- (2-ethylhexyloxy) ethyl group, 1-methyl-2-ethoxyethyl group, 3-methoxypropyl group, 3-ethoxybutyl Group, 1-ethyl-2-methoxyethyl group and the like.

Specific examples of the alkyl group substituted with a C ₂ -C ₈ alkoxyalkoxy group include 2- (2-
Methoxyethoxy) ethyl group, 2- (2-ethoxyethoxy) ethyl group, 2- (2-n-propoxyethoxy)
Examples thereof include an ethyl group and a 2- (2-i-propoxyethoxy) ethyl group. Further, specific examples of the alkyl group substituted with a C _{2 to} C ₈ acyloxy group include a 2-acetyloxyethyl group, a 2-propionyloxyethyl group,
Substituted by a lower alkylcarbonyloxy group which may have a substituent such as a halogen atom such as a 2-i-butyryloxyethyl group, a 2-n-butyryloxyethyl group, a 2-trifluoroacetyloxyethyl group. And the like alkyl groups and the like.

Specific examples of the alkyl group substituted with a C ₂ -C ₁₀ alkoxycarbonyl group include a 2-methoxycarbonylethyl group, a 2-ethoxycarbonylethyl group and a 2-n-butoxycarbonylethyl group. Can be mentioned. In addition, specific examples of the alkyl group substituted with a C _{2 to} C ₁₀ alkoxycarbonyloxy group include a methoxycarbonyloxyethyl group, a 2-ethoxycarbonyloxyethyl group, a 2-n-butoxycarbonyloxyethyl group, and a 2- (2-ethylhexyloxycarbonyloxyethyl group, 2-benzyloxycarbonyloxyethyl group, 2-furfuryloxycarbonyloxyethyl group and the like.

Specific examples of the alkyl group substituted with a heterocycle include a furfuryl group, a tetrahydrofurfuryl group and a 2-tenyl group, and an alkyl group substituted with a heteromonocycle containing an oxygen atom or a sulfur atom. Can be mentioned. Among the indoaniline dyes of the present invention, preferably, in the general formula (I), X represents a hydrogen atom or a methyl group, R ¹ and R ² represent a substituted or unsubstituted alkyl group, and R is a substituted group. Alternatively, those represented by an unsubstituted alkyl group or aryl group can be mentioned.

More preferably, X represents a hydrogen atom or a methyl group, R ¹ and R ² represent an unsubstituted alkyl group, and R represents an unsubstituted alkyl group, an alkoxyalkyl group, a benzyl group or a phenyl group. There are things. Among them, preferred is one in which X represents a methyl group, R ¹ and R ² represent an ethyl group, and R represents a C _{1 to} C ₆ alkyl group, a methoxyethyl group, a benzyl group or a phenyl group.

Table 1 shows specific examples of the dye represented by the general formula (I).

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

The heat-sensitive transfer sheet of the present invention comprises a coloring material layer containing one or more dyes represented by the general formula (I). Further, in addition to the dye represented by the general formula (I), it may be used in combination with a dye having another structure. When the coloring material layer is formed by using the above dye on the heat-sensitive transfer sheet of the present invention, the method is not particularly limited, and the dye is usually dissolved or finely dispersed in a medium together with a binder to form an ink. Is prepared, and the ink is applied to a base film as a substrate and dried.

As the binder, water-soluble resins such as cellulose-based, acrylic acid-based, starch-based, epoxy-based and acrylic resins, methacrylic resins, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl butyral, ethyl cellulose, acetyl cellulose. , Polyester, acrylonitrile / styrene copolymer (AS) resin, phenoxy resin, and other resins soluble in organic solvents.

The mixing ratio (weight) of the binder and the dye is
A range of 1: 2 to 2: 1 is suitable. As a medium for ink preparation, water and alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and isobutyl alcohol, methyl cellosolve, cellosolves such as ethyl cellosolve, aromatic compounds such as toluene, xylene and chlorobenzene, ethyl acetate, Esters such as butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone,
Examples thereof include chlorine-based solvents such as methylene chloride, chloroform and trichloroethylene, ethers such as tetrahydrofuran and dioxane, organic solvents such as N, N-dimethylformamide and N-methylpyrrolidone, and these may be used alone or in combination.

In the above ink, in addition to the above components, if necessary, organic or inorganic non-sublimable fine particles, a dispersant, an antistatic agent, an antifoaming agent, an antioxidant, a thermal transfer agent such as a viscosity adjusting agent. Various additives known to be used can be added to the color material layer of the sheet. The method of applying this ink to the base film can be carried out by using a gravure coater, a reverse roll coater, a rod coater, an air doctor coater or the like. After that, it may be applied so as to have a range of 0.1 to 5 μm.

The base film to which the ink is applied for preparing the transfer sheet is a thin film such as condenser paper or glassine paper, a film of plastic having good heat resistance such as polyester, polycarbonate, polyamide, polyimide, polyaramid, and the like. Stretched materials are suitable, but the thickness thereof may be in the range of 3 to 50 μm.

Of the above base films, the biaxially stretched polyethylene terephthalate film is particularly advantageous in consideration of mechanical strength, solvent resistance, economy and the like. But,
In some cases, the polyethylene terephthalate film does not have sufficient runnability of the thermal head, so that the surface opposite to the color material layer contains a lubricant, fine particles, a surfactant, an antistatic agent, or the like thermosetting, photocuring or By providing a layer of thermoplastic heat resistant resin, a thermal head having improved running properties can be used.

As the heat resistant resin, a thermosetting resin such as a cross-linked product of an isocyanate and a resin containing active hydrogen such as ethyl cellulose resin, cellulose acetate resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl butyral resin, polyester, etc. The glass transition temperature of photocurable resins such as acrylate, epoxy acrylate and polyol acrylate, acrylic resins, vinyl chloride copolymers, acrylonitrile-styrene copolymers, polycarbonate resins, polyester resins, polyvinyl butyral resins and polyacetal resins is 50.
A thermoplastic resin having a temperature of 0 ° C. or higher is included.

As the fine particles, inorganic fine particles such as silica, alumina and titanium oxide, silico hem resin,
Examples thereof include organic fine particles such as urea resin and bezoguanamine resin. As the lubricant, various modified silicone oils, phosphate ester type surfactants and the like are used.

Further, the heat-sensitive transfer sheet of the present invention can use not only a thermal head but also infrared rays, laser light, etc. as a heating means. It is also possible to use as an electrically conductive dye transfer sheet by using an electrically conductive heat-generating film that generates heat by applying electricity to the base film itself.

[0044]

EXAMPLES The present invention will be described in detail below with reference to examples, but the examples are not intended to limit the present invention. Example 1 a) Table 1 No. Synthesis of Dye of 1 2-amino-4,6-dichloro-5-ethylphenol 17.1 g (0.1 mol) was charged into 140 ml of water,
Aqueous sodium hydroxide solution at 15 to 25 ° C (4.2 g of sodium hydroxide dissolved in 100 ml of water)
And 9.7 g of methyl chloroformate were simultaneously added dropwise, and the mixture was stirred at the same temperature for 2 hours. After the reaction was completed, the precipitated crystals were filtered, washed with water and dried to obtain 19.8 g of white crystals.

13.2 g (0.05 mol) of the obtained white crystals were dissolved in 190 ml of acetone, and 5 to 15 of them were dissolved therein.
Ammonia water (28%) (18.8 ml) was added at 0 ° C, and then hydrochloric acid-2-amino-5-diethylaminotoluene aqueous solution (hydrochloric acid-2-amino-5-diethylaminotoluene 12.5 g was added to 70 ml of water at 0-5 ° C). Dissolved) and ammonium persulfate aqueous solution (ammonium persulfate 26.
(3 g dissolved in 70 ml of water) was simultaneously added dropwise, and the mixture was stirred at the same temperature for 2 hours. After the reaction was completed, the precipitated crystals were filtered, washed with water and dried, and the obtained crystals were mixed with methyl alcohol 1
Purification was carried out by washing with 50 ml of suspension to obtain 17.4 g of dark green crystals.

In the mass spectrum of this product, the parent ion peak was 403, and No. 1 in Table 1 was confirmed. Consistent with the molecular weight of the structural formula of 1. The maximum absorption wavelength and the melting point in acetone are shown in Table 2 below. b) Preparation of ink

[0047]

[Table 5] Table 1 No. Dye of 1 6 parts by weight AS resin 10 parts by weight (Product name: Sanlex SAN-A; product of Monsanto Kasei Co., Ltd.) Methyl ethyl ketone 25 parts by weight Toluene 60 parts by weight ──────────────── ──────────────────── Total 101 parts by weight A mixture of the above composition was treated with a paint conditioner for 10 minutes to prepare an ink.

C) Preparation of heat-sensitive transfer sheet Polyethylene terephthalate film (6 μm) whose back surface is heat-resistant and slip-treated with the above ink using a wire bar.
(Thickness) and then dried (dry film thickness: about 1 μm) to obtain a heat-sensitive transfer sheet. The polyethylene terephthalate film is heat-resistant and slip-resistant treated by adding a biaxially stretched polyethylene terephthalate film to an acrylic resin (trade name: BR-8).
0; Mitsubishi Rayon Co., Ltd. product) 10 parts by weight, amino-modified silicone oil (trade name: KF393; Shin-Etsu Chemical Co., Ltd. product) 1 part by weight, toluene 89 parts by weight, and dried (dry film thickness: about 1 μm) ) Was done.

D) Preparation of Image Receptor 70 parts by weight of polyvinyl phenyl acetal resin, 30 parts by weight of vinyl chloride / vinyl acetate / vinyl alcohol copolymer resin (product name: S-REC A; product of Sekisui Chemical Co., Ltd.), silicone varnish (product) Name: TSR-160, solid content concentration 60%, Toshiba Silicone Co., Ltd. product) 30 parts by weight, hexamethylene diisocyanate compound (trade name: Mitec NY-710A, solid content concentration 75%, Mitsubishi Chemical Co., Ltd. product) 15 parts by weight Parts, amino-modified silicone (product name: KF-393; product of Shin-Etsu Chemical Co., Ltd.) 2.5 parts by weight, methyl ethyl ketone 600 parts by weight,
A liquid consisting of 600 parts by weight of toluene is applied to a synthetic paper (product name: YUPO FPG150; manufactured by Oji Yuka Co., Ltd.) having a wall thickness of 150 μm with a wire bar and dried (dry film thickness of about 5 μm).
m) and further processed in an oven at 80 ° C. for 30 minutes.

E) Transfer recording: The ink-coated surface of the heat-sensitive transfer sheet is superposed on the image receiver,
Recording was performed using a thermal head under the following conditions, and a recorded product having the color tone shown in Table 2 and excellent color density was obtained. Recording condition

[0051]

[Table 6] Main-scanning and sub-scanning recording density: 6 dots / mm Recording power: 0.20 W / dot Energization time: 7 ms, 13 ms For color density, use Macbeth Densitometer TR-927 type Measured.

F) Light Stability Test A light stability test of a recording material obtained by transfer recording having a recording density of about 1.0 was carried out using a xenon lamp fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black). The panel temperature: 63 ± 2 ° C.), and the degree of discoloration / fading of the recorded matter after exposure for 80 hours (ΔE (L ^* a ^* b ^* )) is shown in Table 2 below.

G) Darkness storage color test A darkness storage test of a recording density of about 1.0 obtained by transfer recording was carried out with a thermo-hygrostat (manufactured by Yamato Scientific Co., Ltd.).
(60 ° C., 60%), the degree of discoloration and fading of the recorded matter after 2 weeks of storage (concentration storage rate) is shown in Table 2 below. Examples 2 to 10 The dyes shown in Table 2 below were used in place of the dyes used in Example 1, and the dyes were synthesized, the ink was prepared, the transfer sheet was prepared, and the image receptor was prepared in the same manner as in Example 1. Further, transfer recording, light stability test, and darkness storage stability test were conducted, and the results shown in Table 2 below were obtained. Comparative Example 1 Instead of the indoaniline dye used in Example 1, the following structural formula A was used.

[0054]

Embedded image

(Example 2 of JP-A-1-249860)
1) except that the dye represented by the formula (1) is used, and ink is prepared, a transfer sheet is prepared, an image receptor is prepared, transfer recording, a light stability test and storage in a dark place are carried out in the same manner as in Example 1. A sex test was conducted and the results shown in Table 2 below were obtained. As a result, the photostability of this product was ΔE of 6, which was comparable to the case where the dyes of the examples of the present invention were used, but the storage stability in the dark was 74% and the indoaniline dye of the present invention. It was much lower. Example 11 Using the ink prepared by the following method instead of the ink used in Example 1, a transfer sheet was prepared in the same manner as in Example 1, preparation of an image receptor and transfer recording, light resistance test, dark fading. As a result of the property test, it was possible to obtain a record of clear cyan and uniform color density. The light resistance of the obtained recording and the storage stability of the transfer sheet in the dark were both good. a) Preparation of ink

[0056]

[Table 7] Table 1 No. Dye of 1 6 parts by weight AS resin (product name: Denka AS-S; product of Denki Kagaku Kogyo Co., Ltd.) 10 parts by weight Toluene 70 parts by weight Cyclohexanone 10 parts by weight ─────────────── ────────────────────── Total 96 parts by weight

[0057]

[Table 8]

[0058]

When the thermal transfer sheet of the present invention is used,
It is possible to obtain a clear cyan colored recorded matter of high density with low energy, and the recorded matter obtained by this heat-sensitive transfer sheet has good light resistance and storage stability in the dark (dark fading resistance).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location // C07D 307/14 C07D 307/52 307/52 333/32 333/32 B41M 5/26 101K 101G

Claims (6)

[Claims] 1. An indoaniline dye for thermal transfer represented by the following general formula (I). Embedded image (In the formula, X represents a hydrogen atom or a methyl group, R represents a substituted or unsubstituted alkyl group, a cycloalkyl group, an allyl group or a substituted or unsubstituted aryl group, and R
¹ and R ² each independently represent a substituted or unsubstituted alkyl group or allyl group) 2. In the general formula (I), R is unsubstituted C
Linear or branched alkyl group having ₁ -C _8; hydroxy group as a substituent, an amino group, a halogen atom, C ₁ ~
An alkoxy group having C _8, alkoxyalkoxy group C ₂ -C _8, an acyloxy group of _{C 2 ~C 8, C 2 ~C} 10 alkoxycarbonyl group, an alkoxycarbonyloxy group of C ₂ -C _10, phenyl or heteroaryl C ₁ -C ₈ having a ring
A linear or branched alkyl group; cyclohexyl group; cyclopentyl group; unsubstituted phenyl group; 1-naphthyl group; 2-naphthyl group; or as a substituent, a fluorine atom, a chlorine atom, a methyl group, or a methoxy group The indoaniline dye for thermal transfer according to claim 1, which is a group selected from phenyl groups having 3. In the general formula (I), R ¹ and R ² are each independently an unsubstituted C _{1 to} C ₈ linear or branched alkyl group; a hydroxy group, an amino group as a substituent, halogen atom, alkoxy group of _{C 1 ~C 8, C 2 ~C} 8
Alkoxyalkoxy groups, C ₂ -C ₈ acyloxy group, C ₂ -C alkoxycarbonyl group _10, an alkoxycarbonyloxy group of C ₂ -C _10, linear C ₁ -C ₈ having a phenyl group, or a heterocyclic The indoaniline dye for heat-sensitive transfer according to claim 1, which is a group selected from linear or branched alkyl groups. 4. A substrate represented by the following general formula (I): (In the formula, X represents a hydrogen atom or a methyl group, R represents a substituted or unsubstituted alkyl group, a cycloalkyl group, an allyl group or a substituted or unsubstituted aryl group, and R
¹ and R ² each independently represent a substituted or unsubstituted alkyl group or allyl group), and a heat-sensitive transfer sheet having a coloring material layer containing an indoaniline dye and a binder. 5. The heat-sensitive transfer sheet according to claim 4, wherein the color material layer has a dry thickness of 0.1 to 5 μm. 6. A heat-resistant resin layer containing a lubricant and fine particles is provided on the base material and on the surface opposite to the color material layer.
Alternatively, the heat-sensitive transfer sheet according to item 5.