JPH0939421A - Heat transfer recording material and heat transfer recording method used thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of so-called cogation or of the clogging of discharging nozzles and realize an excellent resolution and in-pixel gradation by a method wherein a coloring matter represented by a specified formula is included in a heat transfer recording material, with which the recording on a body to be transferred is performed through the change of state causing by heating. SOLUTION: In this heat transfer recording material, which is led to a transferring part by capillarity and with which the recording on a body to be transferred is performed through the change of state caused by heating, a coloring matter (cyan coloring matter) represented by the formula is included, where R<1> and R<2> are straight-chain alkyl groups and, at least either one of them is a 5C or more of alkyl group. The recording material has the molecular weight of 450 or less, the melting point of 50 deg.C or lower and the boiling point of 150-400 deg.C and is colorless and its residue under the condition being heated up to 200 deg.C in the air is 5wt.% or more of the coloring matter represented by the formula under the temperature range of from room temperature to 50 deg.C and dissolved in a solvent of 0.01wt.% or less residue when heated.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art In recent years, as colorization of video cameras, computer graphics, etc. has progressed, the need for colorization of these hard copies has increased rapidly. 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 a high-quality image with a simple device can be roughly classified into a dye diffusion thermal transfer method (sublimation thermal transfer method) and an inkjet 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, which is characterized by obtaining a full-color image with continuous gradation by repeating each of the image signals decomposed into yellow, magenta, and cyan, is compact, easy to maintain, and instant. It has attracted attention as an excellent technology for obtaining high-quality images that are comparable to silver salt color photographs.

FIG. 5 is a schematic front view of the main part of such a thermal transfer printer. A thermal recording head (hereinafter referred to as a thermal head) 1 and a platen roller 3 face each other, and an ink sheet 12 provided with an ink layer 12a on a base film 12b and a dyeing resin layer 2 on a paper 20b between them.
The recording paper (transferred material) 20 provided with 0a is sandwiched, and these are pressed against the thermal head 1 by the rotating platen roller 3 and run.

The ink (transfer dye) in the ink layer 12a selectively heated by the thermal head 1
Are transferred in a dot shape to the dyeing resin layer 20a of the transferred material 20, and thermal transfer recording is performed. For such thermal transfer recording, a serial method in which a thermal head is scanned in a direction orthogonal to the traveling direction of the recording paper 20 or a single linear thermal head is fixed in a direction orthogonal to the traveling direction of the recording paper. The line method is used.

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 applies not only to the dye diffusion type (sublimation type) thermal transfer recording system but also to the fusion type thermal transfer system. As described above, the conventional thermal transfer method has high image quality, but the running cost is high.

[0008] Although the heat-developable silver salt method has a 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 method is Japanese Patent Publication Sho 61-599
As disclosed in Japanese Patent Publication No. 11 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), a thermal method (bubble jet method), etc. according to image information. A small droplet of liquid is ejected from a nozzle provided on a recording head and adhered to a recording material to perform recording.

Therefore, there is almost no generation of waste as in the case of using an ink sheet or the like, and the running cost is low. Recently, in particular, the thermal method is capable of easily outputting a color image, so that the spread thereof is expanding. 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 the apparatus cost is high. 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 for solving these problems has been proposed (JP-A-7-89107 and European Patent Publication (EP-A) No. 608881). That is, the recording liquid is guided to a transfer portion having a porous structure by a capillary phenomenon, and heated by an appropriate heating means such as laser light,
A non-contact type dye flight type thermal transfer recording in which the recording liquid is vaporized or a mist with a diameter of 1 μm or less is generated and transferred from the transfer section onto the photographic paper oppositely arranged with a gap of 10 to 300 μm. It is a method.

In such a thermal transfer recording system, because of the above-mentioned porous structure, the surface area of the heating portion (transfer portion) is large, and the recording liquid is constantly supplied to and held in the recording liquid heating portion by the capillary phenomenon. In this state, a heating means (for example, a laser beam) selectively applies a heat amount corresponding to the recording information to the transfer portion to evaporate a part of the recording liquid to form a minute vapor or a droplet. It is possible to transfer to the recording material and transfer it onto the recording material according to recording information corresponding to an electric image created by a color video camera or the like.

Therefore, it is possible to form a large number of liquid droplets having a size smaller than that of the known ink jet system, and it is possible to freely control the number of liquid droplets generated according to the heating energy corresponding to the recording information. Value density gradation is possible, and it is possible to obtain a record (for example, a full-color image) having an image quality equal to or higher than that of a silver salt system image.

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 The object of the present invention is to make use of the advantages of both the thermal transfer method and the ink jet method described above, and at the same time solve the drawbacks thereof, especially the problem of kogation, to obtain excellent resolution and pixel. It is an object of the present invention to provide a thermal transfer recording material capable of realizing inner gradation and maintaining recording performance for a long time, and a thermal transfer recording method using the recording material.

[0016]

The inventors of the present invention have found out that the above-mentioned kogation does not occur because the heat resistance of the dye used is insufficient, and by using a specific dye, the heat resistance of the dye can be improved. Therefore, the present invention has been completed by finding that the kogation can be greatly reduced and the head life can be extended.

That is, according to the present invention, the recording material is guided to the transfer portion having a porous structure by a capillary phenomenon, and the state of the recording material is changed by heating such as vaporization or droplet formation,
A thermal transfer recording material, which is transferred to a transfer object facing the transfer part, for recording on the transfer object,
The present invention relates to a thermal transfer recording material containing a dye (cyan dye) represented by the following general formula (I) and a thermal transfer recording method using the same. 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).

[0018]

Embedded image

(However, in the general formula (I), R ¹ and R ² are each a linear alkyl group, and at least one is an alkyl group having 5 or more carbon atoms.) In the recording material of the present invention It is preferable that ^one of R ¹ and R ^{2 is} a linear alkyl group having 1 to 13 carbon atoms, and the other one is a linear alkyl group having 5 to 13 carbon atoms.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Specific examples of the cyan dye represented by the general formula (I) include those shown in Table 1 below.

[0021]

[Table 1]

The thermal transfer recording material of the present invention is specifically
The transfer portion of the recording device is vaporized or a mist having a diameter of 1 μm or less is generated, and 10 to 3 is generated from the transfer portion.
It is a liquid recording material that is transferred onto a transfer-receiving member that is arranged to face each other through a gap of 00 μm. By non-contact transfer through such a gap, as described above, it has high image quality and immediacy, the size and weight of the device can be reduced, and no waste is generated. Can also be transferred to, and can be performed with low power consumption and low running cost.

Further, the above-mentioned porous structure of the transfer portion has a function of introducing the recording material by the capillary action and holding the recording material, and especially the pores have a diameter of 0.2 to 3 μm.
It may have one side or diameter. Also, 0.2-
Small pillars having a side or diameter of 3 μm and a height of 1 to 15 μm are arranged in an interval of 0.3 to 3 μm in three rows or more and 3 or more.
It is preferable that the porous structure is formed by arranging in rows or more.

The porous structure composed of such a group of small pillars is
At least the following three types of remarkable effects are exhibited. That is, the first effect is that the recording material can be supplied to the transfer portion by a spontaneous capillary phenomenon due to the large surface area. The second effect is that the surface tension of the liquid generally decreases as the temperature rises, so that when the recording material is heated, the surface tension of the heating center of the recording liquid becomes lower than the surface tension of the outer peripheral portion of the recording liquid, and Although a force is exerted in the outward direction, the porous structure of the transfer portion can suppress the movement of the recording liquid to the outer peripheral portion and prevent the transfer sensitivity of the central portion from being lowered.

The third effect is that a large number of holes in the porous structure of the transfer portion each function as a fine ejection portion for the recording material, so that the number of holes corresponding to the amount of heat applied to the transfer portion is very large. A fine vapor or droplets of a recording material are ejected, fly in a space between the transfer portion and the recording material, and adhere to a recording material such as photographic paper facing the transfer portion. According to this principle, it is possible to perform gray scale within a pixel, which is not possible with a normal inkjet method.

Such a porous structure (concavo-convex structure) is provided in the transfer portion, and the recording material is constantly supplied to the transfer portion by the capillary phenomenon and held therein, and an appropriate heating means (for example, for this transfer portion) is used. By selectively applying the amount of heat according to the recording information with a thermal head or laser light, a part of the recording material is evaporated and the pressure rises, which corresponds to the electrical image created by a color video camera, etc. It has become possible to transfer an image by forming minute droplets of a recording material in an amount corresponding to the recording information and transferring it to a recording medium.

Therefore, by using the recording apparatus having such a structure, it is possible to thermally transfer the recording material on demand with very small droplets, and at least 128 gradations in one pixel per color or It is possible to realize an ink jet type recording method capable of expressing density gradation higher than that. Such a porous structure can be obtained, for example, by laminating porous alumina having an average particle diameter of 0.1 to 2 μm to a thickness of 5 to 20 μm, or laminating glass beads having an average particle diameter of 0.5 to 3 μm to a thickness of 5 to 20 μm. , Average diameter 0.5-2μ
A large number of silicon whiskers with a height of 2 to 10 μm in 1 m
It can be manufactured by a method such as a method of growing on a substrate at intervals of ˜3 μm.

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

As the porous structure, other than the columnar shape,
It may be formed in a wall shape, a bead aggregate shape, a fibrous shape, or the like. Further, the porous structure preferably has a heat resistance of 300 ° C. or higher. Such a porous structure has the above-mentioned excellent action, but since the size of the pores is minute, deterioration products such as decomposition products due to heating of the recording material during recording (especially repetitive recording) are generated. It tends to adhere to the porous structure and cause clogging, impairing its action.

The dye of the above-mentioned general formula (I) used in the recording material of the present invention has sufficient heat resistance to heating, hardly causes kogation due to decomposition products, and has a porosity even after repeated recording. The quality structure can be retained and its function can be effectively exerted. In the present invention, as the recording material, the heat-fusible dye represented by the general formula (I) may be used alone, but it is preferable to use a recording liquid which is dissolved or uniformly dispersed in a solvent other than water.

When the dye is used alone, the portion (for example, the recording liquid tank) that holds the recording material before being supplied to the porous structure of the transfer portion is vaporized or changes into fine droplets in the transfer portion. It has been heated to a temperature below and the dye must melt at that temperature. Therefore,
The dye preferably has a melting point of, for example, 160 ° C. or lower, preferably 120 ° C. or lower, and has a vaporization temperature of about 250 to 350 ° C. in order to change the state by heating at the transfer portion.

When used as a recording liquid, 90% by weight or more is vaporized when heated to 300 ° C. or higher, and the residue remains 1%.
5% of the above cyan dye and 0% by weight or less
Boiling point to dissolve or disperse 5% by weight or more at 0 ° C or less 1
A recording liquid containing a non-aqueous solvent at 50 ° C. or higher is preferable. The non-aqueous solvent used in this 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 when the temperature is lower than 150 ° C., the solvent is liable to evaporate or volatilize, the transfer portion is dried, and the recording liquid concentration is easily changed, because the porous structure has a large surface area. This is because the performance tends to deteriorate.

In particular, this solvent preferably has a melting point of 50 ° C. or lower, a boiling point of 150 ° C. or higher and 400 ° C. or lower, and is 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 should be in the range of the temperature of the transfer part during non-transfer (usually from room temperature to 50 ° C.). Makes it easier to solidify. Further, if the boiling point is 400 ° C. or higher, the vaporization efficiency is poor, and the transfer sensitivity is likely 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,
Transfer sensitivity tends to decrease. Further, a solvent having a residual content of 0.01% by weight or less when heated to 200 ° C. in air is preferable. Further, in order for the solvent to dissolve the above dye at 5 ° C. or lower at 5% by weight or more, particularly 10% by weight or more,
The value of the solubility parameter of the solvent (as defined by JH Hildebrand) at ° C is preferably in the range of 7.5 to 10.5. Solubility parameter is 10.5
If it exceeds, the solubility of the dye becomes low, and water vapor in the air is adsorbed, so that the reproducibility of transfer sensitivity tends to be deteriorated. Also,
If the solubility parameter is less than 7.5, the solubility of the dye tends to be low.

In addition, the flash point is 150 ° C. or higher,
A solvent having low toxicity to the human body is preferable. Specific examples of such a solvent include aromatic esters such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate and dioctyl phthalate, and aromatic esters including dialkyl phthalates. N-alkylbenzene having 2 to 30 carbon atoms in the chain,
n-alkylnaphthalene, n-dialkylbenzene, n
Aromatic hydrocarbons such as dialkylnaphthalene are preferable. Examples of the above “alkyl” include an ethyl group, an isopropyl group, a dodecyl group and the like. In the case of n-alkylbenzene, an alkyl group having 10 to 15 carbon atoms is preferable, and examples thereof include dodecylbenzene.

When used in the recording liquid, the amount of the dye used is 5 to 50% by weight, preferably 10 to 30% by weight based on the total amount of the recording liquid. The amount of the solvent used is the remaining amount of the amount of the dye and the additive added as necessary,
It is in the range of 95% by weight. Since the dye used in the conventional inkjet method is a water-based recording liquid, it is generally a water-soluble acid dye, but even if it adheres to the recording paper, it easily flows on the recording paper and it is difficult to obtain sufficient color development. Also, the water resistance of the recorded matter is low. Further, heat during recording easily causes kogation due to self-decomposition. On the other hand, the above-mentioned specific dye used in the present invention is a dye having water resistance, good color developability on recording paper, and hardly causing kogation.

In addition, when a phthalic acid dialkyl ester is used as a solvent in combination with the cyan dye, the solvent has good penetrability into the fibers of recording paper such as PPC paper and art paper, and the dye is sufficiently absorbed. It can be attached in two parts, and also acts as a color-forming auxiliary agent for coloring the dye. By using a recording liquid of this composition, it is possible to transfer a high quality image to plain paper such as PPC paper and art paper. Further, the dye concentration of the recording liquid has been at most 5% by weight in the past, but in the recording liquid comprising the above combination, the dye concentration can be increased to 10% by weight or more and the image density can be improved.

A transfer head of a recording apparatus using the recording material of the present invention has at least a transfer section (recording section) provided with a heating means.
A recording liquid tank for storing a liquid recording material (melting dye or recording liquid); and a recording liquid passage connecting the transfer section and the recording liquid tank. When the recording material is a recording liquid containing a solvent and a dye, the transfer head is set to 5 in order to adjust the viscosity.
You may heat to about 0 degreeC. In order to shorten the transfer time, two or more transfer parts can be provided on one recording head. The recording liquid is continuously supplied to the transfer portion through the recording liquid passage.

The heating means is a heating element such as a resistance heater,
A laser whose output changes according to the recorded information, a combination of a laser and a laser light absorber (photothermal converter) provided in the transfer portion, and 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 may be manufactured by directly depositing a conductive material such as polysilicon on the transfer portion.

Examples of the recording material that can be used for transferring the recording material of the present invention include plain paper such as PPC paper and fine paper such as art paper. Particularly, high quality images with high gradation and high density can be obtained. In order to obtain the dye, it is also preferable to use a special paper prepared by coating polyester, polycarbonate, acetate, epoxy resin, polyvinyl chloride, or the like on the base paper as the resin that allows the dye to develop well. In order to improve the storage stability of the obtained image, it is also effective to protect the image by laminating a resin film on the recording surface of the recording material after transfer.

In order to achieve multicolor recording (particularly full color) by using the recording material of the present invention, among the three primary colors of subtractive color mixing, the recording material of the present invention is cyan, and therefore the other two Color recording liquid, prepared in the same manner as the recording material of the present invention,
Full-colorization can be achieved by recording the image signals decomposed into yellow, magenta, and cyan, respectively.

[0042]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. 1 to 4 show an example in which the present invention is applied to a non-contact type thermal printer (for example, a video printer: hereinafter the same).

In the recording method of this embodiment, the head 70 having the structure shown in FIG. 1 is heated by laser light. Further, in order to improve the absorbability of laser light, it is preferable to provide the transfer portion 57 with a light absorbing substance (photothermal converter). When the cyan dye of the general formula (I) is used alone, the recording liquid tank 55 that stores the dye (liquefied dye = recording liquid 62) has at least a temperature at which the dye melts and liquefies (for example, 80 Means (heaters 56a, 5)
6b) must be provided. When the recording material is the recording liquid 62 containing a dye and a solvent, the heaters 56a and 56b may be used to heat the liquid to a temperature of about 50 ° C. or lower in order to adjust the viscosity.

A recording material 80 facing the head 70 is also provided.
A minute gap 51 is provided between Then, a liquefied dye (recording liquid) on the transfer portion is applied by an appropriate heating means such as laser light L
It is possible to selectively heat 62 to vaporize it or to make it into microdroplets, and to fly the gas or microdroplets to move the voids 51 to form an image with gradation on the recording material 80. This operation is performed by subtracting the three primary colors of yellow, magenta,
With respect to the image signal decomposed into cyan, a recording material corresponding to each of yellow and magenta may be used in addition to the cyan recording material of the present invention to repeat recording, thereby forming a full-color recorded material. .

Here, the gap 51 is 10 to 300 μm.
m, particularly preferably 50 to 200 μm. If the gap is less than 50 μm, the head 70 and the recording material 80 may come into contact with each other during the movement of the head, and the stability of image transfer tends to deteriorate, which is not preferable. If the gap 51 exceeds 300 μm, the recording droplets do not efficiently reach the recording material 80, and the transfer sensitivity and the image resolution are likely to decrease.

In this recording method, the recording medium 80 is placed facing the upper side of the head 70, and the laser beam L emitted from the laser 18 and condensed by the lens 19 is irradiated near the upper surface of the transfer portion 57. Then, it is preferable that the recording material in that portion is vaporized or dropletized, and the formed recording droplet 82 is caused to fly to the recording material 80 above and transferred. Further, a recording liquid tank 55 is provided on a laser light transmissive base 54, a liquefied dye (recording liquid) 62 is accommodated between the recording liquid tank 55 and a spacer 58 fixed on the base 54, and a transfer portion is passed from here through a recording liquid passage 67. 57 continuously. The transfer portion 57 has a microporous structure including a large number of small pillars 61 provided by RIE or a lithography technique.

These small pillars 61 have a heat resistance of 300 ° C. or higher and a height of 1 to 15 μm (preferably 2 μm).
10 to 10 μm), the diameter or the length t of one side is 0.2 to 3 μm
(Preferably 0.5 to 3 μm), a structure in which a large number of columns or prisms with a distance d between the small columns of 0.2 to 3 μm (preferably 0.5 to 3 μm) are lined up, particularly 3 rows or more , And 3
It has a structure in which rows or more are regularly arranged (see FIGS. 2 and 3).
reference).

This small pillar structure has a large surface area, so that the recording liquid is spontaneously introduced into the transfer portion (vaporization portion) by a capillary phenomenon and the center of the transfer portion is locally heated during the transfer. It functions to prevent the phenomenon (escape phenomenon) in which the recording liquid moves to the non-heated portion due to the temperature dependence of the surface tension. In this case, the height of one pillar of the small pillar 61 is 1 μm.
If the distance is less than 1 μm or if the distance between one pillar of the small pillar 61 and another adjacent pillar is more than 3 μm, it becomes difficult to prevent the above-mentioned escape phenomenon at the time of transfer, and if it exceeds 15 μm, recording is performed. It is difficult to heat efficiently because there is too much liquid. The diameter of one pillar of the small pillar 61 or the length of one side is 0.2 μ
If it is less than m, the columnar body 61 is likely to be damaged by the wave motion of the fluid generated by heating for recording, and if it exceeds 3 μm, the distance between one columnar body of the columnar body 61 and the other columnar body adjacent to it. Is less than 0.2 μm, the amount of the recording liquid to be transferred is small, so that the transfer sensitivity is likely to decrease.

As shown in FIG. 3, one columnar body of the small columnar body 61 may have various planar shapes such as a square, and the plane pattern of the aggregate is vertical and horizontal. It can be selected so as to form a matrix in the range of 2 to 100 rows and 2 to 100 columns in each direction.
A protective plate 59 is fixed on the spacer 58 in order to hold the space 51 and guide the recording material 80 moving in the X direction of the paper discharge direction from the paper feed direction. The protective plate 59 may be embedded with a liquefied state of the liquefied dye or a heating means for keeping the recording liquid at a preferable viscosity like a heater 56b shown by a phantom line, but on the outer surface of the base 54. Only the fixed heater 56a may be provided, or both may be provided. Alternatively, the above recording liquid passage 67
Alternatively, it may be arranged in the recording liquid tank 55.

In the recording head used in this example, the base 54 is mainly composed of an inorganic material having a high heat resistance such as glass, metal, silicon, or ceramic, or a heat resistance of 300 ° C. or higher such as polyimide or aramid. It is better to be composed of the organic polymer provided. By providing a suitable heat retaining device on the head 70, it becomes possible to use a recording liquid having a melting point of room temperature or higher.

The recording liquid passage 67 for replenishing the recording liquid between the transfer portion 57 and the recording liquid tank 55 has a width of 50 μm ^2.
The cross-sectional area is above, 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, but this dye may be a mixture of two or more dyes within the range of the general formula (I).

Then, a part of the recording liquid is evaporated by heating, and the recording material in an amount corresponding to the image information is made into minute liquid droplets, which are moved in the void 51 and transferred onto the recording material 80.
In the case of the inkjet method, it is possible to
A solvent (carrier) having a melting point of 50 ° C. or lower and a boiling point of 150 ° C. or higher at 1 atmospheric pressure (desirably 250 to 400 ° C.), which causes a volume expansion of 0 times or more to dissolve or disperse the dye, particularly a dialkyl phthalate It is preferable to include an ester.

The recording material 80 suitable for transferring the recording material of this embodiment may have a dye receiving layer 80a.
Any recording material may be used as long as it has an appropriate compatibility with the dye of the general formula (I), easily accepts the dye, promotes the original color development of the dye, and has the effect of fixing the dye. It is possible. As a transfer type heating means according to the present invention, FIG.
When a laser beam is used as described above, the resolution is good, and by increasing the laser beam density in the optical system, it becomes possible to perform intensive heating, the reached temperature is raised, and as a result, the thermal efficiency is improved. There is a feature called.

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 in a line), the time for transferring one screen is greatly shortened. 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 system, a metal thin film having absorption matching the emission wavelength of the laser,
In addition to directly providing a thin film type light absorber such as a two-layer film of a metal thin film and a ceramic thin film having a high dielectric constant in the transfer portion as shown in FIG. 1, a fine particle type light absorber such as carbon black or metal fine particles is recorded. You may use it evenly disperse | distributed in a material. The entire printer head is, for example, a cyan, magenta, and yellow recording liquid tank 55 for full color.
C, 55M, and 55Y are provided on the common base 54 to form the head portions 70C, 70M, and 70Y of the respective colors, and the recording material for the respective colors is formed into a row-shaped transfer portion 57C that forms 12 to 24 large dots. It is supplied to each of 57M and 57Y.

For each of the transfer parts 57C, 57M and 57Y, a multi-laser array 30 in which, for example, 24 corresponding lasers (particularly semiconductor laser chips) 18 are arranged in an array is provided.
Each laser beam L emitted from the laser beam is condensed by a microlens array 31 having a large number of condenser lenses 19. In the case of cyan monocolor printing using only the recording material of the present invention, only one head 70 may be provided on the base 54 to produce a corresponding one-dimensional laser array.

In the head 70, as many recording liquids 62 as dots are accommodated in the porous structure of the transfer section 57 in a number corresponding to the number of recording dots, and the lasers 18 are arranged in an array having light emitting points for the number of recording dots. To do. Further, the printer having the head 70 described above performs printing by, for example, a serial method, by feeding the paper in the vertical direction (X direction) and scanning the head in the direction orthogonal to the X direction (Y direction) in the horizontal direction. The paper feed in the vertical direction and the head scan in the horizontal direction are alternately performed.

As shown in FIG. 4, in this printer 91, for example, the head 70 for multicolor printing is provided with a head feed shaft 92 and a head support shaft 93 which are formed of a feed screw mechanism.
The recording material 80 is reciprocally movable in a head feeding direction Y orthogonal to the paper feeding direction X. Further, a head receiving roller 94 that supports the recording material 80 so as to sandwich the recording material 80 is rotatably provided above the head 70. Then, the recording material 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) or the like via a flexible harness 97.

Example 1 The head 70 shown in FIG. 1 (transfer portion diameter: 50 μm, small pillar diameter: 2 μm) was replaced by No. 1 in Table 1 above. 1 dye, heater 5
6a was heated to 100 ° C. and introduced. And FIG.
The head 70 was mounted on the printer shown in (however, only one head part for mono-color), and the dedicated paper for sublimation heat transfer (product name: VPM30STA, product of Sony Corporation) was set as the recording material 80. In this case, the distance between the recording material and the surface of the transfer portion 57 of the head was 50 μm.

Next, a semiconductor laser beam of 850 nm is condensed to a size of 6 × 10 μm on the transfer portion 57 by an optical system, and 20 m
A laser pulse of 1 ms ON and 1 ms OFF was emitted at W, and at the same time, the recording material 80 was scanned to print a straight line. As a result, a straight line having a width of about 80 μm and a cyan optical density (OD value) of about 0.4 (measured by a Macbeth reflection densitometer) was drawn on the printing paper. Further, after irradiating 1 million pulses, the head 70 was taken out, washed to remove the residual dye, and the transfer portion 57 was observed under a microscope. No charring or sticking was observed.

Example 2 As the dye, No. 1 in Table 1 above was used. The same test as in Example 1 was carried out except that No. 2 was used, but no charring was produced after 1 million pulse irradiation. Example 3 As the dye, No. 1 in Table 1 above was used. The same test as in Example 1 was carried out except that No. 3 was used, but no charring was produced after 1 million pulse irradiation. Example 4 As the dye, No. 1 in Table 1 above was used. The same test as in Example 1 was carried out except that No. 4 was used, but no charring was produced after 1 million pulse irradiation.

Example 5 As the dye, No. 1 in Table 1 above was used. The same test as in Example 1 was carried out except that No. 5 was used, but no charring was produced after 1 million pulse irradiation. Example 6 As the dye, No. 1 in Table 1 above was used. The same test as in Example 1 was carried out except that No. 6 was used, but no charring was produced after 1 million pulse irradiation. Example 7 No. 1 in Table 1 above. A solution (concentration 15% by weight) in which the dye No. 1 was dissolved in dibutyl phthalate was introduced into the transfer section 57 at room temperature as the recording liquid 62, and thereafter, the same test as in Example 1 was performed. As a result, a straight line having a width of 80 μm and an OD value of about 0.1 was printed. Further, there was no generation of scorch 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 was used.

[0064]

Embedded image

As a result, when the number of laser pulses exceeded 100,000, the color density of the printed straight line started to decrease. Transfer became impossible with 200,000 pulses. The head 70 was taken out, washed, and observed under a microscope. As a result, a lump of char was formed on the head of the trabecular member group 61.

Comparative Example 2 The same experiment as in Example 7 was carried out except that the same dye as in Comparative Example 1 was used. As a result, from the vicinity of the number of laser pulses exceeding 100,000 pulses, the color density of the printed straight line was changed. The decline has begun. Transfer became impossible with 200,000 pulses. Head 7
When 0 was taken out, washed, and observed under a microscope, a lump of char was formed on the head of the trabecular body group 61.

[0067]

According to the thermal transfer recording method of the present invention, a large number of droplets of a small size thermal transfer recording material can be formed by the porous structure formed in the transfer portion, and energy corresponding to recorded information can be applied to the transfer portion. By doing so, it is possible to freely control the number of droplets generated and the size of droplets to be formed, so that multi-value density gradation is possible and full-color recording can be performed by combining with recording materials of other color tones. By doing so, it is possible to obtain a record having an image quality equivalent to or higher than that of the silver salt system image. In addition, it has features such as downsizing of the device, ease of maintenance, immediacy, high-quality images, and high gradation. In particular, since the recording material of the present invention uses the dye represented by the general formula (I), it has sufficient heat resistance against heating and hardly causes kogation due to decomposition products. Therefore, the action of the porous structure of the transfer portion can be retained and effectively exhibited even during repeated recording. The recording method shown in this embodiment reduces the waste such as used ink ribbon and transfer energy while making the most of the advantages of both the thermal transfer recording method and the ink jet method, reducing the size and weight of the printer, and providing excellent resolution. And the recording method capable of realizing the in-dot gradation, and there is no problem of kogation of the recording method, and the recording performance can be maintained for a long time.

[Brief description of drawings]

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

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

FIG. 3 is a plan view of a group of small pillars provided in a transfer section (vaporization section) of the head shown in FIG.

FIG. 4 is a schematic perspective view of an example of a recording apparatus equipped with the head of FIG. 1 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) 19 ... Condenser lens 30 ... Multi-laser array 31 ... Micro lens array 51 ... Void 53 ... Vaporization hole 54 ... Base 55 ... Recording liquid tank 56a, 54b ... Heater 57 ... Transfer part (vaporization part) 58 ... Spacer 59 ... Protective plate 61 ... Small column 62 ... Recording liquid (liquefied dye) 67 ... Recording liquid passage 70 ... Head 70C ... Cyan head 70M ... Magenta head 70Y ... Yellow head 80 ... Recording material 80a ... Dye receiving layer 82 ... Recording droplet L ... Laser light X ... Paper feeding direction Y ... Head moving direction t ... One side or diameter of column body d ... Spacing in parallel direction between column bodies 92 ... Head feed shaft 93 ... Head support Shaft 94 ... Head receiving roller 95 ... Driving roller 96 ... Followed roller 97 ... Flexible harness 1 ... Thermal head 12 ... Ink sheet 1 a ... ink layer 12b ... base film 20 ... recording paper 20a ... dyeable resin layer 20b ... paper 3 ... platen roller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location 7416-2H B41M 5/26 101K (72) Inventor Miyuki Kuromiya 6-7 Kitashinagawa, Shinagawa-ku, Tokyo No. 35 Sony Corporation (72) Inventor Yukichi Murata 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi Chemical Corporation Yokohama Research Institute (72) Inventor Miori 1000 Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa Mitsubishi Chemical Co., Ltd. Yokohama Research Institute

Claims (9)

[Claims] 1. A recording medium is transferred onto a transfer body having a porous structure by capillarity, changes its state by heating, and is transferred to a transfer body facing the transfer section for recording on the transfer body. Which is a thermal transfer recording material containing a dye represented by the following general formula (I). Embedded image (However, in the general formula (I), R ¹ and R ² are each a linear alkyl group, and at least one is an alkyl group having 5 or more carbon atoms.) 2. In the general formula (I), R ¹ and R ² have 1 carbon atoms.
The thermal transfer recording material according to claim 1, wherein the thermal transfer recording material is a linear alkyl group having 13 to 13 carbon atoms, and the remaining one is a linear alkyl group having 5 to 13 carbon atoms. 3. A polymer having a molecular weight of 450 or less, a melting point of 50 ° C. or less, a boiling point of 150 ° C. or more and 400 ° C. or less, is colorless, and has a residual content of 0.1% when heated to 200 ° C. in air. The thermal transfer recording material according to claim 1, wherein the dye represented by formula (I) is dissolved in a solvent of 01% by weight or less in an amount of 5% by weight or more in a temperature range of room temperature or higher and 50 ° C. or lower. 4. The thermal transfer recording material according to claim 3, wherein the solvent is an aromatic ester and / or an aromatic hydrocarbon. 5. The thermal transfer recording material according to claim 3, wherein the solvent is a dialkyl phthalate. 6. A recording apparatus having a transfer section having a porous structure is used, a thermal transfer recording material is guided to the transfer section by a capillary phenomenon, and the recording material is heated to change its state,
A thermal transfer recording method in which recording is performed on the transferred material by transferring it to the transferred material facing the transfer part, wherein the recording material contains a dye represented by the following general formula (I): Recording method. Embedded image (However, in the general formula (I), R ¹ and R ² are each a linear alkyl group, and at least one is an alkyl group having 5 or more carbon atoms.) 7. A thermal transfer recording material is vaporized by heating in a transfer section of a recording device or is formed into a mist having a diameter of 1 μm or less, and is transferred onto a transfer target object which is opposed to the transfer section through a gap of 10 to 300 μm. The thermal transfer recording method according to claim 6, wherein the thermal transfer recording is performed. 8. The thermal transfer recording method according to claim 6, wherein the porous structure of the transfer portion has holes having a side or diameter of 0.2 to 3 μm. 9. A fine columnar body having a porous structure of a transfer part having a side or diameter of 0.5 to 3 μm and a height of 1 to 15 μm at intervals of 0.5 to 3 μm in three or more rows. And the thermal transfer recording method according to any one of claims 6 to 8, which is formed by arranging in three or more rows.