JP3367199B2 - Thermal 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 heat-sensitive transfer recording sheet used for heat-sensitive transfer recording, particularly dye transfer type heat-sensitive transfer recording.

[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. In this recording method, the transfer amount of the dye can be controlled by the amount of heating energy, so that gradation expression, which is difficult with other recording methods, can be easily performed.
Therefore, a full-color image can be easily produced by using the three primary color dyes of yellow, magenta and cyan dyes, and it is applied to a video printer and the like.

[0003]

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

However, a dye satisfying all the above conditions has not been found so far, and a yellow dye, in particular, has various drawbacks. For example, in the present invention, the disazo dye represented by the general formula (I) has excellent characteristics in the above ,,,,, etc., but has a wide absorption spectrum and a long wavelength of the absorption spectrum. The hem on the side is bad, 550n
Since it has a weak absorption up to around m, the color purity as a yellow color is poor and there is a problem in color reproduction.

In the present invention, the quinophthalone type dye represented by the general formula (II) is
It has excellent characteristics in ,, and so on. Further, since the absorption spectrum width is narrow and very sharp, it is possible to reproduce a yellow color having excellent color purity. However, since the absorption spectrum is narrow and very sharp, when expressing a black color by mixing with a magenta dye and a cyan dye, in the absorption spectrum of the mixed color, the absorption near the boundary between the absorption of the yellow dye and the magenta dye. Absorption gap occurs. Therefore, when a black color is expressed using the yellow dye represented by the general formula (II), it is difficult to express a black color having a high color density.

Further, since the correlation between the dye structure and various required performances as described above is not clear, it is difficult to predict the performance obtained when the dyes are used in combination, and the composition was actually prepared. It is necessary to select a good combination from among them. As a result of intensive studies to solve such problems, the present inventors have developed a coloring material layer containing a disazo dye and a quinophthalone dye having a specific skeleton selected from a combination of various possible dyes. By carrying out heat-sensitive transfer recording using the yellow-colored heat-sensitive transfer sheet, it is possible to obtain a low-energy, high-concentration medium-yellow recorded material, and a high-concentration black with a mixture of magenta and cyan. The inventors have found that a color can be obtained, and that the obtained recorded matter has very good light resistance in both yellow and black, and have reached the present invention.

That is, an object of the present invention is to obtain a low-energy, high-concentration medium-yellow recorded material,
Further, a yellow color heat-sensitive transfer sheet capable of obtaining a high-concentration black color by mixing with magenta and cyan and having very good light resistance in both the yellow color and the black color of the obtained recorded matter. To provide.

Therefore, the object of the present invention is to provide a heat-sensitive transfer sheet having at least a color material layer on a substrate,
A resin binder in the color material layer, a disazo dye represented by the following general formula (I), and

[0009]

[Chemical 3]

(Wherein X ¹ , X ² and X ³ are each a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group,
It represents a nitro group, a cyano group, an acylamino group, an alkoxycarbonyl group, an alkylsulfonyl group, a substituted or unsubstituted sulfamoyl group, a trifluoromethyl group or a halogen atom, and represents Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom or a hydroxy group, or Y ⁶
And Y ² and Y ⁴ and Y ⁵ may be linked to each other to form an aromatic ring structure. ) A quinophthalone dye represented by the following general formula (II)

[0011]

[Chemical 4]

(In the formula, R ¹ represents a hydrogen atom or a lower alkyl group, Z ¹ represents a hydrogen atom or a halogen atom, Z ² represents a hydrogen atom, —COOR ² Group or -CONR
³ R ⁴ group, wherein R ² , R ³ and R ⁴ each represent an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, a furfuryl group or a tetrahydrofurfuryl group. ) Is easily achieved by a heat-sensitive transfer sheet characterized by containing a).

The present invention will be described in detail below. The disazo dye represented by the general formula (I) used in the present invention can be produced by a conventionally known method. In the general formula (I), X ¹ , X ² and X ³ are each a hydrogen atom; a methyl group, an ethyl group, a linear or branched propyl group, an alkyl group such as a butyl group; a methoxy group, an ethoxy group. Group, linear or branched propoxy group, butoxy group and other alkoxy groups; hydroxy group; nitro group; cyano group; trifluoromethyl group; acetylamino group, propionyl group, benzoyl group and other acylamino groups; methoxycarbonyl group Group, ethoxycarbonyl group, linear or branched propoxycarbonyl group, butoxycarbonyl group or other alkoxycarbonyl group; methylsulfonyl group, ethylsulfonyl group, linear or branched propylsulfonyl group, butylsulfonyl group Alkylsulfonyl groups such as; sulfamoyl groups, methylaminosulfoni Group, ethylaminosulfonyl group, dimethylaminosulfonyl group, diethylaminosulfonyl group, substituted or unsubstituted sulfamoyl group such as linear or branched dipropylaminosulfonyl group, dibutylaminosulfonyl group; fluorine atom, chlorine atom Represents a halogen atom such as a bromine atom or an iodine atom,
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ^5, and Y ⁶ are each a hydrogen atom; a methyl group, an ethyl group, a linear or branched propyl group, an alkyl group such as a butyl group, or a methoxy group. An ethoxy group, a linear or branched propoxy group, an butoxy group or another alkoxy group; a hydroxy group; a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, or Y ¹ and Y ² and Y ⁴ and Y ⁵ may be connected to each other to form an aromatic ring structure such as a benzene ring.

Preferred X ¹ , X ² and X ³ are hydrogen atom, hydroxy group, chlorine atom, fluorine atom, cyano group, ethoxy group, methoxy group, nitro group, trifluoromethyl group, dimethylaminosulfonyl group, Methyl group, ethyl group, acetylamino group,
Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ each represent a hydrogen atom, a methyl group, an ethyl group, a methoxy group, an ethoxy group or a hydroxy group, or Y ^1, Y ² and Y ⁴ And Y ⁵ are linked to each other to form a benzene ring.

In the present invention, the quinophthalone dye represented by the general formula (II) can be produced by a conventionally known method. In the general formula (II),
R ¹ represents a hydrogen atom or a lower alkyl group, Z ¹ represents a hydrogen atom or a halogen atom, Z ² represents a hydrogen atom,
COOR ² A group or a —CONR ³ R ⁴ group,
R ² , R ³ and R ⁴ each represent an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, a furfuryl group or a tetrahydrofurfuryl group.

The lower alkyl group represented by R ¹ is a C1-C4 linear or branched alkyl group, specifically, a methyl group, an ethyl group, a (n) propyl group, or (i ) Propyl group, (n) butyl group, (i)
Examples thereof include a butyl group. Further, the above R ² , R ³ and R
^The alkyl group represented by ⁴ includes C1 to C12
Examples of the straight chain or branched chain alkyl group include a 2-methoxyethyl group and an alkoxyalkyl group.
2-ethoxyethyl group, 2- (n) propoxyethyl group, 2- (i) propoxyethyl group, 2- (n) butoxyethyl group, 2- (i) butoxyethyl group, 2- (se
c) butoxyethyl group, 2- (n) pentyloxyethyl group, 2- (n) hexyloxyethyl group, 2- (n)
Octyloxyethyl group, 2- (2'-ethylhexyloxy) ethyl group, 1-methyl-2-methoxyethyl group, 1-methyl-2-ethoxyethyl group, 1-methyl-
2- (n) propoxyethyl group, 1-methyl-2-
(I) Propoxyethyl group, 1-methyl-2- (n) butoxyethyl group, 1-methyl-2- (i) propoxyethyl group, 1-methyl-2- (n) hexyloxyethyl group, 1-methyl -2- (2'-ethylhexyloxy)
Ethyl group, 3-methoxybutyl group, 3-ethoxybutyl group, 1-ethyl-2-methoxyethyl group, 1-ethyl-
2-ethoxyethyl group and the like can be mentioned, and particularly preferably C
Examples thereof include a 3-C8 2-alkoxyethyl group, examples of the aralkyl group include a benzyl group and 2-phenylethyl group, and examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group. Examples of the halogen atom represented by Z ¹ include a fluorine atom, a chlorine atom and a bromine atom.

R², R³And R^FourThe group represented by
A C1-C8 alkyl group, Z ¹Is a hydrogen atom or
A bromine atom is particularly preferable. Below, the general formula
Regarding the compounds represented by (I) and (II),
Representative examples will be given. The compounds used in the present invention are summarized below.
As long as it does not exceed, it is not limited to these specific examples.
Yes.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

[0022]

[Table 5]

[0023]

[Table 6]

[0024]

[Table 7]

[0025]

[Table 8]

[0026]

[Table 9]

[0027]

[Table 10]

[0028]

[Table 11]

[0029]

[Table 12]

In the present invention, the mixing ratio of the dyes (I) and (II) is not particularly limited, but it is 2: 8 to 8:
It is common to select from the range of 2. When the coloring material layer is formed on the heat-sensitive transfer sheet of the present invention by using the above-mentioned dye, the method is not particularly limited, and the dye represented by the general formulas (I) and (II) may be used in a medium together with a binder. An ink is prepared by dissolving it in or dissolving it in fine particles,
It can be carried out by applying the ink to a base film and drying it according to a conventional method.

As the binder for preparing the ink, 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 are used. Examples thereof include resins soluble in organic solvents such as butyral, ethyl cellulose, acetyl cellulose, polyester, AS resin, and phenoxy resin.

As a medium for ink preparation, in addition to water, alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and isobutyl alcohol, cellosolves such as methyl cellosolve and ethyl cellosolve, and aromatic compounds such as toluene, xylene and chlorobenzene. Group, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, methylene chloride,
Chlorine-based solvents such as chloroform and trichlorethylene,
Ethers such as tetrahydrofuran and dioxane,
Organic solvents such as N, N-dimethylformamide and N-methylpyrrolidone can be mentioned.

In addition to the above components, organic or inorganic non-sublimable fine particles, a dispersant, an antistatic agent, an antifoaming agent, an antioxidant, a viscosity adjusting agent and the like are added to the above ink. be able to. As a base film for applying the ink for producing the transfer sheet, condenser paper, thin paper such as glassine paper, polyester, polycarbonate,
Films of plastics having good heat resistance such as polyamide, polyimide and polyaramid are suitable, and the thickness thereof can be in the range of 3 to 50 μm.

Of the above base films, the polyethylene terephthalate film is particularly advantageous in consideration of mechanical strength, solvent resistance, economy and the like. However, in some cases, the polyethylene terephthalate film does not always have sufficient heat resistance and the running property of the thermal head is insufficient, so that heat resistance that includes a lubricant, heat-resistant particles with high lubricity, etc. on the opposite surface of the color material layer. A thermal head having improved running properties can be used by providing a layer of a functional resin according to a conventional method.

The method of applying the ink to the base film is not particularly limited, but it can be carried out using, for example, a gravure coater, a reverse roll coater, a rod coater, an air doctor coater, etc. The thickness may be applied in a range of 0.1 to 5 μm after drying. The heat-sensitive transfer sheet of the present invention includes
As a heating means, not only a thermal head but also infrared rays, laser light, etc. can be used. Further, it can be used as an electrically conductive dye transfer sheet by using an electrically conductive heat generating film which generates heat by applying electricity to the base film itself.

[0036]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the Examples and Comparative Examples do not limit the present invention as long as the gist thereof is not exceeded.
Example 1 a) Preparation of ink

[0037]

[Table 13]   1) Adjustment of ink (A)       The dye No. 1-3 3 g       The dye No. 2-17 4g       Cellulose acetate 10g         (Product name "L-30"; manufactured by Daicel Chemical Industries, Ltd.)       Methyl ethyl ketone 80g   ──────────────────────────────           97g in total

The mixture having the above composition was treated with a paint conditioner for 10 minutes to prepare an ink. 2) Preparation of Ink (B) (Magenta Ink) Magenta Ink (B) is the same as Ink (A) except that 6 g of magenta dye having the following structure is used instead of the dye used in Ink (A). Was prepared.

[0039]

[Chemical 5]

3) Preparation of Ink (C) (Cyan Ink) Cyan ink is the same as Ink (A) except that 6 g of cyan dye having the following structure is used instead of the dye used in Ink (A). (C) was prepared.

[0041]

[Chemical 6]

B) Preparation of Transfer Sheet Each of the above inks (A), (B) and (C) was applied to a polyethylene terephthalate film (6 μm thick) having a back surface subjected to heat-resistant lubrication treatment using a wire bar and dried. (Dry film thickness about 1 μm) Transfer sheet (A),
(B) and (C) were obtained. In addition, the polyethylene terephthalate film is subjected to the heat-resistant lubricity treatment by applying the following formula

[0043]

[Chemical 7]

8 parts by weight of a polycarbonate resin having a repeating structural unit represented by: 1 part by weight of a phosphate ester type interfacial lubricant (product name "Prysurf A-208B"; manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), toluene It was carried out by applying a solution consisting of 91 parts by weight and drying (dry film thickness: about 1 μm).

C) Preparation of image receptor Vinyl chloride-vinyl acetate copolymer resin (product name "VYH
D "; manufactured by Union Carbide Co., Ltd.), amino-modified silicone (product name" KF-393 "; manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 part, methyl ethyl ketone 15 parts, xylene 15 parts. Product name "Yupo FPG1
50 "; made by Oji Yuka Synthetic Paper Co., Ltd. with a wire bar, dried (dry film thickness: about 5 μm), and further 8 in an oven
It was prepared by treating at 0 ° C. for 30 minutes.

D) Transfer recording 1) Yellow color transfer recording The ink coated surface of the transfer sheet (A) is superposed on the image receiver,
Recording was performed using a thermal head under the following conditions to obtain a medium-colored yellow tone recorded matter. Table 3 shows the color density of the recorded matter and the color measurement results.

[0047]

[Table 14] Recording conditions Recording density in main scanning and sub-scanning: 6 dots / mm Recording power: 0.21 W / dot Energization time: 10 ms For color measurement, a color difference meter SZ-Σ80 manufactured by Nippon Denshoku Industries Co., Ltd. was used. It was measured. Color density is Macbeth Densitometer TR-
It was measured at 927.

2) Black color transfer recording The transfer sheets (A), (B), and (C) described above were transferred and recorded in this order on the same image receptor under the same recording conditions as in 1) above, and black. A color record was obtained. The results of measuring the color density of this recorded product are shown in Table 3.

E) Light fastness test The light fastness test of the obtained yellow and black color recordings was performed with a xenon lamp fade meter (Suga Test Instruments Co., Ltd.).
Manufactured by K.K. (black panel temperature: 63 ± 2)
℃), degree of discoloration and fading of recorded material after irradiation for 80 hours {ΔE
(L ^* a ^* b ^* )} is shown in Table-3.

Comparative Example 1 Dye No. which is one component of the mixed dye instead of the mixed dye used in the preparation of the ink (A) of Example 1 was used. 1-3
Ink was prepared, a transfer sheet was prepared, and transfer recording was carried out in the same manner as in Example 1 using 6 g of the above dye only. Table 3 shows the yellow color transfer recording results, the black color transfer recording results, and the light resistance test results.

Comparative Example 2 Instead of the mixed dye used in the preparation of the ink (A) of Example 1, one of the components of the mixed dye, the above dye No. 2-1
Ink preparation, transfer sheet preparation, and transfer recording were carried out in the same manner as in Example 1 using 8 g of the dye of No. 7 only. Table 3 shows the yellow color transfer recording results, the black color transfer results, and the light resistance test results.

[0052]

[Table 15]

Example 2 Using the ink prepared by the following method instead of the ink used in Example 1, the transfer sheet was prepared, the image receptor was prepared and transferred, and the light resistance test was conducted in the same manner as in Example 1. As a result, it was possible to obtain a recorded product having a medium yellow color tone and a black recorded product having a high color density. The light resistance of the obtained recorded matter and the storage stability of the transfer sheet in the dark were both good.

[0054]

[Table 16]   Ink preparation       7 g of the same dye as in Example 1       AS resin 10g         (Product name "Denka AS-S"; manufactured by Denki Kagaku Kogyo Co., Ltd.)       70g of toluene       Cyclohexanone 10g   ──────────────────────────────         97g in total

[0055]

When the heat-sensitive transfer sheet of the present invention is used,
It is possible to obtain a medium-yellow recorded matter having a high density with low energy, and a black color having a high density can be obtained by mixing with magenta and cyan. Further, the light resistance of the obtained recorded matter is very high. Is very good.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-60-180889 (JP, A) JP-A-5-147366 (JP, A) JP-A-5-201147 (JP, A) JP-A-60- 53565 (JP, A) JP 63-71392 (JP, A) JP 63-71393 (JP, A) JP 63-182192 (JP, A) JP 63-182193 (JP, A) JP-A 63-189289 (JP, A) JP-A 64-85792 (JP, A) JP-A 2-139291 (JP, A) JP-A 5-169854 (JP, A) JP-A 5-229268 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (4)

(57) [Claims] 1. A heat-sensitive transfer sheet having at least a color material layer on a substrate, wherein a binder made of a resin in the color material layer, a disazo dye represented by the following general formula (I), and 1] (In the formula, X ¹ , X ² and X ³ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, a nitro group, a cyano group, an acylamino group, an alkoxycarbonyl group, an alkylsulfonyl group, a substituted or Represents an unsubstituted sulfamoyl group, a trifluoromethyl group or a halogen atom, and Y ¹ , Y ² , Y ³ , Y ⁴ , Y ⁵ and Y ⁶ are each independently a hydrogen atom, an alkyl group, an alkoxy group or a halogen atom. Represents an atom or a hydroxy group, or Y ¹
And Y ² and Y ⁴ and Y ⁵ may be independently linked to each other to form an aromatic ring structure. ) A quinophthalone dye represented by the following general formula (II): (In the formula, R ¹ represents a hydrogen atom or a lower alkyl group, and Z ¹
Represents a hydrogen atom or a halogen atom, Z ² represents a hydrogen atom, a —COOR ² group or a —CONR ³ R ⁴ group,
R ² , R ³ and R ⁴ are each independently a hydroxy group.
Alkyl groups that may be substituted , alkoxy moieties
An alkoxy group which may have a phenyl group or a phenoxy group , a cycloalkyl group, an alkenyl group,
Alkenyloxy group, an aralkyl group, a furfuryl group, a tetrahydrofurfuryl group, or an alkoxy group,
Alkyl group, trifluoromethyl group or halogen source
Represents a phenyl group which may be substituted with a child . ) Is contained in the heat-sensitive transfer sheet. 2. In the general formula (I), X ¹ , X ² And X
³ Are each independently a hydrogen atom, a hydroxy group, a salt
Elemental atom, fluorine atom, cyano group, ethoxy group, methoxy
Group, nitro group, trifluoromethyl group, dimethylamino
Sulfonyl group, methyl group, ethyl group, or acetyl group
Represents a mino group, Y ¹ , Y ² , Y ³ , Y ^Four , Y ^Five And Y ⁶ But,
Independently of each other, hydrogen atom, methyl group, ethyl group,
Represents a toxy group, an ethoxy group, or a hydroxyl group
Suka or Y ¹ And Y ² And Y ^Four And Y ^Five Are independent
And link them together to form a benzene ring.
The heat-sensitive transfer sheet according to claim 1, which is characterized in that. 3. In the general formula (2), R ¹ Is a hydrogen atom
Or C ₁ ~ C _Four Represents an alkyl group of ¹ Is a hydrogen atom,
Represents a fluorine atom, a chlorine atom or a bromine atom, R ² , R ³
And R ^Four But each independently, C ₁ ~ C ₁₂ The alkyl
Base, C ₃ ~ C ₈ 2-alkoxyethyl group, cyclopentyl
Group, cyclohexyl group, alkenyl group, alkenyl group
Xyalkyl group, benzyl group, 2-phenylethyl group,
Furfuryl group, tetrahydrofurfuryl group, or methoxy group
Si group, methyl group, trifluoromethyl group or halogen
Represents a phenyl group which may be substituted with a nitrogen atom.
The heat-sensitive transfer sheet according to claim 1, which is characterized in that: 4. In the general formula (2), R ² , R ³ And R
^Four But each independently, C ₁ ~ C ₈ Is an alkyl group of
R, Z ¹ Is a hydrogen atom or a bromine atom
The heat-sensitive transfer sheet according to any one of claims 1 to 3,
To.