JP2000119577A - Mist-type thermal transfer printing liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject printing liquid with high heat resistance capable of thermal transfer printing while suppressing scorching of misted part by including a color compound with a molecular weight at a specified level or higher as a printing material. SOLUTION: This printing liquid is obtained by including a printing material i.e., a color compound with a molecular weight of >=500, pref. >=800 and a medium capable of dissolving the printing material and having a melting point of <=150 deg.C and boiling point of 150-350 deg.C. This printing liquid is used as follows: using a printer with a porous structure in the printing liquid issue part of the printing head, the printing liquid is fed to the issue part where it is misted and then transferred onto a to-be-printed object placed against the printing head.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mist type thermal transfer recording liquid used in a mist type thermal transfer recording method, and more particularly to a recording liquid excellent in heat resistance.

[0002]

2. Description of the Related Art In recent years, as colorization of video cameras, computer graphics, and the like has progressed, colorization of hard copies has rapidly progressed. Hitherto, color hard copy systems such as a sublimation transfer recording system, an inkjet system, an electrophotographic system, and a heat-developed silver salt system have been proposed. Among these recording systems, a high-quality image can be formed by a simple apparatus. As an easy output method, a sublimation transfer recording method and an ink jet method are often used.

In the sublimation transfer recording system, a sublimation transfer dye in ink is applied to a thin condenser paper or PET film having a thickness of several microns to prepare a transfer sheet, which is superimposed on a recording paper and selected with a thermal head. This is one of the sublimation transfer printing methods in which the image is heated and transferred onto a recording sheet, and is currently used as a means for image recording (hard copy) various image information. Sublimation transfer recording method
This method has a large characteristic not found in other printing methods in that the amount of the dye to be sublimated and transferred depends on thermal energy, and the density after dyeing can be controlled in an analog manner. However, running costs are high because disposable ink ribbons or ink sheets are used.

In the ink jet system, an aqueous or oil-soluble ink is ejected from a fine nozzle to directly form an image on a recording paper. Ink jet printers include a bubble method in which ink is ejected by bubbles generated by rapidly heating the ink, and a piezo method in which ink is ejected using a ceramic (piezo) that deforms when a voltage is applied. In the ink jet system, the density gradation in the pixel is difficult in principle, and it is difficult to reproduce a high-quality image comparable to a silver halide photograph obtained by the sublimation transfer recording system in a short time.

[0005] A new recording method for solving the problems of these recording methods has also been proposed. For example, JP-A-8-169171
As described in JP-A-8-216500 or JP-A-8-216500, a recording liquid containing a sublimable dye is heated by a laser or electricity without using a transfer sheet, and the recording liquid is converted into a mist of 1 μm or less on a recording paper. A mist-type thermal transfer recording system in which an image is formed on a recording medium has been proposed.

In this mist type thermal transfer recording system, a recording liquid flying portion of a recording head such as a recording liquid heating portion is formed of a porous structure (for example, a large number of fine columnar members having a size and an interval of 0.1 to 10 μm). A recording liquid containing a recording material and a medium that dissolves the recording material and expands volume by heating, for example, is supplied to the recording liquid flying unit, and the state of the recording liquid changes by heating, for example. In this case, a mist is generated, and the mist is transferred to a recording medium arranged to face the recording head. According to this recording method, the surface area is increased by providing the above-described porous structure in the recording liquid flying portion, and the recording liquid is constantly supplied to the recording liquid flying portion by capillary action and held there. In this state, a mist generating means, for example, by heating or the like, by selectively applying a heat amount according to the recorded information, a part of the recording liquid is evaporated or the like, and a pressure rise is caused, and a digital camera or the like is used. The recording material corresponding to the formed electrical image is transferred to the recording medium in the form of minute mist.

In this case, the porous structure has a pore size of several tens μm.
m, compared to the conventional inkjet nozzle
Since it has micropores of much smaller size, many mist of extremely small size can be formed, and the number of mist generation can be freely adjusted according to the applied energy such as heating energy corresponding to the recording information to the recording liquid flying part. Since the control can be performed, density gradation can be performed, and recording having image quality equal to or higher than that of a silver halide image can be obtained.

As described in JP-A-8-244363, JP-A-8-244364, and JP-A-8-244366, the recording liquid used in the mist type thermal transfer recording system has a sublimation property. In addition, it is necessary to contain a dye having high heat resistance. However, as described in JP-A-8-244364, a problem has been pointed out that kogation occurs in the recording head unless the molecular weight of the dye used is 400 or less. This has narrowed the choice of dyes.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a mist type thermal transfer recording liquid which has a wide range of choices of dyes and has excellent heat resistance.

[0010]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that the use of a dye compound having an extremely high sublimation temperature or a non-sublimable property in a mist-type thermal transfer recording system has improved heat resistance. It has been found that an excellent mist type thermal transfer recording liquid can be obtained, and the present invention has been completed.
That is, the present invention uses a recording apparatus in which a porous structure is formed in a recording liquid flying section of a recording head, supplies a recording liquid to the recording liquid flying section, mistes the recording liquid, and arranges the recording liquid in a mist facing the recording head. A recording liquid containing a recording material used in a recording method for transferring to a recorded recording medium and a medium capable of dissolving the recording material, wherein the recording material contains a dye compound having a molecular weight of 500 or more. A mist type thermal transfer recording liquid, wherein the recording liquid and the medium, wherein the molecular weight of the dye compound is 800 or more, dissolves the dye compound and has a melting point of 150.
The present invention relates to the above-mentioned recording liquid, which is a medium having a boiling point of 150 to 350 ° C. at a temperature of not higher than 150C.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The mist type thermal transfer recording liquid of the present invention is characterized in that a mist type thermal transfer recording liquid containing a recording material and a medium contains a dye compound having a molecular weight of 500 or more as a recording material. Things. The mist type thermal transfer recording liquid of the present invention is produced, for example, by uniformly mixing a dye compound, a medium, and, if necessary, various additive components using a magnetic stirrer or the like while appropriately heating. be able to.

The dye compound used in the mist type thermal transfer recording liquid of the present invention has a molecular weight of 500 or more, preferably 800 or more. These dye compounds are usually dye compounds having a sublimation temperature of 350 ° C. or higher or having no sublimability. Examples of these dye compounds include, for example, azo dyes, phthalocyanine dyes, pyridone dyes, styryl dyes, quinophthalone dyes, phthalocyanine dyes, indophenolaniline dyes, anthraquinone dyes, naphthoquinone dyes, and tricyanovinyl Dyes such as dyes having a molecular weight of 500 or more are exemplified. These may be used alone or as a mixture of two or more dye compounds.

In the mist type thermal transfer recording liquid of the present invention,
The content of the dye compound is 0.1 to 5 by weight in the recording liquid.
0% by weight, preferably 1 to 30% by weight, more preferably 5 to 20% by weight.

The medium used in the mist type thermal transfer recording liquid of the present invention is capable of dissolving the dye compound, and has a melting point of 150 ° C. or less and a boiling point of 150 to 3 at 1 atm.
There is no particular limitation as long as the substance is at 50 ° C. If the boiling point of the medium is less than 150 ° C., the recording liquid is quickly evaporated and lost in the recording liquid flying portion of the recording head, and the non-volatile components in the recording liquid are likely to remain and easily cause clogging and the like. On the other hand, if the boiling point exceeds 350 ° C., it becomes difficult to efficiently expand the volume of the medium even when heating or the like for recording is performed. Preferably, the medium alone or as a mixture with another third component exhibits a fluidized state at 200 ° C. or lower and has necessary and sufficient heat resistance.

Preferred media include, for example, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, diheptyl phthalate, di-n-octyl phthalate,
Di (2-ethylhexyl) phthalate, diisodecyl phthalate, diisononyl phthalate, benzyl butyl phthalate, dioctyl terephthalate, trihexyl trimellitate, 1,2-propanediol dibenzoate, diethylene glycol dibenzoate, butyl phthalyl butyl glycolate Aromatic esters such as butyl oleate, dibutyl sebacate, di-n-octyl sebacate, di (2-ethylhexyl) sebacate, dibutyl adipate, di-n-hexyl adipate, di-n-adipate Octyl, di (2-ethylhexyl) adipate, di (2-ethylhexyl) azelate, triethylene glycol-2-ethyl butyrate, methyl acetyl ricinoleate, butyl acetyl ricinoleate, tributyl acetyl citrate, etc. Aliphatic esters; phosphorus compounds such as tributyl phosphate, tri (2-ethylhexyl) phosphate, tricresyl phosphate and triphenyl phosphite; aromatics such as 1-phenylnaphthalene, 1-phenylnaphthalene, toluene and ethylnaphthalene Hydrocarbons and the like.

If the content of the medium in the recording liquid is too small, the dye cannot be dissolved sufficiently. If the content is too large, the dye becomes relatively small and the transfer density becomes insufficient. % Or less, preferably 50% by weight or more,
99.5% by weight or less. In the mist-type thermal transfer recording liquid of the present invention, a compatibilizer, a surfactant, and a viscosity which can be used in a normal recording liquid, if necessary, for improving the solubility of a dye or improving the physical properties of the recording material itself. An additive component such as a regulator may be contained.

In the recording liquid of the present invention, a recording liquid flying section of a recording head such as a recording liquid heating section is formed of a porous structure, and the recording liquid is supplied to the recording liquid flying section, and the recording is performed by heating or the like. It is used in a mist-type thermal transfer recording system in which a liquid is converted into a mist and the mist is transferred to a recording medium arranged opposite to a recording head. In this recording method, in a printer head, a liquid recording material, for example, a recording liquid in which a dye is dissolved in a solvent, is guided to a mist-forming portion having a porous structure by capillary action, and is held there. Liquid recording material
A heating means such as a laser is used to selectively apply heat in accordance with the recording information, so that the recording material has a diameter of 10 μm.
Then, the recording material that has been converted into a mist has a thickness of 10 μm to 30 μm.
The image is recorded by transferring the image onto a photographic paper disposed opposite to the mist-forming portion via a gap of 0 μm. here,
By making the mist-forming part a porous structure, the surface area of the mist-forming part (heating part) is increased, whereby the liquid recording material can be constantly supplied to the mist-forming part by capillary action and held there. it can.

When recording is performed using the mist type transfer recording liquid of the present invention, the photographic paper used is plain paper such as PPC paper, high quality paper such as art paper, or the like. The transfer surface does not need to have great compatibility with the transfer dye, but has at least appropriate compatibility, can easily receive the transfer dye, promote the original color development of the dye, and fix the dye. A special paper made by applying an object can also be used. For example, paper having a surface coated with a polyester resin, a polyvinyl chloride resin, an acetate resin, or the like described in JP-A-10-226165 or the like can be used. When fixing the dye transferred to the photographic paper, the transferred image may be heated to diffuse the transfer dye on the surface into the dye receiving layer.

[0019]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. The recording liquid was a recording head shown in FIG. 1 (each side length and interval of the small column was 2 μm, and the height was 10 μm).
The recording was performed using a mist-type thermal transfer recording apparatus having the following formula (1) and evaluated.

Examples 1 to 5 and Comparative Examples Using 5 parts by weight of the dye compound shown in Table 1 (Table 1) and 95 parts by weight of a medium, the mixture was stirred and dissolved at 60 ° C. and cooled to room temperature to form a mist type. A recording liquid for thermal transfer recording was prepared. The dye compounds used were represented by the following formulas (1) to (6).
(Formulas 1 and 2). When each of the obtained recording liquids was introduced into the ink tank shown in FIG. 1, the recording liquid spontaneously introduced to the mist-forming part through the passage. Next, by applying a pulse voltage to the heater of the printer head, the recording liquid was thermally transferred to the printing paper. Solid printing was performed on plain paper, and the evaluation described in the following evaluation items and the evaluation of the recording liquid itself were performed. The results are shown in Table 2 (Table 2).

Evaluation items Recording density: The optical density of the solid recording portion was measured with a reflection type spectrophotometer (UV-3100PC manufactured by Shimadzu Corporation). Heat resistance: The recording liquid is placed in an autoclave at 200 ° C. for 1 hour.
The mixture was heated and stirred for 2 hours, and a composition change was confirmed. ：: No change in composition. X: Decomposition or composition change was observed. This is a practically problematic level. -Burning: After the transfer, the transfer head was washed, and the presence or absence of burn was checked with a microscope. ：: There was no scorch at all. Δ: Slight scorching was observed. This is a level with no practical problems. X: A large amount of scorching was observed. This is a practically problematic level. -Color transfer: Another plain paper was placed on the solid recording portion that had been sufficiently dried, pressed at 100 ° C for 5 minutes, and the presence or absence of coloring was visually checked. ：: No color transfer occurred. X: Color transfer was observed. This is a practically problematic level. Light resistance: After recording samples were stored in a fade meter (60 ° C., 25 hours), the recording density was measured, and the density retention rate was determined.

[0022]

[Table 1] The recording liquid compositions were all dye: medium = 5: 95 (weight ratio).

[0023]

Embedded image

[0024]

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[0025]

[Table 2]

[0026]

The mist type thermal transfer recording liquid of the present invention has a high heat resistance because the dye compound used as a recording material has a molecular weight of 500 or more and has a high sublimation temperature or is non-sublimable. In addition, in the process of transcription, it is possible to perform transcription while suppressing the generation of kogation in the mist-forming portion.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a recording apparatus using a recording liquid of the present invention.

[Explanation of symbols]

 1: recording head 2: recording medium 3: support 4: receiving layer 5: porous structure 6: protective plate 7: base 8: heating source 9: recording liquid 10: mist 11: spacer 12: heater 13: passage 14: Ink tank

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Matsu ▲ saki ▼ ▲ Let ▼ Akira 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Chemicals Co., Ltd. (72) Ryu Ooi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa F term in Mitsui Chemicals Co., Ltd. (reference) 2C057 AF99 AH20 BF06 2H086 AA13 AA31 AA33 AA36 AA49 BA51 BA60 2H111 AA11 AA32 4J039 BC03 BC17 BC20 BC28 BC39 BC56 BC60 BE02 BE12 CA04 DA02 EA37 FA02 GA06

Claims (3)

[Claims] 1. A recording apparatus in which a porous structure is formed in a recording liquid flying portion of a recording head, a recording liquid is supplied to the recording liquid flying portion, and the recording liquid is mist-formed. A recording liquid containing a recording material used in a recording method for transferring to a recording medium and a medium capable of dissolving the recording material, wherein the recording material contains a dye compound having a molecular weight of 500 or more. Mist type thermal transfer recording liquid. 2. The recording liquid according to claim 1, wherein the dye compound has a molecular weight of 800 or more. 3. A medium for dissolving a dye compound, and
The recording liquid according to claim 1, wherein the recording liquid is a medium having a melting point of 150 ° C. or less and a boiling point in a range of 150 to 350 ° C. 4.