JPH07179067A - Dye for thermal transfer recording and ink composition for thermal transfer recording and transfer sheet - Google Patents

Abstract

PURPOSE:To obtain an ink compsn. for thermal transfer recording having high sublimation speed and good image stability after transfer by compounding a dye having a specific structure for thermal transfer recording, a binder resin and an org. solvent and/or water. CONSTITUTION:An ink compsn. for thermal transfer recording is prepared by compounding a dye for thermal transfer recording represented by formula (wherein R1 is a 1-4C alkyl group or a cycloalkyl group R2 and R3 are H, a 1-4C, alkyl group or an alkoxy group and R. and R5 are H, an alkyl group or an alkoxyalkyl group), a binder resin and an org. solvent and/or water. A dye supporting layer is provided on a base material sheet and applied to the dye supporting layer and dried to support the dye for thermal transfer recording to form a transfer sheet. As a pref. example of the base material sheet to be coated with the ink compsn., there are tissue paper such as condenser paper or glassine paper and a plastic film composed of diester or polyamide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording dye (hereinafter abbreviated as sublimation dye) used for color hard copy by a sublimation thermal transfer recording system, a thermal transfer recording ink composition and a transfer sheet.

[0002]

2. Description of the Related Art A thermal transfer method using a sublimation dye is a thermal transfer print in which a sublimation dye in the form of ink is applied to a thin condenser paper or PET film of several microns, and this is selectively heated by a thermal head and transferred to a recording paper. This is one of the methods. At present, it has been used as a means for image recording (hard copy) of various image information.

The sublimation dyes used here are characterized by abundant colors, excellent color mixing properties, strong dyeing power and relatively high stability. The sublimation thermal transfer recording system has a great feature not found in other printing systems in that the amount of dye sublimated depends on thermal energy and the density after dyeing can be controlled in an analog manner.

Indaniline-based compounds (Japanese Patent Laid-Open No. 61-61600) have attracted particular attention as cyan dye sublimation dyes.
No. 22993, JP-A No. 61-31292, etc.), but very few have both a high sublimation rate and image stability after transfer, and it is expected that dyes satisfying optimum conditions as sublimation dyes will appear. It has been.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a thermal transfer recording dye, a thermal transfer recording ink composition, and a transfer sheet which have a high sublimation rate and image stability after transfer. is there.

[0006]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have generally found that in thermal transfer dyes, the sublimation rate at the time of transfer depends on the interaction between dye molecules and the dye. It was found that it is related to the interaction between the molecule and the binder resin for ink. That is, it is preferable that the dye has good solubility in the ink solvent and also has a low melting point, and that the interaction with the binder resin for the ink is small enough not to impair the storage stability after ribbon production. The present invention has been completed, and it was found that the compound represented by the following general formula (1) described below can be an excellent cyan sublimation dye, and the present invention has been completed. That is,
The present invention has the general formula (1)

[0007]

[Chemical 2] [In the formula, R ₁ represents a C ₁ -C ₄ alkyl group, a cycloalkyl group, an alkoxyalkyl group, or a substituted or unsubstituted aryl group, and R ₂ and R ₃ represent a hydrogen atom, a halogen atom, C ₁ To C ₄ alkyl group, alkoxy group, alkylcarbonylamino group, alkoxycarbonylamino group, alkylsulfonylamino group, R ₄ and R ₅ are each a hydrogen atom, an alkyl group, an alkoxyalkyl group, an alkenyl group, an aralkyl group, A substituted or unsubstituted aryl group,
A halogenoalkyl group, a cyanoalkyl group, a hydroxyalkyl group, and an alkylcarboxyalkyl group are shown. ] A heat-sensitive transfer recording dye represented by the following, a heat-sensitive transfer recording ink composition containing the dye, a binder resin and an organic solvent and / or water, and a base sheet and one surface of the base sheet. The present invention relates to a transfer sheet comprising a dye supporting layer, wherein the dye contained in the dye supporting layer is the above dye.

In the general formula (1) (Formula 2), R ₁ is methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, n-hexyl, Alkyl groups such as n-heptyl and n-octyl, cycloalkyl groups such as cyclopentyl and cyclohexyl, methoxyethyl, ethoxyethyl, n-propoxyethyl, iso-propoxyethyl, n-butoxyethyl, methoxypropyl, ethoxypropyl, n
-Propoxypropyl, iso-propoxypropyl,
An alkoxyalkyl group such as n-butoxypropyl and a substituted or unsubstituted aryl group such as phenyl, o-tolyl, m-tolyl, p-tolyl, o-chlorophenyl, m-chlorophenyl and p-chlorophenyl are shown.

R ₂ and R ₃ are hydrogen atoms, halogen atoms such as fluorine, chlorine and bromine, methyl, ethyl, n-propyl,
iso-propyl, n-butyl, iso-butyl, te
alkyl groups such as rt-butyl, methoxy, ethoxy, n
- propoxy, n- alkoxy C ₁ -C ₄ butoxy, etc., methylcarbonylamino, ethylcarbonylamino, n- propyl carbonylamino, iso- propyl carbonylamino, n- butylcarbonyl alkylcarbonylamino group such as an amino, methoxy Carbonylamino, ethoxycarbonylamino, n-propoxycarbonylamino, iso-propoxycarbonylamino, n
An alkoxycarbonylamino group such as butoxycarbonylamino, and an alkylsulfonylamino group such as methylsulfonylamino, ethylsulfonylamino, n-propylsulfonylamino, iso-propylsulfonylamino, and n-butylsulfonylamino.

R ₄ and R ₅ are hydrogen atom, methyl, ethyl,
n-propyl, iso-propyl, n-butyl, iso
-Alkyl groups such as -butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, n-
Alkoxyalkyl groups such as propoxyethyl and n-butoxyethyl, alkenyl groups such as allyl, 2-butenyl and 3-butenyl, aralkyl groups such as benzyl and phenethyl, phenyl, o-tolyl, m-tolyl, p-tolyl,
a substituted or unsubstituted aryl group such as o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, etc., chloromethyl, 2-chloroethyl, 2-chloropropyl, 3-
Chloropropyl and other halogenoalkyl groups, cyanomethyl, cyanoethyl and other cyanoalkyl groups, hydroxymethyl, hydroxyethyl, hydroxypropyl and other hydroxyalkyl groups, methylcarboxyethyl, ethylcarboxyethyl, n-propylcarboxyethyl, is
o-propyl carboxyethyl, n-butyl carboxyethyl, iso-butyl carboxyethyl, tert-
It shows an alkylcarboxyalkyl group such as butylcarboxyethyl, n-pentylcarboxyethyl, n-hexylcarboxyethyl and the like.

The compound represented by the general formula (1) of the present invention can be produced by a conventional method, for example, by oxidative coupling of the following phenols and anilines.

[0012]

[Chemical 3] [In the formula, R _{1 to} R ₇ have the same meanings as described above, and X represents a leaving group such as H or halogen. ]

In order to produce a thermal transfer recording ink using the dye of the present invention, the dye may be mixed with an appropriate resin, solvent or the like to prepare the recording ink. In this case, the amount of the dye in the thermal transfer recording ink is usually 2 to 5% by weight.

As the thermal transfer method, the ink obtained by the above method is applied onto a suitable substrate to prepare a transfer sheet, the transfer sheet is superposed on the recording medium, and then the thermal recording head is used from the back side of the sheet. A method of heating and pressurizing can be mentioned, and by doing so, the dye on the sheet is transferred onto the recording medium.

As the binder resin for preparing the above ink, those used in ordinary printing inks are used, such as rosin type, phenol type, xylene type, petroleum type, vinyl type, polyamide type, alkyd type, Oily resins such as nitrocellulose and alkyl celluloses, or aqueous resins such as maleic acid, acrylic acid, casein, shellac and glue can be used.

Further, as a solvent for preparing the ink,
Alcohols such as methanol, ethanol, propanol and butanol, cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as benzene, toluene and xylene, esters such as ethyl acetate and butyl acetate, acetone, methyl ethyl ketone and cyclohexanone. Hydrocarbons such as ketones, ligroin, cyclohexane and kerosene, and dimethylformamide can be used. When an aqueous resin is used, water or water and a mixture of the above solvents can be used.

As the base material to which the ink is applied, thin paper such as condenser paper and glassine paper, and plastic film having good heat resistance such as polyester, polyamide and polyimide are suitable. These base materials are 5 to 50 μm in order to improve the heat transfer efficiency from the thermal recording head to the dye.
A thickness of about m is suitable. A transfer sheet having a dye carrying layer on the surface of the base material can be produced.

Examples of the recording medium include polyolefin resins such as polyethylene and polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, vinyl polymers such as polyvinyl alcohol, polyvinyl acetate and polyacrylic ester. Polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, ionomers, cellulose diacetate, cellulose triacetate, etc. Examples include fibers, woven fabrics, films, sheets, and molded products made of resin, polycarbonate, polysulfone, polyimide and the like. Particularly preferred are woven fabrics, sheets or films made of polyethylene terephthalate.

Further, as a recording medium, a resin obtained by adding acidic fine particles such as silica gel to a plain paper is coated or impregnated, or a resin film is laminated, or a special acetylation-treated material. Processed paper or the like can be used. In this case, good recording with excellent image stability under high temperature and high humidity can be performed. Further, various resin films or synthetic papers made from them can be used. Furthermore, after transfer recording, a polyester film, for example, is hot pressed and laminated on the transfer recording surface, whereby the coloring of the dye is improved and the storage stability of the recording can be improved.

[0020]

EXAMPLES The present invention will be described in detail below with reference to examples.
In the examples, "part" means "part by weight" and "%" means "% by weight". Example 1 The method for producing the compound of the following formula (A) is as follows. 4-
10 parts of N, N-diethylamino-2-toluidine and 13 parts of the following compound (2) were added.

[0021]

[Chemical 4] To a mixed solution of 60 parts of methanol and 37 parts of water, 28 parts of 25% ammonia water was added dropwise and cooled to 10 ° C. Then 1
While keeping the temperature below 0 ° C, add 1 part of 19 parts ammonium persulfate.
The mixture was added over a period of time and reacted at the same temperature for 2 hours. After completion of the reaction, the product was filtered, washed with water, separated, and purified by column chromatography to obtain the target compound (A). Next, the compound (A) was used to prepare an ink, a transfer sheet and a recording material by the following method, and transfer recording was performed.

[0022]

[Chemical 5] Absorption maximum wavelength (λma) of the compound in toluene
x) was 630 nm.

(1) Method for Preparing Ink Dye of Formula (A) 3 Parts Polybutyral Resin 4.5 Parts Methyl Ethyl Ketone 46.25 Parts Toluene 46.25 Parts A dye mixture of the above composition is used in a glass conditioner and a paint conditioner. The ink was prepared by mixing for about 30 minutes.

(2) Method for producing transfer sheet Using a gravure proofing machine (plate depth: 30 μm), a dry coating amount of 1.0 g / m ² was applied to a polyethylene terephthalate film having a thickness of 9 μm, the back surface of which was heat-treated. Was applied and dried.

(3) Preparation of recording material Polyester resin 0.8 part (bylon 103 Toyobo Tg = 47 ° C.) EVA polymer plasticizer 0.2 part (Elvalloy 741p Mitsui Polychemical Tg = 37 ° C.) Amino Modified silicone 0.04 part (KF-857 manufactured by Shin-Etsu Chemical Co., Ltd.) Epoxy-modified silicone 0.04 part (KF-103 manufactured by Shin-Etsu Chemical Co., Ltd.) Methyl ethyl ketone / toluene / cyclohexane 9.0 parts (weight ratio 4: 4: 2) or more To prepare a coating solution, and then use synthetic paper (Oji Yuka,
Epo FPG # 150) with a bar coater (RK Prin)
No. t Coat Instruments, No.
1) was applied at a rate of 4.5 g / m ² when dried, and dried at 100 ° C for 15 minutes.

(4) Transfer recording The transfer sheet and the recording material are overlaid with the ink application surface and the coating liquid application surface facing each other, and the thermal head applied voltage of 10 V from the back surface of the thermal transfer sheet for printing. Recording was carried out under the condition of a time of 4.0 milliseconds, and a cyan recording having a color density of 2.40 was obtained. The color density was measured using a densitometer RD-514 type (filter: Ratten No. 58) manufactured by Macbeth Co., USA. The color density was calculated by the following formula. Color Density = log ₁₀ (Io / I) Io = Intensity of Light Reflected from Standard White Reflector I = Intensity of Light Reflected from Test Object

The light fastness test of the obtained recording was carried out at a black panel temperature of 63 ± 2 ° C. using a xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.). It was also excellent in image stability under high temperature and high humidity. Further, the fastness was evaluated by determining the sharpness of the image and coloring when the surface was rubbed with a white paper after leaving the obtained recorded image in an atmosphere of 50 ° C. for 48 hours, and the sharpness of the image did not change. Also, the white paper was not colored and the fastness of the recorded image was good.

Example 2 The method for producing the compound of formula (B) is as follows. 4-
10 parts of N, N-diethylamino-2-toluidine and 10.6 parts of the following compound (3)

[0029]

[Chemical 6] In addition to a mixed solution of 63 parts of methanol and 38 parts of water, 28 parts of 25% ammonia water was added dropwise and cooled to 10 ° C. Then, while maintaining the temperature below 10 ° C, add 1 part of 20 parts of sodium persulfate.
The mixture was added over a period of time and reacted at the same temperature for 2 hours. After completion of the reaction, the product was filtered, washed with water, separated, and purified by column chromatography to obtain the target compound (B).

[0030]

[Chemical 7] Absorption maximum wavelength (λma) of the compound in toluene
x) was 630 nm.

Ink was prepared, a transfer sheet and a recording material were prepared and transfer recording was carried out in the same manner as in Example 1 to obtain a color density of 2.45.
A cyan record was obtained. When a light resistance test was performed on all of these recordings by the same method as in Example 1,
The recording hardly changed, and the stability of the image under high temperature and high humidity was excellent. Further, a fastness test was conducted in the same manner as in Example 1, but the sharpness of the image did not change, the white paper was not colored, and the fastness of the recorded image was good.

Examples 3 to 15 The cyan dyes shown in Table 1 were produced in the same manner as in Example 1, and ink was similarly prepared, a transfer sheet was prepared, a recording material was prepared and transfer recording was carried out. , Each record shown in Table 1 was obtained. When a light resistance test was conducted on all of these recordings by the same method as in Example 1, the recordings showed almost no change and the stability of the image under high temperature and high humidity was excellent. A fastness test was conducted in the same manner as in Example 1, but the sharpness of the image did not change, and the white paper was not colored.
The fastness of the recorded image was good. In Table 1, those having good judgment results of light fastness and fastness are indicated by ◯.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

Comparative Examples 1 to 4 In the same manner as in Example 1, cyan dyes shown in Table 2 were used to prepare ink, transfer sheet, recording material and transfer recording. Further, a light resistance test and a fastness test were performed in the same manner as in Example 1. As a result, as shown in Table 2, the maximum transfer density, the light resistance and the fastness were not satisfied at the same time. Further, the compatibility of the dye with the binder resin was poor and the image became unclear. Was markedly colored and was defective. In Table 2, those having good light resistance and fastness determination results are indicated by ◯, and those having poor results are indicated by x.

[0037]

[Table 4]

[0038]

The cyan dye represented by the general formula (1) of the present invention can control the sublimation transfer amount of the dye by changing the energy applied to the thermal head at the time of thermal transfer. Easy and suitable for full color recording. Further, since it is stable against heat, light, moisture, chemicals, etc., it is not thermally decomposed during transfer recording, and the storability of the obtained record is very excellent. Further, since the dye of the present invention has good solubility in an organic solvent and dispersibility in water, it is easy to prepare a uniform solvent or a high-concentration ink dispersed therein, and as a result, a recording having a good color density can be obtained. It is a very valuable dye for practical use.

Claims (3)

[Claims] 1. The following general formula (1) (chemical formula 1): [In the formula, R ₁ represents a C ₁ -C ₄ alkyl group, a cycloalkyl group, an alkoxyalkyl group, or a substituted or unsubstituted aryl group, and R ₂ and R ₃ represent a hydrogen atom, a halogen atom, C ₁ To C ₄ alkyl group, alkoxy group, alkylcarbonylamino group, alkoxycarbonylamino group, alkylsulfonylamino group, R ₄ and R ₅ are each a hydrogen atom, an alkyl group, an alkoxyalkyl group, an alkenyl group, an aralkyl group, A substituted or unsubstituted aryl group,
A halogenoalkyl group, a cyanoalkyl group, a hydroxyalkyl group, and an alkylcarboxyalkyl group are shown. ] The dye for thermal transfer recording which has a structure shown by these. 2. The general formula (1) (formula 1) according to claim 1.
An ink composition for heat-sensitive transfer recording, comprising a dye for heat-sensitive transfer recording having a structure represented by the following, a binder resin, an organic solvent and / or water. 3. The dye according to claim 1, comprising a base material sheet and a dye carrying layer formed on one surface of the base material sheet, and the dye carried on the dye carrying layer is the dye according to claim 1. And transfer sheet.