JPH10193809A - Thermal transfer recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce clogging markedly and lengthen the life of a head by containing specified pigments in a thermal transfer recording material that is guided to a transfer section having a porous structure by a capillary phenomenon, vaporized by heating, and moved to an object of transfer facing the transfer section. SOLUTION: A printer head as a transfer section having a porous structure, contacts a photographic paper 12 as an object of transfer at one end 2a of a base and is held at a prescribed angle with the photographic paper 12. And then a thermal transfer recording material containing pigments expressed by the formula is guided by a capillary phenomenon to the printer head, vaporized or turned into droplets by heating, and moved to the photographic paper 12 facing the printer head. However, in the formula, R represents a substituted or nonsubstituted alkyl group whose carbon number is 2, an alkenyl group or a cycloalkyl group, A a benzene ring having a substituent or not.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a thermal transfer recording method,
For example, the present invention relates to a thermal transfer recording material used in a full-color image recording method of causing a recording liquid to fly from a recording section by selective heating according to image information and transferring the recording liquid to an opposing photographic paper, particularly to a recording liquid containing a cyan 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 the image information from a thermal recording head located on the ink sheet, and the ink sheet is 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. 6 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) 31 and a platen roller 33 face each other,
Between these, the ink layer 32 is formed on the base film 32b.
a and a recording paper (transfer medium) 30 provided with a dyeing resin layer 30a on a paper 30b, which are pressed against the thermal head 31 by a rotating platen roller 33. To run.

The ink (transfer dye) in the ink layer 32a selectively heated by the thermal head 31 is used.
Is transferred to the dyed resin layer 30a of the transfer object 30 in the form of dots, and thermal transfer recording is performed. In such thermal transfer recording, a serial system in which a thermal head scans in a direction perpendicular to the traveling direction of the recording paper 30 or a single thermal head fixed in a direction perpendicular to the traveling direction of the recording paper is arranged. A line system is adopted.

However, this method is disadvantageous in that a large amount of waste is generated due to disposable use of the ink sheet 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 method has high image quality, but the running cost is high because the dedicated photographic paper and the disposable ink ribbon or sheet are used. Although the heat-developed silver salt method has high image quality, the running cost is high and the apparatus cost is high because the dedicated photographic paper and the disposable ink ribbon or sheet are used.

On the other hand, the ink jet system is described in
As described in JP-A-59911 and JP-B-5-217, 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 the pixel is difficult in principle, such as that obtained by the dye diffusion thermal transfer method.
It is difficult to reproduce a high-quality image comparable to a silver halide photograph in a short time.

That is, in the conventional ink jet, since one droplet of ink forms one pixel, in-pixel gradation 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 system cannot be obtained, and the transfer speed has been remarkably 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, there is no recording method that satisfies all requirements such as image quality, running cost, apparatus cost, and transfer time. Recently, a new recording method that solves these problems has been proposed (Japanese Patent Laid-Open No. 7-89107). That is, the recording liquid is guided to a transfer portion having a porous structure by a capillary phenomenon, and is heated by an appropriate 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-flying thermal transfer recording system in which image data is transferred onto photographic papers that are arranged opposite to each other with a gap of 10 to 300 μm.

In such a thermal transfer recording system, the surface area of the heating section (transfer section) increases due to 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 corresponding to the recording information by a heating means (for example, a laser beam) in this state, and an electric image created by a color video camera or the like is formed. A recording material in an amount corresponding to the corresponding recording information is converted into fine vapors or droplets, transferred to a non-recording medium, and transferred onto the recording medium.

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

Further, since it is a thermal transfer recording system, it has the above-mentioned features such as miniaturization, easy maintenance, quickness, high quality of image, high gradation, and the like. 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, when the transfer is repeated by this method, charred (decomposed products of the dye and the like) accumulate in the transfer portion, and the so-called kogation, which causes the ejection holes to be clogged, occurs. As a result, the flying state of the recording material fluctuates, and the recording performance tends to deteriorate.

[0015]

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.

[0016]

Means for Solving the Problems The present inventors have found that kogation as described above occurs due to insufficient heat resistance of a dye used as a recording material, and by using a specific dye, The inventors have found that the heat resistance of the dye 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 an object to be transferred facing the transfer portion. A thermal transfer recording material to be used, comprising a dye (cyan dye) represented by the following general formula (I):
The present invention relates to a thermal transfer recording material containing: 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):

[0018]

Embedded image

(In the formula, R is a substituted or unsubstituted alkyl group, alkenyl group or cycloalkyl group having 2 or more carbon atoms, and A is a benzene ring which may have a substituent.) R has 2 to 13 carbon atoms in the recording material of
Is a linear or branched, substituted or unsubstituted alkyl or alkenyl group. (The carbon number means the carbon number of the alkyl or alkenyl moiety.)

In this case, the substituted alkyl group is 2-
Hydroxyethyl group, 2-hydroxypropyl group, 3-
Hydroxy-substituted alkyl groups such as hydroxypropyl group and 4-hydroxybutyl group; phenyl-substituted alkyl groups such as benzyl group, p-chlorobenzyl group and 2-phenylethyl group; 2-methoxyethyl group, 2-ethoxyethyl group;
2- (n) propoxyethyl group, 2- (iso) propoxyethyl group, 2- (2-ethylhexyloxy) ethyl group, 3-methoxypropyl group, 2-methoxypropyl group, 4-methoxybutyl group, 3-methoxy Butyl group,
Alkoxy-substituted alkyl groups such as 2,3-dimethoxypropyl group and 2,2-dimethoxyethyl group; 2- (2-methoxyethoxy) ethyl group, 2- (2-ethoxyethoxy) ethyl group, 2- (2- ( n) Propoxyethoxy)
Alkoxyalkoxy-substituted alkyl groups such as ethyl group, 2- (2- (n) butoxyethoxy) ethyl group and 2- {2- (2-ethylhexyloxy) ethoxy} ethyl group; aralkyloxy groups such as 2-benzyloxyethyl group Alkyl group; acyloxy-substituted alkyl such as 2-acetyloxyethyl group, 2-propionyloxyethyl group and 2-trifluoroacetyloxyethyl group; alkoxycarbonyl-substituted alkyl such as 2-methoxycarbonylethyl group and 2-ethoxycarbonylethyl group A heterocyclic-substituted alkyl group such as a furfuryl group and a tetrahydrofurfuryl group; an alkenyloxy-substituted alkyl group such as a 2-allyloxyethyl group; a 2-phenoxyethyl group;
And aryloxy-substituted alkyl groups such as -chlorophenoxy) ethyl group.

Examples of the unsubstituted alkyl group include a linear or branched alkyl group having 2 to 19 carbon atoms, preferably 2 to 13 carbon atoms. Examples of the alkenyl group include those having the same carbon number as the above-mentioned alkyl group and having at least one double bond. When R is a cycloalkyl group, examples thereof include a cyclopentyl group and a cyclohexyl group.

When R is a cycloalkyl group, examples thereof include a cyclopentyl group and a cyclohexyl group. Particularly preferred as R is a linear or branched alkyl or alkenyl group C ₂ -C _8; linear or branched alkoxy group of C ₁ -C _4, a phenyl group,
C ₂ -C substituted with a phenoxy group, an allyloxy group, etc.
_4, a linear or branched alkyl group; an alkyl group substituted with a tetrahydrofuryl group; a cyclohexyl group.

The substituent on the benzene ring A is C ₁
Linear or branched alkyl group ~C _8; C ₁ ~
C ₈ linear or branched alkoxy group; phenoxy group; alkoxyalkyl group such as methoxyethyl group, butoxyethyl group and 3-methoxypropyl group; halogen such as fluorine atom, chlorine atom, bromine atom and iodine atom atom;
Examples thereof include an alkylamino group such as a dimethylamino group and a diethylamino group; and an alkyl group substituted with a fluorine atom such as a trifluoromethyl group.

Particularly preferred as the benzene ring A are
Linear or branched alkyl group of C ₁ ~C _4, C
Examples thereof include a linear or branched alkoxy group having ₁ to ₄ carbon atoms, a fluorine atom, a chlorine atom, and a trifluoromethyl group. Unsubstituted benzene rings are also preferred. The number of the substituents may be in the range of 1 to 3 and may be the same or arbitrary. Specific examples of the cyan dye represented by the general formula (I) are shown in Table 1, but the present invention is not limited to the dyes in Table 1.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5]

[0030]

[Table 6]

The thermal transfer recording material of the present invention is, specifically,
This is a liquid recording material which is vaporized by heating or generates a mist having a diameter of 1 μm or less, and is transferred onto an oppositely disposed transfer member via a gap of 10 to 300 μm. By the non-contact transfer through such a gap, as described above, high image quality and immediacy can be obtained, and the device can be reduced in size and size.
It can be reduced in weight, can be transferred to plain paper without generating waste, and can perform color recording with low power consumption and low running cost.

The above-mentioned porous structure has a function of holding and supplying a recording material by its capillary action. In particular, it has a side or diameter of 0.2 to 3 μm and a height of 1 to 15 μm. Good to be. In this case, a porous structure is formed by arranging three or more rows and three or more rows of fine columnar bodies having a side or diameter of 0.2 to 3 μm and a height of 1 to 15 μm at intervals of 0.3 to 3 μm. May be done.

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 the capillary phenomenon 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 periphery thereof, and the recording liquid at the center part is reduced. However, since the heating portion has the above-described uneven structure, the movement of the recording liquid to the outer peripheral portion can be suppressed, and a decrease in transfer sensitivity can be prevented.

A third effect is that a large number of concave portions in the concave-convex structure of the recording portion each act as a fine discharge portion, so that the number of very fine recording liquids corresponding to the amount of heat applied to the recording portion is reduced. Droplets are ejected, fly into the space, and are adsorbed on the opposing recording medium such as photographic paper. Using this principle,
The in-pixel gradation that was impossible with the ordinary ink-jet method was enabled.

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 heat in accordance with the recording information, thereby evaporating a part of the recording liquid to cause an increase in pressure, and an electric power generated by a color video camera or the like. The recording material in an amount corresponding to the recording information corresponding to the typical image is converted into fine 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 control can be performed, multi-value density gradation can be achieved, and recording (for example, a full-color image) having 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 small recording droplets on demand, at least 128 or more density gradations within one pixel per color. An ink jet system capable of expressing can be realized. To form such a porous structure, for example, a method of laminating porous alumina having an average particle size of 0.1 to 2 μm to a thickness of 5 to 20 μm, an average particle size of 0.5 to
A method of laminating 3 μm glass beads to a thickness of 5 to 20 μm, a method of growing a large number of silicon whiskers having an average diameter of 0.5 to 2 μm and a height of 2 to 10 μm on a substrate at an interval of 1 to 3 μm, and the like. Can be manufactured.

However, in order to precisely control the transfer amount, a semiconductor processing technique such as a reactive ion etching (RIE) method or a powder beam etching method is used. 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 heat resistance of 300 ° C. or more is formed, and the generated droplets are supplied to
It is preferable to fly the recording medium opposed to the recording medium with a gap of 300 μm. Such a porous structure has the above-mentioned excellent function. However, since its size is very small, deterioration caused by heating of the recording material during recording (particularly, repetitive recording), for example, decomposition It tends to adhere to the structure and cause clogging and impair 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 when the function of the porous structure is maintained,
It can be used effectively. The recording material of the present invention,
300 ° C. when used for inkjet recording
When heated above, 90% by weight or more is vaporized and the residue is 10% by weight or less, and the above-mentioned cyan dye is dissolved at 50 ° C or less and 5% by weight or more at a boiling point of 150 ° C. It is preferable to use a recording liquid containing the above solvent (a non-aqueous solvent excluding water).

The solvent used in the recording liquid is one that sufficiently dissolves or disperses the above-mentioned dye, and it is preferable that the solvent has a boiling point of 150 ° C. or higher. This is because the above-mentioned porous structure has a large surface area, and if the boiling point is not higher than 150 ° C., the solvent evaporates or volatilizes to dry the recording portion, and the recording liquid concentration fluctuates, and the recording performance changes. Is to deteriorate.

In particular, this 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 the range from room temperature, which is the non-transferred recording part 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 tends to decrease.

The molecular weight of the solvent is preferably 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. The solvent is PPC paper (plain paper),
It is preferable to have the property of being spontaneously absorbed by fibers such as art paper from the viewpoint of transfer to plain paper.

The solvent is 5% by weight of the above dye at 50 ° C. or less.
As described above, especially in order to dissolve 10% by weight or more, the value of the solubility parameter of the solvent at 25 ° C. (as defined by JH Hildebrand) is preferably in the range of 7.5 to 10.5. preferable. Further, it is preferable that the flash point is 150 ° C. or higher, the toxicity to the human body is low, and the color is colorless. When the solubility parameter exceeds 10.5, the solubility of the dye becomes low, and the reproducibility of the transfer sensitivity is liable to deteriorate due to the adsorption of water vapor in the air. When the solubility parameter is less than 7.5, the solubility of the dye tends to be low.

Specific examples include aromatic esters including dialkyl phthalates such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisopropyl phthalate, dioctyl phthalate, and the like. N-alkylbenzene having a number of from 2 to 30,
n-alkylnaphthalene, n-dialkylbenzene, n
-It is desirable to use an aromatic hydrocarbon such as dialkylnaphthalene as a solvent for the recording liquid in the present invention. The above “alkyl” includes an ethyl group, an isopropyl group and a dodecyl group. In the case of n-alkylbenzene, an alkyl group having 10 to 15 carbon atoms is preferable, and examples thereof include 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 cyan dye represented by the general formula (I) does not cause such a phenomenon, it adheres well to recording paper to form a color more than enough, and hardly causes kogation.

In addition, when a dialkyl phthalate is used in combination with the cyan dye, the solvent has good permeability into recording paper, and can sufficiently adhere the dye. 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 composed of the above combination, the solvent amount can be set in a wide range of 50 to 90% by weight, and the dye concentration is 10% by weight. As described above, the image density can be improved.

The transfer head using the recording material of the present invention may comprise a recording section provided with heating means, an ink tank for storing recording liquid, and a recording liquid passage connecting the recording section 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 recording units are provided on one recording head.
More than one can be provided. 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 transferring 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 addition, a special paper prepared by applying polyester, polycarbonate, acetate, epoxy resin, polyvinyl chloride, or the like on a base paper as a resin for coloring a dye 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) by 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, and 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.

[0052]

The present invention will be described below in more detail with reference to examples. First, a description will be given with reference to the drawings. FIGS. 1 to 4 are views showing a vaporized thermal transfer printer head used in Examples and Comparative Examples, and FIG.
(b) is a perspective view, FIG. 2 is a plan view, FIG. 3 is a plan view with a cover 7 described below removed, and FIG. 4 is a partially enlarged view of a part thereof. FIG. 5 is a schematic diagram of a serial type printer. As shown in FIG. 1 to FIG.
Is an aluminum head base 2 that also serves as a heat sink,
A vaporizing section heated by a heater according to image information and a recording liquid introduction path for guiding a recording liquid to the vaporizing section by capillary action are covered with a heater chip 3 and a potting resin 4 integrally formed on a silicon substrate. Driver IC5
And a printed circuit board 6 on which wiring is formed so as to supply a current to each heater in accordance with image data to be transferred.
And a cover 7 which also serves to protect the driver IC 5 and supply the dye.

The head base 2 has a recording liquid introduction hole 8 for introducing a recording liquid into the printer head 1,
When the heater chip 3 is adhered to the head base 2, a groove 9 is formed as an escape area for an excess adhesive that protrudes.
The inside of the cover 7 is a recording liquid supply path 10 for supplying the recording liquid to the recording liquid introduction path of the heater chip 3. In addition, the printed circuit board 6 includes a connector terminal 11.
Is provided.

The surface of the heater chip 3 is made of N for protection.
It is covered with an i-sheet 3a, and a sheet resist 3b for forming a recording liquid introduction path is formed in a line inside the i-sheet 3a. The heater chip 3 also includes a plurality of heaters for heating and vaporizing the recording liquid, wirings for applying signal voltages based on image signals to the respective heaters, and supplying current to the heaters, and supplying the recording liquid to the heaters. Liquid introduction path for this is formed by a lithography process.

That is, as shown in FIG. 4 (enlarged partial view of the vaporizing portion 13 at the end of the heater chip 3 and the vicinity thereof), for example, the pitch of the heater 14 is 24.7 μm and the total of the heaters 14 is 24.7 μm.
56 are formed. At this time, one heater 14 is 1
Since the dots are transferred, a resolution of 300 DPI can be realized. Each of the heaters 14 is formed of polysilicon having a size of 20 μm × 20 μm. The heater 14 is connected to an individual electrode 15 made of aluminum and a common electrode 16 for applying and energizing a signal voltage based on an image signal. Have been. Here, the vaporizing sections 13 are separated from each other by the partition walls 17, and the recording liquid is stored in the concave portion (the recording liquid storing section 18) surrounded by the partition walls 17. On the heater 14 and around it, a fine columnar small column 19 having a diameter of 2 μm, a partition of 2 μm, and a height of 6 μm is formed of 13 × 13 via a protective film SiO ₂ (not shown). A group of books is provided as one of the constituent elements of the vaporizing unit 13.

The height of the small column 19 is determined by the recording liquid container 1.
8, that is, the height from the bottom surface to the top surface thereof, that is, the height of the partition wall 17 surrounding the recording liquid storage portion 18 of each heater 14, Are provided with a minute gap from each other so as to have a porous structure. Accordingly, the porous structure causes a capillary action, and thus each of the small columns 19 can hold the recording liquid in the recording liquid storage portion 18. At the same time, heater 1
When the recording liquid is heated in step 4, the surface tension of the recording liquid decreases as the temperature rises, but the recording liquid can be prevented from escaping from the vicinity of the surface of the heater 14 by the capillary action. Therefore, at the time of image transfer, a necessary recording liquid is continuously supplied.

As shown in FIG. 1A, the printer head 1 comes into contact with the recording material (printing paper) 12 at only one end 2a of the base, and has a predetermined angle with respect to the recording material 12. So it is held. Thus, the distance between the vaporizing section 13 and the recording material 12 can be kept constant. For example, the center position of the heater 14 of the vaporizing section 13 (FIG. 1)
The dashed line in (a)) is located 1.85 mm from the head base end 2 a in contact with the recording material 12, and the heater is formed on a 0.4 mm thick silicon substrate. The angle between the head base 2 and the recording material 12 such that the distance between the recording material 12 and the recording material 12 is 50 μm (however, the thickness of the adhesive layer between the silicon substrate and the head base 2 is 10 μm). At 14 °.

As described above, by appropriately changing the distance from the head base end portion 2a to the center position of the heater and the angle between the recording material 12 and the head base 2, the heater 14 and the recording material 12 Can be set to an arbitrary size. In the present embodiment and the comparative example, the printer head 1Y as described above is used for each color of yellow (Y), magenta (M), and cyan (C).
A serial printer with 1M and 1C as shown in FIG. 5 was used. Each printer head is connected to a head drive circuit board (not shown) via a flexible harness.

This serial type printer has a vertical (X
A paper feed roller 20 for transporting paper in the direction
A head feed shaft 21 for scanning the printer head in a direction (Y direction) orthogonal to the X direction is provided. The head feed shaft 21 is freely rotated by a motor (not shown) based on image information, and the printer head 1 is moved. It can be scanned. The paper feed in the vertical direction and the head scan in the horizontal direction are configured to be performed alternately.

Since each of the printer heads 1Y, 1M and 1C is provided with 256 heaters 14, the serial type printer used in this embodiment is
It has the ability to print 256 lines in one scan. In addition, at the end of one scan, the platen 2 is moved by the paper feed roller 20 also serving as a head support.
The recording material (printing paper) 12 on the sheet 2 is fed by 256 lines,
Since it is possible to start printing by sequentially changing the timing for each color so that the heads 1Y, 1M, and 1C of each color start printing from a predetermined position on the printing paper 12, a color image can be printed by one scan. You can do it. FIG.
Instead of the serial type printer shown in FIG. 1, a color printer having a head configured in a line type can be used. Hereinafter, Examples and Comparative Examples of recording using the above-described serial printer will be specifically described.

Example 1 No. 1 in Table-1 The cyan dye was obtained by dissolving the dye No. 6 in dibutyl phthalic acid at a concentration of 10% by weight.
When this was introduced into the ink tank from the recording liquid introduction hole of the printer head shown in FIG. 1, the recording liquid spontaneously was introduced into the vaporizing portion at the tip of the recording heater chip through the passage. Next, by applying the following pulse voltage to the heater of the printer head, the recording liquid was thermally transferred to photographic paper.

(Pulse voltage condition) 80 mW, 1 pulse per on-time 12 μs and off-time 2 μs per gradation, 256 pulses applied per dot. As a result of thermal transfer under the above conditions, dots having an optical density of 1.5 could be formed on A6 plain paper as measured by a Macbeth reflection densitometer. When this transfer was continued, scorching occurred on the columnar portion of the printer head, and cyan transfer could not be performed. However, a large number of prints of 8,600 could be performed.

Example 2 Nos. In Table 1 were used as dyes. A test was conducted in exactly the same manner as in Example 1 except that the dye 1 was used. As a result, 8000 prints could be made. Example 3 As a dye, No. 1 in Table 1 was used. When exactly the same test as in Example 1 was performed except that the dye No. 3 was used, 8,500 prints could be made.

Example 4 Nos. In Table 1 were used as dyes. The same test as in Example 1 was performed except that the dye No. 8 was used. As a result, 8,200 prints could be made. Example 5 Nos. In Table 1 as dyes were used. A test was conducted in exactly the same manner as in Example 1 except that 11 dyes were used. As a result, 7,800 prints could be made.

Example 6 As the coloring matter, When exactly the same test as in Example 1 was performed except that 22 dyes were used, 7,500 prints could be performed. Comparative Example 1 Solvent Blue 6 represented by the following structural formula as a dye
The same test as in Example 1 was conducted except that No. 3 was used. When 1,300 sheets were printed, scorching occurred on the columnar portion of the printer head, and cyan transfer could not be performed.

[0066]

Embedded image

[0067]

According to the recording material of the present invention, since it comprises the dye of the general formula (I), it has a 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,
In addition, since the number of droplets generated can be freely controlled according to the heating energy corresponding to the recording information to the recording liquid heating section, multi-value density gradation becomes possible, which is equivalent to or equivalent to a silver halide image. It is possible to obtain a record (for example, a full-color image) having a higher image quality. In addition, since the recording is performed by the thermal transfer method, it has the features described above, such as downsizing, easy maintenance, quickness, high-quality images, and high gradation.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (FIG. 1A) and a lower perspective view (FIG. 1B) of a printer head used in an embodiment.

FIG. 2 is a plan view of a printer head used in the embodiment.

FIG. 3 is a plan view of a printer head used in the embodiment.

FIG. 4 is a partially enlarged view of a printer head used in the embodiment.

FIG. 5 is a schematic view of a serial type printer used in the embodiment.

FIG. 6 is a front view of a main part of a recording apparatus using a conventional thermal recording head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer head 2 Head base 3 Heater chip 4 Potting resin 5 Driver IC 6 Printed circuit board 7 Cover 8 Recording liquid introduction hole 9 Groove 10 Recording liquid supply path 11 Connector terminal 12 Recording material (printing paper) 13 Vaporization part 14 Heater 15 Individual electrode 16 Common electrode 17 Partition wall 18 Recording liquid storage unit 19 Column

Continued on the front page (72) Inventor Eiki Hirano 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (10)

[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 an object to be transferred facing the transfer portion. A thermal transfer recording material containing the dye represented by I). Embedded image (Wherein R is a substituted or unsubstituted alkyl group, alkenyl group or cycloalkyl group having 2 or more carbon atoms;
Is a benzene ring which may have a substituent. ) 2. The thermal transfer recording material according to claim 1, wherein R in the general formula (I) is a substituted or unsubstituted alkyl or alkenyl group having 2 to 13 carbon atoms. 3. The thermal transfer recording material according to claim 2, wherein R in the general formula (I) is an alkyl group having 2 to 8 carbon atoms which may be substituted with an alkoxy group. 4. In the general formula (I), A represents 1 to 8 carbon atoms.
4. The thermal transfer recording material according to claim 1, wherein the benzene ring is a benzene ring which may be substituted with an alkyl group, an alkoxy group, a halogen atom or a trifluoromethyl group. 5. Evaporation by heating or a diameter of 1 μm
The thermal transfer recording according to any one of claims 1 to 4, wherein the recording material is a recording material that generates a mist of m or less and is transferred onto an object to be transferred opposed to each other with a gap of 10 to 300 µm. material. 6. The thermal transfer recording material according to claim 1, wherein the porous structure has one side or diameter of 0.2 to 3 μm and a height of 1 to 15 μm. 7. One side or diameter of 0.5 to 3 μm, 1 to 1
The porous structure is formed by arranging three or more rows and three or more rows of fine columnar bodies having a height of 5 μm at intervals of 0.5 to 3 μm, according to claim 6, wherein the porous structure is formed. Thermal transfer recording material. 8. A polymer having a molecular weight of 450 or less and a melting point of 50
C. or lower, a boiling point of 150 ° C. or higher and 400 ° C. or lower, a colorless solvent having a residual content of 0.01% by weight or less when heated to 200 ° C. in the air. The thermal transfer recording material according to any one of claims 1 to 7, wherein the dye represented by I) is dissolved at 50 ° C or less by 5% by weight or more. 9. The thermal transfer recording material according to claim 8, wherein the solvent is an aromatic ester and / or an aromatic hydrocarbon. 10. The thermal transfer recording material according to claim 9, wherein the aromatic ester is a dialkyl phthalate.