JP2000203167A - Thermal transfer recording method and thermal transfer recording ink sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high picture quality and superior image storage properties, form a highly glossy image even when high heat energy is applied, make the high picture quality and high image storage properties compatible with the formation of highly glossy image even when the high heat energy is applied to a thermal head in the formation of the image by the sublimation heat transfer method using a chelate reaction type dye. SOLUTION: In a thermal transfer recording method, an ink layer of an ink sheet having at least one ink layer containing a heat diffusing dye and formed on a substrate is so overlapped on an image receiving layer of an image receiving sheet having at least one image receiving layer on a separate substrate as to face each other, and a dye is transferred onto the image receiving layer by heating the overlapped layers in the form of an image, and then at least the whole of an area whereon the dye is transferred by re-heating by the thermal head to form an image on the image receiving sheet, the non-power application time intervals are set at the given value so that the temperature of a resistor surface of the thermal head in the re-heating is not lowered down to 1/3 or lower of the peak temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording method, and more particularly, to a thermal transfer recording method capable of obtaining a glossy, high-quality, and excellent storage image. The present invention also relates to a thermal transfer recording ink sheet which can form a glossy image having high image quality and excellent storability.

[0002]

2. Description of the Related Art As a technique for forming an image, an ink sheet containing a sublimable dye having a property of diffusing and transferring upon heating is opposed to an image receiving layer of an image receiving sheet, and is heated by a heating printing means such as a thermal head. A sublimation heat transfer system in which an image is formed by transferring a sublimable dye imagewise to an image receiving layer is known. The sublimation thermal transfer system has a reputation as a method that enables digital image formation, does not use a developing solution or the like, and can form high image quality comparable to silver halide photography. However, they have the disadvantage that the glossiness relating to the image quality is inferior to silver halide photographs, and the image storability is weaker than that of silver halide photographs.

As means for improving the latter disadvantage, for example, JP-A-59-78893 and JP-A-59-109394 have been proposed.
JP-A-60-2398, etc., using a chelating heat diffusible dye (hereinafter also referred to as a post-chelating dye) and reacting with a metal ion-containing compound (hereinafter also referred to as a metal source) to form a metal chelate. A method for forming an image is disclosed. Regarding the storability of an image obtained by this metal chelate, the higher the chelate rate at which the post-chelate dye supplied from the ink sheet is combined with the metal source in the image receiving layer, the better the dye fixability and the better the image storability. Is known to be.

As a method for increasing the chelate ratio, an image forming method in which the image after the transfer of the post-chelating dye is further processed at a high temperature by using a heating device is proposed in Japanese Patent Application Laid-Open No. Hei 4-89292. As the heating device, a heat roller, a heat press plate, or the like can be preferably used because it can provide high temperature at low cost without taking up space. However, this method has disadvantages such as the necessity of installing a heating device separately from the thermal transfer recording device and the poor handling properties such as the necessity of two processes for image formation. Further, in order to prevent contamination due to dye transfer to a heat roller or a heat press plate, it is necessary to perform a heat treatment by attaching a sheet-like protective material between the transfer roller and the image receiving sheet, which is disadvantageous in terms of cost.

On the other hand, as a method for heating an image formed by thermal transfer recording, a method using a thermal head has been proposed. For example, Japanese Patent Publication No. 4-55870 discloses a method in which an uncoated area is provided on a surface-sequential sublimation transfer paper, and after the dye is transferred, the image receiving sheet after the dye transfer is reheated by a thermal head through the area. It has been disclosed. In this method, heat treatment can be performed in the same apparatus as the thermal transfer recording apparatus, which is advantageous in terms of cost, handling, and the like.

[0006]

As a process for transferring and diffusing a dye from an ink layer to an image receiving layer using a thermal head, pulse energy is applied from the apparatus main body to a thermal head resistor, and the applied energy is applied. After that, it is normal to set a temperature decrease time during one cycle and shift to the next cycle. By providing this temperature decrease time, the dye is transferred from the non-transferred data portion in the next cycle by the residual heat of the resistor. To prevent them from doing so.

This process is the same when reheating is performed. The shape of the thermal head resistor used here with respect to the surface of the image receiving layer is usually rectangular, and energy is applied in a pulse shape. At that point, the shape of the heat-generating dots approximates an ellipse or a circle, and the oval or circular part of the heat-generating dots at the time of image formation gives a high temperature to the image receiving layer, while the temperature between the heat-generating dots gives the image receiving layer a low temperature. The portion of the dye applied by the thermal head is transferred to the image receiving layer according to its shape to form an image dot, which forms a component to form an image.

However, as a result of the study of the present inventors, in such a thermal transfer recording, the thermal head is designed so as to apply pressure to improve the heat transfer efficiency together with heat generation. It becomes softer and more easily deformed, and the surface of the image receiving layer in contact with the high-temperature heat-generating dot-shaped part is dented by the pressure of the thermal head,
It was found that unevenness was formed on the surface of the image receiving layer due to swelling of the layer surface in the recessed portion between image dots, and the glossiness of the image surface was significantly reduced.

In particular, in the post-chelate dye transfer recording method, in order to complete the reaction of fixing the dye while diffusing the dye by heat, it is necessary to perform reheating treatment with relatively large heat energy. It has been difficult to achieve both high image quality, high image storability, and high glossiness due to the above.

As one method for improving such a defect, it is known to provide a protective layer having uniform smoothness on the surface of an image after dye transfer. A method has been proposed in which a protective layer is thermally transferred so as not to occur as much as possible. For example, the transfer energy of the protective layer is made as small as possible, scanning is performed at a higher speed than that of transferring the dye, and the heat distribution is made as uniform as possible to transfer the protective layer.

However, in the transfer of the protective layer using the thermal head, since at least a part is softened and transferred to the image receiving layer, irregularities are also formed on the surface of the transparent protective layer according to the same principle as described above, and the surface gloss is reduced. Will deteriorate. Therefore, in order to obtain high gloss, it is best to perform thermal transfer on the transparent protective layer with low energy so that heat history does not occur as much as possible.However, in order to complete the chelation reaction, reheating treatment with large heat energy is required. Therefore, problems still remain in terms of image quality and image storability, and at the same time, further studies are needed to achieve both high glossiness.

The present invention has been made in view of the above circumstances, and an object of the present invention is to form a high gloss image even when high heat energy is applied, while having high image quality and excellent image storability. .

In particular, when an image is formed by a sublimation thermal transfer system using a chelate-reactive dye, high image quality, high image storability and high gloss can be obtained even when a thermal head is applied with high thermal energy. The purpose is to balance image formation.

[0014]

The above object of the present invention is attained by the following constitutions.

1. The ink layer of an ink sheet having at least one ink layer containing a heat-diffusable dye on a support and the image receiving layer of an image receiving sheet having at least one image receiving layer on a separate support are superposed. A thermal transfer recording method in which the dye is transferred to the image receiving layer by imagewise heating with a thermal head, and then at least the entire area of the image receiving sheet to which the dye has been transferred is reheated with a thermal head to form an image. 3. The thermal transfer recording method according to claim 1, wherein the non-energization time interval is set to a certain value or less so that the temperature of the surface of the resistor of the thermal head in the reheating treatment does not become 1/3 or less of the peak temperature.

2. The ink layer of an ink sheet having at least one ink layer containing a heat-diffusable dye on a support and the image receiving layer of an image receiving sheet having at least one image receiving layer on a separate support are superposed. A thermal transfer recording method in which the dye is transferred to the image receiving layer by imagewise heating with a thermal head, and then at least the entire area of the image receiving sheet to which the dye has been transferred is reheated with a thermal head to form an image. Wherein the relative movement distance of each line between the thermal head and the image receiving sheet during the reheating process is set to not more than の of the length of the thermal head resistor in the sub-scanning direction. .

3. The ink layer of an ink sheet having at least one ink layer containing a heat-diffusable dye on a support and the image receiving layer of an image receiving sheet having at least one image receiving layer on a separate support are superposed. A thermal transfer recording method in which the dye is transferred to the image receiving layer by imagewise heating with a thermal head, and then at least the entire area of the image receiving sheet to which the dye has been transferred is reheated with a thermal head to form an image. In the reheating process, the shape of the resistor is set so that the resistor of the thermal head exists in any line segment parallel to the sub-scanning direction, or a thermal head having a plurality of rows of resistors is used. A thermal transfer recording method, comprising:

4. 4. The thermal transfer recording method according to any one of claims 1 to 3, wherein at the time of the reheating treatment, at least the entire surface of the image receiving sheet on which the dye has been transferred is heated by a thermal head to transfer the transparent protective layer.

5. The ink layer of the ink sheet contains a heat-diffusible dye capable of chelation, and the image receiving layer of the image receiving sheet contains a metal ion-containing compound capable of performing a chelate reaction with the dye. 5. The thermal transfer recording method according to any one of claims 1 to 4.

6. The thermal transfer recording method according to any one of claims 1 to 5, wherein the application pulse condition is set so that the chelate reaction rate at the time of the reheating treatment is 70% or more and the glossiness is 70 or more. .

7. An ink sheet for thermal transfer recording, comprising a region containing a heat-diffusible dye and a region containing an epoxy-modified resin.

8. 8. The thermal transfer recording ink sheet according to claim 7, wherein the area containing the epoxy-modified resin is formed so as to be transferable.

9. A thermal transfer recording ink sheet having a region containing a heat-diffusible dye, a region containing an epoxy-modified resin, and an image receiving layer of an image receiving sheet having at least one image receiving layer on a separate support are opposed to each other. As described above, the dye is transferred to the image receiving layer by imagewise heating with a thermal head, and then thermal transfer is performed through at least the area containing the epoxy-modified resin to the area where the dye is transferred on the image receiving sheet. A thermal transfer recording method, wherein reheating is performed by a head.

10. The thermal transfer recording ink sheet contains a chelatable thermal diffusible dye, and the image receiving layer of the image receiving sheet contains a metal ion-containing compound capable of performing a chelate reaction with the dye. The thermal transfer recording method described in the above.

[11] 11. The thermal transfer recording method according to claim 9, wherein the region containing the epoxy-modified resin is transferred to an image receiving sheet during the reheating treatment.

According to the present invention, an ink sheet containing a heat-diffusible dye and an image receiving sheet are superposed so as to face each other.
When forming an image by performing a heat treatment with a thermal head, in order to improve the problem of deterioration in glossiness of the image surface due to unevenness of the image receiving layer surface of the image receiving sheet, the thermal head as a reheating unit is used. Focusing on the two aspects of the condition and the configuration of the ink sheet, they were made as a result of intensive studies on these.

That is, under the condition of the thermal head, based on the finding that the glossiness is improved by performing the reheating treatment under the specified condition and leveling the unevenness of the image surface, the image receiving layer made of the resistor of the thermal head is used. It has been found that it is the best method to apply while applying pressure with a thermal head so as to have a uniform heat distribution so as not to cause a difference in heat distribution on the surface, and as a specific means, 1) The non-energizing time interval is set to a certain value or less so that the temperature of the resistor surface of the thermal head does not become 1/3 or less of the peak temperature in the reheating process. 2) In the reheating process, the thermal head and the image receiving sheet are used. 1
Make the relative movement distance of each line less than or equal to 1/2 of the length of the thermal head resistor in the sub-scanning direction. This is achieved by setting the shape of the resistor so that the resistor of the head exists or by using a thermal head in which a plurality of rows of resistors are arranged.

By the reheating treatment employing these conditions, the temperature difference of the heat transmitted to the surface of the image receiving layer when applying the thermal head is reduced, and the unevenness of the surface of the image receiving layer caused by the heat and pressure of the thermal head is suppressed. Therefore, the glossiness of the image surface of the image receiving layer is surprisingly improved. Therefore, even after the transfer of the dye or the transfer of the protective layer to the surface of the image receiving layer, the effect that the glossiness of the image surface is not lost even when high energy is applied during the reheating treatment can be obtained.

On the other hand, referring to the structure of the thermal transfer recording ink sheet, it is surprising that a region containing an epoxy-modified resin is provided, and the region of the image receiving layer to which the dye has been transferred is reheated through this region. What should be clear is that unevenness on the surface of the image receiving layer is suppressed, and as a result, the glossiness of the image surface of the image receiving layer is surprisingly improved.

Hereinafter, the present invention will be described in detail.

According to the present invention, the deterioration of the glossiness of the image surface due to the occurrence of unevenness on the surface of the image receiving layer of the image receiving sheet is improved by leveling the unevenness by reheating treatment. Considering that it is important to reduce the difference in the transfer temperature applied to the layer surface, the reheating treatment described in 1) to 3) above, which specifies the conditions of the thermal head, makes it possible to transfer the dye during dye transfer. The generated irregularities are made uniform, and as a result, the glossiness of the image surface is improved. Hereinafter, each of the above 1) to 3) will be described.

1) The non-energizing time interval is set to a certain value or less so that the temperature of the surface of the resistor of the thermal head in the reheating process does not become 1/3 or less of the peak temperature, that is, the temperature of the surface of the thermal head resistor becomes a peak. The current is supplied so that the difference between the temperature and the temperature drop is as small as possible.

By distributing energy application pulses at appropriate time intervals in one line of printing, the surface of the resistor of the thermal head is prevented from continuing to rise, and the temperature is not lowered below a certain level. As a result, the difference in the distribution of the reheating temperature received by the image receiving layer surface can be reduced, so that the unevenness on the image receiving layer surface is uniformly corrected, and the glossiness of the image surface is improved. In this method, the non-energizing time interval is set such that the temperature of the resistor surface is 1/1 of the peak temperature.
The current may be supplied before the voltage becomes 3 or less, and the interval may be set as appropriate. In the present invention, it is more preferable to set the non-energization time interval to a certain value or less so that the temperature of the resistor surface of the thermal head does not become １ ／ or less of the peak.

2) In the reheating process, the relative moving distance of the thermal head and the image receiving sheet for each line is set to be not more than の of the length of the thermal head resistor in the sub-scanning direction. The purpose is to shorten the moving distance of one line in the scanning direction so as to make the image dots dense, and to level the unevenness of the surface of the image receiving layer to finish the surface evenly. As a result, the image surface becomes glossy. It will increase the degree.

In the present invention, in the case of a line type thermal head, the direction in which the resistors are arranged is called the main scanning direction, and the direction perpendicular to the direction is called the sub-scanning direction. Generally, printing is performed by relatively moving the thermal head and the image receiving sheet in the sub-scanning direction.

In the present invention, it is more preferable that the relative movement distance of each line between the thermal head and the image receiving sheet be one third or less of the length of the thermal head resistor in the sub-scanning direction.

3) In the reheating process, the shape of the resistor is set so that the resistor of the thermal head exists in any line segment parallel to the sub-scanning direction, or the thermal head in which the resistor is arranged in a plurality of rows. to use.

Among the former, "the shape of the resistor is set so that the resistor of the thermal head exists in any line segment parallel to the sub-scanning direction", the heating dots of the thermal head resistor can be formed. The purpose is to bring the surface of the image receiving layer as close as possible into contact with the surface of the image receiving layer. By adopting a deformed version of a normal rectangular resistor, the unevenness on the surface of the image receiving layer is evened out to form a uniform plane. Although the shape is not particularly limited, for example, the surface of the thermal head resistor in contact with the image receiving layer surface has a rhombus that exists in any line segment parallel to the sub-scanning direction, a shape having the same waviness, Circular and the like can be mentioned.

On the other hand, with regard to the latter, “in the reheating process, a plurality of rows of resistors are arranged so that the resistors of the thermal head exist in any line segment parallel to the sub-scanning direction”.
The heating dots of the thermal head resistor can be arranged in a plurality of rows so that the intervals between the heating dots of the thermal head resistor in the sub-scanning direction are not parallel to the sub-scanning direction, for example, the intervals of the resistor rows are alternated. The purpose is to bring the surface of the image receiving layer into contact with the surface of the image receiving layer as densely as possible.

Here, the "line segment parallel to the sub-scanning direction" means
As described above, the sub-scanning direction is defined as a direction perpendicular to the main scanning direction, but means a vertical line that is parallel to the sub-scanning direction. Therefore, this indicates that at least one resistor of the thermal head exists on a vertical line that is parallel to the sub-scanning direction.

In the present invention, in particular, in chelate type sublimation thermal transfer, chelation is terminated after dye transfer.
Post-heating after dye transfer is required. In the subsequent heating step, by heating with a thermal head so that a uniform heat distribution as described above can be obtained, a glossy image can be formed upon completion of the reaction, which is preferable. Further, the post-heating treatment and the transfer of the transparent protective layer may be performed simultaneously, and a glossy image can be formed by heating with a thermal head so that a uniform heat distribution is obtained in the process.

When the reheating treatment or the reheating treatment while transferring the transparent protective layer, the chelate reaction rate is 70%.
It is preferable to set the application pulse condition so that the gloss is 70 or more.

In the present invention, the chelate reaction rate is defined as follows. First, after dye transfer, the image receiving sheet is treated at a high temperature for a long time (for example, at 120 ° C. for 10 minutes) to obtain a sample which has been subjected to a 100% chelation reaction. A sample obtained by transferring only the dye to the image receiving layer side without adding a metal ion-containing compound is used as a sample for the 0% chelate reaction. 100% above
And the spectral absorption spectrum of the 0% sample, and the absorbance at the maximum absorption wavelength of the 0% sample and the absorbance of the sample having a chelate reaction rate of 100% at that wavelength were determined.
The result obtained from the proportional distribution of the two is defined as the chelate reaction rate.

Gloss is a value measured at an incident angle and a reflection angle of 60 ° with a gloss meter. In the present invention, the applied pulse conditions are set so that the value is 70 or more, preferably 80 or more. Setting is preferable in terms of achieving both high image quality, high image storability, and high gloss.

Next, an ink sheet for thermal transfer recording (hereinafter, referred to as an ink sheet) used in the present invention will be described.

In the present invention, the ink sheet has a region containing a heat-diffusible dye and a region containing an epoxy-modified resin, which are formed on a suitable support. Specifically, at least one layer on the support has a multilayer structure of a resin containing an epoxy-modified resin or a single-layer structure of a resin containing an epoxy-modified resin. The ink sheet may be formed such that a region containing the epoxy-modified resin is transferable, and may be transferred to an image receiving sheet as a protective layer, for example. The structure is a multilayer structure such as a release layer or an adhesive layer, or a single-phase structure, and the epoxy-modified resin is not particularly limited as long as it is contained in at least one layer.

The epoxy-modified resin used in the present invention includes epoxy-modified urethane, epoxy-modified polyethylene, epoxy-modified polyethylene terephthalate, epoxy-modified polyphenylsulfite, epoxy-modified cellulose, epoxy-modified polypropylene, epoxy-modified polyvinyl chloride, and epoxy-modified Polycarbonate, epoxy modified acrylic, epoxy modified polystyrene, epoxy modified polymethyl methacrylate, epoxy modified silicone, copolymer of epoxy modified polystyrene and epoxy modified polymethyl methacrylate, copolymer of epoxy modified acrylic and epoxy modified polystyrene, epoxy modified acrylic Epoxy-modified silicone copolymers are preferred.Epoxy-modified acrylic, epoxy-modified polystyrene, epoxy-modified Polymethyl methacrylate,
Epoxy-modified silicone, more preferably a copolymer of epoxy-modified polystyrene and epoxy-modified polymethyl methacrylate, a copolymer of epoxy-modified acrylic and epoxy-modified polystyrene, and a copolymer of epoxy-modified acrylic and epoxy-modified silicone.

The support for the ink sheet is not particularly limited as long as it has good dimensional stability and can withstand the heat at the time of recording with a thermal head, and any known support can be used. Paper, glassine paper, thin paper such as paraffin paper, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone, etc.High heat-resistant polyester, polypropylene, polycarbonate, cellulose acetate, polyethylene A stretched or unstretched film of a plastic such as a derivative, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, or ionomer, or a laminate of these materials may be used. The thickness of the support can be appropriately selected depending on the material so that the strength, thermal conductivity, heat resistance, and the like are appropriate. Usually, a thickness of about 1 to 100 μm is preferably used.

An embodiment in which a region containing a heat-diffusible dye and a region containing an epoxy-modified resin of an ink sheet are supplied in a plane-sequential manner will be described with reference to the drawings.

FIG. 1 is a view showing an ink sheet according to one embodiment of the present invention. The region containing the heat-diffusible dye will be described as an ink layer, and the region containing an epoxy-modified resin will be described as a reheat treatment layer.

In FIG. 1A, yellow (Y), magenta (M), and cyan (C) ink layers 2 are provided on the same plane of a support 3 in the order of the planes. In addition, a region (hereinafter, reheat-treated layer) 1 containing an epoxy-modified resin in the same area as the ink layer for the heat treatment is provided. In FIG. 1B, the Y, M, and C ink layers 2 are provided on the same plane of the support 3 in a plane-sequential manner.
The reheating treatment layer 1 is provided between the respective ink layers.
In FIG. 1, there is no gap between the layers,
A gap may be appropriately provided according to the control method of the thermal transfer recording apparatus. Further, in order to perform the cueing of each layer with good precision, it is preferable to provide a detection mark on an ink sheet 15 described later, but the method of providing the detection mark is not particularly limited.
The definition of the ink layer is that the dye itself contained in the ink layer is a compound before the reaction, and strictly speaking, Y and
Although it cannot be said that they are M and C dyes, they are similarly expressed for convenience in the sense that they are layers for finally forming Y, M and C images.

As the thermal transfer recording apparatus used in the present invention, for example, an apparatus as shown in FIG. 2 can be used. In FIG. 2, reference numeral 10 denotes an ink sheet supply roll, 1
5 is an ink sheet, 11 is an ink sheet 15 used
, A thermal head 13, a platen roller 13, and an image receiving sheet 14 inserted between the thermal head 12 and the platen roller 13.

In order to form an image using, for example, the ink sheet shown in FIG. 1A as an ink sheet by using the thermal transfer recording apparatus shown in FIG. 2, first, an area 2Y containing a yellow dye of the ink sheet is formed. The yellow dye in the ink layer in the area is transferred to the image receiving sheet according to the image data by applying heat from a thermal head to form a yellow image, and then the magenta dye is formed on the yellow image. Similarly, the magenta dye is transferred imagewise from the ink layer of the area 2M containing
Then, on the transferred image, a region 2 containing a cyan dye
Similarly, the cyan dye is transferred imagewise from the C ink layer, and finally, the entire surface of the image is reheated by the reheat treatment layer 1 to complete the image formation. When the area containing the epoxy-modified resin is provided in this way, and the area where the dye of the image receiving layer has been transferred is subjected to reheating treatment through this area, unevenness of the image receiving layer surface is suppressed, and the image surface of the image receiving layer is Is improved.

FIG. 1 (b) shows the ink sheet of FIG.
Is used, first, the area 2Y containing the yellow dye of the ink sheet and the image receiving layer of the image receiving sheet are overlapped,
By applying heat from the thermal head, the yellow dye in the ink layer in the area is transferred to the image receiving sheet in accordance with the image data to form a yellow image, and then the entire surface of the image is reheated by the reheat treatment layer 1. The magenta dye is similarly transferred imagewise from the ink layer in the area 2M containing the magenta dye on the yellow image, and the entire surface of the image is reheated by the reheat treatment layer 1, and then the transferred image Similarly, the cyan dye is transferred imagewise in the same manner from the ink layer in the area 2C containing the cyan dye, and finally the entire surface of the image is reheated by the reheat treatment layer 1 to complete the image formation. I do. Also in such an ink sheet form, the unevenness of the image receiving layer surface is similarly suppressed, and the glossiness of the image surface of the image receiving layer is improved.

In the thermal transfer recording method of the present invention, various types of thermal transfer recording apparatuses can be used. In addition to the above-described type in which the dye transfer and the reheating treatment are integrally printed, for example, as shown in FIG. After the dye transfer shown in (b), a separate type in which reheating is performed using another reheating apparatus, or dye transfer is performed for each of the Y, M, and C ink sheets shown in FIG. 2C. After that, a separate type in which a reheating treatment is finally performed by using another reheating treatment device is exemplified.

FIG. 2B shows a case where the ink sheet has the form shown in FIG. 1C. In this case, first, in the apparatus for dye transfer, the area 2Y containing the yellow dye of the ink sheet and the image receiving layer of the image receiving sheet are overlapped,
By applying heat from the thermal head, the yellow dye in the ink layer in the area is transferred to the image receiving sheet according to the image data to form a yellow image, and then the magenta dye-containing area 2M ink layer is formed on the yellow image. Then, the magenta dye is transferred image-wise, and then the cyan dye is transferred image-wise from the ink layer in the area 2C containing the cyan dye onto the transferred image to form a dye-transferred image. Using a device for heat treatment, the entire surface of this image is subjected to reheat treatment with the reheat treatment layer 1,
Image formation is completed.

FIG. 2C shows a case in which the ink sheet is separated for each color and recorded by the corresponding apparatus. In this case, first, the dye on the yellow ink sheet is transferred to the image receiving sheet according to the image data by the Y transfer device to form a yellow image, and then the magenta ink sheet is formed on the yellow image by the M transfer device. In the same manner, the dye on the cyan ink sheet is transferred to the image receiving sheet according to the image data on the image by the C transfer device, and finally the dye of FIG. In the same manner as in the above case, the entire surface of the image is subjected to the reheating treatment by the reheating treatment layer 1 by the reheating treatment device, thereby completing the image formation.

As the binder for the ink sheet, for example, cellulose-based resins such as cellulose-added compounds, cellulose esters and cellulose ethers; polyvinyl acetal resins such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetoacetal and polyvinyl butyral; polyvinyl pyrrolidone; , Polyacrylamide, styrene resin, poly (meth) acrylic acid ester, poly (meth) acrylic acid, vinyl resin such as (meth) acrylic acid copolymer, rubber resin, ionomer resin, olefin resin, polyester Resins and the like can be mentioned. Among these resins, polyvinyl butyral, polyvinyl acetoacetal, or cellulosic resins having excellent storage stability are preferable.

Further, the following resins can be used. JP-B 5-78437, isocyanates, polyvinyl butyral, polyvinyl formal,
The reaction product with a compound having active hydrogen selected from polyester polyol and acrylic polyol, the isocyanates are diisocyanate or triisocyanate, the reaction product, and 100 parts by weight of the compound having active hydrogen The reaction product in an amount of 10 to 200 parts by weight; an organic solvent-soluble polymer obtained by esterifying and / or urethanizing an intramolecular hydroxyl group of a natural and / or semi-synthetic water-soluble polymer; Synthetic water-soluble polymer; cellulose acetate having a degree of acetylation of 2.4 or more and a total degree of substitution of 2.7 or more described in JP-A-3-264393; polyvinyl alcohol (Tg = 85 ° C.), polyvinyl acetate (Tg = 32 ° C), vinyl resins such as vinyl chloride / vinyl acetate copolymer (Tg = 77 ° C), and polyvinyl butyral (Tg = 8). ° C.), polyvinyl acetal (Tg = 110 ℃) polyvinyl acetal resins such as,
Vinyl resins such as polyacrylamide (Tg = 165 ° C.), polyester resins such as aliphatic polyester (Tg = 130 ° C.), etc .; isocyanates described in JP-A-7-52564, and weight of vinyl alcohol part contained therein In which the isocyanate is diisocyanate or triisocyanate; and JP-A-7-32.
742, a phenyl isocyanate-modified polyvinyl acetal resin of the formula I; JP-A-6-155935, one of isocyanate-reactive cellulose or isocyanate-reactive acetal resin, and an isocyanate-reactive acetal resin; Isocyanate-reactive vinyl resin,
Cured product of a composition containing one resin selected from isocyanate-reactive acrylic resin, isocyanate-reactive phenoxy resin and isocyanate-reactive styrene resin and a polyisocyanate compound; polyvinyl butyral resin (preferably having a molecular weight of 6 Tg is 60 ° C. or more, more preferably 70 ° C. or more and 110 ° C. or less, and the weight% of the vinyl alcohol portion is 1% in the polyvinyl butyral resin.
0 to 40%, preferably 15 to 30%); Acrylic-modified cellulose-based resin, as a cellulose-based resin,
Cellulose resins (preferably ethylcellulose) such as ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, hydroxypropylcellulose, methylcellulose, cellulose acetate, and cellulose butyrate.

One of the above various binders can be used alone, or two or more of them can be used in combination.

As the heat diffusing dye to be contained in the ink sheet used in the present invention, conventionally known dyes can be used, and there is no particular limitation. However, from the viewpoint of obtaining particularly good image storability, post-chelating dyes can be used. It is preferable to use a dye.

The post-chelating dye is not particularly limited as long as thermal transfer is possible, and various known compounds can be appropriately selected and used. Specifically, for example, JP-A-59-78893, JP-A-59-109349,
Japanese Patent Application Nos. 2-213303, 2-214719, 2-203742, 4-94974, 4-97
For example, cyan dyes, magenta dyes, and yellow dyes described in JP-A Nos. 894 and 4-89292 can be used.

Among the above dyes, it is preferable to use a methine dye capable of forming a bidentate chelate with a metal source. Examples of such a dye include a dye represented by the following general formula (1).

[0064]

Embedded image

In the formula, X represents an atomic group having at least a bidentate chelate-forming group or atom, Y represents an atomic group necessary for forming an aromatic carbocyclic or heterocyclic ring,
₁ , R ₂ and R ₃ each represent a hydrogen atom, a halogen atom or 1
Represents a valent substituent. n represents 0, 1 or 2. Y is preferably an atomic group forming a 5- to 6-membered aromatic carbocyclic or heterocyclic ring, and the ring may further have a substituent.

X is particularly preferably represented by the following general formula (2).

[0067]

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In the formula, Z represents an atomic group necessary for forming an aromatic nitrogen-containing heterocyclic ring substituted with at least one group containing a chelatable nitrogen atom.

Specific examples of the ring include benzene, pyridine, pyrimidine, furan, thiophene, thiazole, imidazole, naphthalene and the like. These rings may form a conjugation ring with another carbon ring (such as a benzene ring) or a heterocyclic ring (such as a pyridine ring).

The substituent on the ring includes an alkyl group, an aryl group, an acyl group, an amino group, a nitro group, a cyano group,
Examples thereof include an acylamino group, an alkoxy group, a hydroxy group, an alkoxycarbonyl group, and a halogen atom, and these groups may be further substituted.

The halogen atom represented by R ₁ , R ₂ and R ₃ is a fluorine atom, a chlorine atom and the like, and the monovalent substituent is an alkyl group, an alkoxy group, a cyano group and an alkoxycarbonyl group. No.

As X =, those represented by the following general formulas (3) to (6) are particularly preferred.

[0073]

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In the formula, R ₄ and R ₅ are each a hydrogen atom, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.) or a monovalent substituent (an alkyl group, an aryl group, an acyl group, an amino group, a nitro group). Group, cyano group, acylamino group, alkoxy group, hydroxyl group, alkoxycarbonyl group, etc.). Q represents a substituent.

Specific examples of the compounds are shown below, but the present invention is not limited thereto.

[0076]

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[0077]

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[0078]

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[0079]

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The content of these post-chelating dyes cannot be unconditionally determined from the properties of the respective dyes, the solubility in the binder, the purpose of use, and the like, but is usually 10 to 80% by weight of the total weight of each dye-containing region. Used in

In the present invention, various additives can be appropriately added to the ink layer in addition to the above components. Additives include silicone resin, silicone oil (reaction curing type is also possible), silicone-modified resin; fluororesins, surfactants, release compounds such as waxes, metal fine powder, silica gel, metal oxide , Carbon black, fillers such as resin fine powder, and curing agents (for example, radiation-active compounds such as isocyanates, acryls, and epoxies) that can react with a binder component.

In the present invention, the ink sheet is not limited to the two-layer structure including the support and the ink layer, and other layers may be formed. For example, an overcoat layer may be provided on the surface of the ink layer for the purpose of preventing fusion with the image receiving layer and offset (blocking) of the dye.

The purpose of the ink sheet support is to improve the adhesiveness of the ink layer (area containing the heat diffusible dye) to the binder and to prevent the transfer or dyeing of the heat diffusible dye to the support side. May have an undercoat layer. Further, a sticking prevention layer may be provided on the back surface of the support (opposite side of the ink layer) for the purpose of preventing fusion or sticking of the head to the support and wrinkling of the ink sheet. The thickness of the overcoat layer, the undercoat layer and the anti-sticking layer is usually 0.1 to 1 μm.

The ink sheet is prepared by dispersing or dissolving the above-mentioned various components for forming an ink layer in a solvent to prepare an ink layer forming coating liquid, and applying the coating liquid to the surface of the ink sheet support, for example, by gravure printing. It can be manufactured by coating and drying in a system. The thickness of the ink layer to be formed is usually from 0.2 to 10 μm, preferably from 0.3 to 3 μm.

In the ink layer of the present invention, 5 is used as a sensitizer.
A low molecular weight substance having a melting point of 0 to 150 ° C may be contained. If the melting point is lower than 50 ° C., the sensitizer easily migrates to the surface of the ink layer, causing problems such as blocking. On the other hand, if the melting point is higher than 150 ° C., the sensitizing effect is rapidly lowered, which is not preferable.

The molecular weight of the sensitizer is preferably in the range of 100 to 1500. If the molecular weight is less than 100, the melting point is 50
° C or higher, while the molecular weight is 1
If it exceeds 500, the sharpening of the melting of the sensitizer at the time of thermal transfer is lost and the sensitizing effect becomes insufficient, which is not preferable.

The sensitizer is preferably used in an amount of 1 to 100 parts by weight per 100 parts by weight of the binder forming the ink layer. If the amount is less than 1 part by weight, it is difficult to obtain a satisfactory sensitizing effect, while if it exceeds 100 parts by weight, the heat resistance of the ink layer is undesirably reduced.

The sensitizer as described above may be any known low molecular weight substance as long as it has a melting point of 50 to 150 ° C., but is preferably a thermoplastic resin oligomer such as a polyurethane oligomer, a polystyrene oligomer, or a polyester. Oligomer, polyacryl oligomer, polyethylene oligomer, polyvinyl chloride oligomer, polyvinyl acetate oligomer, ethylene / vinyl acetate copolymer oligomer, ethylene acrylic copolymer oligomer, polyoxyethylene oligomer, polyoxypropylene oligomer, polyoxyethylene propylene oligomer And various fatty acids such as myristic acid, palmitic acid, margaric acid, stearic acid, arachiic acid, and montanic acid, caproic acid amide, caprylic acid amide, and lauric acid amide. Fatty acid amides, such as, stearic acid amide, oleic acid amide, eicosenoic acid amide, etc., fatty acid amides such as methyl behenate, pentadecyl palmitate, hexacosyl stearate, [1,4-phenylenebis (methylene)] carbamic acid bisdimethyl ester, etc. And other aromatic compounds such as 1,4-dicyclohexylbenzene, benzoic acid, aminobenzophenone, dimethyl terephthalate, fluoranthene, phenols, naphthalenes and phenoxys, and various waxes.

Next, the image receiving sheet used in the present invention will be described.

The image receiving sheet of the present invention comprises a support,
It comprises at least an image receiving layer formed on the surface of the support.

The support of the image receiving sheet preferably has a role of holding the image receiving layer and has a mechanical strength that does not hinder handling even in a heated state since heat is applied during thermal transfer. . The material of such a support is not particularly limited. For example, condenser paper, glassine paper, sulfuric acid paper, synthetic paper (polyolefin-based, polystyrene-based), high-quality paper, art paper, coated paper, cast-coated paper, wallpaper, backing Paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, etc., cellulose fiber paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, polyethylene, ethylene -Vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyetheretherketone, polysulfone, polyethersulfone, tetraf Films such as olefin / perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene / hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride and the like. In order to enhance the sharpness of an image formed in a later step, a white pigment or a filler (for example, titanium white, magnesium carbonate, zinc oxide, barium sulfate, silica, talc, clay, calcium carbonate, etc.) is added. A filmed white opaque film or a foamed foam sheet can also be used, and is not particularly limited.

Further, a laminate obtained by combining any of the above supports can be used as the support. As an example of a typical laminate, there is a synthetic paper of cellulose fiber paper and synthetic paper or a synthetic paper of cellulose fiber paper and plastic film.
The above materials may be further laminated on the synthetic paper or plastic film in order to separate functions such as cushioning property and heat conductivity. The thickness of the support may be arbitrarily determined according to the intended use, and is usually about 10 to 300 μm. or,
When the adhesion between the support and the layer provided thereon is poor, it is preferable to apply various primer treatments or corona discharge treatment to the surface of the support.

[0093] The image receiving layer is formed from the ink layer of the ink sheet.
There is no particular limitation as long as it can receive the heat diffusible dye diffused by heating, and it is basically formed of a binder and various additives. As a method of forming the image receiving layer on the surface of the support, a coating solution for an image receiving layer is prepared by dispersing or dissolving the components for forming the image receiving layer in a solvent, and the coating solution for the image receiving layer is coated on the support. Or a coating method in which the mixture having the components for forming the image receiving layer is melt-extruded and then laminated on the surface of the support. The thickness of the image receiving layer formed on the surface of the support is generally 0.5 to 50 μm, preferably about 1 to 20 μm.

As the binder for the image receiving layer, various binders such as a vinyl chloride resin, a polyester resin, a polycarbonate resin, an acrylic resin, a polyvinyl acetal resin and various heat resistant resins can be used. The type of the binder may be selected arbitrarily, but polyvinyl acetal-based resin or vinyl chloride-based resin is preferable in terms of image storability.

Examples of the polyvinyl acetal resin include a polyvinyl acetoacetal resin, a polyvinyl butyral resin, and a polyvinyl formal resin. Examples of the vinyl chloride resin include a polyvinyl chloride resin and a vinyl chloride copolymer. Examples of the vinyl chloride copolymer include a copolymer of vinyl chloride and another comonomer containing vinyl chloride at a ratio of 50 mol% or more as a monomer unit. In addition to the polyvinyl acetal resin and the vinyl chloride resin, a polyester resin can also be suitably used as the image receiving layer for thermal transfer. As the polyester resin, for example, polyethylene terephthalate, polybutylene terephthalate, JP-A-58-188865,
Compounds described in JP-A-62-244696 can be exemplified. As the polycarbonate resin, for example, various compounds described in JP-A-62-169694 can be used. Examples of the acrylic resin include polyacrylester.

The heat-resistant resin has good heat resistance and is not a resin having an extremely low softening point or glass transition point (Tg).
Various known heat-resistant resins can be used as long as they are appropriately compatible with the vinyl chloride resin and are substantially colorless.

The term "heat resistance" as used herein means that the resin itself does not undergo coloring such as yellowing when stored under heat, and the physical strength does not extremely deteriorate.

The heat-resistant resin has a softening point of 30 to 200.
C, especially preferably Tg of 50 to 150C. If the softening point is lower than 30 ° C., the transfer of the heat-diffusible dye is not preferred because the ink sheet and the image receiving layer may be fused. If the softening point exceeds 200 ° C., the sensitivity of the image receiving layer is undesirably lowered. Examples of the heat-resistant resin satisfying the above conditions include a phenol resin, a melamine resin, a urea resin, and a ketone resin. Among them, a urea aldehyde resin and a ketone resin are particularly preferable. Urea aldehyde resin is obtained by condensation of urea and aldehydes (mainly formaldehyde), and ketone resin is obtained by condensation reaction of ketone and formaldehyde.

In the present invention, the image receiving layer contains, in addition to the binder, a dye fixing body which can react with the heat diffusible dye contained in the ink sheet. In a preferred embodiment of the present invention, when a post-chelate dye is contained in the ink layer, a metal source capable of forming a metal chelate with the post-chelate dye is contained in the image receiving layer as a dye fixing body.

Examples of the metal source include inorganic or organic salts and metal complexes of metal ions, and among them, salts and complexes of organic acids are preferred. As the metal, the I-th of the periodic table
Monovalent and polyvalent metals belonging to groups VIII to VIII,
Among them, Al, Co, Cr, Cu, Fe, Mg, Mn, M
o, Ni, Sn, Ti and Zn are preferred, especially Ni,
Cu, Cr, Co and Zn are preferred. Specific examples of the metal source include Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , Co ²⁺ and Z
an aliphatic carboxylate of n ²⁺ with acetic acid, stearic acid, or the like;
Alternatively, an aromatic carboxylate with benzoic acid, salicylic acid or the like may be used. Further, a complex represented by the following formula (M) is particularly preferable because it can be stably added to the image receiving layer and is substantially colorless.

General formula (M) [M (Q ₁ ) _x (Q ₂ ) _y (Q
^{_{3) z] P + (L}} -) in _P-type, M is a metal ion, preferably Ni ^2+, Cu ^2+, C
represents r ²⁺ , Co ²⁺ or Zn ²⁺ . Q ₁ , Q ₂ and Q ₃ are
Each represents a coordination compound capable of coordinating with the metal ion represented by M, and may be the same or different. These coordination compounds can be selected, for example, from the coordination compounds described in Chelate Science (5) (Nankodo). L ⁻ represents an organic anion group, and specific examples thereof include a tetraphenylboron anion and an alkylbenzenesulfonic acid anion. x represents 1, 2 or 3, y represents 1, 2 or 0, z represents 1 or 0,
These are those in which the complex represented by the general formula (M) is tetradentate,
Or Q ₁ , Q ₂ , Q ₃
Is determined by the number of ligands. p represents 1 or 2. Specific examples of this type of metal source include a compound described in U.S. Pat. No. 4,987,049;
Compound No. 11008 1 to 50 and the like.

The amount of addition of the metal source is usually preferably 5 to 80% by weight based on the binder of the image receiving layer.
70% by weight is more preferred. If the amount of the metal source in the image receiving layer is too large, the tint of the metal source appears in the color tone of the white background of the image receiving sheet, which is not preferable.

The image receiving layer may contain a releasing agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a filler, a pigment and the like. Further, a plasticizer, a heat solvent and the like may be added as a sensitizer.

The release agent can improve the releasability between the ink layer of the ink sheet and the image receiving layer of the image receiving sheet.
Examples of such release agents include the aforementioned silicone oils (including those referred to as silicone resins); solid waxes such as polyethylene wax, polypropylene wax, amide wax, and Teflon powder; fluorine compounds, silicon compounds, and the like. Composites, fluorine-based or phosphate-based surfactants; coupling agents;
Long-chain alkyl compounds; polyoxyalkyl polyols, etc., among which silicone oil is preferred.

The filler includes inorganic fine particles and organic resin particles. Examples of the inorganic fine particles include silica gel, calcium carbonate, titanium oxide, acid clay, activated clay, and alumina. Examples of the organic fine particles include resin particles such as fluororesin particles, guanamine resin particles, acrylic resin particles, and silicon resin particles. Can be mentioned. These inorganic / organic resin particles differ depending on the specific gravity, but are preferably added in an amount of 0.1 to 70% by weight. Representative examples of the pigment include titanium white, calcium carbonate, zinc oxide, barium sulfate, silica, talc, clay, kaolin, activated clay, and acid clay.

Examples of the plasticizer include phthalic esters (eg, dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, didecyl phthalate, etc.) and trimellitic esters (eg, octyl trimellitate, isononyl trimellitate) , Pyromellitic acid octyl ester and the like, pyromellitic acid esters such as octyl pyromellitic acid ester, and adipic acid esters. Since the excessive addition of the plasticizer deteriorates the storability of the image, the amount of the plasticizer added is usually
It is in the range of 0.1 to 30% by weight based on the binder of the image receiving layer.

A slippery backside layer may be provided on the backside of the image receiving sheet.

The above fillers can be easily obtained in the market. For example, SPRAY3
0 (manufactured by Sasol), W950 (manufactured by Mitsui Petrochemical Industries)
Examples of the nylon filler include MW330 (manufactured by Shinto Paint). The addition amount of the filler is preferably in the range of 0.01 to 200 parts by weight based on 100 parts by weight of the resin of the layer to be added.

The center line average surface roughness Ra of the surface of the back layer is preferably 0.5 to 2.5 μm. The average number of projections per unit area is preferably 2000 to 4500 / mm ² . As a method of giving such a property,
For example, in addition to adjusting using the filler as described above, the surface shape of the cooling roll at the time of resin extrusion coating is made to have the above-described properties, and the shape is transferred by transferring the shape when cooling the extruded resin. Can be done.

An intermediate layer may be provided between the lubricating back layer and the support for the purpose of increasing the adhesive strength. As a preferred embodiment of the intermediate layer, an intermediate layer having a reaction-curable resin is provided.

The reaction-curable resin is disclosed in JP-A-6-255.
It is preferred to use a thermosetting resin and / or an ionizing radiation-curable resin as described in U.S. Pat.

An intermediate layer having the same structure may be provided between the support and the image receiving layer.

The image-receiving layer of the present invention is described in JP-A-4-24199.
The surface may be subjected to a matting treatment and / or a gloss adjustment by a method as described in No. 3.

[0114]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but embodiments of the present invention are not limited thereto.
Unless otherwise specified, “parts” in the examples are “parts by weight”.
Represents

Example 1 (corresponding to claims 7 to 10) (Preparation of ink sheet 1) As a support, a heat-resistant lubricating layer (SP-712, manufactured by Dainichi Seika Co., Ltd.) was provided on one side. A 6 μm polyethylene terephthalate film (manufactured by Toray Industries, Inc., Lumirror 6CF531) is coated with a yellow, magenta, and cyan ink layer and a reheat treatment layer having the following composition by a gravure method on the side opposite to the side surface of the layer. The dry film thickness of the ink layer is 1.1 μm, the dry film thickness of the reheat treatment layer is 0.6 μm), and the yellow, magenta, cyan ink layers and the reheat treatment layer are arranged in the order shown in FIG. Ink sheet 1) was obtained.

Yellow ink layer Dye Y-1 shown below 3 parts Polyvinyl butyral (Denka Butyral KY-24, manufactured by Denki Kagaku Kogyo KK) 5.5 parts Epoxy-modified acrylic resin (Reseda GP- manufactured by Toa Gosei Chemical Co., Ltd.) 305) 1 part Urethane-modified silicone oil (Dialomer SP-2105 manufactured by Dainichi Seika Kogyo Co., Ltd.) 0.5 part Methyl ethyl ketone 80 parts Toluene 10 parts Magenta ink layer The following pigment M-1 3 parts Polyvinyl butyral (denka butyral mentioned above) KY-24) 5.5 parts Epoxy-modified acrylic resin (Reseda GP-305) 1 part Urethane-modified silicone oil (Dialomer SP-2105) 0.5 parts Methyl ethyl ketone 80 parts Toluene 10 parts Cyan ink layer Dye C below -1 3 parts Polyvinyl butyral (denkabu mentioned above) Lar KY-24) 5.5 parts Epoxy-modified acrylic resin (Reseda GP-305) 1 part Urethane-modified silicone oil (Dialomer SP-2105) 0.5 parts Methyl ethyl ketone 80 parts Toluene 10 parts Reheat treatment layer Epoxy modified acrylic resin (Toagosei Co., Rezeda GP-301) 18 parts ^{_{Ni 2+ (NH 2 COCH 2 NH}} 2) 3 · 2B (C 6 H 5) 4 2 parts Methyl ethyl ketone 80 parts

[0117]

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(Preparation of Ink Sheet 2) Ink Sheet 1
Ink sheet 2 was produced in the same manner except that the reheating treatment layer was changed to the structure shown below.

[0119] reheating layer Polyvinyl butyral resin (Sekisui Chemical Co., Ltd., S-LEC BX-1) 18 parts of ^{_{Ni 2+ (NH 2 COCH 2 NH}} 2) 3 · 2B (C 6 H 5) 4 2 parts Methyl ethyl ketone 80 parts (Preparation of Ink Sheet 3) An ink sheet 3 was prepared in the same manner except that the reheating treatment layer of the ink sheet 1 was changed to the following configuration. The dry thickness of the release layer was 0.6 μm for the protective layer and 1.0 μm for the adhesive layer.

[0120] protective layer peeling layer epoxy-modified acrylic resin (Toagosei Co., Rezeda GP-301) 18 parts ^{_{Ni 2+ (NH 2 COCH 2 NH}} 2) 3 · 2B (C 6 H 5) 4 2 parts Toluene 80 parts Adhesive layer Acrylonitrile styrene resin (manufactured by Sanyo Chemical Industries, Lightac 100A) 80 parts Methyl ethyl ketone 20 parts (Preparation of ink sheet 4) Ink was prepared in the same manner except that the reheating treatment layer of ink sheet 3 was changed to the following structure. Sheet 4 was produced. The dry thickness of the release layer was 0.6 μm for the protective layer and 1.0 μm for the adhesive layer.

[0121] protective layer peeling layer Polyvinyl butyral resin (supra S-LEC BX-1) 18 parts of ^{_{Ni 2+ (NH 2 COCH 2 NH}} 2) 3 · 2B (C 6 H 5) 4 2 parts Toluene 80 parts adhesive layer acrylonitrile-styrene Resin (manufactured by Sanyo Chemical Co., Ltd., Lightac 100A) 80 parts Methyl ethyl ketone 20 parts (Preparation of image-receiving sheet) Anchor layer and image-receiving layer having the following composition are provided on the surface of synthetic paper (Lumilar E60L, manufactured by Toray Industries, Inc.) having a thickness of 188 μm as a support. Were applied in this order to form an anchor layer having a thickness of 0.2 μm and an image receiving layer having a thickness of 4 μm. Thus, an image receiving sheet 1 was obtained.

Anchor layer Polyvinyl acetoacetal (Eslec BL-1 manufactured by Sekisui Chemical Co., Ltd.) 7.5 parts Isocyanate (Coronate HX manufactured by Nippon Polyurethane Industry Co., Ltd.) 2.5 parts Methyl ethyl ketone 80 parts n-butyl acetate 10 parts Image receiving layer Polyvinyl butyral (Eslek BX-1 manufactured by Sekisui Chemical Co., Ltd.) 6.5 parts Polyester modified silicon (X-24-8300 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts Ni ²⁺ (NH ₂ COCH ₂ NH ₂ ) ₃ · 2B (C ₆ H ₅ ) ₄ 3 parts Methyl ethyl ketone 80 parts n-butyl acetate 10 parts (Image formation) No. 4 ink layers were superposed, the resolution was 12 dots / mm, and the average resistance was 3100.
Ω thermal head and platen roll for 5-8
A yellow, magenta, cyan, and neutral (three-color superimposed) step pattern that is sequentially increased in an applied energy range of 0 mJ / mm ² is fed at a feed speed of 10 msec / l.
The dye was transferred onto the image receiving layer by heating from the back side of the ink layer under the condition of ine. Then, the same thermal head and platen roll are pressed against the image receiving sheet to which the dye has been transferred via the reheating treatment layer or the protective layer, and the applied energy is 50 mJ.
/ Mm ² and a feed rate of 8.5 msec / line, the reheating treatment was performed by heating from the back side of the reheating treatment layer or the protective layer.

The obtained images were evaluated as described below.

(Evaluation) (Image Glossiness) Glossmeter (Model VGS-, Nippon Denshoku Industries Co., Ltd.)
In 1D), the glossiness before and after the reheating treatment was measured for the neutral D = 2.0 position and the white portion.

The results are shown in Table 1 below.

[0126]

[Table 1]

As is clear from Table 1, the images formed by transferring the ink sheets 1 and 3 of the present invention have high image quality and excellent image storability, and at the same time, the position of neutral D = 2.0 It can be seen that high gloss can be obtained even when high heat energy is applied to any of the white portions. That is, even when an image is formed by a sublimation thermal transfer method using a chelate reaction type dye, when a reheat treatment layer containing an epoxy-modified resin or an ink sheet provided with a protective layer is used, a thermal head having high thermal energy can be obtained. , An image having high glossiness can be obtained.

Example 2 (corresponding to claim 1) (Image formation) The yellow, magenta, and cyan ink layers and the reheat treatment layer were applied by a gravure method (the dry film thickness of the ink layer was 1.1 μm). The dry film thickness of the reheat treatment layer is 0.6 μm), and the ink sheet 2 of Example 1 in which the yellow, magenta, and cyan ink layers and the reheat treatment layer are formed in the order of the surface, and the procedure of Example 1 is used. The used image receiving sheet was used.

Resistor shape: square (80 μm (length in main scanning direction) × 120 μm (length in sub-scanning direction)), 300 dp
The image receiving layer portion of the image receiving sheet and the ink layer portion of the ink sheet 2 are set in a thermal printer (1 head surface sequential A4 size) carrying the thermal head of the i-line head, and pressed against the thermal head with the platen roll. Meanwhile, yellow, magenta, and cyan were heated from the back side of the ink layer under the condition that the feed length per line was 85 μm to transfer the dye onto the image receiving layer. Then, the image receiving sheet on which the dye was transferred through the reheating treatment layer was pressed against the same thermal head and platen roll under the same feed length per line, and the applied energy was 30 mJ / mm.
^2. The temperature of the resistor surface during reheating is ± 50
% And the chelate reaction rate was set to be 90% or more, and the reheating treatment was performed.

The pulse shape is as shown in FIG.

FIG. 3 is a diagram showing the pulse shape of the thermal head in the reheating process of the second embodiment. The vertical axis represents the applied voltage (V), and the horizontal axis represents the period. One cycle is width A, width 1/2
The pulse shape was set in the order of A, width 1 / 3A, and the non-energizing time interval B was set so that the temperature of the resistor surface of the thermal head was within a range of ± 50% of the peak temperature. Each pulse may be configured by combining a shorter pulse.

Example 3 (corresponding to claim 2) (Image formation) Ink sheet 2 of Example 1 and Example 1
The image receiving sheet prepared in the above procedure was used.

Resistor shape: square (80 μm (length in main scanning direction) × 240 μm (length in sub-scanning direction)), 300 dp
The image receiving layer portion of the image receiving sheet and the ink layer portion of the ink sheet 2 are set in a thermal printer (1 head surface sequential A4 size) carrying the thermal head of the i-line head, and pressed against the thermal head with the platen roll. Meanwhile, yellow, magenta, and cyan were heated from the back side of the ink layer under the condition that the feed length per line was 85 μm to transfer the dye onto the image receiving layer. Next, the image receiving sheet on which the dye was transferred through the reheating treatment layer was pressed against the same thermal head and platen roll under the same feed length per line, and the applied energy was 20 mJ / mm.
^{2. A} reheating treatment was performed under the same pulse conditions as in the dye transfer, and with the chelate reaction rate set to be 90% or more.

Example 4 (corresponding to claim 2) (Image formation) Monochromatic ink sheets each having a yellow, magenta, and cyan ink layer having the same material as that of the ink sheet 2 of Example 1 And a reheat-treated sheet having a reheat-treated layer of the same ink sheet 2 was prepared, and used for image formation together with the image receiving sheet prepared in the procedure of Example 1.

Resistor shape: square (80 μm (length in the main scanning direction) × 120 μm (length in the sub-scanning direction)), 300 dp
The image receiving layer portion of the image receiving sheet and the ink layer portion of the ink sheet are set in a thermal printer device (4 head surface sequential A4 size) carrying the thermal head of the i-line head, and pressed against the thermal head with a platen roll. While the yellow, magenta, and cyan inks were heated from the back side of the ink layer under the condition that the feed length per line was 85 μm, the dye was transferred onto the image receiving layer. Then, a square (240 (length in the main scanning direction) × 300 μm (length in the sub-scanning direction)), a thermal head of a 100 dpi line head and a platen roll, through the reheating layer under the same feed length per line. The image-receiving sheet to which the dye was transferred was pressed against the substrate, and reheating was performed with the applied energy set to 15 mJ / mm ² and the chelate reaction rate set to 90% or more.

Example 5 (corresponding to claim 3) (Image formation) Ink sheet 2 of Example 1 and Example 1
The image receiving sheet prepared in the above procedure was used.

The shape of the resistor shown in FIG.
(Length in main scanning direction) × 240 μm (Length in sub scanning direction)), 3
The image receiving layer portion of the image receiving sheet and the ink layer portion of the ink sheet 2 are set in a thermal printer apparatus (one head surface sequential A4 size) carrying a thermal head of a 00 dpi line head, and pressed against the thermal head with a platen roll. While yellow, magenta and cyan
The dye was transferred onto the image receiving layer by heating from the back side of the ink layer under the condition that the feed length per line was 85 μm. Next, the image receiving sheet on which the dye was transferred via the reheating treatment layer was pressed against the same thermal head and platen roll under the same feed length per line, and the applied energy was 20 m.
J / mm ² , same pulse conditions, and a chelate reaction rate of 9
The reheating treatment was performed so as to be 0% or more.

FIG. 4 is a diagram showing the resistor shape in the thermal head of the fifth embodiment, and shows the resistor 23 in which the shape in contact with the image receiving layer surface is formed in a rhombus shape. In this embodiment, printing was performed using a thermal head having this shape.

Example 6 (corresponding to claim 4) (Image formation) Each of the yellow, magenta, and cyan ink layers and the protective layer were applied by a gravure method (the dry film thickness of the ink layer was 1.1 μm, The ink sheet 4 of Example 1 in which yellow, magenta, and cyan ink layers and a protective layer were formed in a plane-sequential manner, and the dry thickness of the release layer in the layer was 0.6 μm and the adhesive layer was 1.0 μm. The image receiving sheet prepared in the above procedure was used.

Resistor shape: square (80 μm (length in main scanning direction) × 120 μm (length in sub-scanning direction)), 300 dp
The image receiving layer portion of the image receiving sheet and the ink layer portion of the ink sheet 4 are set to be superimposed and set in a thermal printer device (1 head surface sequential A4 size) carrying the thermal head of the i-line head, and is pressed against the thermal head with the platen roll. Meanwhile, yellow, magenta, and cyan were heated from the back side of the ink layer under the condition that the feed length per line was 85 μm to transfer the dye onto the image receiving layer. Next, the image receiving sheet on which the dye was transferred through the reheating treatment layer was pressed against the same thermal head and platen roll under the same feed length per line, and the applied energy was 35 mJ / mm.
^{2. The} reheating treatment was performed by setting the pulse conditions shown in FIG. 3 so that the temperature of the resistor surface during the reheating was in a range of ± 50% and the chelate reaction rate was 90% or more.

Example 7 (Comparative Example) (Image formation) Ink sheet 2 of Example 1 and Example 1
The image receiving sheet prepared in the above procedure was used.

Resistor shape: square (80 μm (length in main scanning direction) × 120 μm (length in sub-scanning direction)), 300 dp
The image receiving layer portion of the image receiving sheet and the ink layer portion of the ink sheet 2 are set in a thermal printer (1 head surface sequential A4 size) carrying the thermal head of the i-line head, and pressed against the thermal head with the platen roll. Meanwhile, yellow, magenta, and cyan were heated from the back side of the ink layer under the condition that the feed length per line was 85 μm to transfer the dye onto the image receiving layer. Next, the image receiving sheet to which the dye was transferred was pressed against the same thermal head and platen roll via the reheating treatment layer, and the reheating treatment was performed under exactly the same conditions as the dye transfer. The applied energy is 30
mj / mm ² .

The following evaluation was performed on the obtained images.

(Evaluation) Gloss The gloss before and after the reheating treatment was measured with a gloss meter (Model VGS-1D, Nippon Denshoku Industries) at an incident angle and a reflection angle of 60 °. The results are shown in Table 2 below.

[0145]

[Table 2]

As is clear from Table 2, according to the thermal transfer recording method of the present invention, it is possible to form a high gloss image even when high thermal energy is applied, at the same time as having high image quality and excellent image storability. Becomes However, in Example 7 in which the reheating treatment was performed by the thermal head under exactly the same conditions as in the dye transfer, the glossiness was deteriorated, indicating that the glossiness was not improved.

[0147]

According to the present invention, it is possible to form a high-quality image with excellent image storability and high gloss even when high heat energy is applied. In particular, when forming an image by a sublimation thermal transfer method using a chelate reactive dye, even when a thermal head is applied with high thermal energy, high image quality, high image storability, and high gloss Significantly superior effects are achieved, such as being able to balance the formation.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an ink sheet having a reheating treatment layer or a protective layer.

FIG. 2 is a conceptual diagram illustrating an example of a thermal transfer recording apparatus and a reheating processing apparatus.

FIG. 3 is a diagram illustrating pulse shapes of a thermal head in a reheating process according to a second embodiment.

FIG. 4 is a diagram showing a thermal head resistor having a rhombus shape in contact with an image receiving layer surface in Example 5.

[Explanation of symbols]

 Reference Signs List 1 reheat treatment layer 2Y area containing yellow dye 2M area containing magenta dye 2C area containing cyan dye 3 support 10 ink sheet supply roll 11 winding roll 12 thermal head 13 platen roller 14 image receiving sheet 15 ink sheet 21 Common electrode 22 Individual electrode 23 Resistor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D06P 1/13 D06P 3/60 A 3/60 5/00 114 5/00 114 B05D 5/04 // B05D 5/04 B41J 3/20 109J B41M 5/26 101B 101K 101A (72) Inventor Hiroshi Watanabe 1 Sakuracho, Hino-shi, Tokyo Konica Stock Company In-house F-term (reference) 2C065 AB03 AC04 AE07 AF01 AF02 CJ02 CJ03 CJ06 CJ08 2C068 AA02 AA06 AA22 BC16 BD15 BD23 BD37 2H111 AA01 AA08 AA27 AA33 AA43 AA50 AA52 BA03 BA11 BA39 BA53 BA74 CA03 CA33 4D075 AC43 CA35 CB04 DA04 DB18 DC27 EB33 EC17 4H057 AA01 AA02 BA22 CA19 CB08 DA34

Claims (11)

[Claims] An ink layer of an ink sheet having at least one ink layer containing a heat-diffusible dye on a support and an image receiving layer of an image sheet having at least one image receiving layer on a support are opposed to each other. After the dye is transferred to the image receiving layer by imagewise heating with a thermal head, at least the entire area of the image receiving sheet where the dye has been transferred is subjected to a reheating treatment with a thermal head to form an image. In the thermal transfer recording method to be formed, the temperature of the surface of the resistor of the thermal head in the reheating process is one of the peak temperature.
A thermal transfer recording method characterized in that the non-energizing time interval is set to a certain value or less so as not to become / 3 or less. 2. The ink layer of an ink sheet having at least one ink layer containing a heat-diffusible dye on a support and the image receiving layer of an image receiving sheet having at least one image receiving layer on a support are opposed to each other. After the dye is transferred to the image receiving layer by imagewise heating with a thermal head, at least the entire area of the image receiving sheet where the dye has been transferred is subjected to a reheating treatment with a thermal head to form an image. In the thermal transfer recording method to be formed, at the time of reheating treatment,
A thermal transfer recording method, wherein the relative movement distance of each line between a thermal head and an image receiving sheet is set to be equal to or less than 1/2 of a length of a thermal head resistor in a sub-scanning direction. 3. The ink layer of an ink sheet having at least one ink layer containing a heat-diffusible dye on a support and the image receiving layer of an image receiving sheet having at least one image receiving layer on a separate support face each other. After the dye is transferred to the image receiving layer by imagewise heating with a thermal head, at least the entire area of the image receiving sheet where the dye has been transferred is subjected to a reheating treatment with a thermal head to form an image. In the thermal transfer recording method to be formed, at the time of reheating treatment,
A thermal transfer recording method, wherein the shape of the resistor is set so that the resistor of the thermal head exists in any line segment parallel to the sub-scanning direction, or a thermal head having a plurality of rows of resistors is used. . 4. A reheating treatment in which a transparent head is transferred by heating at least the entire area of the image receiving sheet to which the dye has been transferred by a thermal head.
The thermal transfer recording method according to any one of the preceding claims. 5. The ink layer of the ink sheet contains a heat-diffusible dye capable of being chelated, and the image receiving layer of the image receiving sheet contains a metal ion-containing compound capable of performing a chelate reaction with the dye. Claims 1 to
5. The thermal transfer recording method according to claim 4. 6. The chelate reaction rate in the reheating treatment is 7
6. The application pulse condition is set so that it is 0% or more and the glossiness is 70 or more.
The thermal transfer recording method according to any one of the preceding claims. 7. An ink sheet for thermal transfer recording, comprising a region containing a heat-diffusible dye and a region containing an epoxy-modified resin. 8. The thermal transfer recording ink sheet according to claim 7, wherein the area containing the epoxy-modified resin is formed so as to be transferable. 9. A thermal transfer recording ink sheet having a region containing a heat-diffusible dye, a region containing an epoxy-modified resin, and at least one image-receiving layer on a support.
After the dye is transferred to the image receiving layer by superimposing the image receiving layers of the image receiving sheet having the layers facing each other and heating imagewise with a thermal head, the epoxy is applied to at least the area of the image receiving sheet where the dye has been transferred. A thermal transfer recording method, wherein reheating is performed by a thermal head through a region containing a modified resin. 10. The thermal transfer recording ink sheet contains a chelatable thermal diffusible dye, and the image receiving layer of the image receiving sheet contains a metal ion-containing compound capable of performing a chelate reaction with the dye. The thermal transfer recording method according to claim 9, wherein: 11. The thermal transfer recording method according to claim 9, wherein, during the reheating treatment, the area containing the epoxy-modified resin is transferred to an image receiving sheet.