JPH10181210A - Thermal transfer recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce kogation by enhancing heat resistance of dye through use of a specified dye. SOLUTION: A coloring matter having melting point 160 deg.C or below shown by a formula is added (where, a phenylene group A is a p-phenylene group which may have a substituent, R<1> and R<2> are a hydrogen atom, an alkyl group which may be substituted by a substituent selected from hydroxy group, cyano group, amino group, halogen atom, alkoxy group, alkoxyalkoxy group, aryloxy group, allyloxy group, aralkyloxy group, acyloxy group, alkoxycarbonyl group and heteroring group, alkenyly group, a cycloalkyl group or a substituted or unsubstituted phenyl group. The R<1> may form a hetero 5-member or 6-member ring in conjunction with the phenylene group A and a nitrogen atom adjacent thereto, or the R<2> may form a hetero 5-member or 6-member ring in conjunction with the phenylene group A and a nitrogen atom adjacent thereto).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a thermal transfer recording method (for example, a full-color image recording method in which a recording liquid is caused to fly from a recording section by selective heating according to image information and transferred to an opposing photographic paper). The present invention relates to a thermal transfer recording material, particularly a recording liquid comprising a magenta dye.

[0002]

2. Description of the Related Art In recent years, as colorization of video cameras, computer graphics, and the like has progressed, the need for colorization of hard copies has rapidly increased. On the other hand, a color hard copy system such as a sublimation thermal transfer system, a melt thermal transfer system, an ink jet system, an electrophotographic system, and a heat-developed silver salt system has been proposed. Among these recording methods, methods for easily outputting high-quality images with a simple apparatus can be broadly classified into a dye diffusion thermal transfer method (sublimation thermal transfer method) and an ink jet method.

Among these recording methods, according to the dye diffusion thermal transfer method, an ink ribbon or sheet in which an ink layer in which a high concentration of transfer dye is dispersed in an appropriate binder resin is applied, and the transferred dye is A transfer medium such as photographic paper coated with a dyeing resin that receives the ink is brought into close contact with a certain pressure, and heat is applied according to image information from a heat-sensitive recording head located on the ink sheet. The transfer dye is thermally transferred according to the amount of heat applied to the dye receiving layer.

The above operation is performed by subtracting the three primary colors of subtraction,
The so-called dye diffusion thermal transfer method is characterized by obtaining a full-color image having continuous gradation by repeating each of the image signals separated into yellow, magenta, and cyan. It is attracting attention as an excellent technology for obtaining high-quality images comparable to silver halide color photographs.

FIG. 5 is a schematic front view of a main part of such a thermal transfer type printer.

A thermal recording head (hereinafter referred to as a thermal head) 1 and a platen roller 3 are opposed to each other, and an ink sheet 12 having an ink layer 12a provided on a base film 12b and a paper 20b provided therebetween. The recording paper (transfer medium) 20 provided with the dyeing resin layer 20a is sandwiched, and these are pressed against the thermal head 1 by the rotating platen roller 3 and run.

[0007] Ink (transfer dye) in the ink layer 12a selectively heated by the thermal head 1
Is transferred to the dyeing resin layer 20a of the recording paper 20 in the form of dots, and thermal transfer recording is performed. In such thermal transfer recording, a serial system in which a thermal head is scanned in a direction perpendicular to the traveling direction of the recording paper 20, or a single thermal head is fixed and arranged perpendicular to the traveling direction of the recording paper. A line system is adopted.

[0008] However, this method is disadvantageous in that a large amount of waste is generated due to disposable ink sheets and high running cost is a major drawback, and its spread is hindered.
This is the same in the fusion heat transfer system.

As described above, the conventional thermal transfer system has high image quality, but the running cost is high due to the use of the dedicated photographic paper and the disposable ink ribbon or sheet.

Although the heat-developed silver salt method has high image quality, the running cost and the apparatus cost are also high because dedicated photographic paper and disposable ink ribbons or sheets are used.

On the other hand, the ink jet system is described in
As shown in -59911 and Japanese Patent Publication No. 5-217, etc., recording is performed by a method such as an electrostatic suction method, a continuous vibration generation method (piezo method), or a thermal method (bubble jet method) according to image information. The recording is performed by causing a small droplet of the liquid to fly from a nozzle provided in the recording head and to adhere to a recording member.

Therefore, there is almost no waste as in the case of using an ink sheet or the like, and the running cost is low. Recently, the thermal method has been widely used because it can easily output a color image.

However, in the ink-jet method, the density gradation in a pixel is difficult in principle, and a high-quality image comparable to a silver halide photograph, which can be obtained by a dye diffusion thermal transfer method, can be reproduced in a short time. It is difficult.

That is, in the conventional ink jet recording, since one droplet of ink forms one pixel, gradation in a pixel is difficult in principle, and a high quality image cannot be formed. Attempts have been made to express the pseudo gradation by the dither method using the high resolution of the ink jet, but the image quality equivalent to that of the sublimation type thermal transfer method cannot be obtained, and the transfer speed has been significantly reduced.

On the other hand, the electrophotographic method has a low running cost and a high transfer speed, but has a high apparatus cost.

As described above, image quality, running cost,
There is no recording method that satisfies all requirements such as apparatus cost and transfer time.

Recently, a new recording method which solves these problems has been proposed (EP94101201.
5). That is, the recording liquid is guided to a transfer portion having a porous structure by a capillary phenomenon, and is heated by a suitable heating means such as a laser beam to vaporize the recording liquid or generate a mist having a diameter of 1 μm or less. This is a non-contact type dye-flight-type thermal transfer recording system in which the image is transferred onto photographic papers which are arranged to face each other via a gap of about 300 μm.

In such a thermal transfer recording system, the surface area of the heating section (transfer section) is increased by the above-mentioned porous structure, and the recording liquid is constantly supplied to the recording liquid heating section by capillary action and held there. In this state, a portion of the recording liquid is evaporated by selectively applying a heat amount according to the recording information by a heating means (for example, a laser beam) in this state, thereby corresponding to an electric image created by a color video camera or the like. The recording material in an amount corresponding to the recorded information thus obtained can be transferred to a recording medium by converting it into fine vapor or droplets and transferred onto the recording medium.

Therefore, a large number of droplets having a smaller size can be formed as compared with the known ink jet system, and the number of droplets generated can be freely controlled according to the heating energy corresponding to the information recorded in the recording liquid heating section. Therefore, multi-value density gradation becomes possible, and it is possible to obtain a recording (for example, a full-color image) having image quality equal to or higher than that of a silver halide image.

Further, since the recording is performed by the thermal transfer method, the recording medium has features such as miniaturization, easy maintenance, quickness, high quality of image, and high gradation as described above.

However, it has been found that this thermal transfer recording system has the above-mentioned excellent features and also has a problem to be improved.

That is, if the transfer is repeated by this method, burns (decomposition products of the dye, etc.) accumulate in the transfer portion, and so-called kogation, in which the ejection holes are clogged, occurs. As a result, the flying state of the recording material fluctuates, and the recording performance tends to deteriorate.

[0023]

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display having excellent resolution and pixel resolution by simultaneously utilizing the advantages of both the above-described thermal transfer system and the ink-jet system while simultaneously solving the drawbacks, particularly the problem of kogation. It is an object of the present invention to provide a thermal transfer recording material that can realize an inner gradation and maintain recording performance for a long time.

[0024]

The present inventors have found that kogation as described above is prevented from occurring due to insufficient heat resistance of a dye used as a recording material, and by using a specific dye, The present inventors have found that the heat resistance of the film is sufficient, kogation can be greatly reduced, and the life of the head can be prolonged.

That is, according to the present invention, the transfer portion having a porous structure is guided by a capillary phenomenon, changes its state such as vaporization or droplet formation by heating, and shifts to a transfer object facing the transfer portion. The present invention relates to a thermal transfer recording material comprising a dye (magenta dye) represented by the following general formula [I] and having a melting point of 160 ° C. or less. Here, “contained” means not only the case where the above-mentioned dye occupies a part but also the case where the above-mentioned dye occupies substantially 100% (the same applies to other parts of this specification). General formula [I]:

Embedded image (However, in the general formula [I], the phenylene group A is a p-phenylene group which may have a substituent, and R ¹ and R ²
Are each selected from a hydrogen atom, a hydroxy group, a cyano group, an amino group, a halogen atom, an alkoxy group, an alkoxyalkoxy group, an allyloxy group, an aryloxy group, an aralkyloxy group, an acyloxy group, an alkoxycarbonyl group, and a hetero ring as a substituent. An alkyl group, an alkenyl group, a cycloalkyl group, or a substituted or unsubstituted phenyl group which may be substituted with a group. R ¹
May further form a 5- or 6-membered heterocyclic ring with phenylene group A and a nitrogen atom adjacent to phenylene group A, or may form a heterocyclic ring with R ² and a nitrogen atom adjacent to phenylene group A. To form a 5-membered heterocyclic ring or a 6-membered heterocyclic ring. )

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION In the recording material of the present invention, the substituent represented by the p-phenylene group represented by the phenylene group A in the dye represented by the general formula [I] is preferably C1 to C4. Is a C1-C2 linear or branched alkyl group, C1-C4, preferably C1
To C2 linear or branched alkoxy groups, fluorine atoms, halogen atoms such as chlorine atoms and bromine atoms, carbon atoms of 1
To 4, preferably a fluoroalkyl group having 1 to 2 carbon atoms (e.g., trifluoromethyl group) and the like, and the substitution position thereof is not particularly limited, and the number of substituents is also possible in the range of 1 to 4. is there. Particularly preferred substituents include a methyl group.

Examples of the alkyl group represented by R ¹ and R ² include C1 to C12, preferably C1 to C8, linear or branched alkyl groups. -Hydroxyethyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-hydroxypropyl group and the like having 1 to 12 carbon atoms, preferably 1 carbon atom
To 8 hydroxy-substituted alkyl groups; 1 to 12 carbon atoms such as 2-cyanoethyl groups, preferably 1 to 8 cyano substituted alkyl groups; 1 to 12 carbon atoms such as 2-amino substituted alkyl groups, preferably carbon atoms An amino-substituted alkyl group of the formulas 1 to 8; 2-chloroethyl group, 3-chloropropyl group, 2
A halogen-substituted alkyl group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms such as a chloropropyl group and a 2,2,2-trifluoroethyl group; a 2-methoxyethyl group,
Ethoxyethyl group, 2- (n) propoxyethyl group, 2
-(Iso) propoxyethyl group, 2- (n) butoxyethyl group, 2- (iso) butoxyethyl group, 2- (2-ethylhexyloxy) ethyl group, 3-methoxypropyl group,
2-methoxypropyl group, 4-methoxybutyl group, 3-
An alkoxy-substituted alkyl group having 2 to 14 carbon atoms, preferably 2 to 10 carbon atoms, such as a methoxybutyl group and a 2,3-dimethoxypropyl group; a 2- (2-methoxyethoxy) ethyl group, a 2- (2-ethoxyethoxy) ) Ethyl group, 2-
(2- (n) propoxyethoxy) ethyl group, 2- (2
-(N) butoxyethoxy) ethyl group, 2- {2- (2
-Alkoxyalkoxy-substituted alkyl groups having 3 to 16 carbon atoms, preferably 3 to 12 carbon atoms, such as -ethylhexyloxy) ethoxydiethyl group; and 4 to 12, preferably 4 to carbon atoms, such as 2-allyloxyethyl groups. An aryloxy group-substituted alkyl group having 8 to 8 carbon atoms such as an aryloxy group-substituted alkyl group having 7 to 16 carbon atoms such as a 2-phenoxyethyl group, or a C8 to 16 carbon atom such as a 2-benzyloxyethyl group; An aralkyloxy group-substituted alkyl group having 8 to 12 carbon atoms; a 3 to 16 carbon atom such as a 2-acetyloxyethyl group, a 2-propionyloxyethyl group, or a 2-trifluoroacetyloxyethyl group; To 12 acyloxy group-substituted alkyl groups; 2-methoxycarbonylethyl group, 2-ethoxycarbonylethyl group, etc. Carbon atoms 3-16, preferably alkoxycarbonyl group-substituted alkyl group having 3 to 12 carbon atoms;
5 carbon atoms such as furfuryl group and tetrahydrofurfuryl group
To 12, preferably a heterocyclic-substituted alkyl group containing oxygen, nitrogen, sulfur or the like as a heteroatom having 5 to 8 carbon atoms.

Examples of the unsubstituted alkyl group include a linear or branched alkyl group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms. Examples of the alkenyl group include a linear or branched alkenyl group having at least one double bond and having 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms.

As the substituted phenyl group represented by R ¹ and R ² , C ^{1 to} C ⁸ , preferably C 1 to C
4 having a linear or branched alkyl group, C1 to C4 having a linear or branched alkoxy group, a fluorine atom, a chlorine atom, a halogen atom such as a bromine atom, Those having a fluoroalkyl group having 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms (for example, a trifluoromethyl group) are exemplified.

Examples of the cycloalkyl group represented by R ¹ and R ² include a cycloalkyl group having 5 to 7 carbon atoms such as a cyclopentyl group and a cyclohexyl group.

Particularly advantageous for R ¹ and R ² are:
A C1-C8 linear or branched unsubstituted alkyl group; a C2-8 linear or branched unsubstituted alkenyl group; or a C1-C4 linear or branched alkoxy group And a C1-C4 linear or branched alkyl group substituted with a heterocyclic group such as a group, a phenyl group, a phenoxy group, an allyloxy group, or a tetrahydrofurfuryl group.

The dye having a heterocyclic ring formed by R ^{1 in combination} with a phenylene group A and a nitrogen atom adjacent to the phenylene group A is represented by the following general formula [II] or [III]: Good. General formula [II]:

Embedded image (However, in the general formula [II], the phenylene groups A and R ² are the same as those defined in the general formula [I], and R ³ and R ⁴
Is a hydrogen atom or C1-8, preferably C1-4
Is an alkyl group. General formula [III]:

Embedded image (However, in the general formula [III], the phenylene groups A and R ² are the same as those defined in the general formula [I], and R ⁵ , R ⁶ and R ⁷ are preferably a hydrogen atom or a carbon number of 1 to 8, preferably Is an alkyl group having 1 to 4 carbon atoms.)

A heterocyclic ring formed by R ¹ together with R ² and a nitrogen atom adjacent to the phenylene group A is

Embedded image (However, R ⁸ has 1 to ⁸ carbon atoms, preferably 1 to 4 carbon atoms.
Is an alkyl group. ).

Specific examples of the magenta dye represented by the general formula [I] used in the present invention include those shown in the following Tables 1A, 1B, 1C, 1D, 1E, 1F and 1G. It is listed.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

[Table 5]

[0040]

[Table 6]

[0041]

[Table 7]

Specifically, the thermal transfer recording material of the present invention comprises
This is a liquid recording material which is vaporized by heating or generates mist having a diameter of 1 μm or less, and is transferred onto an oppositely disposed transfer member via a gap of 10 μm to 300 μm. By non-contact transfer through such a gap,
As described above, it has high image quality and immediacy, can be compact and lightweight, can be transferred to plain paper without generating waste, and has low power consumption and low running cost. Can be implemented. Further, the porous structure described above,
It has a function of holding and supplying the recording material by its capillary action, and particularly preferably has a side or diameter of 0.2 to 3 μm and a height of 1 to 15 μm.

In this case, a fine columnar body having a side or diameter of 0.5 to 3 μm and a height of 1 to 15 μm is formed by 0.5
A porous structure may be formed by arranging three or more rows and three or more columns at intervals of 〜3 μm.

Such a porous structure (for example, a concavo-convex structure composed of a large number of columns) has the following three remarkable effects.

That is, the first effect is that the recording liquid can be spontaneously supplied to the recording portion by capillary action due to the large surface area formed by the above-mentioned uneven structure.

The second effect is that the surface tension of the liquid generally decreases as the temperature increases, so that when the recording liquid is heated, the surface tension at the center of heating of the recording liquid is lower than the surface tension at the outer peripheral portion thereof, and the central portion of the recording liquid is heated. Although an outward force is applied to the recording liquid, the movement of the recording liquid to the outer peripheral portion can be suppressed and a decrease in transfer sensitivity can be prevented because of the above-mentioned uneven structure in the heating section.

A third effect is that a large number of concave portions in the above-mentioned concave and convex structure of the recording portion each serve as a discharge portion of a fine recording liquid, so that a very small number corresponding to the amount of heat applied to the recording portion. The droplets of the recording liquid are ejected, fly in the space, and are adsorbed on the opposing recording medium such as photographic paper. By utilizing this principle, it is possible to achieve gradation in a pixel, which was impossible with a normal ink jet system.

That is, by providing the above-mentioned porous structure (concavo-convex structure) in the heating section, the surface area thereof is increased, and the recording liquid can be constantly supplied to the recording liquid heating section by capillary action and held there. In this state, a heating means (for example, a laser beam) is used to selectively apply an amount of heat in accordance with the recorded information, thereby evaporating a part of the recording liquid to cause an increase in pressure, which is produced by a color video camera or the like. The amount of the recording material corresponding to the recording information corresponding to the electrical image is converted into minute liquid droplets, transferred to the recording medium, and transferred onto the recording medium.

In this case, a large number of droplets having a small size can be formed as compared with the known ink jet system, and the number of droplets generated can be freely adjusted according to the heating energy corresponding to the information recorded in the recording liquid heating section. Since the control can be performed, a multi-value density gradation becomes possible, and a recording (for example, a full-color image) having an image quality equal to or higher than that of a silver halide image can be obtained.

Therefore, using a head having a special structure capable of thermally transferring very fine recording droplets on demand, at least 128 gradations or more in one pixel per color. An ink jet system capable of expressing can be realized.

In order to form such a porous structure, for example, a porous alumina having an average pore diameter of 0.1 to 2 μm is added to a porous alumina of 1 to 2 μm.
A method of laminating to a thickness of 0 μm, preferably 1 to 15 μm,
Glass beads having an average particle size of 0.5 to 3 μm
Thick lamination method, average diameter 0.5 ~ 2μm and height 2 ~
It can also be manufactured by a method of growing a large number of 10 μm silicon whiskers on a substrate at intervals of 1 to 3 μm.

However, in order to precisely control the transfer amount, in particular, a semiconductor processing technique such as RIE (reactive ion etching) or powder beam etching is used to make the size of one side or diameter 0.5 to 3 μm. Height 1-15μ
A structure in which fine columns made of glass or silicon having a size in the range of m are regularly arranged in three or more rows and three or more columns at intervals of 0.5 to 3 μm is preferable.

Further, a porous structure having a heat resistance of 300 ° C. or more is formed, and the generated droplets are supplied to
It is desirable to fly the recording medium facing the recording medium with a gap of 300 μm.

Although such a porous structure has the above-mentioned excellent action, its small size makes it possible to deteriorate the recording material due to heating of the recording material during recording (particularly, repetitive recording), such as decomposition products. Tends to adhere to the porous structure, causing clogging and impairing its action.

However, the dye of the above general formula [I] used in the recording material of the present invention has a sufficient heat resistance to heating and hardly causes kogation due to decomposition products. Even at times, the action of the porous structure can be maintained and effectively exerted.

This is ensured by the fact that the melting point of the dye of the above general formula [I] is as low as 160 ° C. or less (preferably 150 ° C. or less) and hardly hardens.
Further, the melting point of the dye of the general formula [I] is preferably higher than 115 ° C. The melting point can be controlled by selecting R ¹ and R ² described above.

When the recording material of the present invention is used for ink-jet recording, 90% by weight or more of the above-mentioned magenta dye is vaporized when heated to 300 ° C. or more and the residue is 10% by weight or less. At 50 ° C.
A recording containing a solvent having a boiling point of 150 ° C. or higher (a non-aqueous solvent excluding water) which is dissolved or dispersed in an amount of 3% by weight or more, especially 5% by weight or more, particularly 10% by weight or more and usually about 50% by weight or less. It is good to use liquid.

The solvent used in the recording liquid is one that sufficiently dissolves or disperses the above-mentioned dye, and at the same time, its boiling point is preferably 150 ° C. or higher. This is because the above-mentioned porous structure has a large surface area, and unless the boiling point is higher than 150 ° C., the solvent evaporates or volatilizes and the recording portion dries, and the recording liquid concentration fluctuates, and the recording performance changes. Is to deteriorate.

In particular, the solvent has a melting point of 50 ° C. or less, a boiling point in the range of 150 ° C. to 400 ° C., and is preferably colorless. When the melting point exceeds 50 ° C., the melting point of the dye is generally 100 ° C. or higher. Therefore, the recording liquid prepared by mixing the dye and the solvent solidifies in a range from room temperature, which is the non-transferred recording portion temperature, to 50 ° C. Easier to do. If the boiling point is lower than 150 ° C., the recording portion is exposed to the atmosphere, so that only the solvent tends to volatilize from the recording liquid.
When the boiling point is 400 ° C. or higher, the efficiency of vaporization is low, and the transfer sensitivity is likely to decrease.

The solvent preferably has a molecular weight of 450 or less. If the molecular weight is too high, the expansion rate during vaporization is low, and the transfer sensitivity tends to decrease. Further, a solvent having a residual ratio of 0.01% by weight or less when heated to 200 ° C. in air is preferable.

It is preferable that the solvent has the property of being spontaneously absorbed by fibers such as PPC paper (plain paper) and art paper from the viewpoint of transfer to plain paper.

The solvent is 3% by weight of the above dye at 50 ° C. or less.
In order to dissolve 5% by weight or more, especially 10% by weight or more, the solubility parameter of the solvent at 25 ° C. (J.
H. (Defined by Hildebrand) of 7.
It is preferably in the range of 5 to 10.5. Furthermore, the flash point is 150 ° C or higher, and the toxicity to the human body is low,
It is preferably colorless. Solubility parameter is 10.
If it exceeds 5, the solubility of the dye becomes low, and water vapor in the air is adsorbed, so that the reproducibility of the transfer sensitivity is liable to deteriorate. When the solubility parameter is less than 7.5, the solubility of the dye tends to be low.

Specifically, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate,
Examples include aromatic esters including dialkyl phthalates such as dioctyl phthalate. Further, the alkyl chain has 2 to 30 carbon atoms, preferably 4 to 18 carbon atoms.
It is desirable to use aromatic hydrocarbons such as n-alkylbenzene, n-alkylnaphthalene, n-dialkylbenzene and n-dialkylnaphthalene as solvents for the recording liquid in the present invention. The above "alkyl"
Examples thereof include an ethyl group, an isopropyl group, and a dodecyl group. In the case of n-alkylbenzene, it has 10 carbon atoms.
Up to 15 alkyl groups are good, including dodecylbenzene.

The dyes used in the conventional ink-jet system generally include many acidic dyes, which are hydrophilic and flow on the recording paper when they adhere to the recording paper.
It is poor in water resistance, hardly develops color, and easily generates kogation due to self-decomposition due to heat during recording. On the other hand, since the above-mentioned magenta dye does not cause such a phenomenon, it adheres well to recording paper to form a color more than enough, and kogation hardly occurs.

In addition, when a dialkyl phthalate is used in combination with the magenta dye, the solvent has good permeability into the recording paper, and the dye can be sufficiently adhered. It also acts as a color development aid for coloring the dye. Therefore, when this recording liquid is used, transfer to PPC paper is possible, and a high-quality image can be formed. Further, the dye concentration of the recording liquid was conventionally at most 5% by weight, but in the recording liquid comprising the above combination, the solvent amount can be set in a wide range of 50 to 98% by weight, and the dye concentration is 10% by weight. Above
Image density can be improved.

The transfer head using the recording material of the present invention is
The recording unit may include a recording unit provided with a heating unit, an ink tank for storing the recording liquid, and a recording liquid passage connecting the recording unit and the ink tank. The entire transfer head can be heated to 50 ° C. in order to adjust the viscosity of the recording liquid. In order to shorten the transfer time, two or more recording sections can be provided on one recording head. The recording liquid consumed in the recording unit can be continuously supplied to the recording unit through the recording liquid passage.

The heating means is a heating element such as a resistance heater,
A laser whose output changes in accordance with recording information, a combination of a laser and a laser light absorber (photothermal converter) provided in a recording unit, or the like can be used. When a semiconductor laser is used as a laser, a small and lightweight head can be configured with high controllability. The resistance heater is manufactured by directly attaching a conductive substance such as polysilicon on the recording unit.

The photographic paper which can be used for the transfer of the recording material of the present invention is plain paper such as PPC paper, high-quality paper such as art paper, etc. In order to obtain a high quality image having particularly high gradation and density. In the, as a resin that develops the dye, polyester,
Special paper made by applying polycarbonate, acetate, epoxy resin, polyvinyl chloride, etc. on a base paper can also be used. In order to improve the storage stability of the obtained image, it is effective to laminate a resin film on the photographic paper after transfer.

In order to achieve multicolor recording (especially full color) using the recording material of the present invention, a recording liquid containing a dye exhibiting one of the three primary colors of subtractive color mixing, A recording liquid containing at least one dye exhibiting three subtractive primary colors is selectively heated, and for example, this operation is repeated for each of image signals decomposed into yellow, magenta, and cyan to obtain a full-color image. Can be achieved.

[0070]

Embodiments of the present invention will be described below.

FIGS. 1 to 4 show a non-contact type thermal printer (for example, a video printer: the same applies hereinafter) according to the present invention.
1 shows an example applied to the present invention.

In the recording method of this embodiment, the head 70 having the structure shown in FIG. 1 is used for heating by laser light. (Light-to-heat converter) is preferably provided. And
A recording liquid 62 comprising a heat-fusible magenta dye of the above general formula (I) (in some cases, this dye and a carrier: solvent) is accommodated, and a certain minute gap 51 is provided between the recording liquid 62 and the opposing photographic paper 80. ing.

Then, the liquefied dye (recording liquid) 62 on the recording portion is selectively heated by a suitable heating means such as a laser L to form fine droplets, and the gap 51 is moved by flying, so that the recording medium 80 , An image having a continuous gradation is obtained. This operation is performed by subtracting the three primary colors of yellow, magenta,
By repeating each of the image signals separated into cyan, full colorization can be achieved.

Here, the space 51 is 10 to 300 μm.
m, particularly preferably 50 to 200 μm. If the gap is less than 10 μm, the head is likely to come into contact with the photographic paper during the movement of the head, and the stability of image transfer is likely to be reduced. If the gap 51 exceeds 300 μm, the recording droplets do not efficiently reach the photographic paper, and the transfer sensitivity and the resolution of the image tend to decrease.

In this recording method, the printing paper 80 is opposed to the recording head 70, for example, on the upper side, and the laser light L emitted from the laser 18 and condensed by the lens 19 is emitted near the upper surface of the vaporizing section 57. It is preferable that the recording liquid 82 be caused to fly or move upward by irradiation.

A dye reservoir 55 is provided on a head base 54 having a laser beam transmitting property, and a liquefied dye (recording liquid) 62 is accommodated between a head 58 and a spacer 58 fixed on the head base 54. And is continuously supplied to the vaporization section 57. In this case, in order to improve the supply efficiency and the vaporization efficiency of the dye to the vaporization section 57, the fine irregularities composed of a large number of small pillars 61 for supplying and holding the dye using the capillary phenomenon are formed by RIE or lithography technology. And is provided in the vaporizing section 57.

These small pillars 61 have a heat resistance of 300 ° C. or higher, and a height of 1 to 15 μm (preferably 2 to 15 μm).
〜１０10 μm), diameter or length t of one side is 0.2 to 3 μm
(Preferably 0.5 to 3 μm), and the distance d between the columns is 0.
It has a structure in which a large number of cylinders or prisms each having a size of 2 to 3 μm (preferably 0.5 to 3 μm) are arranged, particularly a structure in which three or more rows and three or more columns are regularly arranged (see FIGS. 2 and 3).

This pillar structure has a large surface area.
The recording liquid is spontaneously introduced into the heating section (transfer section or vaporizing section) by capillary action, and even if the center of the transfer section is locally heated during transfer, the recording liquid is not heated due to the temperature dependency of surface tension. It works to prevent the phenomenon of moving to (escape phenomenon).

In this case, if the height of the column 61 is less than 1 μm, it is difficult to prevent the escape phenomenon at the time of transfer, and
If it exceeds m, it is difficult to efficiently heat the recording liquid because the amount of the recording liquid is too large. The diameter of the column 61 or the length of one side is 0.2 μm
If it is less than 3, the column is likely to be damaged by the wave of the fluid generated by heating for recording, and if it exceeds 3 μm, the volume that can be occupied by the recording liquid is small, and the transfer sensitivity tends to be lowered. When the distance between the columns 61 is less than 0.2 μm, the volume that can be occupied by the recording liquid is small, and the transfer sensitivity is likely to decrease.
If it exceeds 3 μm, it is difficult to prevent the escape phenomenon during transfer.

As shown in FIG. 3, the planar shape of the small column 61 may be various shapes such as a square, and the aggregate has a planar pattern of 2 to 2 in the vertical and horizontal directions, respectively. The matrix can be selected within a range of 100 rows and 2 to 100 columns.

The spacer 5 is used to hold the gap 51 and guide the photographic paper 80 moving in the X direction.
A protective plate 59 is fixed on 8. A heater 56 for maintaining the above liquefied state may be buried in the protective plate 59 as shown by a virtual line. Here, the heater 56 is fixed to the outer surface of the base 54 of the dye container. Alternatively, it can be disposed in the passage 67 and the dye reservoir 55 described above.

In the recording head used in this embodiment, the base 54 is mainly made of a heat-resistant inorganic material such as glass, metal, silicon, or ceramic, or has a heat resistance of 300 ° C. or more such as polyimide or aramid. It is composed of an organic polymer provided. By providing an appropriate heat retaining device for this head, it is possible to use a recording liquid having a melting point of room temperature or higher.

The supply passage 67 between the transfer section 57 and the ink tank 55 for replenishing the recording liquid is 50 μm ^2.
When the recording liquid 62 has the above sectional area and the viscosity of the recording liquid 62 is 150
If the temperature is 10 ° C. or lower at 10 ° C. or lower, the recording liquid 62
Can be supplied to the transfer portion, and the sensitivity does not decrease during the transfer.

As the coloring material in the recording liquid 62, the above-described dye of the general formula [I] according to the present invention is used, and within the range of the general formula [I], two or more kinds of the dyes are used in combination. You may.

Then, a part of the recording liquid is evaporated by heating, and the color material in an amount corresponding to the image information is converted into minute liquid droplets, moved in the gap 51, and transferred onto the recording paper 80. In the case of the ink jet system, volume expansion is increased by 50 times or more by vaporization, and the dye or pigment is dissolved or dispersed. The melting point is 50 ° C. or less, and the boiling point at 1 atm is 150 ° C.
It is preferable to add a solvent (carrier) of the above (desirably, 250 to 400 ° C.), particularly a dialkyl phthalate.

A recording medium suitable for transferring the recording material of this embodiment may be a photographic paper 80 having a dye receiving layer 80a, which has an appropriate compatibility with the transfer dye and easily receives the transfer dye. Any photographic paper can be used as long as it promotes the original color development of the dye and fixes the dye.

The transfer-type heating means according to the present invention can be roughly divided into a method using a thermal head, a method using a laser beam, and a material that has absorption including a laser beam and a wavelength region of the laser beam and converts light energy into heat energy ( Light-to-heat converter).

When a laser beam is used, the resolution is remarkably improved, and intensive heating is possible by increasing the laser beam density by an optical system, so that the ultimate temperature is raised, and as a result, the thermal efficiency is improved. There is a feature.

In particular, by using a semiconductor multi-laser (a laser having a structure in which several to several hundreds of semiconductor laser elements are arranged on a line), the time for transferring one screen is greatly reduced. However, the light-to-heat converter (indicated by a dashed-dotted line 60 in FIG. 1) must have sufficient heat resistance in order to continuously absorb the light energy of the laser light.

Therefore, as the photothermal converter 60 of this type, a metal thin film having an absorption corresponding to the emission wavelength of the laser,
A thin-film light absorber such as a two-layer film of a metal thin film and a ceramic thin film having a high dielectric constant is directly provided on the transfer portion as shown in FIG. 1, and a fine particle light absorber such as carbon black or metal fine particles is transferred. It may be used by uniformly dispersing it in a dye.

The entire printer head including the above-described heads, for example, is provided with cyan, magenta, and yellow dye reservoirs on a common base 54 for full color use to constitute respective storage units or supply head units 70C, 70M, and 70Y.
The liquid for each color is supplied to each vaporizer in a row forming a large number of 12 to 24 dots.

Each laser beam emitted from a multi-laser array 30 in which, for example, 24 corresponding lasers (especially semiconductor laser chips) 18 are arranged in an array is provided with a plurality of condenser lenses 19 for each vaporizing section. The light is condensed by the microlens array 31 thus obtained.

In the case of mono-color printing, only one supply head is provided and a corresponding one-dimensional laser array is manufactured.

The above-described printer head 70 is provided with the same number of liquids 62 as the number corresponding to the number of recording dots in the dye container.
Are housed in the form of dots, and the lasers 18 are also arranged in an array having light emitting points of the number of recording dots.

The printer having the above-described printer head 70 is, for example, of a serial type, which is vertically (X
Direction) and horizontal scanning (Y direction) of the head in a direction orthogonal to the X direction, and printing is performed. These vertical paper feeding and horizontal head scanning are performed alternately. Is configured.

As shown in FIG. 4, in this printer 91, for example, the printer head 70 for multicolor printing is moved in the paper feed direction of the photographic paper 80 by a head feed shaft 92 and a head support shaft 93 formed by a feed screw mechanism. It is reciprocally movable in a head feed direction Y orthogonal to X.

On the upper side of the head 70, photographic paper 80
A head receiving roller 94 that supports so as to sandwich it is rotatably provided. The printing paper 80 is sandwiched between the paper feed drive roller 95 and the driven roller 96 and moves in the paper feed direction X.

The head 70 is connected to a head drive circuit board (not shown) and the like via a flexible harness 97.

In the recording method of this embodiment, a group of small pillars 61 having a porous structure is provided in the vaporizing portion, and a non-contact type dye vaporizing printer is used. While taking advantage of both, reduce waste and transfer energy, reduce the size and weight of the printer, achieve excellent resolution and dot gradation, and
Recording performance can be maintained for a long time without kogation.

Next, the recording results (Examples 1 to 11) according to the above-described embodiment will be described together with Comparative Examples.

Example 1 The above-described No. 1 in Table 1A was applied to the transfer head (transfer portion size 50 μm, small column diameter 2 μm) shown in FIG. One dye (melting point 69-70 ° C) was introduced by heating the entire head to 100 ° C. Then, the transfer head is attached to the printer shown in FIG. 4 (however, only one head portion is used for monocolor),
Sublimation thermal transfer paper (VPM30STA,
(Manufactured by Sony Corporation). In this case, the distance between the printing paper and the transfer head was 50 μm.

Next, a semiconductor laser beam of 850 nm is condensed to a transfer head portion to a size of 6 × 10 μm by an optical system,
The transfer section was irradiated with a laser pulse of 1 ms ON and 1 ms OFF at mW, and the printing paper was simultaneously scanned to print a line. As a result, a line having a width of about 80 μm and a magenta OD of about 0.4 (measured with a Macbeth reflection densitometer) was drawn on the printing paper.

After the irradiation of 1 million pulses, the transfer head was taken out and washed to remove the residual dye. When the transfer portion was observed with a microscope, no scorching or sticking was observed at all.

Example 2 As a dye, No. 1 in Table 1A described above was used. 4 (melting point 88-8
The same test as in Example 1 was carried out except using (9 ° C.), and there was no generation of burn after irradiation of 1 million pulses.

Example 3 As the dye, No. 1 in Table 1A described above was used. 9 (melting point 109-
110 ° C.) and the same test as in Example 1 was carried out except that the heating temperature of the head was set to 120 ° C., and no scorching was generated after irradiation of 1 million pulses.

Example 4 As the dye, No. 1 in Table 1C described above was used. 31 (melting point 112
To 113 ° C.), and the same test as in Example 1 was performed except that the heating temperature of the head was set to 120 ° C.
There was no generation of burn after irradiation of every pulse.

Example 5 No. 1 in Table 1A described above. A solution prepared by dissolving the dye No. 1 in dibutyl phthalate (concentration: 15% by weight) was introduced as a recording liquid into a transfer head at room temperature, and thereafter the test was performed in exactly the same manner as in Example 1.

As a result, a line having a width of 80 μm and an OD of about 0.1 was drawn. Further, there was no generation of scorch after irradiation of 1 million pulses.

Example 6 As a dye, No. 1 in Table 1C described above was used. 35 (mp 155
156 ° C.) in dibutyl phthalate (concentration: 4% by weight) as a recording liquid, and introduced into the head at room temperature.
Thereafter, the same experiment as in Example 1 was performed.
There was no generation of scorch after the irradiation of 100,000 pulses.

Example 7 As a dye, No. 1 in Table 1D described above was used. 40 (melting point 128
129 ° C.), and the same experiment as in Example 1 was performed except that the heating temperature of the head was 130 ° C.
There was no generation of burn after irradiation of every pulse.

Example 8 As a dye, No. 1 in Table 1D described above was used. 41 (melting point 127
The same experiment as in Example 1 was performed except that the heating temperature of the head was 130 ° C.
There was no generation of burn after irradiation of every pulse.

Example 9 As a dye, Table 1D No. Using 36 dyes (melting point 140-141 ° C), the head heating temperature was set to 150
The same experiment as in Example 1 was conducted except that the temperature was changed to ° C.
There was no burning after irradiation of 1 million pulses.

Example 10 As a dye, Table 1C No. Using 34 dyes (melting point: 133 to 134 ° C.), the heating temperature of the head was set to 140
The same experiment as in Example 1 was conducted except that the temperature was changed to ° C.
There was no burning after irradiation of 1 million pulses.

Example 11 The dyes described in Table 1F No. Using 60 dyes (melting point: 145 to 146 ° C.), the heating temperature of the head was set to 150
The same experiment as in Example 1 was conducted except that the temperature was changed to ° C.
There was no burning after irradiation of 1 million pulses.

Comparative Example 1 The same test as in Example 1 was carried out except that a dye having the following structure (melting point: 164 ° C.) was used and the heating temperature of the head was 170 ° C.

Embedded image

As a result, when the number of laser pulses exceeded 100,000 pulses, the amount of transfer decreased, and the color density of the printed line began to decrease. Transfer became impossible with 200,000 pulses. The head was taken out, washed, and observed with a microscope. As a result, a scorched lump was formed on the head of the small column group.

Comparative Example 2 Using the same dye as in Comparative Example 1, an attempt was made to prepare a 3% by weight solution with respect to dibutyl phthalate, but the dye was not completely dissolved.

Although the embodiment of the present invention has been described above, the above-described embodiment can be further modified based on the technical idea of the present invention.

For example, for recording dyes, magenta,
Three colors, yellow and cyan (plus black)
In addition to full-color recording, two-color printing, one-color monocolor or black-and-white recording can be performed.

Further, each of the above-mentioned solvents and dyes can be used variously or in combination of two or more.

Further, the porous structure to be formed in the transfer section (heating section or vaporizing section) is not limited to the above-mentioned one. For example, in the case of a column, the height, plane or cross-sectional shape, density, etc. are changed. It may be applied to any part where fine patterning or porosity formation or enlargement of surface area is required. The porous structure may be formed of a bead aggregate, a fibrous body, or the like in addition to the columnar body or the wall-like body.

As energy for forming a recording material such as a dye into droplets, a heating beam other than laser light may be used, or another heating method such as resistance heating may be used.
For this purpose, a conductive substance can be added to the recording material. In addition, an appropriate heating method can be adopted in order to obtain density gradation.

Also, the number of recording material storage sections and the number of dots for storing the recording material (dye) and the number of laser array beams (the number of light emitting points) corresponding thereto may be variously changed.
The arrangement shape and size are not limited to those described above.

Although the head and the printer used in the present invention use a laser or a heating element for heating the dye, they may be combined. in this case,
Even if the power of each heating means is lowered, good vaporization can be realized.

The structure and shape of the head and the printer are as follows.
Any other appropriate structure and shape may be used, and other appropriate materials may be used for the material of each part constituting the head.

In addition to recording the solid dye once in a liquid state and forming it into droplets, a liquefied dye (liquid at room temperature) can be stored in the dye reservoir. Further, unlike the above-described printer, a laser beam may be irradiated from above the head to perform recording on a recording sheet positioned below the head.

[0127]

According to the recording material of the present invention, since the recording material is composed of the dye represented by the general formula [I], the recording material has sufficient heat resistance to heating, and hardly causes kogation due to decomposition products. . For this reason, the function of the porous structure can be maintained even during repeated recording, and can be effectively exerted.

In this case, a large number of small-sized droplets can be formed by the porous structure, and the number of generated droplets can be freely controlled in accordance with the heating energy corresponding to the information recorded in the recording liquid heating section. Therefore, multi-value density gradation becomes possible, and it is possible to obtain a recording (for example, a full-color image) having image quality equal to or higher than that of a silver halide image. In addition, since the recording is performed by the thermal transfer method, the recording medium has features such as miniaturization, easy maintenance, quickness, high-quality image, and high gradation as described above.

[Brief description of the drawings]

FIG. 1 is a sectional view of a printer head used in an embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the printer head.

FIG. 3 is a plan pattern diagram of a small column group provided in a transfer section (vaporization section) of the printer head.

FIG. 4 is a schematic perspective view of the printer as viewed from below.

FIG. 5 is a front view of a main part of a recording apparatus using a conventional thermal recording head.

[Explanation of symbols]

 18 ・ ・ ・ Laser (semiconductor laser) 30 ・ ・ ・ Multi laser array 31 ・ ・ ・ Micro lens array 51 ・ ・ ・ Void 53 ・ ・ ・ Vaporization hole 54 ・ ・ ・ Base 56 ・ ・ ・ Heater 57 ・ ・ ・ Vaporization section 58 ・ ・ Spacer 59 ・ ・ ・ Protective plate 61 ・ ・ ・ Small column 62 ・ ・ ・ Recording liquid (liquefied dye) 67 ・ ・ ・ Dye passage 70 ・ ・ ・ Printer head 80 ・ ・ ・ Print paper 80a ・ ・ ・ Dye Receiving layer 82: recording droplet L: laser beam

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09B 57/00 C07D 209/08 // C07D 209/08 B41M 5/26 101K 101Z (72) Inventor Yuyoshi Murata Aoba, Yokohama-shi, Kanagawa Prefecture 1000 Kamo-shida-ku, Yokohama Mitsubishi Research Institute, Yokohama Research Institute (72) Inventor Miori Ishida 1000 Kamo-shida-cho, Aoba-ku, Yokohama-shi, Kanagawa Pref.

Claims (12)

[Claims] 1. A thermal transfer recording material which is guided by a capillary phenomenon to a transfer portion having a porous structure, changes its state by heating, and is transferred to a transfer object facing the transfer portion, wherein the heat transfer recording material has the following general formula [ I] and has a melting point of 16
A thermal transfer recording material containing a dye of 0 ° C. or lower. General formula [I]: (However, in the general formula [I], the phenylene group A is a p-phenylene group which may have a substituent, and R ¹ and R ²
Are each selected from a hydrogen atom, a hydroxy group, a cyano group, an amino group, a halogen atom, an alkoxy group, an alkoxyalkoxy group, an allyloxy group, an aryloxy group, an aralkyloxy group, an acyloxy group, an alkoxycarbonyl group, and a hetero ring as a substituent. An alkyl group, an alkenyl group, a cycloalkyl group, or a substituted or unsubstituted phenyl group which may be substituted with a group. R ¹
May further form a 5- or 6-membered heterocyclic ring with phenylene group A and a nitrogen atom adjacent to phenylene group A, or may form a heterocyclic ring with R ² and a nitrogen atom adjacent to phenylene group A. To form a 5-membered heterocyclic ring or a 6-membered heterocyclic ring. ) 2. A phenylene group A is a linear or branched alkyl group having 1 to 4 carbon atoms, a linear or branched alkoxy group having 1 to 4 carbon atoms, a halogen atom, or a carbon atom having 1 to 4 carbon atoms. The thermal transfer recording material according to claim 1, which has a substituent consisting of 1 to 4 fluoroalkyl groups. 3. R ¹ and R ^{2 each} have a straight or branched chain having 1 to 12 carbon atoms and have a substituent such as a hydroxy group, a cyano group, an amino group, a halogen atom, an alkoxy group, an alkoxyalkoxy group, an allyloxy group. Group, an aryloxy group, an aralkyloxy group, an acyloxy group, an alkyl group which may be substituted with a group selected from an alkoxycarbonyl group and a heterocyclic ring, a linear or branched alkenyl group having 2 to 12 carbon atoms, A cycloalkyl group having 5 or 6 carbon atoms, or a linear or branched alkyl group having 1 to 8 carbon atoms, a linear or branched alkoxy group having 1 to 8 carbon atoms, a halogen atom or a carbon number 1-4
The thermal transfer recording material according to claim 1, which is a phenyl group having a fluoroalkyl group as a substituent. 4. R ¹ and R ^{2 each} represent a linear or branched unsubstituted alkyl group having 1 to 8 carbon atoms, and 2 to 8 carbon atoms.
A linear or branched alkenyl group, or a linear or branched alkoxy group having 1 to 4 carbon atoms, 1 to 4 carbon atoms substituted with a phenoxy group or an allyloxy group.
The thermal transfer recording material according to claim 1, which is a linear or branched alkyl group or an alkyl group substituted with a heterocyclic group. 5. A dye having a heterocyclic ring formed by R ¹ together with a phenylene group A and a nitrogen atom adjacent to the phenylene group A is represented by the following general formula [II] or [III]. The thermal transfer recording material according to claim 1. General formula [II]: (However, in the general formula [II], the phenylene groups A and R ² are the same as those defined in the general formula [I], and R ³ and R ⁴
Is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. ) General formula [III]: (However, in the general formula [III], the phenylene groups A and R ² are the same as those defined in the general formula [I], and R ⁵ , R ⁶ and R ⁷ are a hydrogen atom or an alkyl having 1 to 8 carbon atoms. Group.) 6. A heterocyclic ring formed by R ¹ together with R ² and a nitrogen atom adjacent to the phenylene group A is represented by the following formula: The thermal transfer recording material according to claim 1, wherein 7. A gas which is vaporized by heating or has a diameter of 1
2. The thermal transfer recording material according to claim 1, wherein the thermal transfer recording material is a liquid recording material that generates a mist of not more than [mu] m and is transferred onto an object to be transferred that is opposed to the transfer member with a gap of 10 [mu] m to 300 [mu] m. 8. The thermal transfer recording material according to claim 1, wherein the porous structure of the transfer portion has a side or a diameter of 0.2 to 3 μm and a height of 1 to 15 μm. 9. A side or a diameter of 0.5 to 3 μm,
0.5 to 3 μm fine columnar bodies with a height of 1 to 15 μm
9. The thermal transfer recording material according to claim 8, wherein a porous structure is formed by arranging three or more rows and three or more columns at intervals of m. 10. The polymer has a molecular weight of 450 or less, a melting point of 50 ° C. or less, a boiling point of 150 ° C. to 400 ° C., is colorless, and has a residual content of 0.04% when heated to 200 ° C. in air.
The dye represented by the general formula [I] is dissolved in a solvent of 1% by weight or less at 3 ° C or less at 50 ° C or less.
Thermal transfer recording material described in 1. 11. The thermal transfer recording material according to claim 10, wherein the solvent is an aromatic ester and / or an aromatic hydrocarbon. 12. The thermal transfer recording material according to claim 11, wherein the aromatic ester is a dialkyl phthalate.