JP2000263953A - Recording liquid for mist type thermal transfer recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording liquid for a mist type thermal transfer recording containing a specified coloring matter wherein there are no scorch and clogging on a head, a high heat-resistance and a high light-resistance are provided, and by which a printed image of a clear cyan color can be obtained. SOLUTION: By using a recording device wherein a porous structure is formed in a recording liquid flying section of the recording head, a recording liquid containing a coloring matter and a solvent to dissolve the coloring matter, is fed to the recording liquid flying section, and atomized, and transferred to a body to be recorded which is arranged in a manner to be confronted with the recording head, for a mist type thermal transfer recording method, and in such a recording method, at least a coloring matter represented by the formula is contained. In the formula, R1, R2 each independently represent an alkyl group which may be substituted, a cycloalkyl group which may be substituted, or an aryl group which may be substituted.

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.

[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 methods such as a sublimation recording method, an ink jet method, an electrophotographic method, and a heat-developable silver salt method have been proposed. Among these recording methods, high-quality images can be easily obtained with a simple apparatus. The sublimation recording method and the ink jet method are often used as a method of outputting the image data to the printer.

In the sublimation recording system, a transfer sheet is prepared by applying an ink-sublimation dye to a thin condenser paper or PET film having a thickness of several microns, and the transfer sheet is superimposed on the recording sheet and selectively heated by a thermal head. This is one of the thermal transfer printing methods for transferring to recording paper, and is currently used as a means for image recording (hard copy) various image information. In order to obtain higher image quality, it is desirable that the dye is dissolved in the coating solution and dispersed in a single molecule when the transfer sheet is prepared. The sublimation recording method has a large characteristic not found in other printing methods in that the amount of dye to be sublimated 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 image is formed directly on a recording paper by jetting an aqueous or oil-soluble ink from a fine nozzle. Ink jet printers include a bubble method in which ink is ejected by bubbles generated by rapidly heating 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 basically difficult, and it is difficult to reproduce a high-quality image comparable to a silver halide photograph obtained by the sublimation transfer system in a short time.

[0005] New recording methods have been proposed to solve the problems of these recording methods. JP-A-8-169171
As described in JP-A-8-216500, a recording liquid containing a sublimable dye is heated by laser or electricity or the like to form an image on recording paper as a mist of 1 μm or less, A mist-type thermal transfer recording system that does not use a transfer sheet has been proposed.

In this mist-type transfer recording method, 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 recording medium that dissolves the recording material and that expands volume by heating, for example, is supplied to the recording liquid flying section, and the state of the recording liquid is heated, for example. This is a recording method in which a mist is generated by changing the mist and the mist is transferred to a recording medium arranged opposite to a recording head. According to this recording method, by providing the above-mentioned porous structure in the recording liquid flying section, the surface area increases, and the recording liquid is constantly supplied to the recording liquid flying section 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 corresponding to the recording information, a part of the recording liquid is evaporated or the like, and a pressure rise is caused. The recording material corresponding to the produced electric image is transferred into a minute mist on the recording medium.

[0007] In this case, the porous structure has micropores of a size much smaller than that of a conventional ink jet type nozzle having a pore size of several tens of μm, so that a large number of extremely small mist is formed. And the number of mist generation can be freely controlled according to the applied energy such as heating energy corresponding to the recording information to the recording liquid flying section, so that the density gradation can be achieved and the silver halide image can be obtained. It is possible to obtain a recording having an image quality equal to or higher than that of the recording.

As dyes used for mist type thermal transfer recording, for example, JP-A-9-39421,
JP-A-193809 describes a 1,4-substituted aminoanthraquinone compound. However, these compounds have not yet sufficiently solved the problem of the occurrence of so-called kogation, in which, when transfer is repeated, scorch (decomposition products of dyes) accumulates in the transfer portion, and the ejection holes are clogged. As a result, the flying state of the recording material fluctuates, and the recording performance tends to deteriorate. Further, there is a problem that the color tone deviates from the original cyan color, a clear cyan image cannot be obtained, and the image obtained after transfer has faded.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mist type thermal transfer recording liquid having high solubility, high heat resistance and high light resistance, which is suitable for a mist type thermal transfer recording system which has solved the above-mentioned problems. Is provided.

[0010]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a certain kind of anthraquinone compound can be an excellent recording dye material, and have completed the present invention. 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, and supplies a recording liquid containing a dye and a solvent that dissolves the dye to the recording liquid flying section. A mist-type thermal transfer recording method for forming a mist and transferring the recording medium to a recording medium disposed opposite to the recording head, wherein at least one kind of a dye represented by the following general formula (1) or (2) is contained. And a mist type thermal transfer recording liquid, wherein at least one of R ₁ and R _{2 in} the general formula (1) is an alkyl group which may be substituted. It relates to a recording liquid for use.

[0011]

Embedded image (Wherein, R ₁ and R ₂ each independently represent an optionally substituted alkyl group, an optionally substituted cycloalkyl group, or an optionally substituted aryl group)

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The mist type recording liquid for thermal transfer recording of the present invention is characterized by containing at least one kind of dye represented by the general formula (1). R ₁ and R ₂ in the general formula (1) each independently represent an optionally substituted alkyl group, an optionally substituted cycloalkyl group, or an optionally substituted aryl group.

As the optionally substituted alkyl group,
Although not particularly limited, for example, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, ter
t-butyl group, n-pentyl group, n-hexyl group, n-
Heptyl group, n-octyl group, 2-ethylhexyl group,
Alkyl groups such as 1,3-dimethylbutyl group, 1,1,3,3-trimethylbutyl group, chloroethyl group, chloropropyl group, bromoethyl group, trifluoromethyl group, heptafluoroisopropyl group, 2-chloroethyl group, etc. Halogenoalkyl group, methoxymethyl group, ethoxymethyl group, ethoxyethyl group, methoxyethyl group, methoxy-n
-Propyl group, n-propoxyethyl group, iso-propoxyethyl group, n-butoxyethyl group, iso-butoxyethyl group, tert-butoxyethyl group, n-pentyloxyethyl group, n-hexyloxyethyl group, γ
An alkoxyalkyl group such as -methoxybutyl group, a methoxyethoxyethyl group, an ethoxyethoxyethyl group, an alkoxyalkoxyalkyl group such as a propoxyethoxyethyl group, a hydroxyethyl group, a hydroxypropyl group,
Hydroxyalkyl group such as hydroxybutyl group, hydroxyethoxyethyl group, polyetheralkyl group such as 2-hydroxyethoxyethoxyethyl group, etc., methoxycarbonylmethyl group, ethoxycarbonylmethyl group, propoxycarbonylmethyl group, methoxycarbonylethyl group, ethoxy And alkoxycarbonylalkyl groups such as carbonylethyl group and propoxycarbonylethyl group.

The cycloalkyl group which may be substituted is not particularly restricted but includes, for example, cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group, 4-ethylcyclohexyl, And an alkylcycloalkyl group such as a 6,6-dimethylcyclohexyl group.

As the optionally substituted aryl group,
Although not particularly limited, for example, a phenyl group,
It is a phenyl group having various substituents. Examples of the phenyl substituent include a halogen atom, an optionally substituted alkyl group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an alkoxy group such as a pentyloxy group and a hexyloxy group, a methoxycarbonyl group, and an ethoxycarbonyl group. , Propoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, alkoxycarbonyl group such as hexyloxycarbonyl group, methoxymethoxycarbonyl group, ethoxymethoxycarbonyl group, methoxyethoxycarbonyl group, ethoxyethoxycarbonyl group, propoxyethoxycarbonyl group, butoxy Alkoxyalkoxycarbonyl group such as ethoxycarbonyl group, methoxyethoxyethoxycarbonyl group, ethoxyethoxyethoxycarbonyl group, propoxyethoxyethoxy Rubynyl group, alkoxyalkoxyalkoxycarbonyl group such as butoxyethoxyethoxycarbonyl group, hydroxyethoxycarbonyl group, hydroxypropoxycarbonyl group, hydroxyalkoxycarbonyl group such as hydroxybutoxycarbonyl group, hydroxyethoxyethoxycarbonyl group, hydroxypropoxypropoxycarbonyl group etc. Hydroxyalkoxyalkoxycarbonyl, methylaminocarbonyl, dimethylaminocarbonyl, ethylaminocarbonyl, diethylaminocarbonyl, propylaminocarbonyl, dipropylaminocarbonyl, butylaminocarbonyl, dibutylaminocarbonyl, pentylaminocarbonyl , Dipentylaminocarbonyl group, hexylaminocarbonyl group Alkylaminocarbonyl group such as dihexylaminocarbonyl group, methylcarbonylamino group, ethylcarbonylamino group, propylcarbonylamino group, butylcarbonylamino group, pentylcarbonylamino group, hexylcarbonylamino group, heptylcarbonylamino group, octylcarbonylamino group Alkylcarbonylamino group, phenylcarbonylamino group, methylphenylcarbonylamino group, ethylphenylcarbonylamino group, chlorophenylcarbonylamino group, bromophenylcarbonylamino group, fluorophenylcarbonylamino group, trifluoromethylphenylcarbonylamino group, etc. Arylcarbonylamino group, methylaminosulfonyl group, dimethylaminosulfonyl group, ethylaminosulfonyl group, Ethylaminosulfonyl group, propylaminosulfonyl group, dipropylaminosulfonyl group, butylaminosulfonyl group,
Examples thereof include an alkylaminosulfonyl group such as a dibutylaminosulfonyl group, a pentylaminosulfonyl group, a dipentylaminosulfonyl group, a hexylaminosulfonyl group, and a dihexylaminosulfonyl group.

In the dye represented by the general formula (1) used in the recording liquid for mist type thermal transfer recording of the present invention, a preferable dye is an alkyl in which at least one of R ₁ and R ₂ may be substituted. Is the dye that is the group. Specific examples of the cyan dye represented by the general formula (1) are shown in Table 1 (Table 1), but the present invention is not limited to these dyes.

[0017]

[Table 1]

The dye represented by the general formula (1) used in the recording liquid of the present invention is produced by a conventional method, for example, by Yutaka Hosoda, "Theoretical Production Dye Chemistry", July 15, 1968, Gihodo Co., Ltd. Published on pages 674-675, 693-694,
It is produced according to the method described in JP-A-63-193887. Specifically, in a solvent, a starting material, leuco-1,4,5,8-tetrahydroxyanthraquinone, and an amine or aniline having a substituent R ₁ or R ₂ are combined with zinc, iron, or mineral acid. , Boric acid, hydrosulfite and the like at 30 to 150 ° C. The amount of the amine or aniline in which the amino group is substituted with R ₁ or R ₂ is 1 to 5 with respect to the starting material.
A 0 molar ratio is appropriate.

Examples of the solvent include amines, anilines, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone,
Examples include polar solvents such as N, N-dimethyl-2-imidazolidinone and sulfolane, aromatic solvents such as dichlorobenzene, trichlorobenzene, chloronaphthalene, nitrobenzene and quinoline, alcohols, cellolobs, and glycols. Can be The amount of the solvent to be used is 1 to 100 times, preferably 5 to 20 times the weight of the starting material.

The dye represented by the general formula (1) can be obtained by discharging the reaction solution to a poor solvent after the completion of the reaction, and filtering the precipitate. Further, a compound of higher purity can be obtained by further purifying the solvent sludge with a poor solvent, recrystallization, or column chromatography.

The recording liquid for mist type thermal transfer recording of the present invention comprises:
It comprises at least one dye represented by the general formula (1) and a solvent that dissolves the dye. Further, the recording liquid of the present invention may contain additives such as a compatibilizer, a surfactant, and a viscosity adjuster, if necessary, for improving the solubility of the solvent or improving the physical properties of the recording material itself. You may. In the recording liquid of the present invention, the dye represented by the general formula (1)
You may use individually or in mixture of 2 or more types. Further, as long as the effects of the present invention are not impaired, a plurality of dyes having a structure other than the dye represented by the general formula (1) may be mixed and used for color tone adjustment.

The content of the dye represented by the general formula (1) in the recording liquid of the present invention is 0.1 to 50% by weight, preferably 1 to 50% by weight.
３０30% by weight. If the content is too low, the transfer concentration becomes insufficient, and if it is too high, problems such as insufficient dissolution in a solvent are caused. The recording liquid for mist-type thermal transfer recording of the present invention, in addition to the above-described dyes and solvents, if necessary, various additives usually added to the recording liquid, while appropriately heating, a magnetic stirrer or the like. It can be manufactured by using and uniformly mixing.

In the recording liquid of the present invention, the solvent used is a solvent which dissolves the dye represented by the general formula (1) or the dye mixture containing the dye represented by the general formula (1). Is 150 ° C or less, and the boiling point at 1 atm is 150 to 3
Substances at 50 ° C. are preferred. If the boiling point of the medium is lower than 150 ° C., the medium evaporates quickly in the recording liquid flying portion of the recording head and disappears, and the non-volatile components in the recording liquid tend 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 solvent even when heating or the like for recording is performed. Preferably, the solvent alone or as a mixture with another third component is 20%.
It shows a fluid state at 0 ° C. or lower and has necessary and sufficient heat resistance.

The preferred solvent is not particularly restricted but includes, for example, dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-phthalyl phthalate. (2-ethylhexyl), diisodecyl phthalate, diisononyl phthalate, benzyl butyl phthalate, dioctyl terephthalate, trihexyl trimellitate, 1,2-propanediol dibenzoate, diethylene glycol dibenzoate, butyl phthalyl butyl glycolate, etc. Group esters, butyl oleate, dibutyl sebacate, di-n-octyl sebacate, di-sebacate (2-
Ethylhexyl), dibutyl adipate, di-n-hexyl adipate, di-n-octyl adipate, di (2-ethylhexyl) adipate, di (2-ethyl azelate)
Ethyl hexyl), aliphatic esters such as triethylene glycol-2-ethyl butyrate, butyl acetyl ricinoleate, and tributyl acetyl citrate; tributyl phosphate; tri (2-ethylhexyl) phosphate; tricresyl phosphate; Phosphorus compounds such as phenyl, 1
N-methyl-2-pyrrolidone, aromatic hydrocarbons such as phenylnaphthalene, toluene and ethylnaphthalene;
N, N-dimethyl-2-imidazolidinone, N, N-diethyl-2-imidazolidinone, N, N-dipropyl-
Examples include nitrogen-containing organic solvents such as 2-imidazolidinone and N, N-dibutyl-2-imidazolidinone.

If the content of the solvent in the recording liquid is too small, the dye cannot be sufficiently dissolved, and 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 recording liquid containing the dye of the present invention, the recording liquid flying section of the recording head such as the recording liquid heating section is formed of a porous structure, and the recording liquid is supplied to the recording liquid flying section. The mist is used in a mist-type thermal transfer recording system in which a recording liquid is converted into a mist by means of, for example, the 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 section having a porous structure by capillary action, and is held there. The heating amount such as a laser is used to selectively apply heat to the liquid recording material held at a diameter of 10 μm.
The recording is performed by generating a mist of the recording material of m or less, and then transferring the mist-converted recording material to a photographic paper facing the mist-forming portion through a gap of 10 μm to 300 μm.

Here, the surface area of the mist-forming portion (heating portion) is increased by making the mist-forming portion a porous structure, whereby the liquid recording liquid is constantly supplied to the mist-forming portion by capillary action, and Can be held there. The photographic paper used in this recording method is PPC
Examples include plain paper such as paper and high quality paper such as art paper. The transfer surface does not need to have great compatibility with the transfer dye,
A special paper prepared by applying a material which has at least appropriate compatibility, easily receives a transfer dye, promotes the original coloration of the dye, and can fix the dye can also be used. For example, as described in Japanese Patent Application Laid-Open No. 10-226165, there is paper having a polyester resin, polyvinyl chloride resin, acetate resin or the like coated on the surface.
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.

[0028]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. Regarding the recording liquid containing the dye of the present invention,
Recording was performed using a mist-type transfer recording apparatus having a recording head (each side of a small column having a side length and spacing of 2 μm and a height of 10 μm) shown in FIG. 1 and evaluated.

Example 1 Cyan dye Nos. 1 (Chemical Formula 3) 10 parts were added to 90 parts of dibutyl phthalate, and stirred at 60 ° C.
It was dissolved and cooled to room temperature to prepare a mist type recording liquid for thermal transfer recording. When the obtained recording liquid was introduced into the ink tank (14) shown in FIG. 1, the recording liquid passed through the passage (13) and was naturally introduced into the mist forming part. Next, by applying a pulse voltage to the heater (12) of the print head, the recording liquid was thermally transferred to photographic paper to obtain a printed image. The characteristics of the following items were evaluated for the obtained printed images. As a result, (A) recording density 1.54, (B)
Burning: 、, (C) Color transfer (heat resistance): 、, (D) Light resistance: ○, no practical problem.

[0030]

Embedded image

Evaluation items (A) Recording density: The optical density of the solid recording portion was measured with a reflection type spectrophotometer (UV-3100PC manufactured by Shimadzu Corporation). (B) Burning: After the transfer, the transfer head was washed, and the presence or absence of burning was confirmed with a microscope. ：: No scorch at all △: Slight scorch is recognized but no problem in practical use ×: A large amount of scorch is recognized and poses a problem in practical use (C) Color transfer (heat resistance): solid recording sufficiently dried Another plain paper was overlapped on the part, and pressed at 100 ° C. for 5 minutes, and the presence or absence of coloring was visually confirmed. ：: No color transfer ×: Color transfer is observed, which is a problem in practical use. (D) Light fastness: The recorded sample is stored in a fade meter (60 ° C., 25 hours), and then the recording density is measured. The maintenance rate was calculated. ：: The density maintenance rate is 100 to 80% Δ: The density maintenance rate is 80 to 70% ×: The density maintenance rate is lower than 70%, which is a practical problem.

Examples 2 to 15 In Example 1, a recording solution having a dye concentration of 10% by weight was prepared using the dyes and solvents shown in Table 2 (Table 2). Using this recording liquid, a printed image was obtained in the same manner as in Example 1. The characteristics of the obtained printed image were evaluated in the same manner as in Example 1. The results are shown in Table 2. As a result, there was no practical problem in all cases. The dye numbers in the table represent the dye numbers in Table 1.

[0033]

[Table 2]

Comparative Example 1 The following dye described in JP-A-9-39421 (Chemical Formula 4)
, A recording liquid was prepared and evaluated in the same manner as in Example 1. As a result, (A) recording density 1.40, (B) scorching: Δ, (C) color transfer (heat resistance): ×, (D) light resistance:
The result was x, indicating extremely poor characteristics as compared with the recording liquid using the mist type dye for thermal transfer recording of the present invention, which was at a level causing a problem in practical use. Also, the color tone was shorter in wavelength than cyan and was reddish blue.

[0035]

Embedded image

[0036]

The mist type recording liquid for thermal transfer recording containing the specific dye represented by the general formula (1) of the present invention does not have scorching and clogging on the head, and has high heat resistance and high light resistance. Further, by using this recording liquid, a clear cyan print image can be obtained.

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

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 2H086 BA01 BA02 BA03 BA54 BA56 2H111 AA01 AA09 AA11 AA27 AA32 AB00 BA23 BA41 BA47 BA74 BA75 4J039 BC03 BC68 BC73 BC74 BC77 BE02 BE12 EA35 EA37 EA48 GA06

Claims (2)

[Claims] 1. A recording liquid containing a dye and a solvent for dissolving the dye is supplied to the recording liquid flying section by using a recording apparatus having a porous structure formed in the recording liquid flying section of a recording head. A mist-type thermal transfer recording method for forming a mist and transferring the recording medium to a recording medium arranged opposite to the recording head, wherein at least one kind of a dye represented by the following general formula (1) (Formula 1) is contained. Mist type recording liquid for thermal transfer recording. Embedded image (Wherein, R ₁ and R ₂ each independently represent an optionally substituted alkyl group, an optionally substituted cycloalkyl group, or an optionally substituted aryl group) _2. The recording liquid for mist type thermal transfer recording according to claim ₁ , wherein in the general formula (1), at least one of R ₁ and R ₂ is an alkyl group which may be substituted. .