JPH0361085A - Color for thermal recording and transfer sheet - Google Patents

Abstract

PURPOSE:To enable stable and color-fast recording with sufficient color density to be obtained by blending at least a single or more than two color components selected from a specific color group. CONSTITUTION:A recording ink is prepared by blending a pyridon azo color expressed by formula I, any appropriate resin and solvent, and applied to a transfer base. In formula I, R<1> indicates formulae II, III, X is hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a halogenoalkyl group, an alkoxy group, an aryloxy group, an alkynyloxy group, a cycloalkyloxy group or a halogenoalkyloxy group, Y is an alkyl group, a cycloalkyl group, an aryl group or a halogenoalkyl group, R<2> is hydrogen atom, an alkyl group, an alkyl group which may have a substituted group, halogen atom or an alkoxy group, R<3> is hydrogen atom, an alkyl group or an alkyl group which may have a substituted group.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a dye for thermal transfer recording and a transfer sheet used for color hard copying using a heat transfer recording method.

[Conventional technology]

The sublimation thermal transfer image recording method uses heat to sublimate pigments to form images.Currently, full-color hard copies are produced from televisions, CRT color displays, color facsimiles, magnetic cameras, etc. It is attracting attention as a method of obtaining As the heat source, a heating element such as a Leemarhend or a laser, particularly a semiconductor laser, is used, and the amount of pigment transferred can be controlled by the applied thermal energy, so that good gradation recording can be obtained.

This method uses a heat-sensitive transfer sheet coated with sublimable dye on the transfer substrate, and transfers and records onto the receiver using a thermal head controlled by an image signal. By using it, full color can be achieved.

Such heat-sensitive recording dyes include pyridone azo dyes represented by formula (II) (Reference: JP-A-62-290
583) is known.

[In formula (II), 8 is unsubstituted or has a substituent at the 2- or 4-position with respect to the ab bond. ] [Problems to be Solved by the Invention] The dye used for thermal transfer must satisfy various required performances as described below, and good image recording is only possible when these are satisfied.

- The dye has good solubility in the resin or solvent component used to create the heat-sensitive transfer sheet.

(2) The dye sublimes easily from the heat-sensitive transfer sheet to the image receptor (image recording layer) and has good affinity to the image receptor resin.

■The molecular extinction coefficient of the dye is large.

■Have optimal color characteristics as the three primary colors for full-color display.

■The imaged record must have excellent fastness in terms of both light resistance, heat resistance, and stain resistance.

In this recording method, for example, a pyridone azo dye represented by the above general formula (TI) has been used, but there is no one that satisfies the above conditions and is practical. No records were obtained.

[Means to solve the problem]

As a result of testing various dyes, we found that the following general formula (1) having a substituent at the 3-position relative to the azo bond: alkyl group, cycloalkyl group, alkenyl group, aryl group, halogenoalkyl group , represents an alkoxy group, an aryloxy group, an aryloxy group, a cycloalkyloxy group, or a halogenoalkyloxy group, Y represents an alkyl group, a cycloalkyl group, an aryl group, or a halogenoalkyl group, and R2 represents a hydrogen atom, an alkyl group, R3 represents an alkyl group, a halogen atom, or an alkoxy group that may have a substituent, and R3 represents a hydrogen atom, an alkyl group, or an alkyl group that may have a substituent. ) is a yellow pigment that satisfies the above conditions, and it has been discovered that by containing one or more of these pigments, robust recording with sufficient color density can be achieved117. 7 The present invention was completed.

In this case, the pyridone azo dye represented by the above general formula (1) may be used alone as a yellow component, or if necessary, it may be used in combination with other yellow components to achieve the same color density. A robust record can be obtained.

Next, the present invention will be explained in detail.

The alkyl groups in R1, R2, and R3 in the above general 2N) include methyl group, ethyl group, propyl group, butyl group,
Represents pentyl group, hexyl group, heptyl group, octyl group, etc. As a cycloalkyl group, cyclohexyl group,
It represents a socrobentyl group, etc., and alkenyl groups include an allyl group, a 2-methylallyl group, a 2-chloroallyl group, a 2-chloroallyl group, and an alkenyl group.
-Represents a pro-allyl group, a crotyl group, a 3-phenylallyl group, etc.

Aryl groups include phenyl group, o-tolyl group, m
-tolyl group, p-hruyl group, p-lyl group, p-21-11
Phenyl! Examples of the halogenoalkyl group include a chloroethyl group, a chloropropyl group, a bromoethyl group, and an iodoethyl group.

Alkoxy groups include methoxy, ethoxy, propoxy, butoxy, T-methoxy, etc. Aryloxy includes phenyloxy, p-chlorophenyl, I, +i, etc. Examples of alkenyloxy groups include allyloxy groups and 2-methylallyloxy groups, and examples of Schiffl coregyloxy groups include:
It represents a cyclo-xyloxy group, a cyclopentyloxy group, etc., and examples of the halogenoalkyloxy group include a chloroethyloxy group, a chloropropyloxy group, a promoedyloxy group, an iodoethyl group, and the like.

In addition, an alkyl group that may have a substituent is a
Alkoxyalkyl groups such as xyethyl group, γ-methoxypropyl group, and xyethyl group, halogenoalkyl group such as trifluoromethyl group and β-chloroethyl group, hydroxyalkyl group such as hydroxyethyl group and hydroxypropyl group, cyanoethyl group etc., and examples of the halogen atom include chlorine, fluorine, and iodine.

The compound of the present invention can be produced, for example, by the reaction route shown below.

(The following is a blank space) 3 [In the formula, R2, R3, and X have the same meanings as in the general formula (1). ] -C Formula (I[[) An aniline derivative represented by, for example,
In hydrochloric acid water, in the presence of sodium nitrite at a molar ratio of 1.0 to 1.3 times, it is reacted at 0 to 5°C for 1 to 2 hours to diazotize, and then excess sodium nitrite is decomposed with sulfamic acid. Pyridone represented by the general formula (TV) and O~5''C l~
General formula (V) is obtained by carrying out a camping reaction for 2 hours.
The dye shown is obtained.

Then, the obtained compound of formula (V) is used in a proportion of 3 to 7 times by weight to a MK compound such as toluene, xylene, or chlorobenzene, and then mixed with pyridine at a molar ratio of 0.01 to 1.0 times. - In the presence of acid chloride represented by general formula (Vl) at a molar ratio of 1.0 to 3.0 times, 80 to 100''C11
By reacting for ~3 hours, a dye represented by general formula N) is obtained.

As a method for producing a thermal transfer recording ink using the dye of the present invention, the dye may be mixed with a suitable resin, solvent, etc. to prepare the recording ink. The transfer sheet can be produced by applying a dye ink containing the dye of the present invention onto a transfer substrate.

In addition, as a thermal transfer method, the ink obtained above is applied onto a suitable base material to create a transfer sheet, the sheet is overlapped with the recording medium, and then heated and heated from the back side of the sheet with a heat-sensitive recording head. In this way, the dye on the second sheet is transferred onto the recording medium.

The resin used for adjusting the above ink may be those used in ordinary printing inks, such as rosin-based, phenol-based, xylene-based, petroleum-based, vinyl-based, polyamide-based,
Oil-based resins such as alkyd-based, nitrocellulose-based, and alkyl celluloses, or water-based resins such as maleic acid-based, acrylic acid-based, casein, shruck, and glue can be used.

In addition, solvents for ink preparation include alcohols such as methanol, ethanol, propatool, and butanol, cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as Hensen, I-luene, and xylene, ethyl acetate, and acetic acid. Esters such as butyl, ace I
-, methyl ethyl ketone, cyclohexanone, hydrocarbons such as ligroin, cyclohexane, kerosene, dimethylformamide, etc. can be used, but when using an aqueous resin, water or water and the above solvents can be used. You can also use 7 combinations.

Suitable substrates for applying ink include thin paper such as condenser paper and glassine paper, and plastic films with good heat resistance such as polyester, polyamide, and polyimide. In order to improve the heat transfer efficiency to the pigment by 1, a thickness of 5 to 50 μrn culm is appropriate.

In addition, examples of recording materials include polyethylene, boria, etc.
Polyolefin resins such as l-pyrene, polyvinyl chloride,
Halogenated polymers such as polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetate, vinyl polymers such as polyacrylic ester, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, ethylene and propylene cola'. Consisting of copolymer resins of olefins and other hini/l-acrylates, ionomers, cellulose resins such as cellulose diacetate-1, cellulose 1-lyacetate I, polysulfone-1, polysulfone, polyimide, etc. Examples include fibers, woven fabrics, films, sheets, and molded products.

Particularly preferred are woven fabrics, sheets or films made of polyethylene terephthalate.

In addition, in the present invention, ordinary paper coated with or impregnated with acidic fine particles such as silica gel added to the resin, or laminated with a resin film, or special paper treated with acetylation. By using processed paper, good recording with excellent image stability under high temperature and high humidity conditions can be achieved. It is also possible to use films of various resins or synthetic papers made from them.

Furthermore, by heat-pressing, for example, a polyester film on the transfer recording surface after transfer recording, it is possible to improve the color development of the dye and to stabilize the recording during storage.

[Action and effect]

The pyridone azo dye represented by the general formula (1) of the present invention has a vivid yellow color, and therefore, for example, the magenta color dye represented by the following structural formula and the cyan color dye represented by the following structural formula (hereinafter referred to as the margin). Suitable for obtaining full color in combination with

In this case, it may be possible to improve the solubility of the yellow dye component in the resin and solvent used when producing the transfer sheet by mixing other dyes, so if necessary, it may be possible to Other yellow pigments may be mixed.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to the present invention.

In addition, parts represent parts by weight, and % represents weight %.

Example 1 20 parts of m-aminophenol was dissolved in 250 parts of 6.8% hydrochloric acid water, and 100 parts of ice was added and cooled to 0 to 5°C. Add 44.5 parts of 30% nitrous acid aqueous solution to the solution,
The mixture was stirred at 0 to 5°C for 1 hour to perform diazotization and obtain a diazotized liquid. Next, 1.5% hydroxide ~ zolium solution 550
The previously obtained diazotized solution was added dropwise to 1.28.9 parts of a pyridine compound of the following formula (Vl) at 0 to 5°C, and the pH was adjusted to 4 with a 30% aqueous sodium hydroxide solution. , 5, and then stirred at 0 to 5°C for 1 hour to perform coupling. The obtained yellow pigment was separated by filtration, washed with water, and then dried to obtain 35.5 parts of yellow powder.

Add 9.8 parts of the obtained yellow powder to 45 parts of toluene,
Furthermore, add 1 part of pyridine and 6.1 parts of acetic anhydride,
The mixture was heated and stirred at °C for 1 hour. Then cooled to 50'C,
After adding 45 parts of methanol and allowing the mixture to cool to room temperature, the precipitated solid was separated by filtration, washed with methanol, and dried to obtain 5.7 parts of yellow dye (A) represented by the following formula.

Using the obtained compound (A), prepare the ink as follows,
A transfer sheet and recording material were prepared, and transfer recording was performed. The absorption maximum wavelength (λma) of this compound in chloroform was 440 nm.

(1) Ink preparation method Pigment of the above formula (A) 3-part polybutyral resin 4.5 Methyl ethyl ketone
46.25 Toluene
46.25 The ink was prepared by partially treating the pigment mixture of the above composition with a paint conditioner for about 30 minutes using a glass piece.

(11) How to create a transfer sheet Using a gravure proofing machine (plate depth 30 μm), apply the above ink to a 9 μm thick polyethylene terephthalate film whose back side has been heat-resistant treated so that the dry coating amount is 1.0 g/11 (1.0 g/11). applied and dried.

(iii) Preparation of recording material Polyester resin 0.8 parts (vy
lon 103 Toyobo Tg-47°C) EVA-based high needle polymer plasticizer 0.2 parts (Elharoia 4
1p Mitsui Polygemical Tg = -37°C) Adanno modified silicone 0.04 part (KF
~857 Shin-Etsu Chemical Co., Ltd.) Epoxy modified silicone 0.04 part (KF
-103 manufactured by Shin-Etsu Chemical Co., Ltd.) Nozile ethyl getone / toluene / cyclohexane (weighted 4: / I: 2) 9.0 parts or more were mixed, the coating liquid was adjusted, and synthetic paper (manufactured by Tamago Yuka Co., Ltd.) was mixed. ′
, Lbo I'PG#150) to bar coke (1?K
Pr1nt Coat Instruments
It was coated at a rate of 4.5 g/rJ when dry using N01 manufactured by Co., Ltd., and dried at 10"C for 15 minutes.

(iv) Transfer recording The above-mentioned transfer sheets 1 to 1 and the above-mentioned recorded sheets are placed one on top of the other with their respective ink-coated surfaces and coating liquid-coated surfaces facing each other, and a voltage of 10 V is applied to the thermal head from the back side of the thermal transfer sheet for a printing time of 4. Recording was performed under conditions of .0 millisecond, and a yellow record with a color density of 2.7 was obtained.

The color density is determined by Densitometer RD manufactured by Macbeth Co., Ltd. in the United States.
-514 type (filter m: Utten No. 58).

Color density was calculated using the following formula.

Color density - Nog. (Io/I) To - Intensity of reflected light from standard white reflector 1 = Intensity of reflected light from test object In addition, the light-opening test of the obtained record was performed using a xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.). ) at a black panel temperature of 63±2"C, but +t <
It was also excellent in image stability at high temperatures and under SIJ humidity, with almost no discoloration at ta=+.

In addition, the fastness was determined by leaving the obtained recorded image in an atmosphere of 50'C for 48 hours, and the sharpness of the image and the surface 1'
: When judged by the coloring when rubbed with J paper, the image clarity did not change, and the white paper was not colored either, and the fastness of the recorded image was good.

Example 2 Preparation of ink using 1.5 parts each of a compound (B) represented by the following formula synthesized by the same method as in Example 1 and a compound (C) coupled in the same manner, for a total of 3 parts. When a transfer sheet and a recording material were prepared and transfer recording was performed, a yellow recording with a color density of 2.6 was obtained.

When these recordings were subjected to a light fastness test in the same manner as in Example 1, the recordings showed almost no change and were excellent in image stability under high temperature and high humidity.

Further, a fastness test was conducted in the same manner as in Example 1, but the sharpness of the 9 images did not change, the white paper did not become colored, and the fastness of the recorded images was good.

Examples 3 to 17 Using the pyridone-azure dye shown in Table 1, which was prepared in the same manner as in Example 1, the ink was adjusted, the transfer sheet was prepared, the recording material was prepared, and the L and L dyes were prepared. Transfer recording was performed to obtain records for each group shown in Table 1.

All of these records were subjected to a light fastness test in the same manner as in Example 1, and the records showed almost no change and were excellent in image stability at and under high temperatures.

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 did not become colored, and the fastness of the recorded image was good.

Comparative Example According to a method similar to Example 1, dye 3 of formula (C) above was prepared.
Using 0 copies, ink adjustment, transfer sheets, and recording materials were created.

When the pigment (C) was used alone, it was not completely dissolved in the ink and some crystals were deposited on the sheet surface. Transfer recording was performed using this transfer sheet, and the density was measured in the same manner as in Example 1 and found to be 0.9. Further, when a light fastness test was conducted in the same manner as in Example 1, the color of the recording was faded.

In addition, a fastness test was conducted in the same manner as in Example 1, but the image was not bright, the blank paper was also colored, and the fastness of the recording was poor.

(Margin below)

Claims (1)

[Claims] 1. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, where X is a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a halogenoalkyl group, an alkoxy group, an aryloxy group, an alkenyloxy group, a cycloalkyloxy group , represents a halogenoalkyloxy group, Y represents an alkyl group, cycloalkyl group, aryl group, or halogenoalkyl group, R^2 represents a hydrogen atom, an alkyl group, an alkyl group that may have a substituent, or a halogen atom or represents an alkoxy group, and R^3 represents a hydrogen atom, an alkyl group, or an alkyl group which may have a substituent. ) is a dye for sublimation type heat-sensitive recording. 2. General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 is ▲There are mathematical formulas, chemical formulas, tables, etc.▼,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, where X is a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, a halogenoalkyl group, an alkoxy group, an aryloxy group, an alkenyloxy group, a cycloalkyloxy group , represents a halogenoalkyloxy group, Y represents an alkyl group, cycloalkyl group, aryl group, or halogenoalkyl group, R^2 represents a hydrogen atom, an alkyl group, an alkyl group that may have a substituent, or a halogen atom or represents an alkoxy group, and R^3 represents a hydrogen atom, an alkyl group, or an alkyl group which may have a substituent. 1. A transfer sheet for sublimation type heat-sensitive recording, comprising at least one or two or more dye components selected from the group of dyes represented by: