JP3110832B2 - Dye for thermal transfer recording, ink composition for thermal transfer recording, and transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A thermal transfer method using a sublimation dye uses a thin condenser paper having a thickness of several microns or a transfer sheet obtained by applying a sublimable dye formed into an ink on a PET film or the like. This is one of the thermal transfer printing methods of selectively heating and transferring the image to a recording material, that is, a recording paper, and is currently used as a means for image recording (hard copy) various image information.

[0003] The sublimation dye used here is required to be rich in color, excellent in color mixing, strong in dyeing power, and relatively high in stability. The above recording method has a great characteristic not found in other printing methods in that the amount of sublimated dye depends on thermal energy and the dye concentration after dyeing can be controlled in an analog manner.

As a cyan-based dye for sublimation transfer, an indoaniline-based compound having particularly high light fastness (JP-A-61-1986)
49893, JP-A-61-57651, JP-A-2-
98492, and JP-A-2-55192), but very few of these compounds have both high sublimation speed and image stability after transfer, and have satisfied the optimum conditions as a sublimation dye. The appearance of dyes has been expected.

[0005]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, generally, in a dye for thermal transfer recording, the sublimation speed at the time of transfer is determined by the mutual transfer between the dye molecules. It was found that the action was related to the interaction between the dye molecules and the binder resin for ink.

That is, it is preferable that the dye has good solubility in the ink solvent and 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 the production of the transfer sheet. It was clarified that the dye was the best dye, and it was found that the compound represented by the following general formula (1) could be an excellent cyan-based dye for thermal transfer recording, thereby completing the present invention.

Accordingly, it is an object of the present invention to provide a high sublimation rate,
Dye for thermal transfer recording that also has image stability after transfer,
An object of the present invention is to provide an ink composition for thermal transfer recording and a transfer sheet.

[0008]

In order to solve the above-mentioned problems, the present invention provides the following general formula (1)

[0009]

Embedded image [Wherein, R ¹ represents a substituted or unsubstituted alkyl group or a cycloalkyl group, R ² represents an aryl group or a heterocyclic ring, R ³ and R ⁵ represent a hydrogen atom, substituted or unsubstituted R ⁴ and R ^{6 each} represent a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or a halogen atom; R ⁷ and R ^{8 each} represent a hydrogen atom; It represents a substituted or unsubstituted alkyl group, alkenyl group, aralkyl group or aryl group. And a transfer sheet ink composition comprising at least the above-described sublimation dye, a binder resin, and an organic solvent and / or water; and a base sheet and a base sheet. The dye sheet comprises a dye-supporting layer formed on one surface of a material sheet, and the dye contained in the dye-supporting layer includes the above-described dye transfer sheet.

The sublimation dye represented by the general formula (1) of the present invention satisfies the above-mentioned conditions and can obtain a relatively good sublimation speed.

Hereinafter, the present invention will be described in detail.

The sublimation dye according to the present invention has the general formula (1)
Wherein R ¹ represents a substituted or unsubstituted alkyl group or a cycloalkyl group in the general formula (1).

Unsubstituted alkyl groups include methyl, ethyl, n-propyl, iso-propyl, n-butyl, i
so-butyl, sec-butyl, tert-butyl, n
-Pentyl, n-hexyl, n-heptyl, n-octyl and the like having 1 to 8 carbon atoms are preferred.

The substituted alkyl group includes alkoxy groups such as methoxy, ethoxy, n-propoxy and iso-propoxy, phenoxy, p-methylphenoxy, m-methylphenoxy, o-methylphenoxy, p-chlorophenoxy, m- Aryloxy groups such as chlorophenoxy and o-chlorophenoxy; alkylcarboxy groups such as methylcarboxy, ethylcarboxy, n-propylcarboxy, iso-propylcarboxy, n-butylcarboxy, methoxycarboxy, ethoxycarboxy, n-
Alkoxycarboxy groups such as propoxycarboxy, iso-propoxycarboxy, n-butoxycarboxy, methoxycarbonylmethoxy, ethoxycarbonylmethoxy, n-propoxycarbonylmethoxy, iso
-Alkoxycarbonylalkoxy groups such as -propoxycarbonylmethoxy, n-butoxycarbonylmethoxy,
A halogen atom such as fluorine, chlorine and bromine, and an alkyl group having 2 to 6 carbon atoms substituted by a cyano group and the like are preferable.

As the cycloalkyl group, those having 4 to 7 carbon atoms, such as cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl, are desirable.

[0016]

R ² represents an aryl group or a heterocyclic group.

As the aryl group, a phenyl group, p-methylphenyl, m-methylphenyl, o-methylphenyl, pn-propylphenyl, p-tert-butylphenyl, pn-butylphenyl, p-chlorophenyl, Substituted aryl groups such as m-chlorophenyl and o-chlorophenyl are preferred, and heterocyclic groups are preferably furan, pyridine, thiazole, oxazole, benzoxazole, benzothiazole and the like.

R ³ and R ⁵ represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a halogen atom.

Unsubstituted alkyl groups include methyl, ethyl, n-propyl, iso-propyl, n-butyl,
iso- butyl, alkyl group of C ₁ -C _4, such as sec- butyl are preferred.

The substituted alkyl group is an alkoxy group such as methoxy, ethoxy, n-propoxy, iso-propoxy, phenoxy, p-methylphenoxy, m-methylphenoxy, o-methylphenoxy, p-chlorophenoxy, m-propoxy. Aryloxy groups such as chlorophenoxy and o-chlorophenoxy; alkylcarboxy groups such as methylcarboxy, ethylcarboxy, n-propylcarboxy, iso-propylcarboxy, n-butylcarboxy, methoxycarboxy, ethoxycarboxy, n-
Alkoxycarboxy groups such as propoxycarboxy, iso-propoxycarboxy, n-butoxycarboxy, methoxycarbonylmethoxy, ethoxycarbonylmethoxy, n-propoxycarbonylmethoxy, iso
-Alkoxycarbonylalkoxy groups such as -propoxycarbonylmethoxy, n-butoxycarbonylmethoxy,
A halogen atom such as fluorine, chlorine and bromine, and an alkyl group having 2 to 6 carbon atoms substituted by a cyano group and the like are preferable.

As the halogen atom, fluorine, chlorine, bromine and the like are preferable.

R ⁴ and R ^{6 each} represent a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or a halogen atom.

Examples of the unsubstituted alkyl group include methyl, ethyl, n-propyl, iso-propyl, n-butyl, i
so-butyl, sec-butyl, tert-butyl, n
-Pentyl, n-hexyl, n-heptyl, n-octyl and the like having 1 to 8 carbon atoms are preferred.

The substituted alkyl group means an alkoxy group such as methoxy, ethoxy, n-propoxy, iso-propoxy, phenoxy, p-methylphenoxy, m-methylphenoxy, o-methylphenoxy, p-chlorophenoxy, m-chlorophenoxy. Aryloxy groups such as chlorophenoxy and o-chlorophenoxy; alkylcarboxy groups such as methylcarboxy, ethylcarboxy, n-propylcarboxy, iso-propylcarboxy, n-butylcarboxy, methoxycarboxy, ethoxycarboxy, n-
Alkoxycarboxy groups such as propoxycarboxy, iso-propoxycarboxy, n-butoxycarboxy, methoxycarbonylmethoxy, ethoxycarbonylmethoxy, n-propoxycarbonylmethoxy, iso
-Alkoxycarbonylalkoxy groups such as -propoxycarbonylmethoxy, n-butoxycarbonylmethoxy,
A halogen atom such as fluorine, chlorine and bromine, and an alkyl group having 2 to 6 carbon atoms substituted by a cyano group and the like are preferable.

The alkoxy group has 1 to 8 carbon atoms,
For example, methoxy, ethoxy, n-propoxy, iso-
Propoxy, n-butoxy, iso-butoxy, sec
Alkoxy groups such as -butoxy, tert-butoxy and n-hexyloxy are preferred.

As the halogen atom, fluorine, chlorine, bromine and the like are preferable.

R ⁷ and R ⁸ represent a hydrogen atom, a substituted or unsubstituted alkyl, alkenyl, aralkyl or aryl group having 1 to 8 carbon atoms.

The unsubstituted alkyl group having 1 to 8 carbon atoms includes methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl , N-hexyl,
n-Heptyl, n-octyl and the like are preferred.

The substituted alkyl group having 1 to 8 carbon atoms means an alkoxy group such as methoxy, ethoxy, n-propoxy, iso-propoxy, phenoxy, p-methylphenoxy, m-methylphenoxy, o-methylphenoxy,
aryloxy groups such as p-chlorophenoxy, m-chlorophenoxy, o-chlorophenoxy, methylcarboxy, ethylcarboxy, n-propylcarboxy, is
Alkoxy carboxy groups such as o-propyl carboxy and n-butyl carboxy, methoxy carboxy, ethoxy carboxy, n-propoxy carboxy, iso-propoxy carboxy, n-butoxy carboxy and the like, methoxy carbonyl methoxy, ethoxy carbonyl methoxy, n Alkoxycarbonylalkoxy groups such as -propoxycarbonylmethoxy, iso-propoxycarbonylmethoxy and n-butoxycarbonylmethoxy, halogen atoms such as fluorine, chlorine and bromine, and alkyl groups substituted with cyano groups are preferred.

As the alkenyl group, 2-butenyl, 2-
Pentenyl and the like are preferred. As an aralkyl group, benzyl, phenethyl and 3-phenylpropyl are preferred.

As the aryl group, phenyl, p-
Those having 6 to 8 carbon atoms, such as tolyl, m-tolyl, o-tolyl, p-ethylphenyl, p-chlorophenyl, m-chlorophenyl and o-chlorophenyl, are preferred.

The dye represented by formula (1) of the present invention can be obtained by an oxidative bond between a substituted aniline and a substituted phenol by a conventional method according to the following reaction formula.

[0034]

Embedded image Here, x represents a leaving group such as H or halogen.

In the present invention, it is also possible to produce an ink composition for thermal transfer recording using the dye produced by the above-mentioned method and supply it in the form of an ink.

As a method for producing a thermal transfer recording ink composition using the sublimation dye of the present invention, the dye may be mixed with an appropriate resin, solvent or the like to obtain the recording ink composition.

In this case, the amount of the dye in the thermal transfer recording ink composition is usually 2 to 5% by weight.

As a thermal transfer method, a transfer sheet is prepared by applying the ink composition obtained as described above on a suitable substrate sheet, and the transfer sheet is superimposed on a recording material. A method of heating and pressurizing with a thermal recording head from the back surface of the recording sheet can be exemplified. In such a case, the dye on the transfer sheet is transferred onto the recording material.

The transfer sheet of the present invention is characterized by using the specific dyes as described above, and other constitutions may be the same as those of the conventionally known transfer sheet.

As the base sheet used in the transfer sheet of the present invention containing the above-mentioned dye, any known base sheet having a certain degree of heat resistance and strength may be used. 50 μm, preferably 3 to 1
Paper having a thickness of about 0 μm, various processed papers, polyester films, polystyrene films, polypropylene films, polysulfone films, polycarbonate films, aramid films, polyvinyl alcohol films, cellophane, and the like, with polyester films being particularly preferred.

The dye-carrying layer provided on the surface of the substrate sheet as described above is a layer in which the dye represented by the general formula (1) is carried by an arbitrary binder resin.

As the binder resin for supporting the above-mentioned dye, any of conventionally known binder resins can be used. Preferred examples thereof include ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, hydroxypropylcellulose, methylcellulose, and cellulose acetate. cellulose resins such as butyric acid cellulose, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, vinyl resins such as polyacrylamide, and the like, in particular polyvinyl butyral among these, and polyvinyl acetal Are preferred from the viewpoints of heat resistance, dye transferability, and the like.

The dye-carrying layer of the transfer sheet of the present invention is basically formed of the above-mentioned materials, but may further contain various conventionally known additives as necessary.

Such a dye-carrying layer is preferably prepared by adding the above-described dye, binder resin and other optional components in an appropriate solvent and dissolving or dispersing each component to prepare an ink composition for forming a support layer. This is applied and dried on the above-mentioned base material sheet to form.

The carrier layer thus formed has a thickness of about 0.2 to 5.0 μm, preferably about 0.4 to 2.0 μm, and the above-mentioned dye in the carrier layer depends on the weight of the carrier layer. Suitably, it is present in an amount of 5 to 70% by weight, preferably 10 to 60% by weight.

The transfer sheet of the present invention as described above is sufficiently useful for thermal transfer as it is. However, an anti-adhesion layer, that is, a release layer may be further provided on the surface of the dye-carrying layer.
By providing such a layer, adhesion between the transfer sheet and the recording material at the time of thermal transfer can be prevented, and an even higher density image can be formed by using a higher thermal transfer density.

As this release layer, a layer obtained by simply attaching an inorganic powder having anti-adhesive properties can also provide a considerable effect.
Furthermore, for example, a resin having excellent releasability, such as a silicone polymer, an acrylic polymer, or a fluorinated polymer, is used.
It can also be formed by providing a release layer having a thickness of 01 to 5 μm, preferably 0.05 to 2 μm.

It should be noted that the inorganic powder or the releasable polymer as described above has a sufficient effect even if it is included in the dye-supporting layer.

Further, a heat-resistant layer may be provided on the surface of such a transfer sheet in order to prevent adverse effects due to heat of the thermal head.

The recording material used to form an image by overlapping the transfer sheet as described above may be any recording material as long as its recording surface has a dye acceptability for the above-mentioned dye. In the case of paper, metal, glass, synthetic resin, or the like having no receptivity, a dye receiving layer may be formed on at least one surface thereof.

As a means for applying thermal energy used when performing thermal transfer using the transfer sheet of the present invention as described above and the recording material as described above, any conventionally known applying means can be used. For example, a thermal printer (for example,
By controlling the recording time using a recording device such as a video printer VY-100 (manufactured by Hitachi, Ltd.), heat energy of about 5 to 100 mJ / mm ³ can be applied, thereby sufficiently satisfying the intended purpose. Can be achieved.

[0052]

The cyan dye represented by the general formula (1) of the present invention can control the amount of sublimation transfer of the dye by changing the energy applied to the thermal head during thermal transfer, so that gradation recording is possible. Easy and suitable for full color recording.

Furthermore, since it is stable against heat, light, moisture, chemicals, etc., it does not decompose during transfer recording, and the obtained record has excellent storage stability.

Further, since the dye of the present invention has good solubility in organic solvents and good dispersibility in water, it is easy to prepare a uniformly-dissolved or dispersed high-density ink. Is a practically valuable dye that can provide good recording of

[0055]

The present invention will be specifically described below with reference to examples. Parts in the examples indicate parts by weight. % Indicates% by weight. Example 1 25 parts of 10 parts of 4-diethylamino-o-toluidine and 12 parts of 2-acetylamino-5-benzoylamino-4-chlorophenol were dissolved in 120 parts of methanol.
After dropping 27 parts of aqueous ammonia, 25 parts of ammonium persulfate was added in about 1 hour while keeping the liquid temperature at 20 ° C., and reacted at room temperature for 2 hours.

After the reaction, the product was separated, washed well with water,
Purification using a column chromatograph gave the target compound (A). Next, using the compound (A), an ink was prepared, a transfer sheet and a recording material were prepared by the following method, and transfer recording was performed.

The maximum absorption wavelength (λmax) of the compound in toluene was 613 nm.

[0058]

Embedded image (1) Preparation method of ink Dye of the above formula (A) 3 parts Polybutyral resin 4.5〃 Methyl ethyl ketone 46.25〃 Toluene 46.25〃 The dye mixture of the above composition is mixed with a glass bead using a paint conditioner for about 30 minutes. The ink was prepared by mixing for minutes. (2) Transfer Sheet Manufacturing Method Using a gravure calibrator (plate depth 30 μm), the above ink was applied to a 9 μm-thick polyethylene terephthalate film whose back surface was heat-treated so that the dry coating amount was 1.0 g / m ^2. And dried. (3) Preparation 0.8 parts Polyester resin (V ylon 103 manufactured by Toyobo Co. Tg = 47 ° C.) EVA polymer plasticizer 0.2 parts (ELVALOY 741p Mitsui Poly Chemical Co. Tg = -37 ° C.) of the recording material amino-modified Silicone 0.04 parts (KF-857 Shin-Etsu Chemical Co., Ltd.) Epoxy-modified silicone 0.04 parts (KF-103 Shin-Etsu Chemical Co., Ltd.) 9.0 parts of methyl ethyl ketone / toluene / cyclohexane (weight ratio 4: 4: 2) Mix to prepare a coating solution, synthetic paper (Oji Yuka,
Bar coater (RK Prin) on Yupo FPG # 150
t Coat Instruments, manufactured by No.
The coating was performed so as to be 4.5 g / m ² when dried using 1), and then dried at 100 ° C. for 15 minutes. (4) Transfer Recording The transfer sheet and the recording material are superposed on each other with the ink-coated surface and the coating liquid-coated surface facing each other.
Recording was performed under the condition of 0 millisecond, and a cyan color recording with a color density of 2.00 was obtained.

The color density was determined by densitometer RD-514 manufactured by Macbeth Co., USA (filter: Wratten No.
58).

The color density was calculated by the following equation.

Color density = log ₁₀ (Io / I) Io = intensity of light reflected from a standard white reflector I = intensity of light reflected from a test object Using a meter (manufactured by Suga Test Instruments Co., Ltd.) at a black panel temperature of 63 ± 2 ° C., the color hardly changed after irradiation for 40 hours, and the image stability under high temperature and high humidity was excellent.

The fastness of the obtained recorded image was measured at 50 ° C.
After being left in the atmosphere for 48 hours, the sharpness of the image was determined by the sharpness of the image and the coloring when the surface was rubbed with white paper. The sharpness of the image did not change, and the white paper was not colored. Was good. Example 2 11 parts of N, N-diethylphenylenediamine and 13 parts of 2-ethylcarbonylamino-5-benzoylamino-4-chlorophenol were dissolved in a mixture of 63 parts of methanol and 38 parts of water. Add 31 parts,
The liquid temperature was maintained at 20 ° C., and a 25% aqueous silver nitrate solution was added thereto.
6 parts were dropped in about 1 hour, and reacted at room temperature for 2 hours.

After the reaction, the product was extracted with chloroform.
After washing well with water and purifying by column chromatography, the desired product (B) was obtained.

The maximum absorption wavelength (λmax) of the compound in toluene was 608 nm.

[0065]

Embedded image Preparation of an ink, a transfer sheet, and a recording material were performed in the same manner as in Example 1, and transfer recording was performed to obtain a cyan color record having a color density of 2.00.

All of these recordings were subjected to a light resistance test in the same manner as in Example 1. As a result, the recordings hardly changed, and the stability of images under high temperature and high humidity was excellent.

A fastness test was conducted in the same manner as in Example 1. However, the sharpness of the image did not change, and the white paper was not colored.
The fastness of the recorded image was good. Examples 3 to 19 The cyan dyes shown in Table 1 were produced in the same manner as in Example 1, and the preparation of ink, the preparation of a transfer sheet, the preparation of a recording material, and the transfer recording were performed in the same manner. Each record shown was obtained.

All of these recordings were subjected to a light fastness test in the same manner as in Example 1. As a result, the recordings hardly changed and the stability of images under high temperature and high humidity was excellent.

A fastness test was conducted in the same manner as in Example 1. However, the sharpness of the image did not change, and the white paper was not colored.
The fastness of the recorded image was good.

Table 1 shows the results of the measurement of the maximum transfer density and the results of the determination of light fastness and fastness.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

[Table 4] The evaluation results of the light fastness and the fastness were evaluated as "good", and those of poor evaluation were evaluated as "x".

Comparative Example Preparation of ink, preparation of a transfer sheet, preparation of a recording material, and transfer recording were performed on the compounds shown in Table 2 in the same manner as in Example-1. Further, a light resistance test and a fastness test were performed in the same manner as in Example-1.

Table 2 also shows the results.

[0077]

[Table 5] The evaluation results of the light fastness and the fastness were evaluated as "good", and those of poor evaluation were evaluated as "x".

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hitoshi Koshida 12-5-510 Koshienguchi Kitamachi, Nishinomiya City, Hyogo Prefecture (72) Inventor Keisuke Takuma 300, Hiraharamachi, Omuta City, Fukuoka Prefecture Ryo ▼ Akira 2-13 Koganecho, Omuta-shi, Fukuoka (72) Ryohei Takiguchi 1-1-1, Kagacho, Ichigaya, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (72) Hiroshi Eguchi Ichigaya, Shinjuku-ku, Tokyo 1-1-1, Kagacho, Dai Nippon Printing Co., Ltd. (72) Inventor Kimiaki Kafuku 1-1-1, Ichigaya Kagacho, Shinjuku-ku, Tokyo Dainippon Printing Co., Ltd. (56) References JP-A-3-3 142287 (JP, A) JP-A-4-94973 (JP, A) JP-A-4-147890 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5 / 40 CAPLUS (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] [Claim 1] The following general formula (1) [Wherein, R ¹ represents a substituted or unsubstituted alkyl group or a cycloalkyl group, R ² represents an aryl group or a heterocyclic ring, R ³ and R ⁵ represent a hydrogen atom, substituted or unsubstituted R ⁴ and R ^{6 each} represent a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or a halogen atom; R ⁷ and R ^{8 each} represent a hydrogen atom; It represents a substituted or unsubstituted alkyl group, alkenyl group, aralkyl group or aryl group. ] The dye for thermal transfer recording represented by the formula: 2. An ink for thermal transfer recording, comprising at least a dye for thermal transfer recording represented by the general formula (1) according to claim 1, a binder resin, and an organic solvent and / or water. Composition. 3. A substrate comprising a base sheet and a dye-supporting layer formed on one surface of the base sheet, wherein the dye contained in the dye-supporting layer is represented by the general formula ( 1 ) according to claim 1. A transfer sheet, which is a dye for thermal transfer recording.