JP2002362043A - Laser heat transfer recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser heat transfer recording method by stably feeding a heat transfer sheet without generating deviation and jamming capable of obtaining an image free from image defects due to the deposition of a foreign substance and errors in color recording sequence due to human errors. SOLUTION: An image receiving sheet with an image receiving layer and a plurality of heat transfer sheets having at least a photothermal conversion layer and an imaging layer formed on a support, are supplied from a cassette for a recording medium, and the image receiving layer of the image receiving sheet and the imaging layer of the heat transfer sheet are superposed in such a way that both layers are opposite to each other and further, these image receiving layer and the imaging layer are retained on a recording medium support member. Next, the heat transfer sheet is irradiated with a laser beam complying with image information and the region irradiated with a laser beam of the imaging layer is transferred onto the image receiving layer of the image receiving sheet to record an image. In the laser heat transfer recording method having the described process, the image receiving sheet and the heat transfer sheet are laminated in the order that these sheets are supplied onto the recording medium support member and stored into the recording medium cassette and the coefficient of static friction of the back layer surface of the heat transfer sheet is not more than 0.7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a multicolor image forming method for forming a high-resolution full-color image using a laser beam. In particular, the present invention relates to color proofing (D) in the printing field by laser recording from digital image signals.
DCP: direct digital color proof)
Alternatively, the present invention relates to a multicolor image forming method useful for producing a mask image.

[0002]

2. Description of the Related Art In the field of graphic arts, a printing plate is printed using a set of color separation films prepared from a color original by using a lithographic film. In order to check for errors in the color separation process and the necessity of color correction, a color proof is made from the color separation film. A color proof is required to have high resolution which enables high reproducibility of a halftone image, and high performance such as high process stability. In addition, in order to obtain a color proof similar to an actual printed matter, as a material used for the color proof, a material used for an actual printed matter, for example, a printing paper as a base material and a pigment as a coloring material are used. Is preferred. Also,
As a method for producing a color proof, there is a high demand for a dry method using no developer.

As a dry-type color proofing method, with the recent widespread use of digitization systems in the pre-printing process (prepress field), a recording system for directly producing a color proof from digital signals has been developed. The purpose of such an electronic system is to produce a color proof having a high image quality, and generally reproduces a halftone image of 150 lines / inch or more. In order to record a proof of high image quality from a digital signal, a laser beam that can be modulated by the digital signal and that can narrow down the recording light is used as a recording head. For this reason, it is necessary to develop a recording material that exhibits high recording sensitivity to laser light and high resolution that enables high-definition halftone dots to be reproduced.

As a recording material used in a transfer image forming method using a laser beam, a photothermal conversion layer which absorbs a laser beam and generates heat, a wax having a heat-fusible pigment, a binder, etc. are provided on a support. Heat-melt transfer sheet having an image forming layer dispersed in the components
58045) is known. In the image forming method using these recording materials, the heat generated in the laser light irradiation area of the light-to-heat conversion layer melts the image forming layer corresponding to the area, and is transferred onto the image receiving sheet laminated on the transfer sheet. Then, a transfer image is formed on the image receiving sheet.

Japanese Patent Application Laid-Open No. 6-219052 discloses that a light-to-heat conversion layer containing a light-to-heat conversion substance, a very thin (0.03-0.3 μm) heat-peeling layer, and a coloring material are provided on a support. There is disclosed a thermal transfer sheet provided with an image forming layer in this order. In this thermal transfer sheet, by being irradiated with laser light, the bonding force between the image forming layer and the light-to-heat conversion layer that are bonded by the interposition of the thermal release layer is reduced, and the thermal transfer sheet is laminated on the thermal transfer sheet. A high-definition image is formed on the image receiving sheet. The image forming method using the thermal transfer sheet utilizes so-called "ablation", and specifically, in a region irradiated with laser light, the heat release layer partially decomposes and evaporates. This utilizes a phenomenon in which the bonding force between the image forming layer and the light-to-heat conversion layer is weakened, and the image forming layer in that region is transferred to the image receiving sheet laminated thereon.

According to these image forming methods, a printing paper having an image receiving layer (adhesive layer) attached thereto can be used as an image receiving sheet material. It has the advantage that it can be easily obtained and a high-definition image can be easily obtained, and is useful for producing a color proof (DDCP: direct digital color proof) or a high-definition mask image. .

When recording an image with a laser beam, a plurality of laser beams are used to shorten the recording time.
In recent years, multi-beam laser light has been used. When recording is performed using a laser beam that is a multi-beam using a conventional thermal transfer sheet, the image density of a transferred image formed on the image receiving sheet may be insufficient. In particular, the decrease in image density becomes significant when laser recording is performed with high energy. As a result of the study by the present inventors, it has been found that the decrease in image density is caused by transfer unevenness that occurs when laser irradiation is performed at high energy.

By the way, the recording method described above includes a kind of image receiving sheet R, K (black), C (cyan), M
A plurality of types of thermal transfer sheets such as (magenta) and Y (yellow) are used. Conventionally, about 20 to 100 such recording media are stacked and packed. For example, in the case of a packaging form of about 25 sheets, as shown in FIG. 10, the same type of recording medium 1 is vacuum-packed by a packing material 3 made of a synthetic resin bag such as polyethylene, and the outside thereof is cardboard. The package 7 is packed in a decorative box 5 or the like.

Prior to setting the package 7 in a recording apparatus, a total of five types of image receiving sheet R, thermal transfer sheets K, C, M, and Y are unpacked. The unpacked recording medium is manually set in the recording medium cassette of the recording apparatus in the reverse order of the recording order. That is, first, one Y-color thermal transfer sheet is taken out of the plurality of unpacked packages 7 and set in a cassette. Similarly, the M color heat transfer sheet, the C color heat transfer sheet, the K color heat transfer sheet, and the image receiving sheet are set in a cassette. Therefore, the cassette contains
A plurality of recording media are set in a stacked state in the order of image receiving sheet, K, C, M, and Y from the upper layer. When a plurality of recording media are set, these are set repeatedly.

[0010]

However, since the conventional package is packed for each recording medium of the same type, when the recording medium is set in the cassette, the unpacked image receiving sheet R, thermal transfer sheet K, It was necessary to take out the recording medium one by one from each of the C, M, and Y packages and set it in a cassette. For this reason, each of the recording media is exposed to the external environment, and the probability of adhesion of foreign matter increases. There was a problem. Each recording medium has to be manually set in the cassette in the reverse order of the recording order, so that the order of the set is apt to be wrong, and as a result, the problem that the recording order of the colors is changed easily occurs.
Further, when a pickup mechanism such as a rubber roller or a suction / suction mechanism picks up the image receiving sheet or the thermal transfer sheet one by one from the recording medium cassette and conveys the sheet to the recording apparatus, deviation and jamming may occur. Was.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, the present invention provides: 1) a heat transfer sheet which is not affected by an illumination light source even in comparison with a pigment color material and a printed material;
2) The image receiving sheet should be able to receive the image forming layer of the laser energy transfer film stably and reliably. 3) Art (coated) paper, matte paper, finely coated paper, etc. 64-157 g /
The purpose of the present invention is to transfer the paper to the range corresponding to the range of m ² , to reproduce a delicate texture and to accurately reproduce the white paper (high-key portion), and 4) to obtain an extremely stable transfer releasability. Under different temperature and humidity conditions, a multi-color image forming method that has good image quality and can form an image of stable transfer density on an image receiving sheet even when laser recording is performed with high energy using a multi-beam laser beam. The purpose is to provide. In particular, the present invention provides a laser thermal transfer recording method capable of stably transporting and supplying a thermal transfer sheet without causing displacement or jamming, and obtaining an image without an image defect due to the adhesion of a foreign substance or an incorrect color recording order due to a human error. The purpose is to.

[0012]

[Means for Solving the Problems] CTP (Computer To Pl
ate) In the era, it becomes filmless and requires proofs and contract proofs that replace analog color proofs. To obtain customer approval, color reproducibility that matches printed matter and analog color proofs is required. DDCP system was developed. The goal is a large-size (A2 / B2) digital direct color proof system that can transfer to real paper, uses the same pigment-based color material as the printing ink, and has high print similarity. The present invention uses a laser thin film thermal transfer method,
This is a system in which actual halftone dot recording is performed using a pigment coloring material and can be transferred to a real paper.

The means for solving the above problems are as follows. (1) An image receiving sheet having an image receiving layer, and a plurality of thermal transfer sheets having at least a light-to-heat conversion layer and an image forming layer on a support are supplied from a recording medium cassette, and the image receiving layer of the image receiving sheet and the thermal transfer sheet are supplied. The image forming layer of the image receiving layer is superposed on the recording medium support member and held on a recording medium supporting member, and a laser beam corresponding to image information is irradiated on the thermal transfer sheet, and a laser beam irradiated area of the image forming layer is formed on the image receiving sheet. In the laser thermal transfer recording method having a step of transferring and image recording on the image receiving layer, the image receiving sheet and the thermal transfer sheet are stacked and housed in the order in which the image receiving sheet and the thermal transfer sheet are supplied onto the recording medium support member in the recording medium cassette, And a laser thermal transfer recording method, wherein the coefficient of static friction on the surface of the back layer of the thermal transfer sheet is 0.7 or less. (2) The package is unsealed from the recording medium package in which the image receiving sheet and the thermal transfer sheet are stacked in the order in which they are supplied onto the recording medium support member, and are then stacked on the recording medium cassette. The thermal transfer recording method according to (1), wherein the image receiving sheet and the thermal transfer sheet are set at once. (3) The laser thermal transfer recording method according to (1) or (2), wherein the coefficient of static friction of the surface of the image forming layer of the thermal transfer sheet is 0.5 or less. (4) Surface roughness R of the image forming layer surface of the thermal transfer sheet
The laser thermal transfer recording method according to any one of (1) to (3), wherein z is 3 μ or less. (5) Surface roughness Rz of the back layer surface of the thermal transfer sheet
Is 7 μm or less. (6) The laser thermal transfer according to any one of (1) to (5), wherein the surface electric resistance SR of the surface of the image forming layer of the thermal transfer sheet is 10 ¹¹ Ω or less at 23 ° C. and 55% RH. Recording method.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention realizes a thermal transfer image with sharp halftone dots, and transfers the paper and B2 size recording (515 mm x 728 mm, B2 size is 54 mm).
(3 mm × 765 mm) is effective and suitable for a system capable of performing the measurement. This thermal transfer image can be a halftone image having a resolution of 2400 dpi or more and corresponding to the number of printing lines. Since each halftone dot has very little bleeding or chipping and a very sharp shape, a high range of halftone dots from highlights to shadows can be formed clearly. as a result,
It can output high-quality halftone dots at the same resolution as the image setter and CTP setter, and can reproduce halftone dots and gradations with good print similarity.

The thermal transfer image has a sharp halftone dot shape, so that a halftone dot corresponding to a laser beam can be faithfully reproduced. In addition, since the dependence of recording characteristics on environmental temperature and humidity is very small, a wide range of temperature and humidity environments can be obtained. Under the above conditions, stable reproducibility of both hue and density can be obtained. This thermal transfer image is formed using the coloring pigment used in the printing ink, and has high repetition
A CMS (color management system) can be realized. Also, this thermal transfer image can be made to substantially match the hue of Japan color, SWOP color, etc., that is, the hue of the printed matter, and the appearance of the color when the light source changes, such as a fluorescent lamp or incandescent lamp, is the same as that of the printed matter. Can be shown.

Since the thermal transfer image has a sharp dot shape, fine lines of fine characters can be reproduced clearly.
The heat generated by the laser beam is transmitted to the transfer interface without diffusing in the plane direction, and the image forming layer is sharply broken at the interface between the heated portion and the non-heated portion. For this purpose, the thinning of the light-to-heat conversion layer in the thermal transfer sheet and the mechanical properties of the image forming layer are controlled. By the way, in the simulation, it is estimated that the light-to-heat conversion layer instantaneously reaches approximately 700 ° C., and if the film is thin, deformation or destruction is likely to occur. When the deformation / destruction occurs, the light-to-heat conversion layer is transferred to the image receiving sheet together with the transfer layer, or the transferred image becomes non-uniform. On the other hand, in order to obtain a predetermined temperature, the photothermal conversion substance must be present in a high concentration in the film, which causes problems such as precipitation of a dye and migration to an adjacent layer. For this reason, it is preferable to reduce the thickness of the light-to-heat conversion layer to about 0.5 μm or less by selecting an infrared-absorbing dye having excellent light-to-heat conversion properties and a heat-resistant binder such as polyimide.

Generally, when the light-to-heat conversion layer is deformed or the image forming layer itself is deformed by high heat, the image forming layer transferred to the image receiving layer has a thickness unevenness corresponding to the sub-scanning pattern of the laser beam. , Resulting in an uneven image and a reduced apparent transfer density. This tendency is more remarkable as the thickness of the image forming layer is smaller. On the other hand, when the thickness of the image forming layer is large, the sharpness of the dots is impaired and the sensitivity is lowered. In order to balance these conflicting performances, it is preferable to improve transfer unevenness by adding a low melting point substance such as a wax to the image forming layer. Also, by adding inorganic fine particles instead of the binder, the layer thickness is appropriately increased, so that the image forming layer is sharply broken at the interface between the heated part and the unheated part, and the sharpness and sensitivity of the dots are maintained. In addition, transfer unevenness can be improved.

In general, low-melting substances such as wax are
There is a tendency to seep or crystallize on the surface of the image forming layer,
In some cases, a problem may occur in the image quality or the temporal stability of the thermal transfer sheet. In order to cope with this problem, it is preferable to use a low melting point substance having a small difference in SP value from the polymer of the image forming layer, to increase the compatibility with the polymer and to separate the low melting point substance from the image forming layer. Can be prevented. It is also preferable to mix several kinds of low-melting substances having different structures so as to make them eutectic to prevent crystallization. As a result, an image having a sharp dot shape and less unevenness can be obtained.
In general, when the coating layer of the thermal transfer sheet absorbs moisture, the mechanical and thermal properties of the layer change, and the recording environment becomes dependent on humidity. In order to reduce the temperature / humidity dependency, it is preferable that the dye / binder system of the light-to-heat conversion layer and the binder system of the image forming layer are organic solvent systems. Further, it is preferable to select polyvinyl butyral as a binder for the image receiving layer and to introduce a polymer hydrophobizing technique in order to reduce the water absorption. Examples of the polymer hydrophobization technique include reacting a hydroxyl group with a hydrophobic group as described in JP-A-8-238858, and crosslinking two or more hydroxyl groups with a hardener.

In general, when the image is formed by laser exposure, the image forming layer is also heated to about 500 ° C. or more. This can be prevented by adopting it in the image forming layer. And, by high heat at the time of printing,
When the infrared-absorbing dye migrates from the light-to-heat conversion layer to the image forming layer, the light-to-heat conversion layer is combined with a strong holding power of the infrared-absorbing dye / binder as described above to prevent the hue from being changed. It is preferable to design. Generally, in high-speed printing, energy is insufficient, and a gap corresponding to the interval between laser sub-scans is generated. As described above, increasing the concentration of the dye in the light-to-heat conversion layer and reducing the thickness of the light-to-heat conversion layer / image forming layer can increase the efficiency of heat generation / transmission. Further, it is preferable to add a low-melting substance to the image forming layer for the purpose of increasing the effect of slightly flowing the image forming layer upon heating and filling the gap and the adhesiveness to the image receiving layer. Further, in order to increase the adhesiveness between the image receiving layer and the image forming layer and to sufficiently impart the strength of the transferred image, it is preferable to employ, for example, the same polyvinyl butyral as the image forming layer as the binder of the image receiving layer.

The image receiving sheet and the thermal transfer sheet are preferably held on a drum by vacuum contact. This vacuum adhesion is important because the image transfer behavior is very sensitive to the clearance between the image receiving layer surface of the image receiving sheet and the image forming layer surface of the transfer sheet since an image is formed by controlling the adhesive force between the two sheets. If the clearance between the materials is widened due to foreign matter such as dust, image defects and image transfer unevenness occur. In order to prevent such image defects and image transfer unevenness, it is preferable that uniform unevenness is provided on the thermal transfer sheet so that the air can be flowed well and uniform clearance can be obtained.

As a method of forming irregularities on the thermal transfer sheet, there are generally post-treatments such as embossing, and addition of a matting agent to the coating layer. However, addition of a matting agent is preferable for simplifying the manufacturing process and stabilizing the material over time. . The matting agent needs to be larger than the thickness of the coating layer, and if the matting agent is added to the image forming layer, a problem occurs in that the image of the portion where the matting agent is present will be lost. It is preferable to add it to the conversion layer, whereby the image forming layer itself has a substantially uniform thickness, and a defect-free image can be obtained on the image receiving sheet.

In order to reliably reproduce the sharp dots as described above, a high-precision design is also required on the recording device side. The basic configuration is the same as that of the conventional laser thermal transfer recording apparatus. This configuration is a so-called heat mode outer drum recording system in which a recording head having a plurality of high-power lasers irradiates a laser onto a thermal transfer sheet and an image receiving sheet fixed on a drum to perform recording. Among them, the following embodiments are preferred configurations. The supply of the image receiving sheet and the thermal transfer sheet is a fully automatic roll supply. The image receiving sheet and the thermal transfer sheet are fixed to the recording drum by vacuum suction. A number of vacuum suction holes are formed on the recording drum, and the inside of the drum is depressurized by a blower, a decompression pump, or the like, so that the sheet is adsorbed to the drum.
The size of the thermal transfer sheet is made larger than that of the image receiving sheet because the thermal transfer sheet is further attracted from above the image receiving sheet. The air between the thermal transfer sheet and the image receiving sheet, which has the greatest effect on the recording performance, is sucked from the area of the thermal transfer sheet only outside the image receiving sheet. In this apparatus, it is assumed that many sheets having a large area of B2 size can be stacked and stacked on the discharge table. For this purpose, a method is employed in which air is blown out between the two sheets to float the sheet discharged later.

FIG. 1 and FIG. 2 show an example of the configuration of the present apparatus. FIG.
As shown in FIG. 2, a recording unit of the recording apparatus 21 is provided with a recording rotating drum 23 as a recording medium support member. The recording drum 23 has a hollow cylindrical shape and is rotatably held by a frame 25 shown in FIG. In the recording device 21, the rotation direction of the recording rotary drum 23 is the main scanning direction. The recording rotary drum 23 is connected to a rotating shaft of a motor and is rotationally driven by the motor.

Further, the recording section is provided with a recording head 27. The recording head 27 emits a laser beam Lb. The image forming layer of the thermal transfer sheet 33 at the position irradiated with the laser beam Lb is transferred to the surface of the image receiving sheet 31. The recording head 27 is moved along the guide rail 35 by a driving mechanism (not shown).
3 linearly moves in a direction parallel to the rotation axis. This moving direction is the sub-scanning direction. Therefore, the recording rotary drum 2
A desired position on the thermal transfer sheet 33 covering the image receiving sheet 31 can be subjected to laser exposure by a combination of the rotational movement 3 and the linear movement of the recording head 27. Therefore, a desired image can be transferred to the image receiving sheet 31 by scanning the thermal transfer sheet 33 with the drawing laser light Lb and exposing only the corresponding position based on the image information.

A cassette mount 37 is provided at the recording medium mounting portion of the recording apparatus 21.
A recording medium cassette 41 containing a recording medium serving as an image receiving sheet 31 or a thermal transfer sheet 33 is directly detachable. The recording apparatus 21 takes out the recording medium from the recording medium cassette 41 and supplies and conveys the recording medium to the recording medium support member 23 of the recording apparatus 21 by mounting the recording medium cassette 41 on the cassette mounting table 37. I have.

FIG. 3 is a sectional view of a recording medium cassette. In the recording medium cassette 41, the image receiving sheet 31 and the thermal transfer sheet 33, which are recording media, are stacked and stored in the order in which they are supplied to the recording rotary drum 23. For example, when the supply and conveyance order to the recording rotary drum 23 is the image receiving sheet R, the K heat transfer sheet, the C heat transfer sheet, the M heat transfer sheet, and the Y heat transfer sheet, they are stacked in the order of RKCMY from the upper layer. The simple cassette 41 for the recording medium mounted on the recording device 21 is taken out from the uppermost recording medium by the pickup mechanism 22 provided on the recording device 21 and supplied into the recording device 21. In addition,
In the figure, the recording media are drawn with a space between them, but in reality, the recording media are stacked in contact with each other.

As described above, since the cassette mounting base 37 is provided at the cassette mounting portion in the recording device 21, it is not necessary to secure a space for accommodating the recording medium simple cassette 41 inside the recording device 21. In addition, the size of the recording device 21 can be reduced.

Cassette body 4 of cassette 41 for recording medium
1a is preferably made of metal, and the cassette body 4
If 1a is made of metal, even when recording media in a stacked state move with each other during transport and generate static electricity, the static electricity can be released to the cassette main body 41a made of metal, making it difficult to be charged. . Thereby, the electrostatic attraction force can be prevented, and the double feed due to the close contact at the time of taking out the recording medium is reduced. If the cassette body 41a is made of cardboard, material costs can be reduced. Also,
Since the processing is easy, the manufacturing cost is also low. Furthermore, since recycled paper and the like can be used, resources can be effectively used, and adverse effects on the environment can be reduced.

Even if the recording medium cassette 41 has a low strength, the recording medium cassette 41 is stably and securely fixed to the recording apparatus 21 by being mounted on the robust cassette mounting base 37. Therefore, the recording medium cassette 41 made of cardboard or plastic and manufactured with relatively low strength can be used.

As shown in FIG. 4, the recording medium cassette 41 includes a plurality of sets (one set) of recording media RKCMY stacked in the order in which they are supplied to the recording rotary drum 23 (in this example, a plurality of sets). 3 sets) may be stacked. The number of sets is an integer. As the stacking order of the recording media in each set (that is, the recording order), for example, R
Various types such as KYMC, RYMCK, RCMYK and the like can be mentioned, but it is essential that R be R at first.

The recording medium accommodated in the recording medium cassette 41 is laminated such that the image receiving layer 31c of the image receiving sheet 31 and the image forming layer 33c of the thermal transfer sheet 33 are in opposite directions. . Since the directions are opposite to each other, as shown in FIG. 5, the image receiving layer 31c (R film surface) faces upward and the image forming layer 33c (K, C, M, Y film surface) faces downward. As shown, there are cases where the image receiving layer 31c faces downward and the image forming layer 33c faces upward. Image receiving layer 31
When c is directed upward and the image forming layer 33c is directed downward, as shown in FIG. 7A, the recording medium is supplied from the upper outer periphery of the recording rotary drum 23. Therefore, when the uppermost image receiving sheet 31 is fixed to the recording rotary drum 23 and then the thermal transfer sheet 33 is supplied to the recording rotary drum 23, the image forming of the thermal transfer sheet 33 is performed on the image receiving layer 31c of the image receiving sheet 31. The layer 33c will be overlaid.

When the image receiving layer 31c faces downward and the image forming layer 33c faces upward, the recording medium is supplied from the lower part of the outer periphery of the recording rotary drum 23 as shown in FIG. . Therefore, when the uppermost image receiving sheet 31 is fixed to the rotating drum 23 for recording and then the thermal transfer sheet 33 is supplied to the rotating drum 23 for recording, the image forming of the thermal transfer sheet 33 is performed on the image receiving layer 31c of the image receiving sheet 31. Layer 33c
Will be superimposed.

Next, the accommodated image receiving sheet and the thermal transfer sheets of the four colors K, C, M, and Y are pulled out from the above-described recording medium cassette, and a desired color image is obtained.
The procedure for forming the upper layer 1 will be described with reference to FIG. As shown in FIG. 1, when the recording medium cassette 41 is mounted on the recording device 21, the pickup mechanism 22 operates. In this way, in step 1 shown in FIG. 8, the uppermost image receiving sheet 31 is supplied to the recording rotating drum 23.
Next, in step 2, the K thermal transfer sheet 33 is supplied to the recording rotary drum 23. In the next step 3, the thermal transfer sheet 33 is laminated by heating and pressing. This laminating step may be omitted in some cases.

In the next step 4, an image is transferred and output on the image receiving sheet 31 based on the image data given in advance. Here, the given image data is further color-separated into an image for each color, and laser exposure is performed based on the color-separated image data for each color. Thereby, the image forming layer of the thermal transfer sheet 33 is transferred to the image receiving sheet 31, and an image is formed on the image receiving sheet 31.

Then, in step 5, only the (K) thermal transfer sheet 33 is peeled off from the recording rotary drum 23. Here, it is determined whether the transfer has been completed for the thermal transfer sheets 33 of all colors. Then, when it is necessary to supply another type of thermal transfer sheet 33, the processes of steps 2 to 5 are repeated. That is, the other C, M,
Steps 6 to 17 for the transfer sheet 33 of each color of Y
Each operation up to is repeated. As a result, the images KCMY of the four-color thermal transfer sheet 33 are transferred to one image receiving sheet 31, and a color image is formed on the image receiving sheet 31.
Thereafter, the image receiving sheet 31 is peeled from the recording rotary drum 23. The transferred image on the image receiving sheet 31 is further transferred to an arbitrary printing sheet by a separate image transfer unit. Thus, color printing for proofing is performed.

If the image receiving sheet and the thermal transfer sheet are stacked and packed in the order in which they are supplied to the recording rotary drum 23, and a package is prepared in advance, after the package is opened, the recording medium is loaded into the recording apparatus together with the cassette body 41a. 21 can be set at one time, which eliminates the need to manually set each one. As a result, the amount of foreign matter attached to the recording medium is reduced, so that image defects due to foreign matter can be reduced. In addition, it is possible to prevent a color recording order error due to a human error. Furthermore, since a plurality of recording media can be set at once, labor for supplying the recording media can be saved. FIG. 9 shows an example of such a package. For example, when the supply and conveyance order to the recording rotary drum 15 is R (image receiving sheet), K (black thermal transfer sheet), C (cyan thermal transfer sheet), M (magenta thermal transfer sheet), and Y (yellow thermal transfer sheet) The recording medium 53 is stacked in the order of RKCMY from the upper layer. The recording medium 53 thus laminated is vacuum-packed by a packing material 55 made of a synthetic resin bag such as polyethylene, and the outside thereof is further packed by a cardboard decorative box 57 or the like.
It becomes 1. In the drawing, the recording media 53 are drawn with a space between them, but actually,
They are stacked in contact with each other. As the stacking order of the recording medium 53 (that is, the recording order), for example, RKYMC, RY
Various types such as MCK, RCMYK, etc. are listed.
Is essential.

According to the recording apparatus 21, the following effects can be further obtained. Since the image receiving sheet 31 is located on the uppermost layer, when the image receiving sheet 31 is supplied to the recording device 21, the image receiving sheet 31 on the uppermost layer is supplied to the rotating drum 23 for recording. That is,
It is always possible to supply the image receiving sheet 31 which must first be fixed to the rotating drum 23 for recording. Thereby, the thermal transfer sheet 33 of each color can be selectively superimposed on one image receiving sheet 31 fixed to the recording rotary drum 23.

When a plurality of sets of recording media are stacked, a plurality of sets of recording media can be set in the recording device 21 at the same time. That is, the first set of the image receiving sheets 31 is fixed to the recording rotating drum 23, and the recording is completed on the image receiving sheet 31 by the thermal transfer sheets 33 of each color. When discharged, the second set of image receiving sheets 31
Are again fixed to the recording rotary drum 23, and recording is performed on the image receiving sheet 31 by the thermal transfer sheets 33 of each color. In other words, after the first set, recording can be performed without setting a recording medium, and color image recording for the number of sets can be performed a plurality of times without manually setting the recording medium. Thus, the number of steps for setting the recording medium can be reduced and labor can be saved.

Further, an image receiving layer 31c of the image receiving sheet 31;
Since the image forming layer 33c of the thermal transfer sheet 33 and the image forming layer 33c of the thermal transfer sheet 33 are stacked in opposite directions, either one of the image receiving sheet 31 and the thermal transfer sheet 33 is not turned upside down in the process of transporting the image receiving sheet 31 and the thermal transfer sheet 33. To
The image receiving layer 31c and the image forming layer 33c can be overlapped. As a result, it is possible to quickly supply the recording medium in the recording medium supply transport path. In the case where a plurality of sets of recording media are stacked in the recording medium cassette 41, the image receiving sheet 31 is used as the image receiving layer 31c.
Are all laminated in the same direction.
No. 3 is laminated so that the image forming layers 33c are all in the same direction.

In the recording apparatus 21, since the recording medium cassette 41 can be directly attached and detached, there is no need to set the recording medium in a conventional apparatus cassette or the like. Set becomes possible. As a result, the amount of foreign matter attached to the recording medium is reduced, the color recording order is not erroneously recorded, and the labor for supplying the recording medium can be greatly reduced.

As a transport roller usually used for a supply portion or a transport portion of the thermal transfer sheet and the image receiving sheet, it is preferable to use an adhesive roll having an adhesive material disposed on the surface at any portion.

By providing the adhesive roll, the surfaces of the thermal transfer sheet and the image receiving sheet can be cleaned.

The adhesive material provided on the surface of the adhesive roll includes ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyolefin resin, polybutadiene resin, styrene-butadiene copolymer (SB
R), styrene-ethylene-butene-styrene copolymer (SEBS), acrylonitrile-butadiene copolymer (NBR), polyisoprene resin (IR), styrene-
Examples include isoprene copolymer (SIS), acrylate copolymer, polyester resin, polyurethane resin, acrylic resin, butyl rubber, and polynorbornene.

The surface of the adhesive roll can be cleaned by contacting the surface of the thermal transfer sheet and the image receiving sheet, and the contact pressure is not particularly limited as long as it is in contact.

The Vickers hardness Hv of the adhesive material used for the adhesive roll should be 50 kg / mm ² (≒ 490 MPa) or less. Is preferred.

The Vickers hardness means that the facing angle is 13
This is a hardness measured by applying a static load to a 6-degree square pyramidal diamond indenter, and the Vickers hardness Hv is obtained by the following equation.

Hardness Hv = 1.854 P / d ² (kg / mm ² ) ≒ 1
8.1692 P / d ² (MPa) Here, P: magnitude of load (kg), d: diagonal length (mm) of the square of the hollow.

In the present invention, the elastic material at 20 ° C. of the adhesive material used for the above-mentioned adhesive roll has an elastic modulus at 20 ° C.
It is preferable that the pressure be 200 kg / cm ² (≒ 19.6 MPa) or less, as in the above case, dusts as foreign substances can be sufficiently removed and image defects can be suppressed.

Surface roughness of image forming layer surface of thermal transfer sheet
The absolute value of the difference between Rz and the surface roughness Rz of the back layer surface is 3.0 or less, and the absolute value of the difference between the surface roughness Rz of the image receiving layer surface of the image receiving sheet and the surface roughness Rz of the back layer surface is 3.0. The following is preferred. With such a configuration, image defects can be prevented in combination with the above-described cleaning means, transport jams can be eliminated, and dot gain stability can be improved.

In this specification, the surface roughness Rz is defined by JIS
Means the ten-point average surface roughness corresponding to the Rz (maximum height) of the mountain, from the highest surface to the fifth mountain height, using the average surface of the part extracted from the surface of the roughness by the reference area as the reference surface The distance between the average value of the valley floor and the average value of the depths of the valley bottoms from the deepest to the fifth is input and converted. For measurement, Tokyo Seimitsu Co., Ltd.
Use a 3D roughness gauge (Surfcom 570A-3DF) made by Nissan.
The measurement direction is the vertical direction, the cutoff value is 0.08 mm, the measurement area is 0.6 mm × 0.4 mm, the feed pitch is 0.005 mm, and the measurement speed is 0.12 mm / s.

The absolute value of the difference between the surface roughness Rz of the surface of the image forming layer of the thermal transfer sheet and the surface roughness Rz of the surface of the back layer is as follows.
1.0 or less, and the absolute value of the difference between the surface roughness Rz of the image receiving layer surface of the image receiving sheet and the surface roughness Rz of the backside layer surface is 1.0.
The following is preferred from the viewpoint of further improving the above effects.

The glossiness of the image forming layer of the thermal transfer sheet is
It is also preferably 80 to 99. The glossiness largely depends on the smoothness of the surface of the image forming layer, and can affect the uniformity of the thickness of the image forming layer. Higher glossiness is more suitable for use as an image forming layer for uniform and high-definition images, but high smoothness results in greater resistance during conveyance, and the two are in a trade-off relationship. When the glossiness is in the range of 80 to 99, both can be compatible and the balance can be maintained.

Next, an outline of a mechanism for forming a multicolor image by thin-film thermal transfer using a laser will be described with reference to FIG.
An image forming laminate 30 in which the image receiving sheet 20 is laminated on the surface of the image forming layer 16 containing the black (K), cyan (C), magenta (M), or yellow (Y) pigment of the thermal transfer sheet 10 is prepared. . The thermal transfer sheet 10 has a support 12, a light-to-heat conversion layer 14 thereon, and an image forming layer 16 thereon, and the image receiving sheet 20 has a support 15, a And a thermal transfer sheet 1
The image receiving layer 24 is laminated on the surface of the image forming layer 16 of No. 0 (FIG. 11A). When the laser light is radiated imagewise in time from the support 12 side of the thermal transfer sheet 10 of the laminate 30, the laser light irradiated area of the photothermal conversion layer 14 of the thermal transfer sheet 10 generates heat, and the image forming layer 16 is heated. The adhesive strength with the adhesive decreases (FIG. 11B). Thereafter, when the image receiving sheet 20 and the thermal transfer sheet 10 are peeled off, the laser light irradiated area 16 ′ of the image forming layer 16 becomes
The image is transferred onto the image receiving layer 24 of the image receiving sheet 20 (FIG. 11).
(C)).

In forming a multicolor image, the laser beam used for light irradiation is preferably a multi-beam beam, and more preferably a multi-beam two-dimensional array. The multi-beam two-dimensional arrangement means that when recording by laser irradiation, a plurality of laser beams are used, and the spot arrangement of these laser beams is plural in a row in the main scanning direction and plural in a sub-scanning direction. This means that a two-dimensional plane array consisting of rows is used. By using a laser beam having a multi-beam two-dimensional array, the time required for laser recording can be reduced.

The laser beam to be used can be used without particular limitation as long as it is a multi-beam, and is a gas laser beam such as an argon ion laser beam, a helium neon laser beam, a helium cadmium laser beam, or a solid laser beam such as a YAG laser beam. Light, semiconductor laser light, dye laser light,
Direct laser light such as excimer laser light is used. Alternatively, light obtained by converting these laser lights to half the wavelength through a second harmonic element can be used. In the multicolor image forming method, it is preferable to use a semiconductor laser beam in consideration of output power, ease of modulation, and the like. In the multicolor image forming method, the laser beam has a beam diameter on the photothermal conversion layer of 5 to 50 μm (particularly 6 to 30 μm).
μm), and the scanning speed is 1 m / sec or more (especially 3 m / sec or more).
It is preferable that

In the multicolor image formation, the layer thickness of the image forming layer in the black thermal transfer sheet is larger than the layer thickness of the image forming layer in each of the yellow, magenta and cyan thermal transfer sheets, and 0.5 to 0.5. It is preferably 0.7 μm. By doing so, it is possible to suppress a decrease in density due to uneven transfer when the black thermal transfer sheet is irradiated with laser. When the thickness of the image forming layer in the black thermal transfer sheet is less than 0.5 μm, when recording with high energy, the image density is greatly reduced due to transfer unevenness, and the image density required as a proof of printing is achieved. It can be difficult. This tendency becomes more remarkable under high-humidity conditions, and the concentration change due to the environment may be large. On the other hand, if the layer thickness exceeds 0.7 μm, the transfer sensitivity may decrease during laser recording, and the attachment of small dots may worsen, or the thin line may become thin. This tendency is more pronounced under low humidity conditions. Further, the resolution may be deteriorated. The layer thickness of the image forming layer in the black thermal transfer sheet is more preferably 0.55 to 0.65 μm, and particularly preferably 0.60 μm.

Further, the thickness of the image forming layer in the black thermal transfer sheet is 0.5 to 0.7 μm, and the thickness of the image forming layer in each of the yellow, magenta and cyan thermal transfer sheets is 0 to 0.7 μm. .2μm or more and 0.5μm
It is preferably less than. The yellow, magenta,
When the thickness of the image forming layer in each of the thermal transfer sheets of cyan and cyan is less than 0.2 μm, the density may be reduced due to transfer unevenness during laser recording.
Above, the transfer sensitivity may decrease or the resolution may deteriorate. More preferably, it is 0.3 to 0.45 μm.

The image forming layer in the black thermal transfer sheet preferably contains carbon black, and the carbon black is composed of at least two types of carbon blacks having different coloring powers. This is preferable because the reflection density can be adjusted while keeping the ratio in a certain range. The coloring power of carbon black can be represented by various methods. For example, the coloring power of PVC described in JP-A-10-140033 is disclosed.
Blackness and the like. PVC blackness refers to the addition of carbon black to a PVC resin, dispersion and sheeting by two rolls, and carbon black “# 40” manufactured by Mitsubishi Chemical Corporation.
The blackness of “# 45” is set to 1 point and 10 points, respectively, and a reference value is determined.
The blackness of the sample was evaluated by visual sensation determination. PV
Two or more types of carbon blacks having different C blackness can be appropriately selected and used according to the purpose.

Hereinafter, a specific sample preparation method will be described. <Sample preparation method> Using a 250 cc Banbury mixer, 40% by mass of a sample carbon black is mixed with LDPE (low density polyethylene) resin, and the mixture is kneaded at 115 ° C for 4 minutes. Compounding conditions LDPE resin 101.89 g Calcium stearate 1.39 g Irganox 1010 0.87 g Sample carbon black 69.43 g Next, the mixture is diluted with a two-roll mill at 120 ° C. so that the carbon black concentration becomes 1% by mass.

Diluting compound preparation conditions LDPE resin 58.3 g Calcium stearate 0.2 g Carbon black 40 mass% blended resin 1.5 g A sheet with slit width 0.3 mm, cut into chips and cut on a hot plate at 240 ° C. 65 ± 3μm
Into a film.

As a method of forming a multicolor image, as described above, the thermal transfer sheet is used, and a large number of image layers (image forming layers on which images are formed) are repeatedly superimposed on the same image receiving sheet. A color image may be formed, or a multicolor image may be formed by forming an image once on the image receiving layers of a plurality of image receiving sheets and then retransferring the image to printing paper or the like.
For the latter, for example, a thermal transfer sheet having an image forming layer containing colorants having mutually different hues is prepared, and four types of image forming laminates (four colors: Cyan, magenta, yellow and black). To each of the laminates, for example, through a color separation filter, perform laser light irradiation according to a digital signal based on the image, and subsequently, peel off the thermal transfer sheet and the image receiving sheet, color separation images of each color on each image receiving sheet Are formed independently. Next, each of the formed color separation images is
A multicolor image can be formed by sequentially laminating on an actual support such as a separately prepared printing paper or a similar support.

The thermal transfer recording using laser beam irradiation can convert a laser beam into heat, transfer the image forming layer containing a pigment to an image receiving sheet using the heat energy, and form an image on the image receiving sheet. If present, transfer pigment,
The state change of the dye or the image forming layer is not particularly limited, and includes any of a solid state, a softened state, a liquid state, and a gaseous state, and is preferably a solid state or a softened state. The thermal transfer recording using laser beam irradiation includes, for example, conventionally known melt-type transfer, transfer by ablation, sublimation-type transfer, and the like. Above all, the above-mentioned thin film transfer type,
The ablation type is preferable in that an image having a hue similar to printing is created.

In order to perform a step of transferring the image receiving sheet on which the image has been printed by the recording apparatus to the printing paper (hereinafter referred to as “book paper”), a thermal laminator is usually used. When the image receiving sheet and the paper are overlapped and heat and pressure are applied, the two adhere to each other. Then, when the image receiving sheet is peeled off from the paper, only the image receiving layer containing the image remains on the paper. By connecting the above devices to the plate making system, a system that can exhibit the function as a color proof is constructed. As a system, it is necessary that a printed matter having an image quality as close as possible to a printed matter output from certain platemaking data be output from the recording device. Therefore, software for bringing colors and halftone dots closer to printed matter is required. Specific connection examples are described below. When proofing a printed matter from a plate making system (for example, Celebra made by Fuji Photo Film Co., Ltd.), the system connection is as follows. Connect a CTP (Computer To Plate) system to the plate making system.
By applying the printing plate thus output to a printing machine, a final printed matter is obtained. The recording device is connected to the plate making system as a color proof, and a PD system (registered trademark) is connected as proof drive software for bringing colors and halftone dots closer to the printed matter. Contone (continuous tone) data converted to raster data by the plate making system is converted to binary data for halftone dots, output to the CTP system, and finally printed. On the other hand, the same contone data is also output to the PD system. The PD system converts the received data according to a four-dimensional (black, cyan, magenta, yellow) table so that the color matches the printed matter. Finally, the data is converted into binary data for a halftone dot so as to match the halftone dot of the printed matter, and output to a recording device. The four-dimensional table is created experimentally in advance and stored in the system. The experiment for making is as follows. An image in which important color data is printed via a CTP system and an image output from a recording device via a PD system are prepared, and their colorimetric values are compared and a table is created so that the difference is minimized.

Hereinafter, the thermal transfer sheet and the image receiving sheet suitably used in the recording apparatus of the above system will be described. [Thermal Transfer Sheet] The thermal transfer sheet has at least a light-to-heat conversion layer and an image forming layer on a support, and further has other layers as necessary.

(Support) The material of the support of the thermal transfer sheet is not particularly limited, and various support materials can be used according to the purpose. The support preferably has rigidity, good dimensional stability, and withstands heat during image formation. Preferred examples of the support material include polyethylene terephthalate, polyethylene-2,6-naphthalate, polycarbonate, polymethyl methacrylate, polyethylene,
Polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene-acrylonitrile copolymer, polyamide (aromatic or aliphatic), polyimide,
Synthetic resin materials such as polyamide imide and polysulfone can be mentioned. Among them, biaxially stretched polyethylene terephthalate is preferable in consideration of mechanical strength and dimensional stability against heat. When a color proof is produced using laser recording, the support of the thermal transfer sheet is preferably formed of a transparent synthetic resin material that transmits laser light. The thickness of the support is 25 to 130 μm
Is preferably, and particularly preferably 50 to 120 μm. The center line average surface roughness Ra (measured based on JIS B0601 using a surface roughness measuring device (Surfcom, manufactured by Tokyo Seiki Co., Ltd.)) of the support on the image forming layer side may be less than 0.1 μm. preferable. The Young's modulus of the support in the longitudinal direction is 200 to 1200 kg / mm.
² (≒ ^{2 to} 12 GPa) is preferable, and the Young's modulus in the width direction is 250 to 1600 kg / mm ² (≒ 2.5 to 16 GPa).
a) is preferred. F-5 in the longitudinal direction of the support
The value is preferably 5 to 50 kg / mm ² ($ 49 to 49
0 MPa), and the F-5 value in the support width direction is preferably 3
３０30 kg / mm ² (≒ 29.4 to 294 MPa), and the F-5 value in the support longitudinal direction is F-5 in the support width direction.
It is generally higher than the value, but this is not particularly necessary when it is necessary to increase the strength in the width direction. Further, the heat shrinkage in the longitudinal direction and the width direction of the support at 100 ° C. for 30 minutes is preferably 3% or less, more preferably 1.5% or less, and the heat shrinkage at 80 ° C. for 30 minutes is preferably 1%. Less than,
More preferably, it is 0.5% or less. The breaking strength is 5 to 100 kg / mm ² (ｍｍ49 to 980 MP in both directions).
a), the elastic modulus is 100 to 2000 kg / mm ² (≒ 0.
98 to 19.6 GPa).

The support of the thermal transfer sheet is subjected to a surface activation treatment and / or to the provision of one or more undercoat layers in order to improve the adhesion to the light-to-heat conversion layer provided thereon. Is also good. Examples of the surface activation treatment include a glow discharge treatment and a corona discharge treatment. The material of the undercoat layer preferably has high adhesiveness to both surfaces of the support and the light-to-heat conversion layer, low thermal conductivity, and excellent heat resistance. Examples of such a material for the undercoat layer include styrene, styrene-butadiene copolymer, and gelatin. The thickness of the entire undercoat layer is usually from 0.01 to 2 μm. Further, on the surface of the thermal transfer sheet opposite to the side on which the light-to-heat conversion layer is provided, various functional layers such as an anti-reflection layer and an anti-static layer can be provided or a surface treatment can be performed, if necessary.

(Back Layer) It is preferable to provide a back layer on the surface of the thermal transfer sheet of the present invention opposite to the side on which the light-to-heat conversion layer is provided. The back layer is preferably composed of two layers, a first back layer adjacent to the support and a second back layer provided on the side of the first back layer opposite to the support. In the present invention, the ratio B / A of the mass A of the antistatic agent contained in the first back layer to the mass B of the antistatic agent contained in the second back layer is preferably less than 0.3.
When B / A is 0.3 or more, slipperiness and powder dropping of the back layer tend to be deteriorated.

The thickness C of the first back layer is 0.01 to 1 μm.
m, more preferably 0.01 to 0.2 μm. In addition, the thickness D of the second back layer
Is preferably 0.01 to 1 μm, and 0.01 to 1 μm.
More preferably, it is 0.2 μm. The ratio C: D of the thickness of the first and second back layers is preferably 1: 2 to 5: 1.

Examples of the antistatic agent used for the first and second back layers include polyoxyethylene alkylamine,
Nonionic surfactants such as glycerin fatty acid esters,
Compounds such as cationic surfactants such as quaternary ammonium salts, anionic surfactants such as alkyl phosphate, amphoteric surfactants, and conductive resins can be used.

Further, conductive fine particles are used as an antistatic agent.
Can also be. As such conductive fine particles,
For example, ZnO, TiO_Two, SnO_Two, Al_TwoO_Three, In_Two
O_Three, MgO, BaO, CoO, CuO, Cu_TwoO, Ca
O, SrO, BaO_Two, PbO, PbO_Two, MnO_Three, M
oO_Three, SiO_Two, ZrO_Two, Ag_TwoO, Y_TwoO_Three, Bi
_TwoO_Three, Ti_TwoO_Three, Sb_TwoO_Three, Sb_TwoO_Five, K_TwoTi₆O₁₃,
NaCaP_TwoO₁₈, MgB_TwoO _FiveOxides such as CuS, Z
Sulfides such as nS; SiC, TiC, ZrC, VC, Nb
Carbides such as C, MoC and WC; Si_ThreeN_Four, TiN, Zr
N, VN, NbN, Cr_TwoNitride such as N; TiB_Two, Zr
B_Two, NbB_Two, TaB_Two, CrB, MoB, WB, La
B_FiveBorides such as TiSi_Two, ZrSi_Two, NbSi_Two, T
aSi_Two, CrSi_Two, MoSi_Two, WSi_TwoSilicides such as;
BaCO_Three, CaCO_Three, SrCO_Three, BaSO_Four, CaS
O_FourMetal salts such as SiN_Four-SiC, 9Al_TwoO_Three-2B_Two
O_ThreeAnd the like. One of these compounds may be used alone or in combination.
More than one species may be used in combination. Of these, SnO_Two, Z
nO, Al_TwoO_Three, TiO_Two, In_TwoO_Three, MgO, BaO
And MoO_ThreeAre preferred, and SnO_Two, ZnO, In_TwoO_ThreePassing
And TiO_TwoIs more preferable, and SnO_TwoIs particularly preferred.

When the thermal transfer material of the present invention is used in a laser thermal transfer recording system, the antistatic agent used in the back layer is preferably substantially transparent so that laser light can be transmitted.

When a conductive metal oxide is used as an antistatic agent, the particle size is preferably as small as possible to minimize light scattering. It is to be determined and can be determined using Mie's theory. Generally, the average particle size is in the range of 0.001 to 0.5 μm, preferably in the range of 0.003 to 0.2 μm. Here, the average particle diameter is a value including not only the primary particle diameter of the conductive metal oxide but also the particle diameter of a higher-order structure.

In order to prevent foreign matter such as dust or dust, which is a cause of image defects such as white spots, from adhering to the thermal transfer sheet, the above-mentioned antistatic agent is used to reduce the surface electricity of the back layer surface of the thermal transfer sheet. The resistance SR is preferably 10 ¹¹ or less at 23 ° C. and 55% RH, more preferably 1 × 10 ⁹ or less.

In addition to the antistatic agent, various additives and binders such as a surfactant, a slipping agent and a matting agent can be added to the first and second back layers. The amount of the antistatic agent contained in the first back layer is preferably from 10 to 1,000 parts by mass, and more preferably from 200 to 80 parts by mass based on 100 parts by mass of the binder.
0 parts by mass is more preferred. The amount of the antistatic agent contained in the second back layer is preferably from 0 to 300 parts by mass, more preferably from 0 to 100 parts by mass, based on 100 parts by mass of the binder.

The binder used for forming the first and second back layers is, for example, a homopolymer or a copolymer of an acrylic acid monomer such as acrylic acid, methacrylic acid, acrylic ester, methacrylic ester and the like. , Nitrocellulose, methylcellulose, ethylcellulose,
Cellulosic polymers such as cellulose acetate,
Polyethylene, polypropylene, polystyrene, vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, polyvinylpyrrolidone, polyvinylbutyral, copolymer of vinyl compound such as polyvinyl alcohol and vinyl compound, polyester, polyurethane, polyamide Such condensation polymers, rubber-based thermoplastic polymers such as butadiene-styrene copolymers, polymers obtained by polymerizing or crosslinking photopolymerizable or thermopolymerizable compounds such as epoxy compounds, melamine compounds, and the like. .

(Light-to-heat conversion layer) The light-to-heat conversion layer contains a light-to-heat conversion material, a binder, and if necessary, a matting agent.
Further, if necessary, other components are contained. The photothermal conversion substance is a substance having a function of converting irradiated light energy into heat energy. Generally, it is a dye capable of absorbing laser light (including a pigment; the same applies hereinafter). When performing image recording with an infrared laser, it is preferable to use an infrared absorbing dye as the photothermal conversion substance. Examples of the dye include black pigments such as carbon black, phthalocyanines, macrocyclic compound pigments having absorption in the visible to near-infrared region such as naphthalocyanine, and laser absorbing materials for high-density laser recording such as optical disks. Examples thereof include organic dyes (cyanine dyes such as indolenine dyes, anthraquinone dyes, azulene dyes, and phthalocyanine dyes), and organic metal compound dyes such as dithiol nickel complexes. Above all, cyanine dyes have a high absorption coefficient for light in the infrared region, so when used as a light-to-heat conversion material, the light-to-heat conversion layer can be made thinner, and as a result, the recording sensitivity of the heat transfer sheet is reduced. It is preferable because it can be further improved. As the light-to-heat conversion material, an inorganic material such as a particulate metal material such as blackened silver can be used in addition to the pigment.

The binder contained in the light-to-heat conversion layer has at least a strength capable of forming a layer on a support,
Resins having high thermal conductivity are preferred. Furthermore, in the case of image recording, when the resin is heat-resistant and does not decompose even by the heat generated from the light-to-heat conversion material, even if high-energy light irradiation is performed, the surface of the light-heat conversion layer after light irradiation can be smoothed. It is preferable because it can be maintained. Specifically, the thermal decomposition temperature (T
A resin having a temperature of 10 ° C./min in a GA method (temperature at which the mass is reduced by 5% in an air stream at a temperature rising rate of 10 ° C./min.) Is preferably 400 ° C. or higher, and the resin having a thermal decomposition temperature of 500 ° C. or higher is preferable. More preferred. Also, the binder is 200 to 400 ° C.
It preferably has a glass transition temperature of 250 to 35.
More preferably, it has a glass transition temperature of 0 ° C. When the glass transition temperature is lower than 200 ° C., fogging may occur in an image to be formed, and when the glass transition temperature is higher than 400 ° C., the solubility of the resin may be reduced and the production efficiency may be reduced.
In addition, it is preferable that the heat resistance (for example, heat deformation temperature and thermal decomposition temperature) of the binder of the light-to-heat conversion layer is higher than that of the material used for the other layers provided on the light-to-heat conversion layer.

Specifically, acrylic resins such as polymethyl methacrylate, polycarbonate, polystyrene,
Vinyl chloride / vinyl acetate copolymer, vinyl resin such as polyvinyl alcohol, polyvinyl butyral, polyester, polyvinyl chloride, polyamide, polyimide, polyetherimide, polysulfone, polyethersulfone, aramid, polyurethane, epoxy resin, urea / melamine Resins. Among these, a polyimide resin is preferable.

In particular, the polyimide resins represented by the following general formulas (I) to (VII) are soluble in organic solvents, and the use of these polyimide resins is preferable because the productivity of the thermal transfer sheet is improved. It is also preferable in that the viscosity stability, long-term storage property, and moisture resistance of the coating solution for the light-to-heat conversion layer are improved.

[0080]

Embedded image

In the above general formulas (I) and (II), Ar
¹ represents an aromatic group represented by the following structural formulas (1) to (3), and n represents an integer of 10 to 100.

[0082]

Embedded image

[0083]

Embedded image

In the general formulas (III) and (IV), Ar
² represents an aromatic group represented by the following structural formulas (4) to (7), and n represents an integer of 10 to 100.

[0085]

Embedded image

[0086]

Embedded image

In the above general formulas (V) to (VII), n and m
Represents an integer of 10 to 100. In the formula (VI), n:
The ratio of m is from 6: 4 to 9: 1.

As a criterion for judging whether or not the resin is soluble in an organic solvent, it is based on the fact that at 25 ° C., at least 10 parts by mass of the resin is dissolved with respect to 100 parts by mass of N-methylpyrrolidone. When it is dissolved in 10 parts by mass or more, it is preferably used as a resin for the light-to-heat conversion layer. More preferably, the resin dissolves in 100 parts by mass or more based on 100 parts by mass of N-methylpyrrolidone.

The matting agent contained in the light-to-heat conversion layer includes inorganic fine particles and organic fine particles. Examples of the inorganic fine particles include silica, titanium oxide, aluminum oxide, zinc oxide, magnesium oxide, barium sulfate, magnesium sulfate, aluminum hydroxide, magnesium hydroxide, metal salts such as boron nitride, kaolin, clay, talc, zinc oxide, and the like. Examples include lead white, zeeklite, quartz, diatomaceous earth, barlite, bentonite, mica, and synthetic mica. As organic fine particles, fluororesin particles,
Resin particles such as guanamine resin particles, acrylic resin particles, styrene-acryl copolymer resin particles, silicone resin particles, melamine resin particles, and epoxy resin particles can be exemplified.

The particle size of the matting agent is usually 0.3 to 30 μm.
m, preferably 0.5 to 20 μm, and the addition amount is preferably 0.1 to 100 mg / m ² .

A surfactant, a thickener, an antistatic agent, and the like may be further added to the light-to-heat conversion layer, if necessary.

The light-to-heat conversion layer is prepared by dissolving a light-to-heat conversion substance and a binder, preparing a coating solution containing a matting agent and other components as necessary, coating the solution on a support, and drying. Can be provided. Examples of the organic solvent for dissolving the polyimide resin include, for example, n
-Hexane, cyclohexane, diglyme, xylene,
Toluene, ethyl acetate, tetrahydrofuran, methyl ethyl ketone, acetone, cyclohexanone, 1,4-dioxane, 1,3-dioxane, dimethyl acetate,
N-methyl-2-pyrrolidone, dimethylsulfoxide, dimethylformamide, dimethylacetamide, γ
-Butyrolactone, ethanol, methanol and the like. Coating and drying can be performed by using ordinary coating and drying methods. Drying is usually performed at a temperature of 300 ° C. or lower, preferably at a temperature of 200 ° C. or lower. When polyethylene terephthalate is used as the support, drying is preferably performed at a temperature of 80 to 150 ° C.

If the amount of the binder in the light-to-heat conversion layer is too small, the cohesive force of the light-to-heat conversion layer is reduced, and when the formed image is transferred to the image receiving sheet, the light-to-heat conversion layer is easily transferred together. It causes color mixing. On the other hand, if the amount of the polyimide resin is too large, the layer thickness of the light-to-heat conversion layer becomes large in order to achieve a certain light absorption rate, and the sensitivity tends to decrease. The mass ratio of the solid content of the light-to-heat conversion material to the binder in the light-to-heat conversion layer is preferably from 1:20 to 2: 1, and more preferably from 1:10 to 2: 1.
Further, it is preferable to make the light-to-heat conversion layer thin, as described above, since the sensitivity of the heat transfer sheet can be increased. The light-to-heat conversion layer preferably has a thickness of 0.03 to 1.0 μm,
More preferably, it is 5 to 0.5 μm. The light-to-heat conversion layer has a wavelength of 808 nm and is 0.80 to 1.0.
Having an optical density of 26 is preferable because the transfer sensitivity of the image forming layer is improved.
More preferably, it has an optical density of 2 to 1.15.
If the optical density at the laser peak wavelength is less than 0.80, it becomes insufficient to convert the irradiated light into heat, and the transfer sensitivity may decrease. On the other hand, when the ratio exceeds 1.26, the function of the light-to-heat conversion layer is affected during recording, and fog may occur.

(Image Forming Layer) The image forming layer contains at least a pigment which is transferred to an image receiving sheet to form an image, and further contains a binder for forming a layer and, if desired, other components. I do. Pigments are generally classified into organic pigments and inorganic pigments.The former has properties such as excellent transparency of the coating film, and the latter generally has properties such as excellent concealing properties. Just fine. When the thermal transfer sheet is used for printing color proofing, an organic pigment having a color tone similar to or close to yellow, magenta, cyan, and black generally used for printing ink is preferably used. In addition, a metal powder, a fluorescent pigment, or the like may be used. Examples of preferably used pigments include azo pigments, phthalocyanine pigments, anthraquinone pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, and nitro pigments. The pigments used in the image forming layer are listed below for each hue, but are not limited thereto.

1) Yellow Pigment Pigment Yellow
12 (CI No. 21090) Example) Permanent Yellow (Permanent Yellow) DHG (Clariant Japan K.K.)
Manufactured by Toyo Ink Mfg. Co., Ltd.), Lionol Yellow 1212B (manufactured by Toyo Ink Mfg. Co., Ltd.), Irg
alite Yellow (Ilgarite Yellow)
LCT (Ciba Specialty Chemicals Co., Ltd.)
Pigment Yellow (manufactured by Dainippon Ink and Chemicals, Inc.)
13 (CI No. 21100) Example: Permanent Yellow (Permanent Yellow) GR (manufactured by Clariant Japan K.K.),
Lionol Yellow
1313 (manufactured by Toyo Ink Mfg. Co., Ltd.) Pigment Yellow
14 (CI No. 21095) Example) Permanent Yellow (Permanent Yellow) G (manufactured by Clariant Japan KK), L
ionol Yellow 1
401-G (manufactured by Toyo Ink Mfg. Co., Ltd.), Seika
Fast Yellow (Seika First Yellow)
2270 (manufactured by Dainichi Seika Kogyo Co., Ltd.), Symuler
Fast Yellow 4400 (manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Yellow (Pigment Yellow)
17 (CI No. 21105) Example) Permanent Yellow (Permanent Yellow) GG02 (Clariant Japan K.K.)
Pigment Yellow (manufactured by Dainippon Ink and Chemicals, Inc.) 8GF (manufactured by Dainippon Ink and Chemicals, Inc.)
155 Example) Graphtol Yellow (Graftor Yellow) 3GP (manufactured by Clariant Japan KK) Pigment Yellow (Pigment Yellow)
180 (CI No. 21290) Example) Novoperm Yellow (Novo Palm Yellow) P-HG (manufactured by Clariant Japan K.K.),
PV Fast Yellow
HG (manufactured by Clariant Japan KK) Pigment Yellow (Pigment Yellow)
139 (CI No. 56298) Example) Novoperm Yellow (Novo Palm Yellow) M2R 70 (Clariant Japan K.K.)
Made)

2) Magenta pigment Pigment Red (Pigment Red) 57:
1 (CI No. 15850: 1) Example) Graphtol Rubine L6B (manufactured by Clariant Japan KK), L
ionol Red (Rionol Red) 6B-42
90G (manufactured by Toyo Ink Mfg. Co., Ltd.), Irgalite
Rubine (Ilgarite Rubin) 4BL (Ciba Specialty Chemicals Co., Ltd.), Symu
ler Brilliant Carmine 6B-229 (manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Red (Pigment Red) 122
(C.I. No. 73915) Example) Hosterperm Pink (Hoster Palm Pink) E (manufactured by Clariant Japan K.K.), Li
onogen Magenta
5790 (manufactured by Toyo Ink Mfg. Co., Ltd.), Fastog
en Super Magenta RH (Dainippon Ink & Chemicals, Inc.)
Manufactured) Pigment Red 53:
1 (CI No. 15585: 1) Example) Permanent Lake Red (Permanent Lake Red) LCY (manufactured by Clariant Japan KK), Symler Lake Red (Shimla Lake Red) C conc (Dainippon Ink & Chemicals, Inc.) )) Pigment Red (Pigment Red) 48:
1 (CI No. 15865: 1) Example) Lionol Red 2B
3300 (manufactured by Toyo Ink Mfg. Co., Ltd.), Symule
r Red (Shimler Red) NRY (manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Red (Pigment Red) 48:
2 (CI No. 15865: 2) Example) Permanent Red (Permanent Red) W2T (manufactured by Clariant Japan KK), Li
onol Red (Lionol Red) LX235
(Manufactured by Toyo Ink Manufacturing Co., Ltd.), Symler Red
(Shimler Red) 3012 (manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Red 48:
3 (CI No. 15865: 3) Example) Permanent Red (Permanent Red) 3RL (manufactured by Clariant Japan KK), Sy
muller Red (Shimler Red) 2BS (manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Red (Pigment Red) 177
(CI. No. 65300) Example) Cromophthal Red (Chromophthal Red) A2B (manufactured by Ciba Specialty Chemicals Co., Ltd.)

3) Cyan pigment Pigment Blue (Pigment Blue) 15
(C.I. No. 74160) Example) Lionol Blue 7
027 (manufactured by Toyo Ink Manufacturing Co., Ltd.), Fastogen
Blue (fastogen blue) BB (manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Blue (pigment blue) 1
5: 1 (CI No. 74160) Example) Hosterperm Blue (Hoster Palm Blue) A2R (manufactured by Clariant Japan KK),
Fastogen Blue (fastogen blue)
5050 (manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Blue 1
5: 2 (CI No. 74160) Example) Hosterperm Blue (Hoster Palm Blue) AFL (manufactured by Clariant Japan KK),
Irgalite Blue (Irgalite Blue)
BSP (Ciba Specialty Chemicals Co., Ltd.)
Pigment Blue (Pigment Blue) 1 Fastogen Blue (Fastgen Blue) GP (Dai Nippon Ink Chemical Industry Co., Ltd.)
5: 3 (CI No. 74160) Example) Hosterperm Blue (Hoster Palm Blue) B2G (manufactured by Clariant Japan K.K.),
Lionol Blue FG73
30 (manufactured by Toyo Ink Manufacturing Co., Ltd.), Cromophta
l Blue (Chromophthal Blue) 4GNP (Ciba Specialty Chemicals Co., Ltd.), Fast
oogen Blue FGF
(Manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Blue 1
5: 4 (CI No. 74160) Example) Hosterperm Blue (Hoster Palm Blue) BFL (manufactured by Clariant Japan KK),
Cyanine Blue (Cyanine Blue) 700-
10FG (manufactured by Toyo Ink Mfg. Co., Ltd.), Irgalit
e Blue (Irgarite Blue) GLNF (Ciba Specialty Chemicals Co., Ltd.), Fast
oogen Blue FGS
(Manufactured by Dainippon Ink and Chemicals, Inc.) Pigment Blue 1
5: 6 (CI No. 74160) Example) Lionol Blue E
S (manufactured by Toyo Ink Mfg. Co., Ltd.) Pigment Blue 60
(C.I. No. 69800) Example) Hosterperm Blue (Hoster Palm Blue) RL01 (Clariant Japan K.K.)
Co., Ltd.), Lionogen Blue (Lionogen Blue) 6501 (manufactured by Toyo Ink Mfg. Co., Ltd.)

4) Black Pigment Pigment Black
7 (carbon black CI No. 77266) Example) Mitsubishi carbon black MA100 (manufactured by Mitsubishi Chemical Corporation), Mitsubishi carbon black # 5 (manufactured by Mitsubishi Chemical Corporation), Black Pearls (Black Pearls) 430 (Cabot) Co. (Cabot Corporation)
Pigments that can be used in the present invention include “Pigment Handbook, edited by Japan Pigment Technical Association, Seibundo Shinkosha, 198
9 "," COLOUR INDEX, THE SOCIETY OF
DYES & COLOURIST, THIRD EDITION, 1987 "
The product can be selected as appropriate by referring to the table.

The average particle size of the pigment is from 0.03 to
1 μm is preferable, and 0.05 to 0.5 μm is more preferable. When the particle size is less than 0.03 μm, the dispersion cost may increase, or the dispersion may cause gelation,
On the other hand, if it exceeds 1 μm, coarse particles in the pigment may hinder the adhesion between the image forming layer and the image receiving layer,
This may hinder the transparency of the image forming layer.

The binder for the image forming layer is preferably an amorphous organic high molecular polymer having a softening point of 40 to 150 ° C. As the amorphous organic high-molecular polymer, for example, butyral resin, polyamide resin, polyethyleneimine resin, sulfonamide resin, polyester polyol resin, petroleum resin, styrene, vinyltoluene, α-methylstyrene, 2-methylstyrene, Styrene and its derivatives such as chlorostyrene, vinylbenzoic acid, sodium vinylbenzenesulfonate and aminostyrene, homopolymers and copolymers of substituted products, methacrylates such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and hydroxyethyl methacrylate And acrylates such as methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate and α-ethylhexyl acrylate, and dienes such as acrylic acid, butadiene and isoprene; Use of vinyl monomers such as rilonitrile, vinyl ethers, maleic acid and maleic esters, maleic anhydride, cinnamic acid, vinyl chloride, vinyl acetate, or copolymers with other monomers Can be. These resins can be used as a mixture of two or more kinds.

The image forming layer preferably contains 30 to 70% by mass of a pigment, more preferably 30 to 50% by mass. In addition, the image forming layer is made of 70% resin.
The content is preferably from 30 to 30% by mass, more preferably from 70 to 40% by mass.

The image forming layer can contain the following components as the other components. Waxes Examples of the waxes include mineral waxes, natural waxes, and synthetic waxes. Examples of the mineral wax include petroleum wax such as paraffin wax, microcrystalline wax, ester wax, and oxidized wax, montan wax, ozokerite, and ceresin. Among them, paraffin wax is preferred. The paraffin wax is separated from petroleum, and various types are commercially available depending on the melting point. Examples of the natural waxes include vegetable waxes such as carnauba wax, wood wax, ouriculi wax, and spal wax, and animal waxes such as beeswax, insect wax, shellac wax, and whale wax.

The synthetic wax is generally used as a lubricant, and usually comprises a higher fatty acid compound. Examples of such synthetic waxes include the following. 1) Fatty acid-based wax Linear saturated fatty acid represented by the following general formula: CH ₃ (CH ₂ ) _n COOH In the above formula, n represents an integer of 6 to 28. Specific examples include stearic acid, behenic acid, palmitic acid, 12-hydroxystearic acid, azelaic acid and the like.
In addition, metal salts such as the above fatty acids (eg, K, Ca, Z
n, Mg, etc.). 2) Fatty acid ester-based wax Specific examples of the fatty acid ester include ethyl stearate, lauryl stearate, ethyl behenate, hexyl behenate, and behenyl myristate. 3) Fatty acid amide-based wax Specific examples of the amide of the fatty acid include stearic acid amide and lauric acid amide. 4) Aliphatic alcohol wax A linear saturated aliphatic alcohol represented by the following general formula: CH ₃ (CH ₂ ) _n OH In the above formula, n represents an integer of 6 to 28. Specific examples include stearyl alcohol.

Among the synthetic waxes 1) to 4), higher fatty acid amides such as stearic acid amide and lauric acid amide are particularly preferable. In addition, the said wax-type compound can be used individually or suitably in combination as needed.

Plasticizer The plasticizer is preferably an ester compound. Dibutyl phthalate, di-n-octyl phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, dilauryl phthalate, butyllauryl phthalate, Phthalates such as butylbenzyl phthalate and di (2-diphenyl adipate)
Aliphatic dibasic acid esters such as ethylhexyl) and di (2-ethylhexyl) sebacate; phosphoric acid triesters such as tricresyl phosphate and tri (2-ethylhexyl) phosphate; polyol polyesters such as polyethylene glycol ester; epoxy Known plasticizers such as an epoxy compound such as a fatty acid ester can be used. Of these, esters of vinyl monomers, particularly esters of acrylic acid or methacrylic acid, are preferred because they have a large effect of improving transfer sensitivity, improving transfer unevenness, and controlling elongation at break by addition.

Examples of the ester compound of acrylic acid or methacrylic acid include polyethylene glycol dimethacrylate, 1,2,4-butanetriol trimethacrylate, trimethylolethane triacrylate, pentaerythritol acrylate, pentaerythritol tetraacrylate, and dipentaerythritol. Polyacrylate and the like.

The plasticizer may be a polymer, and among them, polyester is preferred because of its large addition effect and difficulty in diffusing under storage conditions. Examples of the polyester include sebacic acid-based polyester and adipic acid-based polyester. The additives to be contained in the image forming layer are not limited to these. The plasticizer may be used alone or in combination of two or more.

If the content of the additive in the image forming layer is too large, the resolution of the transferred image is reduced, the film strength of the image forming layer itself is reduced, and the adhesion between the photothermal conversion layer and the image forming layer is reduced. In some cases, the transfer of the unexposed portion to the image receiving sheet occurs due to a decrease in the force. From the above viewpoint, the content of the wax is preferably from 0.1 to 30% by mass, more preferably from 1 to 20% by mass of the total solids in the image forming layer. The content of the plasticizer is preferably from 0.1 to 20% by mass, more preferably from 0.1 to 10% by mass of the total solids in the image forming layer.

Others The image forming layer further comprises a surfactant,
It may contain inorganic or organic fine particles (metal powder, silica gel, etc.), oils (linseed oil, mineral oil, etc.), thickeners, antistatic agents and the like. Except for obtaining a black image, the energy required for transfer can be reduced by including a substance that absorbs the wavelength of the light source used for image recording. The substance absorbing the wavelength of the light source may be any of a pigment and a dye. It is preferable in terms of color reproduction to use a dye having a large absorption at the wavelength of the light source. Examples of near infrared dyes include:
The compounds described in JP-A-3-103476 can be exemplified.

For the image forming layer, a coating solution prepared by dissolving or dispersing the pigment and the binder and the like is prepared, and the coating solution is coated on the light-to-heat conversion layer (when the light-to-heat conversion layer is provided with the following heat-sensitive release layer, On the layer) and dried. As the solvent used for preparing the coating solution,
Examples include n-propyl alcohol, methyl ethyl ketone, propylene glycol monomethyl ether (MFG), methanol, water and the like. Coating and drying are normal coating,
It can be performed using a drying method.

On the light-to-heat conversion layer of the thermal transfer sheet,
Providing a heat-sensitive release layer containing a heat-sensitive material that generates gas by the action of heat generated in the light-to-heat conversion layer or releases attached water, thereby weakening the bonding strength between the light-to-heat conversion layer and the image forming layer. Can be. Examples of such heat-sensitive materials include compounds (polymers or low-molecular compounds) that themselves decompose or degrade due to heat to generate gas, and compounds that absorb or adsorb a considerable amount of easily vaporizable gas such as water (polymer). Or a low molecular compound). These may be used in combination.

Examples of the polymer which is decomposed or deteriorated by heat to generate a gas include a self-oxidizing polymer such as nitrocellulose, chlorinated polyolefin, chlorinated rubber, polyvinyl chloride, polyvinyl chloride, and polyvinylidene chloride. Such halogen-containing polymers, acrylic compounds such as polyisobutyl methacrylate in which volatile compounds such as water are adsorbed, cellulose esters such as ethyl cellulose in which volatile compounds such as water are adsorbed, and volatile compounds such as water. Natural polymer compounds such as adsorbed gelatin can be exemplified. Examples of the low molecular weight compound which decomposes or degrades by heat to generate a gas include a compound which generates a gas upon exothermic decomposition such as a diazo compound or azide. In addition, the decomposition or deterioration of the heat-sensitive material due to heat as described above preferably occurs at 280 ° C. or lower, particularly preferably at 230 ° C. or lower.

When a low molecular weight compound is used as the heat-sensitive material of the heat-sensitive release layer, it is desirable to combine it with a binder. As the binder, the above-mentioned polymer which itself decomposes or degrades by heat to generate a gas can be used, but an ordinary binder having no such properties can also be used. When a heat-sensitive low-molecular compound and a binder are used in combination, the mass ratio of the former to the latter is preferably 0.02: 1 to 3: 1,
More preferably, the ratio is 0.05: 1 to 2: 1. The heat-sensitive release layer desirably covers the light-to-heat conversion layer over substantially the entire surface thereof.
1 μm, and preferably in the range of 0.05 to 0.5 μm.

A light-to-heat conversion layer, a heat-sensitive release layer,
In the case of a thermal transfer sheet having a configuration in which image forming layers are laminated in this order, the heat-sensitive release layer decomposes and degrades due to heat transmitted from the light-to-heat conversion layer to generate gas. Then, due to the decomposition or the generation of gas, the heat-sensitive peeling layer partially disappears, or cohesive failure occurs in the heat-sensitive peeling layer, and the bonding force between the light-heat conversion layer and the image forming layer decreases. For this reason, depending on the behavior of the heat-sensitive release layer, a part of the heat-sensitive release layer adheres to the image forming layer and appears on the surface of the finally formed image, which may cause color mixing of the image. Therefore, even when such transfer of the heat-sensitive release layer occurs, the heat-sensitive release layer is hardly colored, that is, high in visible light, so that no visual color mixture appears in the formed image. It is desirable to show permeability. Specifically, the light-absorbing rate of the heat-sensitive release layer is 50% or less, preferably 1 to visible light.
0% or less. In addition, instead of providing an independent heat-sensitive release layer on the thermal transfer sheet, the heat-sensitive material is added to a light-to-heat conversion layer coating solution to form a light-to-heat conversion layer. It can also be set as a structure.

The coefficient of static friction on the back layer surface of the thermal transfer sheet is 0.7 or less, preferably 0.4 or less. Further, the coefficient of static friction on the surface of the image forming layer is preferably 0.5 or less, more preferably 0.2 or less. By setting the static friction coefficient of the surface of the back layer and the image forming layer within the above range, it is possible to eliminate roll contamination when transporting the thermal transfer sheet, to enable stable transport without causing displacement or jamming, and to improve the formed image. Image quality can be improved. The coefficient of static friction was measured by the following method. A sample of the thermal transfer sheet (5 cm × 20 cm) is adhered on a gantry. Adhesion is performed with an adhesive tape (for example, polyester adhesive tape, No.
Using 31B75 Hi, manufactured by Nitto Denko Corporation, the thermal transfer sheet is adhered with the support of the thermal transfer sheet facing the pedestal (image forming layer facing upward). A stainless terminal having a smooth surface (35 mm × 75 mm, 2.5 mmr curved surface, 200 mm
g) and slowly tilt the gantry, and measure the tilt angle θ of the gantry when the stainless steel terminal starts to slide. The coefficient of static friction is tan θ.

The smoother value of the surface of the image forming layer is 23 ° C. 55
% RH is preferably 0.5 to 50 mmHg (≒ 0.0665 to 6.65 kPa), which can reduce a large number of micro voids at the contact surface where the image receiving layer and the image forming layer cannot come into contact with each other. Is preferred. The surface hardness of the image forming layer is preferably 10 g or more with a sapphire needle. After the thermal transfer sheet is charged according to US Federal Government Test Standard 4046, the charge potential of the image forming layer 1 second after the thermal transfer sheet is grounded is preferably -100 to 100V. The surface electric resistance SR of the image forming layer is 10 ¹¹ or less at 23 ° C. and 55% RH, and 1
It is preferably at most ^{9 9} Ω.

The surface roughness Rz of the surface of the image forming layer is preferably 3 μm or less, more preferably 1.5 μm or less. The surface roughness Rz of the back layer surface is preferably 7 μm or less,
μ or less is more preferable. As a result, the transferability of the thermal transfer sheet is stabilized, and the transferability of the image forming layer to the image receiving layer is also improved. As a result, a transferred image of good quality is obtained.

Next, an image receiving sheet that can be used in combination with the thermal transfer sheet will be described. [Image-Receiving Sheet] (Layer Structure) The image-receiving sheet is usually composed of a support,
One or more image receiving layers are provided, and if necessary, any one or more of a cushion layer, a release layer, and an intermediate layer are provided between the support and the image receiving layer. It is preferable from the viewpoint of transportability that a back layer is provided on the surface of the support opposite to the image receiving layer.

(Support) As a support, a plastic sheet, a metal sheet, a glass sheet, a resin-coated paper,
Examples include ordinary sheet-like substrates such as paper and various composites. Examples of the plastic sheet include a polyethylene terephthalate sheet, a polycarbonate sheet, a polyethylene sheet, a polyvinyl chloride sheet, a polyvinylidene chloride sheet, a polystyrene sheet, a styrene-acrylonitrile sheet, and a polyester sheet. As the paper, printing paper, coated paper, or the like can be used.

It is preferable that the support has minute voids (voids) because the image quality can be improved. Such a support may be, for example, a thermoplastic resin, a mixed melt obtained by mixing a filler made of an inorganic pigment or a polymer incompatible with the thermoplastic resin or the like, a single layer or a multilayer by a melt extruder. It can be produced by forming a film and further stretching it uniaxially or biaxially. In this case, the porosity is determined by the selection of the resin and the filler, the mixing ratio, the stretching conditions, and the like.

As the thermoplastic resin, a polyolefin resin such as polypropylene and a polyethylene terephthalate resin are preferable because of their good crystallinity, good stretchability and easy void formation. It is preferable to use the polyolefin resin or the polyethylene terephthalate resin as a main component, and appropriately use a small amount of another thermoplastic resin in combination. As the inorganic pigment used as the filler, those having an average particle diameter of 1 to 20 μm are preferable, and calcium carbonate, clay, diatomaceous earth, titanium oxide, aluminum hydroxide, silica and the like can be used. When polypropylene is used as the thermoplastic resin as the incompatible resin used as the filler, it is preferable to combine polyethylene terephthalate as the filler. The details of the support having minute voids (voids) are described in Japanese Patent Application No. 11-290570. The content of the filler such as an inorganic pigment in the support is 2 to 30 by volume.
% Is common.

The thickness of the support of the image receiving sheet is usually from 10 to
It is 400 μm, preferably 25 to 200 μm. Further, the surface of the support is subjected to a surface treatment such as a corona discharge treatment or a glow discharge treatment in order to enhance the adhesion with the image receiving layer (or the cushion layer) or the adhesion with the image forming layer of the thermal transfer sheet. It may be.

(Image-Receiving Layer) It is preferable to provide one or more image-receiving layers on a support in order to transfer and fix the image-forming layer on the surface of the image-receiving sheet. The image receiving layer is preferably a layer formed mainly of an organic polymer binder. The binder is preferably a thermoplastic resin, for example, acrylic acid, methacrylic acid,
Acrylic esters, homopolymers of acrylic monomers such as methacrylic esters and copolymers thereof, methyl cellulose, ethyl cellulose, cellulose polymers such as cellulose acetate, polystyrene, polyvinylpyrrolidone, polyvinyl butyral, polyvinyl alcohol, polyvinyl chloride, etc. And homopolymers and copolymers of vinyl monomers such as polyesters, condensation polymers such as polyesters and polyamides, and rubber polymers such as butadiene-styrene copolymers.
The binder of the image receiving layer is preferably a polymer having a glass transition temperature (Tg) lower than 90 ° C. in order to obtain a proper adhesive strength with the image forming layer. For this purpose, a plasticizer can be added to the image receiving layer. Further, the binder polymer preferably has a Tg of 30 ° C. or higher in order to prevent blocking between sheets. The binder polymer of the image receiving layer is the same as the binder polymer of the image forming layer, in that the adhesiveness with the image forming layer during laser recording is improved, and the sensitivity and the image strength are improved.
Or it is particularly preferable to use a similar polymer.

The smoother value of the image receiving layer surface is 23 ° C. and 55% RH
Is preferably 0.5 to 50 mmHg (≒ 0.0665 to 6.65 kPa), and Ra is preferably 0.05 to 0.4 μm, so that the image receiving layer and the image forming layer cannot come into contact with the contact surface. Micro gaps can be reduced, transfer,
Further, it is preferable in terms of image quality. The Ra value can be measured based on JIS B0601 using a surface roughness measuring device (Surfcom, manufactured by Tokyo Seiki Co., Ltd.) or the like. After the image receiving sheet is charged according to the US Federal Government Test Standard 4046, the charging potential of the image receiving layer 1 second after the image receiving sheet is grounded is preferably -100 to 100 V. The surface resistance of the image receiving layer is preferably 10 ⁹ Ω or less at 23 ° C. and 55% RH. The coefficient of static friction of the surface of the image receiving layer is preferably 0.2 or less. The surface energy of the surface of the image receiving layer is preferably 23 to 35 mg / m ² .

In the case where an image is once formed on the image receiving layer and then retransferred to printing paper or the like, it is preferable that at least one of the image receiving layers is formed of a photocurable material. Examples of the composition of such a photocurable material include: a) a photopolymerizable monomer comprising at least one of a polyfunctional vinyl or a vinylidene compound capable of forming a photopolymer by addition polymerization;
Examples of the combination include b) an organic polymer, c) a photopolymerization initiator, and if necessary, additives such as a thermal polymerization inhibitor. As the above polyfunctional vinyl monomer,
Unsaturated esters of polyols, especially esters of acrylic or methacrylic acid (eg, ethylene glycol diacrylate, pentaerythritol tetraacrylate) are used.

Examples of the organic polymer include the polymer for forming an image receiving layer. In addition, as the photopolymerization initiator, a general photoradical polymerization initiator such as benzophenone, Michler's ketone or the like is used in a ratio of 0.1 to 20% by mass in the layer.

The thickness of the image receiving layer is 0.3 to 7 μm, preferably 0.7 to 4 μm. When the thickness is less than 0.3 μm, the film strength is insufficient at the time of retransfer to the printing paper, and the film is easily broken. If it is too thick, the gloss of the image after retransfer of the paper increases, and the closeness to the printed matter decreases.

(Other layers) Between the support and the image receiving layer,
A cushion layer may be provided. When the cushion layer is provided, the adhesion between the image forming layer and the image receiving layer during laser thermal transfer can be improved, and the image quality can be improved. Further, at the time of recording, even if foreign matter is mixed between the thermal transfer sheet and the image receiving sheet, the gap between the image receiving layer and the image forming layer is reduced due to the deformation action of the cushion layer, and as a result, the size of image defects such as white spots is reduced. You can also. Further, when an image is transferred and formed and then transferred to a separately prepared printing paper or the like, the image receiving surface is deformed according to the uneven surface of the paper, so that the transferability of the image receiving layer can be improved, and By reducing the gloss of the object, the similarity with the printed matter can be improved.

The cushion layer is configured to be easily deformed when a stress is applied to the image receiving layer. To achieve the above effect, a material having a low elastic modulus, a material having rubber elasticity, or easily softened by heating. It is preferred to be made of a thermoplastic resin. The elastic modulus of the cushion layer at room temperature is preferably 0.5 MPa to 1.0 GPa, particularly preferably 1 MPa to 0.5 GPa, and more preferably 10 to 100 GPa.
MPa. In addition, in order to allow foreign matter such as dust to be sunk, the penetration (25
(C, 100 g, 5 seconds) is preferably 10 or more. Further, the glass transition temperature of the cushion layer is 80 ° C. or less, preferably 25 ° C. or less, and the softening point is preferably 50 to 200 ° C. It is also possible to suitably add a plasticizer to the binder to adjust these physical properties, for example, Tg.

Specific materials used as a binder for the cushion layer include rubbers such as urethane rubber, butadiene rubber, nitrile rubber, acrylic rubber, and natural rubber, as well as polyethylene, polypropylene, polyester, and styrene-butadiene copolymer. Copolymer, ethylene-vinyl acetate copolymer, ethylene-acryl copolymer, vinyl chloride-vinyl acetate copolymer, vinylidene chloride resin, vinyl chloride resin containing a plasticizer, polyamide resin, phenol resin and the like. Although the thickness of the cushion layer varies depending on the resin used and other conditions, it is usually 3 to 100 μm,
Preferably it is 10 to 52 μm.

The image receiving layer and the cushion layer need to be adhered to each other up to the stage of laser recording, but are preferably provided so as to be peelable in order to transfer the image to the printing paper. In order to facilitate peeling, it is also preferable to provide a peeling layer having a thickness of about 0.1 to 2 μm between the cushion layer and the image receiving layer. If the layer thickness is too large, the performance of the cushion layer becomes difficult to appear, so it is necessary to adjust the thickness depending on the type of the release layer. Specific examples of the binder for the release layer include polyolefin, polyester, polyvinyl acetal, polyvinyl formal, polyparabanic acid, polymethyl methacrylate, polycarbonate, ethyl cellulose, nitrocellulose, methylcellulose, carboxymethylcellulose, hydroxypropylcellulose, polyvinyl alcohol, and polyvinyl chloride. , Urethane resin,
Tg of fluorine-based resin, styrenes such as polystyrene, acrylonitrile styrene and the like, and those obtained by cross-linking these resins, polyamide, polyimide, polyetherimide, polysulfone, polyethersulfone, and aramid have a Tg of 65 ° C.
The above-mentioned thermosetting resins and cured products of these resins are included. As the curing agent, a general curing agent such as isocyanate and melamine can be used.

When a binder for the release layer is selected in accordance with the above physical properties, polycarbonate, acetal and ethyl cellulose are preferred in terms of storability. Further, when an acrylic resin is used for the image receiving layer, release when retransferring an image after laser thermal transfer is performed. This is particularly preferable because the properties are good. Separately, a layer having extremely low adhesiveness to the image receiving layer upon cooling can be used as the release layer. Specifically, a layer mainly composed of a heat-fusible compound such as a wax or a binder or a thermoplastic resin can be used. Examples of the heat-fusible compound include substances described in JP-A-63-193886. In particular, microcrystalline wax, paraffin wax, carnauba wax and the like are preferably used. As the thermoplastic resin, an ethylene copolymer such as an ethylene-vinyl acetate resin, a cellulose resin, or the like is preferably used.

As needed, higher fatty acids, higher alcohols, higher fatty acid esters, amides, higher amines and the like can be added to such a release layer.
Another configuration of the release layer is a layer that has a releasability by melting or softening during heating to cause cohesive failure itself. Preferably, such a release layer contains a supercooled substance. Examples of the supercooled substance include poly-ε-caprolactone, polyoxyethylene, benzotriazole, tribenzylamine, and vanillin. Further, the peelable layer having another configuration contains a compound that reduces the adhesiveness to the image receiving layer. Examples of such compounds include silicone resins such as silicone oil; fluorine resins such as Teflon (registered trademark) and fluorine-containing acrylic resins; polysiloxane resins; acetal resins such as polyvinyl butyral, polyvinyl acetal and polyvinyl formal; Solid waxes such as waxes and amide waxes; and fluorine-based and phosphate-based surfactants. As a method of forming the release layer,
A material obtained by dissolving the material in a solvent or dispersing in a latex state is a blade coater, a roll coater, a bar coater,
A coating method such as a curtain coater, a gravure coater, or the like, an extrusion lamination method using a hot melt, or the like can be applied, and can be formed by coating on a cushion layer. Alternatively, there is a method in which a material obtained by dissolving or dispersing the material in a solvent or in the form of latex on a temporary base is applied by the above-described method and bonded to a cushion layer, and then the temporary base is peeled off.

The image-receiving sheet combined with the thermal transfer sheet may have a structure in which the image-receiving layer also serves as a cushion layer. In this case, the image-receiving sheet may be a support / cushion-type image receiving layer or a support / undercoat layer. / Cushioning image receiving layer may be used. Also in this case, it is preferable that the cushioning image-receiving layer is provided so as to be releasable so that it can be retransferred to the printing paper. In this case, the image after retransfer to the printing paper becomes an image having excellent gloss. The thickness of the cushioning image receiving layer is 5 to 100 μm, preferably 10 to 100 μm.
４０40 μm.

It is preferable that the backing layer is provided on the surface of the support opposite to the surface on which the image receiving layer is provided, since the transportability of the image receiving sheet is improved. It is preferable to add an antistatic agent such as a surfactant and tin oxide fine particles and a matting agent such as silicon oxide and PMMA particles to the back layer in terms of improving the transportability in the recording apparatus. The additives can be added not only to the back layer but also to the image receiving layer and other layers as needed. Although the type of additive cannot be specified unconditionally depending on the purpose,
For example, in the case of a matting agent, particles having an average particle size of 0.5 to 10 μm can be added to the layer in an amount of about 0.5 to 80%. As an antistatic agent, the surface electric resistance of the layer is 23 ° C.5
10 ¹² Ω or less under the condition of 0% RH, more preferably 10 ⁹ Ω
Any of various surfactants and conductive agents can be appropriately selected and used so as to be Ω or less.

Examples of the binder used for the back layer include gelatin, polyvinyl alcohol, methyl cellulose, nitrocellulose, acetyl cellulose, aromatic polyamide resin, silicone resin, epoxy resin, alkyd resin, phenol resin, melamine resin, fluorine resin, and polyimide resin. , Urethane resin, acrylic resin, urethane modified silicone resin, polyethylene resin, polypropylene resin, polyester resin, Teflon resin, polyvinyl butyral resin, vinyl chloride resin, polyvinyl acetate, polycarbonate, organic boron compounds, aromatic esters, fluorinated polyurethane A general-purpose polymer such as polyether sulfone can be used. Cross-linking using a cross-linkable water-soluble binder as the binder for the back layer is effective in preventing the matting agent from falling off and improving the scratch resistance of the back layer. It is also highly effective in blocking during storage. This cross-linking means can employ any one or combination of heat, actinic rays, and pressure without particular limitation, depending on the characteristics of the cross-linking agent used. In some cases, an optional adhesive layer may be provided on the side of the support on which the back layer is provided, in order to impart adhesiveness to the support.

As a matting agent preferably added to the back layer, organic or inorganic fine particles can be used. As an organic matting agent, polymethyl methacrylate (PMM
A), polystyrene, polyethylene, polypropylene,
Other examples include fine particles of a radical polymerizable polymer, and fine particles of a condensation polymer such as polyester and polycarbonate. The back layer is preferably provided with a coverage of about 0.5 to 5 g / m ² . If it is less than 0.5 g / m ² , the coating properties are unstable and problems such as powder dropping of the matting agent are likely to occur.
Further, when the coating is applied more than 5 g / m ² , the particle size of the suitable matting agent becomes very large, and the image receiving layer surface is embossed by the back layer during storage, and especially the thermal transfer for transferring the thin image forming layer. In this case, missing or unevenness of a recorded image is likely to occur. The matting agent preferably has a number average particle size that is larger by 2.5 to 20 μm than the layer thickness of only the binder in the back layer. Among the matting agents, particles having a particle size of 8 μm or more require 5 mg / m ² or more, and preferably 6 to 600 mg / m ^2.
a m ^2. This improves, in particular, foreign object failure.
The value σ / r is obtained by dividing the standard deviation of the particle size distribution by the number average particle size.
By using a material having a narrow particle size distribution such that n (= coefficient of variation of the particle size distribution) is 0.3 or less, defects caused by particles having an abnormally large particle size can be improved.
Desired performance can be obtained with a smaller amount of addition. This coefficient of variation is more preferably 0.15 or less.

It is preferable to add an antistatic agent to the back layer in order to prevent adhesion of foreign matter due to frictional charging with the transport roll. Examples of the antistatic agent include cationic surfactants, anionic surfactants, nonionic surfactants, polymer antistatic agents, conductive fine particles, and “1129”.
Compounds described in Chemical Industry No. 0, pp. 875-876, etc. are widely used. As the antistatic agent that can be used in combination with the back layer, among the above substances, conductive fine particles such as carbon black, metal oxides such as zinc oxide, titanium oxide and tin oxide, and organic semiconductors are preferably used. In particular, the use of conductive fine particles is preferable because the antistatic agent does not dissociate from the back layer and a stable antistatic effect can be obtained regardless of the environment. In addition, the back layer, in order to impart coating properties and release properties, various activators,
It is also possible to add a release agent such as silicone oil or fluorine-based resin. The back layer is particularly preferable when the softening points of the cushion layer and the image receiving layer as measured by TMA (Thermomechanical Analysis) are 70 ° C. or less.

The TMA softening point is determined by raising the temperature of an object to be measured at a constant heating rate while applying a constant load, and observing the phase of the object. In the present invention, the TMA softening point is defined as the temperature at which the phase of the measurement object starts to change. The measurement of the softening point by TMA can be performed using a device such as Thermoflex manufactured by Rigaku Denki Co., Ltd.

The thermal transfer sheet and the image receiving sheet can be used for image formation as a laminate in which the image forming layer of the thermal transfer sheet and the image receiving layer of the image receiving sheet are overlapped. The laminate of the thermal transfer sheet and the image receiving sheet can be formed by various methods. For example, it can be easily obtained by stacking the image forming layer of the thermal transfer sheet and the image receiving layer of the image receiving sheet and passing them through a pressure and heating roller. The heating temperature in this case is preferably 160 ° C. or lower, or 130 ° C. or lower.

As another method for obtaining a laminate, the above-described vacuum contact method is also suitably used. In the vacuum contact method, first, an image receiving sheet is wound on a drum provided with a suction hole for evacuation, and then a thermal transfer sheet slightly larger than the image receiving sheet is pressed while uniformly extruding air with a squeeze roller. This is a method of vacuum contact. As another method, there is a method in which an image receiving sheet is mechanically attached to a metal drum while being pulled, and a thermal transfer sheet is further applied and adhered to the metal drum while being mechanically pulled. Among these methods, the vacuum adhesion method is particularly preferable because temperature control of a heat roller or the like is not required and lamination can be performed quickly and uniformly.

[0142]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.
In the following description, “parts” means “parts by mass” unless otherwise specified.

(I) —Preparation of Thermal Transfer Sheet C— (Formation of Back Layer) If necessary, a 100 μm-thick polyethylene terephthalate (PET) support (Ra on both sides)
Was subjected to corona treatment on one surface (rear surface), and then a back layer was formed. Longitudinal Young's modulus of the support is ^{450Kg / mm 2 (≒ 4.4GPa)} , the Young's modulus in the width direction is ^{500Kg / mm 2 (≒ 4.9GPa)} . The F-5 value in the longitudinal direction of the support is 10 kg / mm ²
(≒ 98 MPa), the F-5 value in the support width direction is 13 K
g / mm ² (≒ 127.4 MPa).
The heat shrinkage at 00 ° C for 30 minutes is 0.3% in the longitudinal direction.
The width direction is 0.1%. Breaking strength is 20K in the longitudinal direction
g / mm ² (≒ 196 MPa) and the width direction is 25 kg /
mm ² (≒ 245 MPa), elastic modulus is 400 kg / mm ²
(≒ 3.9 GPa). When the back layer was formed, either the following back layer a or back layer b was formed.

A) Back layer a [Preparation of back layer first layer coating solution] Acrylic resin aqueous dispersion 2 parts (Julima ET410, solid content 20% by mass, manufactured by Nippon Pure Chemical Co., Ltd.) Antistatic agent (tin oxide) -Aqueous dispersion of antimony oxide) 7.0 parts (average particle size: 0.1 μm, 17% by mass) Polyoxyethylene phenyl ether 0.1 part Melamine compound 0.3 part (Sumitic Resin M-3, Sumitomo Chemical) (Formation of Industrial Co., Ltd.) Distilled water Prepared so that the total would be 100 parts [Formation of back 1st layer] A coating solution of back 1st layer was applied on one surface of a PET support subjected to corona treatment.
And dried at 180 ° C. for 30 seconds to form a back first layer.

[Preparation of Back Layer Second Layer Coating Solution] Polyolefin 3.0 parts (Chemipearl S-120, 27% by mass, manufactured by Mitsui Petrochemical Co., Ltd.) Antistatic agent (tin oxide-antimony oxide aqueous dispersion) 2.0 parts (Average particle size: 0.1 μm, 17% by mass) Colloidal silica 2.0 parts (Snowtex C, 20% by mass, manufactured by Nissan Chemical Co., Ltd.) Epoxy compound 0.3 part (Dinacol EX- 614B, manufactured by Nagase Kasei Co., Ltd.) Distilled water was prepared so that the total would be 100 parts. [Formation of back second layer] Apply coating solution of back second layer on top of first back layer. Dry layer thickness becomes 0.03 μm. 170 ℃ after applying
For 30 seconds to form a back second layer.

B) Back layer b The back layer a was the same as the back layer a except that neither the first back layer nor the second back layer contained an aqueous dispersion of tin oxide-antimony oxide as an antistatic agent. The first layer and the second layer of the bag were formed by the prescription.

1) Preparation of Coating Solution for Light-to-Heat Conversion Layer The following components were mixed while stirring with a stirrer to prepare a coating solution A or B for a light-to-heat conversion layer. [Coating solution composition A for photothermal conversion layer]-7.6 parts of infrared absorbing dye ("NK-2014", a cyanine dye having the following structure, manufactured by Nippon Kogaku Dye Co., Ltd.)

[0148]

Embedded image

(Wherein, R represents CH ₃ and X ⁻ represents ClO ₄ ⁻ ) 29.3 parts of a polyimide resin having the following structure (“Licacoat SN-20F”, manufactured by Shin Nippon Rika Co., Ltd., thermal decomposition) (Temperature: 510 ° C)

[0150]

Embedded image

[0151] (wherein, .R ₂ R ₁ is showing the SO ₂ is

[0152]

Embedded image

Is shown. Exonnaphtha 5.8 parts N-methylpyrrolidone (NMP) 1500 parts Methyl ethyl ketone 360 parts Surfactant 0.5 part Activator) ・ Mat agent dispersion of the following composition 14.1 parts

[0154] Matting Agent Dispersion-N-methyl-2-pyrrolidone (NMP) 69 parts Methyl ethyl ketone 20 parts Styrene acrylic resin 3 parts ( "Joncryl 611", manufactured by Johnson Polymer (Ltd.)) · SiO ₂ particles 8 parts ("Sea Hostar KEP150": silica particles, manufactured by Nippon Shokubai Co., Ltd.)

[Coating Composition B for Light-to-Heat Conversion Layer] In the composition A, the SiO ₂ particles (“Seahoster KEP150”: silica particles, manufactured by Nippon Shokubai Co., Ltd.) in the matting agent dispersion were mixed with polymethyl methacrylate having a particle size of 5 μm. Particles ("MX5
00 ", manufactured by Soken Chemical Co., Ltd.).

2) Formation of a light-to-heat conversion layer on the surface of the support The above-mentioned coating for the light-to-heat conversion layer was formed on one surface of a PET support having a thickness of 100 μm (on the opposite side when a back layer was provided). After applying liquid A or B using a wire bar, the applied material was dried in an oven at 120 ° C. for 2 minutes,
A light-to-heat conversion layer was formed on the support. The optical density of the obtained light-to-heat conversion layer at a wavelength of 808 nm was measured using a UV-
When measured with a spectrophotometer UV-240, OD = 1.
03. The thickness of the layer was 0.3 μm on average when the cross section of the light-to-heat conversion layer was observed with a scanning electron microscope.

3) Preparation of Coating Solution for Cyan Image Forming Layer The following components were placed in a kneader mill, and a pre-dispersion treatment was performed by applying a shearing force while adding a small amount of a solvent. A solvent was further added to the dispersion, and the dispersion was finally adjusted to have the following composition, followed by sand mill dispersion for 2 hours to obtain a pigment dispersion mother liquor. [Cyan Pigment Dispersion Mother Liquid Composition] Cyan Pigment Composition 1: 12.6 parts of polyvinyl butyral ("ESLEC B BL-SH", manufactured by Sekisui Chemical Co., Ltd.)-Pigment Blue 15: 4 (CI. No. 74160) 15.0 parts (“Cyanine Blue (Cyanine Blue) 700-10FG”, manufactured by Toyo Ink Mfg. Co., Ltd.) 0.8 parts of dispersing aid (“PW-36”, Kusumoto Kasei Co., Ltd. 110 parts of n-propyl alcohol [Cyan pigment dispersed mother liquor composition] Cyan pigment composition 2: 12.6 parts of polyvinyl butyral ("ESLEC B BL-SH", manufactured by Sekisui Chemical Co., Ltd.) Pigment Blue ( Pigment Blue) 15 (CI No. 74 160) 15.0 parts ("Lionol Blue" Chromatography) 7027 ", Toyo Ink Manufacturing Co., Ltd.) Dispersion aid 0.8 parts (" PW-36 ", manufactured by Kusumoto Kasei Co.), n-propyl alcohol 110 parts

Next, the following components were mixed while stirring with a stirrer to prepare a coating solution for a cyan image forming layer. [Coating liquid composition for cyan image forming layer]-118 parts of the above-mentioned cyan pigment-dispersed mother liquor-Cyan pigment composition 1: Cyan pigment composition 2 = 90:10 (parts)-5.2 parts of polyvinyl butyral ("ESLEC B BL-SH", (Sekisui Chemical Co., Ltd.)-1.3 parts of inorganic pigment "MEK-ST"-Wax-based compound (stearic amide "Neutron 2", manufactured by Nippon Seika Co., Ltd.) 1.0 part (behenamide) "Diamid BM", manufactured by Nippon Kasei Co., Ltd.) 1.0 part (lauric amide "Diamid Y", manufactured by Nippon Kasei Co., Ltd.) 1.0 part (palmitic acid amide "Diamind KP", Nippon Kasei ( 1.0 part (erucamide "Diamid L-200" (manufactured by Nippon Kasei Co., Ltd.) 1.0 part (oleic amide "Diamid O-200", manufactured by Nippon Kasei Co., Ltd.) 1.0・ Rosin 2.8 parts (“KE-311”, manufactured by Arakawa Chemical Co., Ltd.) (Ingredients: resin acid 80-97%; resin acid components: abietic acid 30-40%, neoabietic acid 10-20%, dihydro Abietic acid 14%, tetrahydroabietic acid 14%) 1.7 parts of pentaerythritol tetraacrylate ("NK Ester A-TMMT", manufactured by Shin-Nakamura Chemical Co., Ltd.) 1.7 parts of surfactant ("MegaFac F" -176PF ", solid content 20%, manufactured by Dainippon Ink and Chemicals, Inc.)-890 parts of n-propyl alcohol-247 parts of methyl ethyl ketone

4) Formation of Cyan Image Forming Layer on Surface of Light-to-Heat Conversion Layer The above-mentioned coating solution for cyan image forming layer was applied to the surface of the light-to-heat conversion layer for 1 minute using a wire bar, and then the coated material was heated to 100 ° C. To form a cyan image-forming layer on the light-to-heat conversion layer. The physical properties of the obtained image forming layer were as follows. The surface hardness of the image forming layer is preferably 10 g or more with a sapphire needle, and specifically, 20 g.
It was 0 g or more. Surface smoother value is 23 ℃ 55% RH
0.5 to 50 mmHg (≒ 0.0665 to 6.65 kPa), more specifically, 7.0 mmHg (≒ 0.93 kPa).

Through the above steps, a heat transfer sheet C (cyan) was prepared in which a light-to-heat conversion layer and a cyan image forming layer were provided in this order on a support. The optical density (optical density: OD) of the cyan image forming layer of the thermal transfer sheet C was measured with a Macbeth densitometer “TD-904” (W filter), and it was OD = 0.91. When the thickness of the cyan image forming layer was measured, it was 0.45 μm on average.

-Preparation of Image Receiving Sheet- A coating solution for a cushion layer and a coating solution for an image receiving layer having the following compositions were prepared. 1) Coating solution for cushion layer-Vinyl chloride-vinyl acetate copolymer 20 parts (main binder) ("MPR-TSL", manufactured by Nissin Chemical Co., Ltd.)-Plasticizer 10 parts ("Paraplex G-40" , CP.HALL.COMPANY Co., Ltd.)-Surfactant (fluorine-based: coating aid) 0.5 parts ("Megafac F-177", manufactured by Dainippon Ink and Chemicals, Inc.)-Antistatic agent ( (Quaternary ammonium salt) 0.3 part ("SAT-5 Super (IC)", manufactured by Nippon Pure Chemical Co., Ltd.)-60 parts of methyl ethyl ketone-10 parts of toluene-3 parts of N, N-dimethylformamide

2) Coating solution for image receiving layer ・ Polyvinyl butyral 8 parts (“ESREC B BL-SH”, manufactured by Sekisui Chemical Co., Ltd.) ・ Antistatic agent 0.7 parts (“Sunstat 2012A”, Sanyo Chemical Industries, Ltd.)・ Surfactant 0.1 part (“MegaFac F-177”, manufactured by Dainippon Ink & Chemicals, Inc.) ・ n-propyl alcohol 20 parts ・ Methanol 20 parts ・ 1-methoxy-2- 50 parts of propanol

Using a small width applicator, a white PET support (“Lumirror # 130E58”, manufactured by Toray Industries, Inc., thickness 1)
30 μm), the above-mentioned coating solution for forming a cushion layer is applied, the coating layer is dried, and then a coating solution for an image receiving layer is applied.
Dried. The thickness of the cushion layer after drying is about 20 μm,
The coating amount was adjusted so that the thickness of the image receiving layer was about 2 μm. The white PET support is a laminate of a void-containing polyethylene terephthalate layer (thickness: 116 μm, porosity: 20%) and titanium oxide-containing polyethylene terephthalate layers (thickness: 7 μm, titanium oxide content: 2%) provided on both sides thereof. (Total thickness: 130 μm, specific gravity: 0.8) is a void-containing plastic support. The produced material was wound up in a roll form, stored at room temperature for one week, and then used for image recording with the following laser beam. The physical properties of the obtained image receiving layer were as follows. Surface roughness Ra 0.4-0.01
μm was preferred, and specifically 0.02 μm. The undulation on the surface of the image receiving layer was preferably 2 μm or less, specifically 1.2 μm. The smoother value of the surface of the image receiving layer is 0.5 to 50 mmHg (≒ 0.0665 to 6.65 kPa) at 23 ° C. and 55% RH.
Is preferable, and specifically, 0.8 mmHg (≒ 0.11 kP
a). The coefficient of static friction of the surface of the image receiving layer is preferably 0.8 or less, and specifically 0.37.

The image receiving sheet and the thermal transfer sheet C prepared above are subjected to surface cleaning, laminated in the order of conveyance, and one set of the laminated body is packed together and stored at room temperature for one week. Used for recording.

-Formation of Transfer Image- The packing of the above-described recording medium is opened, one set of the laminate of the image receiving sheet and the thermal transfer sheet is directly accommodated in a recording medium cassette, and the cassette is attached to a recording medium supply portion of a recording apparatus. Recordings were made. The recording device used was Creo S
Citex "Plate Setter Spec"
trum ". First, an image receiving sheet (56 cm x 79 cm) is picked up and conveyed from the recording medium cassette, and has a diameter of 38 cm with a vacuum section hole of 1 mm diameter (one area density in an area of 3 cm x 8 cm).
Was vacuum-adsorbed to a rotary drum. Next, the thermal transfer sheet C (61 cm × 84 cm) was conveyed from the cassette, stacked so as to protrude evenly from the image receiving sheet, and squeezed by a squeeze roller, and adhered and laminated so that air was sucked into the section holes. The degree of pressure reduction when the section hole is closed is -150 mmH with respect to 1 atm.
g (≒ 81.13 kPa). The drum is rotated and a wavelength of 80 is applied from the outside to the surface of the laminate on the drum.
8 nm semiconductor laser light is applied to the surface of the photothermal conversion layer by 7 μm.
The laser beam (image) was recorded on the laminated body while condensed so as to form a spot of m and moving in a direction perpendicular to the rotation direction (main scanning direction) of the rotating drum (main scanning direction). Laser irradiation conditions are as follows. Further, the laser beam used in this embodiment is
A laser beam composed of a multi-beam two-dimensional array consisting of three parallelograms in rows and subscanning directions was used. Laser power 110 mW Drum rotation speed 500 rpm Sub-scanning pitch 6.35 μm Ambient temperature and humidity 18 ° C. 30%, 23 ° C. 50%, 2
Three Conditions of 6 ° C. and 65% The diameter of the exposure drum is preferably 360 mm or more, and specifically, the one having 380 mm was used. The image size is 5
The size is 15 mm × 728 mm, and the resolution is 2600 dpi. When the laminated body after the laser recording was removed from the drum and the thermal transfer sheet C was peeled off from the image receiving sheet by hand, only the light irradiation area of the image forming layer of the thermal transfer sheet C was transferred from the thermal transfer sheet C to the image receiving sheet. It has been confirmed that.

Table 1 shows the thermal transfer sheet C used for image recording.

[0167]

[Table 1]

In Comparative Example 2, the sheet was directly set on the drum by a human hand without using the recording medium cassette.

-Evaluation- 1) Material transportability The thermal transfer sheet was transported from the recording medium supply site to the recording rotary drum 20 times, and the material transportability was evaluated based on the following criteria. ：: Stable conveyance can be performed without causing displacement or jamming. ×: Dislocation or jamming occurs. 2) Image Defects Obtained transferred images are visually observed, and the number of image defects caused by foreign matters such as white spots is counted. Evaluation was based on criteria. ： １: 1 or less per m ² Δ: ^{2 to} 10 per m ² ×: 11 or more per 1 m ² 3) Resolution An image having 2% halftone dots and an image having 98% halftone dots were recorded, and a desired halftone dot was recorded. ○: Reproduce dot image (both 2, 98%) ×: Do not reproduce (either 2, 98% do not reproduce)

Table 2 shows the evaluation results.

[0171]

[Table 2]

It can be seen that the present invention has better material transportability and can obtain a transferred image with less image defects. In particular, the material transportability depends on both the use of the recording medium cassette in which the sheets are stacked and accommodated in the supply order, which is a feature of the present invention, and the value of the static friction coefficient (0.7 or less) of the back layer surface of the thermal transfer sheet. Good results have been obtained for the first time.

Note that the images transferred in Examples 1 to 3 were
When the image was further transferred to recording paper to form a multi-color image, the image quality was good and stable even when laser recording was performed at a high energy with a laser beam having a multi-beam two-dimensional array under different temperature and humidity conditions. A multicolor image having the transfer density obtained was able to be formed. The transfer to the paper is carried out at a dynamic friction coefficient of 0.1 to 0.7 with respect to polyethylene terephthalate of the material of the insertion table, and at a transport speed of 15 to 50.
A thermal transfer device of mm / sec was used. The Vickers hardness of the heat roll material of the thermal transfer device is preferably 10 to 100, and specifically, a Vickers hardness of 70 was used. The obtained image was good in all three environment temperature and humidity.

(II) Thermal transfer sheets K (black), Y (yellow), and M (magenta) were prepared by the same formulation except that the preparation of the thermal transfer sheet C (cyan) and the change of the coating solution for the image forming layer were performed. . -Thermal transfer sheet K (black)-A coating solution for a black image forming layer having the following composition was used. The thickness of the image forming layer of the obtained thermal transfer sheet K is 0.60 μm.
m. [Black pigment dispersion mother liquor composition] Composition 1-12.6 parts of polyvinyl butyral ("ESLEC B BL-SH", manufactured by Sekisui Chemical Co., Ltd.)-Pigment Black (pigment black) 7 (carbon black CI No. 77266) 4.5 parts ("Mitsubishi Carbon Black # 5", manufactured by Mitsubishi Chemical Corporation, PVC blackness: 1) ・ Dispersing aid 0.8 parts ("Solsperse S-20000", manufactured by ICI Corporation) -79.4 parts of n-propyl alcohol, composition 2-12.6 parts of polyvinyl butyral ("ESLEC B BL-SH", manufactured by Sekisui Chemical Co., Ltd.)-Pigment Black 7 (carbon black CI. No. 77266) 10.5 parts ("Mitsubishi Carbon Black MA100", manufactured by Mitsubishi Chemical Corporation, PVC black) : 1 0) Dispersion aid 0.8 parts ( "SOLSPERSE S-20000", ICI (Ltd.)) - n-propyl alcohol 79.4 parts

[Composition of Black Image Forming Layer Coating Solution] 185.7 parts of the above-mentioned black pigment-dispersed mother liquor Composition 1: Composition 2 = 70: 30 (parts) Polyvinyl butyral 11.9 parts (“ESLEC B BL-SH” , Sekisui Chemical Co., Ltd.)-Wax compound (Stearic acid amide "Neutron 2", manufactured by Nippon Seika Co., Ltd.) 1.7 parts (Behenic amide "Diamid BM", Nippon Kasei Co., Ltd.) 1.7 parts (Laurilic acid amide "Diamid Y", manufactured by Nippon Kasei Co., Ltd.) 1.7 parts (Palmitic acid amide "Diamid KP", manufactured by Nippon Kasei Co., Ltd.) 1.7 parts (Elka 1.7 parts of acid amide “Diamid L-200”, manufactured by Nippon Kasei Co., Ltd. ("KE- 11 ", manufactured by Arakawa Chemical Co., Ltd. (Ingredients: resin acid 80-97%; resin acid components: abietic acid 30-40%, neoabietic acid 10-20%, dihydroabietic acid 14%, tetrahydroabietic acid 14%・ Surfactant 2.1 parts (“MegaFac F-176PF”, solid content 20%, manufactured by Dainippon Ink and Chemicals, Inc.) ・ Inorganic pigment 7.1 parts (“MEK-ST”, 30% methyl ethyl ketone solution,・ Nissan Chemical Co., Ltd.) ・ N-propyl alcohol 1050 parts ・ Methyl ethyl ketone 295 parts

-Thermal transfer sheet Y (yellow)-A coating solution for a yellow image forming layer having the following composition was used. The layer thickness of the image forming layer of the obtained thermal transfer sheet Y is 0.42 μm.
m. [Yellow pigment dispersion mother liquor composition] Yellow pigment composition 1: 7.1 parts of polyvinyl butyral ("S-lec B BL-SH", manufactured by Sekisui Chemical Co., Ltd.) Pigment Yellow 180 (C.I.N.) 12.9 parts (“Novoperm Yellow (Novo Palm Yellow) P-HG”, manufactured by Clariant Japan K.K.) ・ 0.6 parts of dispersing aid (“Solsperse S-20000”, ICI Corporation)・ N-propyl alcohol 79.4 parts [Yellow pigment dispersion mother liquor composition] Yellow pigment composition 2: ・ Polyvinyl butyral 7.1 parts (“ESLEC B BL-SH”, manufactured by Sekisui Chemical Co., Ltd.) ・ Pigment Yellow (Pigment Yellow) 139 (CINO 56298) 12.9 parts ("Novoperm Yellow (Novo Palm Yellow) M2R 70", Clariant Japan K.K.)-0.6 parts of dispersing aid ("Solsperse S-20000", ICI K.K.)-n-propyl alcohol 79.4 Department

[Composition of Yellow Image Forming Layer Coating Liquid] 126 parts of the above yellow pigment dispersion mother liquor Yellow pigment composition 1: yellow pigment composition 2 = 95: 5 (parts) 4.6 parts of polyvinyl butyral SH ”, manufactured by Sekisui Chemical Co., Ltd.) • Wax compound (stearic amide“ Neutron 2 ”, manufactured by Nippon Seika Co., Ltd.) 0.7 parts (behenic amide“ Diamid BM ”, Nippon Kasei (Manufactured by Nippon Kasei Co., Ltd.) 0.7 parts (lauric amide “Diamid Y”, manufactured by Nippon Kasei Co., Ltd.) 0.7 parts (palmitic acid amide “Diamit KP”, manufactured by Nippon Kasei Co., Ltd.) 0.7 Part (Ercamidamide "Diamid L-200", manufactured by Nippon Kasei Co., Ltd.) 0.7 part (Oleic acid amide "Diamid O-200", manufactured by Nippon Kasei Co., Ltd.) 0.7 part Nonionic World Activator 0.4 part ("Chemistat 1100", manufactured by Sanyo Chemical Co., Ltd.) 2.4 parts of rosin ("KE-311", manufactured by Arakawa Chemical Co., Ltd.) (Ingredient: resin acid 80-97%; resin) Acid component: abietic acid 30-40%, neoabietic acid 10-20%, dihydroabietic acid 14%, tetrahydroabietic acid 14%)-Surfactant 0.8 part ("MegaFac F-176PF", solid content 20) %, Manufactured by Dainippon Ink and Chemicals, Inc.)-793 parts of n-propyl alcohol-198 parts of methyl ethyl ketone

-Thermal transfer sheet M (magenta)-A coating liquid for a magenta image forming layer having the following composition was used. The layer thickness of the image forming layer of the obtained thermal transfer sheet M is 0.38 μm.
m. [Magenta pigment dispersion mother liquor composition] Magenta pigment composition 1; 12.6 parts of polyvinyl butyral ("Denka butyral # 2000-L", manufactured by Denki Kagaku Kogyo Co., Ltd., Vicat softening point 57C)-Pigment Red (Pigment Red) 57: 1 (CI No. 1 5850: 1) 15.0 parts ("Simuller Brilliant Carmine 6B-229", manufactured by Dainippon Ink and Chemicals, Inc.) 6 parts ("Solsperse S-20000", manufactured by ICI Co., Ltd.) n-propyl alcohol 80.4 parts [magenta pigment dispersed mother liquor composition] magenta pigment composition 2; polyvinyl butyral 12.6 parts -L ", manufactured by Denki Kagaku Kogyo KK, Vicat softening point 57 ℃) Pigment Red 57: 1 (CI No. 1 5850: 1) 15.0 parts ("Lionol Red 6B-4290G", manufactured by Toyo Ink Manufacturing Co., Ltd.) Auxiliary agent 0.6 part (“Solsperse S-20000”, manufactured by ICI Corporation) n-propyl alcohol 79.4 parts

[Coating liquid composition for magenta image forming layer] 163 parts of the above-mentioned magenta pigment dispersed mother liquor Magenta pigment composition 1: magenta pigment composition 2 = 95: 5 (parts) ・ Polyvinyl butyral 4.0 parts (“Denka butyral # 2000”) -L ", manufactured by Denki Kagaku Kogyo Co., Ltd., Vicat softening point 57 ° C)-Wax compound (stearic amide" Neutron 2 ", manufactured by Nippon Seika Co., Ltd.) 1.0 part (behenamide" Diamond " Mid BM, manufactured by Nippon Kasei Co., Ltd.) 1.0 part (lauric amide “Diamid Y”, manufactured by Nippon Kasei Co., Ltd.) 1.0 part (palmitic acid amide “Diamid KP”, Nippon Kasei Co., Ltd.) 1.0 part (erucamide "Diamind L-200", manufactured by Nippon Kasei Co., Ltd.) 1.0 part (oleic amide "Diamid O-200", Nippon Kasei ( )) 1.0 part Nonionic surfactant 0.7 part ("Chemistat 1100", manufactured by Sanyo Chemical Co., Ltd.) 4.6 parts of rosin ("KE-311", manufactured by Arakawa Chemical Co., Ltd.) (Ingredients: resin acid 80-97%; resin acid component abietic acid 30-40%, neoabietic acid 10-20% dihydroabietic acid 14%, tetrahydroabietic acid 14%)-pentaerythritol tetraacrylate 2.5 parts (" NK Ester A-TMMT, manufactured by Shin-Nakamura Chemical Co., Ltd.) 1.3 parts of surfactant ("Megafac F-176PF", solid content 20%, manufactured by Dainippon Ink and Chemicals, Inc.) n-propyl alcohol 848 parts ・ Methyl ethyl ketone 246 parts

Table 3 shows the physical properties of the surface of the image forming layer and the back layer of the produced thermal transfer sheets K, Y, and M.

[0181]

[Table 3]

The thermal transfer sheet (K, M,
The image receiving sheet and the thermal transfer sheet C prepared in Y) and (I) were subjected to surface cleaning, laminated in the order of transport and supplied, and one set of the laminated bodies was packed together and stored at room temperature for one week.

The above-mentioned packing of the recording medium is opened, one set of the laminated body of the image receiving sheet and the thermal transfer sheet is stored as it is in the cassette for the recording medium, and the cassette is attached to the recording medium supply portion of the recording apparatus in the same manner as in (I). When the recording was performed, the transfer of the thermal transfer sheet could be performed stably without causing displacement or jamming, and the obtained image had good image quality without image defects due to foreign matter. .

[0184]

According to the present invention, the thermal transfer sheet can be stably conveyed and supplied without causing displacement or jamming.
It is possible to provide a laser thermal transfer recording method capable of obtaining an image without an error in the recording order of colors due to image defects due to foreign matter attachment or human error. In addition, we can provide a proof print and a contract proof that can replace analog color proofs in response to filmlessness in the CTP era. This proof can reproduce color reproduction consistent with printed materials and analog color proofs for customer approval. . It is possible to provide a DDCP system that uses the same pigment-based color material as the printing ink, can transfer to a real paper, and has no moire or the like. Further, according to the present invention, paper transfer is possible, and the same pigment-based coloring material as the printing ink is used.
/ B2) A digital direct color proof system can be provided. The present invention uses a laser thin film thermal transfer method,
This is a system in which actual halftone dot recording is performed using a pigment coloring material and can be transferred to a real paper. Even when laser recording is performed with high energy using a laser beam having a multi-beam two-dimensional array under different temperature and humidity conditions, the image quality is good and a multicolor image capable of forming an image with a stable transfer density on an image receiving sheet. An image forming method can be provided.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a schematic configuration of a recording apparatus according to the present invention.

FIG. 2 is a configuration diagram illustrating a configuration of a recording head unit of the recording apparatus according to the present invention.

FIG. 3 is a cross-sectional view of the simple cassette for a recording medium according to the first embodiment.

FIG. 4 shows a plurality (one in this example) of a plurality of sets (one set) of recording media stacked in the order in which they are supplied to the recording rotary drum.
FIG. 6 is a diagram showing a state of stacking.

FIG. 5 is a diagram showing an image forming layer (K,
FIG. 4 is a diagram illustrating a case where C, M, and Y film surfaces face downward.

FIG. 6 illustrates a case where an image receiving layer faces downward and an image forming layer faces upward.

FIG. 7 is a diagram illustrating a direction in which a recording medium is supplied to a recording rotary drum.

FIG. 8 is an explanatory diagram showing a recording procedure on a recording medium.

FIG. 9 is a diagram showing a configuration of a recording medium package.

FIG. 10 is a cross-sectional view of a conventional recording medium package.

FIG. 11 is a diagram schematically illustrating a mechanism of forming a multicolor image by thin-film thermal transfer using a laser.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Thermal transfer sheet 12 Support 14 Light-to-heat conversion layer 15 Image receiving sheet support 16 Image forming layer 20 Image receiving sheet 21 Recording device 22 Pickup mechanism 23 Recording rotating drum (recording medium support member) 27 Recording head 31 Image receiving sheet 31c Image receiving layer 31a Support Layer 33 Thermal transfer sheet 33c Image forming layer 33a Support layer 37 Cassette mount 41a Cassette body 41 Cassette for recording medium 51 Package 53 Recording medium 55 Packing material Lb Laser beam

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B41J 3/20 109A F-term (Reference) 2C065 AC01 CA03 CA08 2C068 AA02 AA06 BB18 BB21 BB31 BC13 2H111 AA01 AA26 AA35 AA47 BA02 BA07 BA08 BA55 BA64 BA68

Claims (6)

[Claims] An image receiving sheet having an image receiving layer and a plurality of thermal transfer sheets having at least a light-to-heat conversion layer and an image forming layer on a support are supplied from a recording medium cassette. The image forming layer of the thermal transfer sheet is superposed facing and held on the recording medium support member, and a laser beam corresponding to image information is irradiated on the thermal transfer sheet, and the laser light irradiated area of the image forming layer is image-received. In a laser thermal transfer recording method having a step of transferring an image onto an image receiving layer of a sheet and recording the image, the image receiving sheet and the thermal transfer sheet are stacked and accommodated in the cassette for the recording medium in an order in which the image receiving sheet and the thermal transfer sheet are supplied onto a recording medium supporting member. Wherein the coefficient of static friction of the back layer surface of the thermal transfer sheet is 0.7 or less. 2. After unpacking a recording medium from a package of recording media stacked and packed in the order in which the image receiving sheet and the thermal transfer sheet are supplied onto a recording medium supporting member, the recording medium is inserted into the recording medium cassette. 2. The laser thermal transfer recording method according to claim 1, wherein the laminated image receiving sheet and thermal transfer sheet are set at once. 3. The laser thermal transfer recording method according to claim 1, wherein the coefficient of static friction of the surface of the image forming layer of the thermal transfer sheet is 0.5 or less. 4. The thermal transfer sheet according to claim 1, wherein the surface roughness Rz of the surface of the image forming layer is 3 μm or less.
3. The laser thermal transfer recording method according to any one of 3. 5. The thermal transfer sheet according to claim 1, wherein the surface roughness Rz of the back layer surface is 7 μm or less.
The laser thermal transfer recording method according to any one of the above. 6. The laser thermal transfer according to claim 1, wherein the surface electrical resistance SR of the surface of the image forming layer of the thermal transfer sheet is 10 ¹¹ Ω or less at 23 ° C. and 55% RH. Recording method.