JPH05330254A - Cyan dye for thermal sublimation transfer recording - Google Patents

Abstract

PURPOSE:To enhance a sublimation speed and image stability by using a cyan dye having a structure represented by a predetermined general formula as a dye for color hard copy. CONSTITUTION:A cyan dye has a structure represented by general formula (I) (wherein R1-R3 are a hydrogen atom, a hydroxyl group, a 1-4C alkyl group, a trifluoromethyl group, an alkoxy group, an alkoxyalkyl group, a hydroxyalkyl group, an alkylcarboxyl group, an alkoxycarbonyl group or a halogen atom and, as examples of R1-R3 there are a 1-8C alkyl group such as methyl, ethyl or n-octyl, a trifluoromethyl group, a 1-4C alkoxy group such as methoxy or tert-buthoxy, a 1-8C alkoxycarbonyl group such as methoxycarbonyl or tert- buthoxycarbonyl, fluorine or chlorine).

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 used for color hard copy by a sublimation thermal transfer recording system.

[0002]

2. Description of the Related Art In the thermal transfer method using a sublimation dye, a sublimable dye that has been made into an ink is applied to a thin condenser paper or PET film having a thickness of several microns, and this is selectively heated by a thermal head and transferred to a recording paper. It is one of the thermal transfer printing methods, and is currently used as a means for recording various types of image information (hard copy).

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

However, there are very few cyan dyes proposed so far, which have both a high sublimation rate and image stability after transfer, and it is expected that a dye satisfying the optimum conditions as a sublimable dye will appear. There is.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sublimable dye having a high sublimation rate and image stability after transfer.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have shown the following general formula (1):
The present invention has been completed by finding that the compound represented by Chemical formula 2 can be an excellent dye for sublimation transfer. That is, the present invention has the general formula (1)

[0007]

[Chemical 2]

[Wherein R ₁ , R ₂ and R ₃ are a hydrogen atom, a hydroxyl group, a C _{1 to} C ₄ alkyl group, a trifluoromethyl group,
An alkoxy group, an alkoxyalkyl group, a hydroxyalkyl group, an alkylcarboxy group, an alkoxycarbonyl group, and a halogen atom are shown. ] A cyan dye for thermal sublimation transfer recording represented by the following formula.

[0009] In the studies by the present inventors, generally, in sublimation transfer dyes, the sublimation rate at the time of transfer relates to the interaction between the dye molecules and the interaction between the dye molecules and the binder resin for ink. The knowledge was obtained. 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. It became clear.

The dye represented by the general formula (1) or (Chemical formula 2) of the present invention has the above-mentioned various conditions and can obtain a relatively good sublimation rate. Hereinafter, the present invention will be described in detail. The dye represented by the general formula (1) or (Chemical Formula 2) of the present invention can be obtained by a conventional method, for example, by reacting quinizarin represented by the following reaction formula (Chemical Formula 3) with a substituted aniline.

[0011]

[Chemical 3]

R in the general formula (1) (formula 2) of the present invention
Specific examples of ₁ , R ₂ and R ₃ include hydrogen atom, hydroxyl group, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, n-pentyl, n. -Hexyl, n-heptyl, n
- alkyl C ₁ -C ₈ of octyl, trifluoromethyl group, methoxy, ethoxy, n- propoxy, iso
-Propoxy, n-butoxy, iso-butoxy, te
rt- alkoxy group C ₁ -C ₄ the butoxy, methoxymethyl, ethoxymethyl, ethoxyethyl, methoxyethyl, n- propoxymethyl, iso- propoxymethyl, n- butoxymethyl, iso- butoxymethyl, t
ert-butoxymethyl, n-pentyloxymethyl,
n- hexyloxy alkoxyalkyl group of C ₁ -C _8, such as methyl, hydroxymethyl, hydroxyalkyl groups such as hydroxyethyl, methyl carboxyethyl, ethyl carboxy, n- propyl carboxymethyl, iso- propyl carboxymethyl, n- butyl carboxymethyl, tert - butyl carboxyalkyl carboxy group of C ₁ -C _8, such as, methoxycarbonyl, ethoxycarbonyl, n- propoxycarbonyl, iso- propoxycarbonyl, n- butoxycarbonyl, tert- butoxy C ₁ ~ such as carbonyl
Examples thereof include C ₈ alkoxycarbonyl groups and halogen atoms such as fluorine, chlorine and bromine.

As a method for producing 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 above is applied onto a suitable substrate to prepare a transfer sheet,
A method in which the sheet is superposed on a recording medium and then heated and pressed from the back surface of the sheet with a thermal recording head can be mentioned, whereby the dye on the sheet is transferred onto the recording medium.

[0015]

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) (Formula 4) is as follows. 10 parts of leucoquinizarin and 150 p-toluidine
Part, and 10 parts of boric acid are mixed, and 130-140 under air aeration.
The mixture was heated and stirred at 4 ° C for 4 hours. The mixture was cooled to 60 ° C., 150 parts of methanol was added, and the precipitated dye was filtered and dried to obtain 21 parts of the compound of the following formula (A) (formula 4). The maximum absorption wavelength (λmax) of this compound in toluene is 655n.
It was m.

[0016]

[Chemical 4]

(1) Method for preparing ink Ingredient of the formula (A) 3 parts Polybutyral resin 4.5 parts Methyl ethyl ketone 46.25 parts Toluene 46.25 parts The pigment mixture of the above composition is used in a glass conditioner and 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 (Vylon 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) The above is mixed to prepare a coating liquid, and synthetic paper (manufactured by 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 overlapped with the ink application surface and the coating liquid application surface facing each other, and the thermal head applied voltage of 10 V and printing are performed from the back surface of the thermal transfer sheet. Recording was carried out under the condition of a time of 4.0 milliseconds, and a cyan recording having a color density of 1.83 was obtained. The color density was measured using a Densitometer Model RD-514 (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

Further, a light resistance test of the obtained recording was carried out using a xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.) at a black panel temperature of 63 ± 2 ° C., but there was almost no discoloration by irradiation for 40 hours, 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.

Examples 2 to 16 The cyan color dyes shown in Table 1 (Tables 1 to 3) were produced in the same manner as in Example 1, and the ink was adjusted, the transfer sheet was produced, and the recording material was similarly obtained. And the transfer recording,
The respective records shown in Table 1 (Tables 1 to 3) were obtained. When a light fastness test was conducted on all of these recordings by the same method as in Example 1, the recordings showed almost no change and the image stability under high temperature and high humidity was excellent. In addition, Example 1
A fastness test was conducted in the same manner as in Example 1. However, the sharpness of the image did not change, the white paper was not colored, and the fastness of the recorded image was good. In addition, "○" indicates that the judgment results of light resistance and fastness are good, and "X" indicates that the results are poor.
It showed with.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

[Table 3]

Comparative Examples 1 to 4 In the same manner as in Example 1, using cyan dyes shown in Table 2 (Table 4), ink preparation, transfer sheet preparation, recording material preparation and transfer recording were carried out. I went. Further, a light resistance test and a fastness test were conducted in the same manner as in Example 1. As a result, as shown in Table 2 (Table 4), none satisfying the conditions of maximum transfer density, light resistance and fastness was obtained, and the image became unclear, and the white paper was markedly colored and defective.

[0027]

[Table 4]

[0028]

The cyan dye represented by the general formula (1) or (Chemical Formula 2) of the present invention can control the sublimation transfer amount of the dye by changing the energy applied to the thermal head during thermal transfer. , Gradation recording is 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 preservability of the obtained record is 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, good color density is obtained. It is a dye that is practically valuable because it can obtain various records.

Claims (1)

[Claims] 1. The following general formula (1) (Chemical formula 1) [In the formula, R ₁ , R ₂ , and R ₃ are a hydrogen atom, a hydroxyl group, and C ₁ to C.
_{4 represents} an alkyl group, a trifluoromethyl group, an alkoxy group, an alkoxyalkyl group, a hydroxyalkyl group, an alkylcarboxy group, an alkoxycarbonyl group and a halogen atom. ] A cyan dye for thermal sublimation transfer recording represented by the following formula.