JP2002355997A - Method and material for forming multicolor image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming multicolor images whereby images having a good image quality, a stable transfer density and a good approximation of printed matter can be formed on an image-receiving sheet. SOLUTION: In the method for forming multicolor images, the image-receiving sheet having at least an image-receiving layer on a support, and at least four kinds or more different color thermal transfer sheets each having at least a photothermal conversion layer and an imaging layer on a support are used. While the imaging layer of each thermal transfer sheet and the image-receiving layer of the image-receiving sheet are overlapped to be opposed to each other and irradiated with a laser light to transfer the imaging layer of a laser- irradiated region onto the image-receiving layer of the image-receiving sheet, whereby images are recorded. An OD/film thickness ratio between an optical density(OD) and a film thickness (by a unit of μ) of the imaging layer of each thermal transfer sheet is made not smaller than 1.50, and a resolution of transfer images is made not smaller than 2400 dpi. Moreover, thermal transfer images are passed through a color matching process before recorded to the image- receiving sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a multicolor image forming method and a multicolor image forming material for forming a high-resolution full-color image using a laser beam. In particular, the present invention relates to a multicolor image forming method and a multicolor image forming method useful for producing a color proof (DDCP: direct digital color proof) or a mask image in the printing field by laser recording from a digital image signal. About the material.

[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 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 an image forming material that exhibits high recording sensitivity to laser light and high resolution to reproduce high-definition halftone dots.

As an image forming material used in a transfer image forming method using a laser beam, a photothermal conversion layer which absorbs a laser beam to generate heat, a wax having a heat-meltable pigment and a binder are provided on a support. A hot-melt transfer sheet having an image forming layer dispersed in such components in this order (JP-A-5-58045) is known. In the image forming method using these image forming 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 transfers it to 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, and multicolor images can be formed by transferring images of different colors onto the image receiving sheet one after another. The image forming method has an advantage that it can be easily obtained. In particular, an image forming method utilizing ablation has an advantage that a high-definition image can be easily obtained, and is color proof (DDCP: direct digital color proof) Alternatively, it is useful for producing a high-definition mask image.

As the DTP environment progresses, CTP (Compu
Ter To Plate) uses no intermediate film unloading process, and the need for proofing from the proof printing and the analog type proofing to the DDCP type is becoming stronger. An excellent large-sized DDCP is desired. The laser thermal transfer method is capable of printing at high resolution, and has conventionally been laser sublimation method, laser ablation method,
There are systems such as a laser melting system, but there is a problem that the recording dot shape is not sharp. The laser sublimation method uses a dye as a coloring material, so the approximation of printed matter is not sufficient, and since the coloring material is sublimated, the outline of halftone dots is blurred and the resolution is not sufficiently high. there were. On the other hand, the laser ablation method uses a pigment as a coloring material, so the printed matter approximation is good. There was a problem that it was not high. Further, the laser melting method also has a problem that a clear contour does not appear because the melt flows.

Further, in the step of transferring the image receiving sheet to the actual paper, there are the following problems. That is, in the related art, when the image receiving sheet is transferred to the actual paper sheet by the laminator, the image receiving sheet may be transferred by overlapping the original paper and the image receiving sheet on an aluminum guide plate and passing the heat receiving roller. The use of the aluminum guide plate is to prevent the paper from being deformed. However, if this is adopted in a recording system compatible with the B2 size, a problem arises in that an aluminum guide plate larger than the B2 is required, and the installation space of the apparatus is increased. Therefore, as shown in FIG. 3, by using a structure in which the transport path is rotated by 180 degrees and discharged to the insertion side without using the aluminum guide plate,
Installation space can be made compact. However, in this laminator, there is a problem that the paper is deformed because the aluminum guide plate is not used.
Specifically, the pair of the discharged paper and image receiving sheet curls with the image receiving sheet inside, and rolls on the discharge table. It is very difficult to peel off the image receiving sheet from the curled book.

[0009]

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 object of the present invention is high quality and high stability,
It is an object of the present invention to provide a large-sized DDCP having excellent print consistency. Specifically, the object of the present invention is to provide: 1) a heat transfer sheet which is not affected by an illumination light source even in comparison with a pigment coloring material and printed matter; The transfer of the color material thin film should be excellent in sharpness of dot and excellent stability. 2) The image receiving sheet should be able to receive the image forming layer of the laser energy thermal transfer sheet stably and reliably. 3).
Art (coated) paper, matte paper, finely coated paper, etc. can be transferred to real paper at least in the range of 64-157 g / m ² ,
The object is to achieve delicate texture depiction and accurate reproduction of paper white (high-key portion). Also, under different temperature and humidity conditions, even when laser recording is performed with high energy using a multi-beam laser beam, the image quality is good, and a multicolor image capable of forming an image with a stable transfer density on an image receiving sheet. It is to provide a forming method.

Another object of the present invention is to transfer an image receiving sheet on which a multicolor image has been formed to a sheet of paper, the pair of the sheet of paper and the image receiving sheet discharged from the laminator curl with the image receiving sheet inside. It is an object of the present invention to provide a multicolor image forming method capable of preventing the paper from being deformed.

Still another object of the present invention is to make the image transferred on the paper clearer and higher quality, and furthermore, when supplying an image receiving sheet and a thermal transfer sheet to a recording apparatus. Another object of the present invention is to prevent a decrease in image quality due to a foreign substance entering the recording apparatus.

[0012]

That is, means according to the present invention for solving the above problems are as follows. (1) An image of each thermal transfer sheet using an image receiving sheet having at least an image receiving layer on a support and at least four or more different color thermal transfer sheets having at least a light-to-heat conversion layer and an image forming layer on the support. A multi-color image forming method in which a forming layer and an image receiving layer of an image receiving sheet are superimposed on each other, irradiated with laser light, and a laser light irradiation area of the image forming layer is transferred onto the image receiving layer of the image receiving sheet to record an image. Wherein the ratio OD / layer thickness of the optical density (OD) and the layer thickness (in μm) of the image forming layer of each thermal transfer sheet is 1.50.
A multicolor image forming method, wherein the resolution of the transferred image is 2400 dpi or more, and a color matching step is performed before recording the heat transferred image on the image receiving sheet. (2) the color matching step is a color image data conversion processing step of converting color image data for creating a printed matter into color image data for a proof output device, and a color and / or halftone dot of the printed matter. A color and / or a color to be subjected to data conversion processing for matching a color and / or a halftone dot of a color image output by the proof output device;
The multicolor image forming method according to the above (1), comprising a halftone dot conversion process. (3) The color / dot matching conversion processing step converts the continuous tone data into raster data, and converts the received raster data into a four-dimensional (black, cyan, magenta, magenta, , Yellow), the data is converted to match the color of the printed matter created based on the same raster data, and finally converted to binary data for halftone so as to match the halftone of the printed matter. The multicolor image forming method according to the above (2), which is a step.

(4) Thermal transfer using an image receiving sheet having at least an image receiving layer on a support and at least four or more different color thermal transfer sheets having at least a photothermal conversion layer and an image forming layer on the support. A multi-color image forming apparatus in which an image forming layer of a sheet and an image receiving layer of an image receiving sheet are superposed facing each other, irradiated with laser light, and a laser light irradiation area of the image forming layer is transferred onto the image receiving layer of the image receiving sheet to record an image. In the image forming method, the recording area of the multicolor image of each of the thermal transfer sheets is a size of 515 mm × 728 mm or more, and the image receiving sheet is wound around a heat roller so that the image receiving sheet is outside the actual paper at the time of actual paper transfer. Multicolor image forming method. (5) The multicolor image forming method as described in any one of (1) to (4) above, wherein the thermal transfer sheet comprises at least four types of thermal transfer sheets including at least yellow, magenta, cyan, and black. . (6) The multicolor image according to (1), wherein the order in which the image forming layers of the thermal transfer sheets are transferred onto the image receiving layer of the image receiving sheet is black, cyan, magenta, and yellow. Forming method. (7) The image forming layer on the image receiving sheet is transferred to the main paper in the order of yellow, magenta, cyan, and black image forming layers on the real paper in the order from the support, in the order described above. The multicolor image forming method described in the above. (8) Four or more types of thermal transfer sheets including at least yellow, magenta, cyan, and black and an image receiving sheet are supplied to a recording device in a roll state, and the respective sheets are fed out of the roll in the recording device. The multicolor image forming method according to the above (6) or (7), wherein the multicolor image is automatically conveyed.

(9) The multicolor image forming apparatus according to any one of the above (1) to (8), wherein the image forming layer in the laser beam irradiation area is transferred to the image receiving sheet in a thin film state. Method. (10) The multicolor image forming method according to any one of (1) to (9), wherein the transfer image has an image resolution of 2600 dpi or more. (11) The above (1) to (10), wherein the ratio OD / layer thickness of the optical density (OD) and the layer thickness (unit: μ) of the image forming layer of each thermal transfer sheet is 1.80 or more. The multicolor image forming method according to any one of the above. (12) The above (1) to (11), wherein the ratio OD / layer thickness of the optical density (OD) and the layer thickness (unit: μ) of the image forming layer of each thermal transfer sheet is 2.50 or more. The multicolor image forming method according to any one of the above. (13) The contact angle of the image forming layer of each of the thermal transfer sheets and the image receiving layer of the image receiving sheet with water is 7.0 to 120.
(1) to (1), which are in the range of 0 °.
The multicolor image forming method according to any one of 2). (14) The recording area of the multicolor image is 594 × 841 mm
The above sizes (1) to (1)
The multicolor image forming method according to any one of 3). (15) The ratio (OD / layer thickness) between the optical density (OD) and the layer thickness (μ unit) of the image forming layer of each thermal transfer sheet is 1.80 or more, and the contact angle of the image receiving sheet to water is 86 °.
The multicolor image forming method according to any one of the above (1) to (14), wherein:

(16) Each thermal transfer is performed by using an image receiving sheet having at least an image receiving layer on a support, and at least four or more different color thermal transfer sheets having at least a photothermal conversion layer and an image forming layer on the support. A multi-color image forming apparatus in which an image forming layer of a sheet and an image receiving layer of an image receiving sheet are superposed facing each other, irradiated with laser light, and a laser light irradiation area of the image forming layer is transferred onto the image receiving layer of the image receiving sheet to record an image. In the image forming material, the ratio OD / layer thickness of the optical density (OD) and the layer thickness (in μm) of the image forming layer of each thermal transfer sheet is 1.50 or more, and the resolution of the transferred image is 240
A multicolor image forming material having a resolution of 0 dpi or more and being subjected to a color matching step before recording a thermal transfer image on the image receiving sheet. (17) The recording area of the multicolor image of each thermal transfer sheet is 5
(16) The multicolor image forming material as described in (16) above, wherein the material has a size of 15 mm × 728 mm or more and is wound around a heat roller so that the image receiving sheet is outside the paper at the time of paper transfer. (18) The thermal transfer sheet is composed of at least four types of thermal transfer sheets including at least yellow, magenta, cyan, and black, and the image forming layers of each thermal transfer sheet are transferred in the order of black, cyan, magenta, and yellow. (16) characterized by including an image receiving sheet.
2. The multicolor image forming material according to item 1. (19) The above (18), wherein the image forming layer on the image receiving sheet is transferred to the main paper in the order of yellow, magenta, cyan, and black image forming layers in the order from the support on the real paper. 2. The multicolor image forming material according to item 1.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present applicant has high quality and high stability,
As a result of intensive studies to provide a large-sized DDCP of B2 / A2 or more and B1 / A1 or more excellent in print consistency, this paper transfer / real dot output / pigment type image forming material of B2 size or more; We have developed a laser thermal transfer recording system for DDCP consisting of an output unit and high-quality CMS software.

The characteristics of the performance of the laser thermal transfer recording system developed by the present applicant, the system configuration and the outline of the technical points are as follows. The characteristic of the performance is that the dot shape is sharp, so that it is possible to reproduce a halftone dot with excellent printed matter approximation. Good hue print similarity. Since the recording quality is hardly affected by the environmental temperature and humidity, and the reproducibility is good, a stable proof can be created. The technical points of materials that can achieve such performance characteristics are the establishment of thin film transfer technology, the vacuum adhesion retention of materials required for laser thermal transfer systems, the follow-up to high-resolution recording,
The point is to improve the heat resistance. Specifically, thinning the photothermal conversion layer by introducing an infrared absorbing dye,
g To enhance the heat resistance of the light-to-heat conversion layer by introducing a polymer, to stabilize the hue by introducing a heat-resistant pigment,
Adhesive strength by adding low molecular components such as wax and inorganic pigment
Controlling the cohesive force and imparting vacuum adhesion without deteriorating the image quality by adding a matting material to the light-to-heat conversion layer can be mentioned. The technical point of the system is air conveyance for continuous stacking of many recording devices,
Insertion on paper to reduce curl after transfer of thermal transfer device,
For example, connection of a general-purpose output driver having system connection expandability may be used. As described above, the laser thermal transfer recording system developed by the present applicant is composed of various performance features, system configuration, and technical points. However, these are examples, and the present invention is not limited to these means.

The applicant of the present invention recognizes that the individual materials, the light-to-heat conversion layer, the image forming layer, the image receiving layer, and other coating layers, the thermal transfer sheets and the image receiving sheets do not exist individually but function organically and comprehensively. In addition, the image forming material was developed based on the idea that the image forming material would exhibit the best performance in combination with a recording device and a thermal transfer device. The present applicant thoroughly examines each coating layer of the image forming material and the constituent materials, creates a coating layer that maximizes the characteristics of those materials, and uses it as an image forming material, so that this image forming material exhibits the best performance. Appropriate ranges of various physical properties have been found. As a result, the relationship between each material, each coating layer, each sheet and the physical properties is extremely high, and furthermore, by making the image forming material and the recording device or the thermal transfer device function organically and comprehensively, unexpectedly, High performance image forming materials could be found. The position of the present invention in such a system developed by the present applicant is based on a multi-color that defines a combination with a color matching process in order to bring out the characteristics of a high-performance image forming material that supports the system developed by the present applicant. This is a key invention relating to an image forming method and a multicolor image forming material used for the method.

First, the contents, operation, and effects of the color matching step used in the present invention will be described. Before creating a color print,
A proof similar to the image obtained by printing on the printing plate created from the color image data is created, and the finish of the printed matter is confirmed in advance. Therefore, in order to output a proof color image based on the color image data for creating a printed matter, in order to obtain a color image that faithfully reproduces the colors of the printed matter, that is, to obtain an image with high print similarity For this purpose, it is necessary to provide a color matching process, perform various corrections and color conversions on the color image data corresponding to various given color image data. In order to perform various corrections and color conversion processing in the color matching process, for example, when a proof of a printed matter is created using a proof output device, printing conditions (for example, type of printing paper, printing A printing condition correction conversion table for converting color image data in consideration of the type of ink, etc., and an output method (for example, a halftone modulation method or a dot modulation method) of the proof output device or the color printing machine without depending on the printing conditions A standard color conversion table for performing standard color correction according to the density modulation method, etc., and a calibration conversion table for correcting machine differences, use environments, temporal changes, etc. of the proof output device are required. It is. These conversion tables for various corrections may be experimentally created in advance as four-dimensional (black, cyan, magenta, and yellow) tables and stored in a system that implements the present invention. The four-dimensional table prepares an image actually printed by a printing machine and an image recorded by a proof output device under various conditions (printing conditions, output method, use environment, etc.) for important color data in advance. The colorimetric values may be compared and created so as to minimize the difference.

In the color matching step of the present invention, the color image data for producing a printed matter is converted into color image data for a proof output device (color image conversion processing step), and the color image data for the proof output device is converted. Is subjected to data conversion processing so that the color / halftone of the printed matter matches the color / halftone of the output proof (color / halftone matching conversion processing step). In the color / dot matching conversion step, the color image data (contone (continuous tone) data) for the proof output device is converted into raster data through a RIP (raster image processor) system or the like.
Next, the raster data is converted by a color conversion four-dimensional table having various correction data as described above so that the colors match the printed matter, and finally, the halftone dots are converted so as to match the halftone dots of the printed matter. Is converted to binary data. By performing data conversion processing of colors and halftone dots in these color matching processes, a color proof image can be easily created that is highly accurate for printed matter. In addition, efficient color matching corresponding to a large screen can be realized. Details of such data conversion and the like are described in JP-A-11-41.
475 and JP-A-2001-169110.

The multicolor image forming method of the present invention in which the above-mentioned color matching steps are combined includes another invention as one embodiment. The positioning of this other invention in the system developed by the applicant described above specifies a combination with a fixed arrangement of the image receiving sheet with respect to the paper in order to derive the characteristics of the high-performance image forming material supporting the system. It has become a key technology.

According to another aspect of the present invention, there is provided a method of preventing a curl in which a pair of a paper and an image receiving sheet curls with the image receiving sheet inside. This prevention effect can be obtained by the bimetal effect due to the difference in the amount of contraction between the actual paper and the image receiving sheet, and the ironing effect due to the structure wound around the heat roller. That is, as in the conventional case, when the image receiving sheet is conveyed so as to be wound around a heat roller so as to be inside the actual paper at the time of transferring the actual paper, the thermal contraction of the image receiving sheet is larger than the thermal shrinkage of the actual paper. Since the image receiving sheet is on the inside and is in the same direction as the ironing effect, the curl becomes severe due to the synergistic effect. However, if the image receiving sheet is conveyed so as to be wound around a heat roller so that the image receiving sheet is on the outside of the paper at the time of the paper transfer, the curl of the bimetal effect and the curl of the iron effect are canceled out, and the problem of curling can be eliminated.

Further, the multicolor image forming method of the present invention in which the above-described color matching step is combined includes another invention as another embodiment. The position of this still another invention in the system developed by the applicant described above is based on the order of color recording, and also the fully automatic roll supply, in order to derive the characteristics of the high-performance imaging material supporting the present system. The key technology that defines the combination of

Usually, in order to form a color image, it is necessary to transfer an image forming layer of at least four colors including at least yellow, magenta, cyan and black onto an image receiving layer of an image receiving sheet and to further laminate it on the actual paper. is necessary. As in one embodiment of the present invention, it is preferable to transfer the four color image forming layers on the image receiving layer in the order of black, cyan, magenta, and yellow. , Magenta, cyan, and black in this order. By doing so, the black color of the obtained image is very clear and the image quality is good, which is a great advantage particularly in the case of a high-resolution image having a resolution of 2400 dpi or more.

It is preferable that the ratio OD / layer thickness of the image forming layer is not less than a certain value. The OD / layer thickness in the present invention is a ratio of the optical density (OD) of the image forming layer to the thickness of the image forming layer measured in “μm”. The optical density referred to here is an image which is transferred from a thermal transfer sheet to an image receiving sheet and further transferred to a special paper on a real paper by a densitometer X-write.
938 (manufactured by X-rite), yellow (Y color),
Magenta (M color), Cyan (C color), Black (K color)
These are reflection optical densities measured in the Y, M, C, and K modes, respectively. The thickness of the image forming layer is measured by observing a cross section of the thermal transfer sheet before image recording with a scanning electron microscope. By setting the OD / layer thickness to 1.50 or more, the image density required for a print proof can be easily obtained, and at the same time, the image forming layer can be made thin, and the transfer to the image receiving layer can be performed efficiently. This makes it possible to stabilize the breakability of the image forming layer and sharpen the dot shape, thereby enabling follow-up to high-resolution recording according to image information and excellent dot reproduction. Further, since the image forming layer can be made thinner, the influence of environmental temperature and humidity can be minimized, the repetition reproducibility of the image is improved, and more stable transfer peelability is obtained.
Proofs with higher print similarity can be created. When the OD / layer thickness is 1.80 or more, the effect can be further promoted. When the OD / layer thickness is 2.50 or more, the transfer density and the resolving power can be greatly increased. If the OD / layer thickness is less than 1.50, a sufficient image density cannot be obtained, or the breakability of the image forming layer is poor and the resolution is reduced, and a good image cannot be obtained anyway.

In the present invention, it is preferable that the thermal transfer sheet and the image receiving sheet are supplied to the recording apparatus in the form of a roll, and that each sheet is unwound from the roll in the apparatus so as to be completely automatically conveyed. "Fully automatic" here means that a human performs setting of a thermal transfer sheet and an image receiving sheet on a recording device,
Thereafter, the operation until the recording is completed is a method in which the operation is performed without using any manual operation. In the present invention, a recording image is formed by irradiating a laser beam while superposing the thermal transfer sheet and the image receiving sheet on each other. At this time, if a foreign substance is present between the thermal transfer sheet and the image receiving sheet, the transfer of the image forming layer is hindered, and a white spot-shaped non-transfer portion, so-called "white spots", is generated, and the image quality is greatly reduced. By making the printing apparatus fully automatic, it is possible to prevent minute foreign substances such as dust from entering the recording apparatus, and prevent such deterioration in image quality. In general, the probability of occurrence of the above-described failure due to a foreign substance in one screen is proportional to the image area. Particularly, in the case of an image having an area of 515 mm × 728 mm or more, white spots are a very serious problem. However, by setting “fully automatic”, a good image with very few white spots can be obtained.

The present invention has the following features. That is, one of them is characterized by a multicolor image forming material. Specifically, the contact angle of water between the image forming layer of each thermal transfer sheet and the image receiving layer of the image receiving sheet is from 7.0 ° to 12 °.
It is in the range of 0.0 °. As a result, a sufficient adhesive force can be obtained at the time of image formation, the dot shape can be sharpened, and excellent dot reproduction according to image information can be achieved. Further, even when transferred to a printing paper, it is possible to create a high-quality proof without defects without causing transfer failure. Furthermore, in order to obtain a high quality image having a sufficient density including the above viewpoints, the OD / layer thickness of each thermal transfer sheet is 1.80 or more, and the contact angle of the image receiving layer of the image receiving sheet with water is water. Is preferably 86 ° or less. The contact angle of each layer surface with water, such as the value of the contact angle of each layer surface with water, referred to in the present invention is a contact angle meter (Contact Angle Met).
er) Value measured using CA-A type (manufactured by Kyowa Interface Science Co., Ltd.).

Another feature is that the image forming layer in the laser light irradiation area is transferred to the image receiving sheet in a thin film state. According to the present invention, the thin film transfer method developed by the present applicant provides an excellent resolution in which the line width reproducibility of the transferred image is from 0.9 to 1.1. This thin film transfer method is a method superior to the conventional laser sublimation method, laser ablation method, laser melting method, etc., but the multicolor image forming method of the present invention is naturally limited to that method. Not something. At the same time, various techniques woven into the system developed by the present applicant can be applied to each of the above-mentioned conventional systems, and there are many techniques that can be improved to obtain a high-resolution multicolor image forming material and a multicolor image forming method. It can contribute to The line width reproducibility referred to in the present invention is defined as 2 of the laser beam spot.
The dimensional energy distribution is integrated in the main scanning direction, the half-width a of the energy distribution in the sub-scanning direction is taken, and the ratio of the line width b of the transferred image to the length 2a, which is twice as large, is taken. (B / 2a).

Next, the entire system developed by the present applicant, including the contents of the present invention, will be described below. The system of the present invention achieves high resolution and high image quality by inventing and adopting the thin film thermal transfer method. In the system of the present invention, the resolution is 2400 dpi or more, preferably 26 dpi.
This is a system that can obtain a transfer image of 00 dpi or more. The layer thickness is 0.01 to 0.9μ compared with the thin film thermal transfer method.
In this method, the image forming layer having a thin film thickness of m is transferred to the image receiving sheet in a state where it is not partially melted or hardly melted. That is, since the recorded portion is transferred as a thin film, a thermal transfer system with extremely high resolution has been developed. A preferred method of efficiently performing thin-film thermal transfer is to deform the inside of the light-to-heat conversion layer into a dome shape by optical recording, push up the image forming layer, increase the adhesion between the image forming layer and the image receiving layer, and facilitate transfer. is there. If this deformation is large, the force for pressing the image forming layer against the image receiving layer is large, so that the image is easily transferred. come. Thus, the preferred deformation for the thin film transfer was observed with a laser microscope (VK8500, manufactured by KEYENCE CORPORATION). The value obtained by adding the value obtained by adding the cross-sectional area (b) of the recording portion of the light-to-heat conversion layer before the optical recording to the value obtained by adding the cross-sectional area (b) of the recording portion of the light-to-heat conversion layer was multiplied by 100 and evaluated by the deformation ratio calculated. it can. That is, the deformation ratio = ｛(a + b)
/ (B)｝ × 100. The deformation rate is 110% or more, preferably 125% or more, and more preferably 150% or more. If the elongation at break is increased, the deformation ratio may be larger than 250%, but it is usually preferable to suppress the deformation ratio to about 250%.

The technical points of the image forming material in the thin film transfer are as follows. 1. Compatibility of high thermal response and preservation To achieve high image quality, it is necessary to transfer a submicron-order thin film, but in order to obtain the desired density, it is necessary to create a layer in which pigment is dispersed at a high density. , Contrary to thermal responsiveness. In addition, the thermal responsiveness is in a relationship opposite to the preservability (adhesion). These conflicting relations were solved by the development of new polymers and additives. 2. Ensuring high vacuum adhesion In thin film transfer pursuing high resolution, it is preferable that the transfer interface is smooth, but sufficient vacuum adhesion cannot be obtained with that.
The standard gap between the thermal transfer sheet and the image receiving sheet is evenly distributed by adding a large amount of a matting agent with a relatively small particle size to the layer below the image forming layer, regardless of the conventional sense of providing vacuum adhesion. In this case, vacuum adhesion was imparted while maintaining the characteristics of the thin-film transfer without causing the image to be removed by the matting agent. 3. Use of heat-resistant organic material The photothermal conversion layer that converts laser light into heat at the time of laser recording is about 700 ° C, and the image forming layer containing a pigment coloring material is about 500 ° C.
℃. Along with developing a modified polyimide that can be coated with an organic solvent as a material for the light-to-heat conversion layer, it has higher heat resistance than printing pigments as a pigment coloring material, and has a safe and hue.
Pigments have been developed. 4. Ensuring surface cleanliness In thin film transfer, dust between the thermal transfer sheet and the image receiving sheet causes image defects, which is a serious problem. Entry from outside the device
Due to the occurrence of material cutting, etc., material management alone was not enough, and it was necessary to attach a mechanism to remove debris from the equipment. By changing the material of the transport roller, it was possible to remove dust without lowering the productivity.

Hereinafter, the entire system of the present invention will be described in detail. The present invention realizes a thermal transfer image with a sharp halftone dot, and also transfers to a paper sheet and records a size of B2 or more (515).
It is preferable to be able to measure the size of mm × 728 mm or more. More preferably, the B2 size is 543 mm × 765 mm, and a size larger than this (particularly preferably 594 × 841 mm).
mm or more). One of the performance features of the system developed by the present invention is that a sharp dot shape can be obtained. The thermal transfer image obtained by this system can be a halftone image corresponding to the number of printing lines at a resolution of 2400 dpi or more. Since each halftone dot has almost no bleeding or chipping and a very sharp shape, a high range of halftone dots from highlight to shadow can be formed clearly. as a result,
It is possible to output high-quality halftone dots at the same resolution as that of the image setter or CTP setter, and to reproduce halftone dots and gradations with good print similarity.

The second characteristic of the performance of the system developed by the present invention is that the repeatability is good. Since this thermal transfer image has a sharp halftone dot shape, it can faithfully reproduce halftone dots corresponding to the laser beam,
In addition, because the environmental temperature and humidity dependence of the recording characteristics is very small,
It is possible to obtain stable reproducibility of hue and density in a wide range of temperature and humidity environments. A third feature of the performance of the system developed by the present invention is that color reproduction is good. The thermal transfer image obtained by this system is formed by using the coloring pigment used in the printing ink, and has high repetition reproducibility.
(Color management system) can be realized. Further, 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 color appearance when the light source such as a fluorescent lamp or an incandescent lamp is changed is the same as that of the printed matter. Can be shown.

The fourth feature of the performance of the system developed by the present invention is that the character quality is good. Since the thermal transfer image obtained by this system has a sharp dot shape, fine lines of fine characters can be clearly reproduced. Next, the characteristics of the material technology of the system of the present invention will be described in more detail. As a thermal transfer method for DDCP, there is a sublimation method, an ablation method, and a heat melting method. In the method (1), the color material is sublimated or scattered, so that the outline of the halftone dot is blurred. In either method, the melt flows and clear contours do not appear. The present applicant has incorporated the following technology in order to solve a new problem in the laser thermal transfer system based on the thin film transfer technology and further improve the image quality.

The first characteristic of the material technology is the sharpening of the dot shape. Laser light is converted to heat by the light-to-heat conversion layer,
The image is transmitted to an adjacent image forming layer, and the image forming layer is adhered to the image receiving layer to perform image recording. In order to sharpen the dot shape, 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 boundary 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. Technique 1 for sharpening the dot shape is to reduce the thickness of the light-to-heat conversion layer. 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 photothermal conversion layer is transferred to the image receiving sheet together with the image forming 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. Conventionally, carbon was often used as the light-to-heat conversion material. However, in the present material, an infrared absorbing dye that requires less use than carbon was used. The binder has sufficient mechanical strength even at high temperatures,
Further, a polyimide compound having a good infrared absorbing dye retention property was introduced. As described above, 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 characteristics and a heat-resistant binder such as polyimide.

The second technique for sharpening the dot shape is to improve the characteristics of the image forming layer. If 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 will have a thickness unevenness corresponding to the sub-scanning pattern of the laser light, and the image will be non-uniform. The apparent transfer density decreases. 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.

Generally, 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.

The second characteristic of the material technology is that it has been found that the recording sensitivity has a temperature and humidity dependency. Generally, when a coating layer of a thermal transfer sheet absorbs moisture, the physical and thermal properties of the layer change, and the recording environment becomes dependent on humidity. In order to reduce the temperature / humidity dependence, 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. As polymer hydrophobization technology,
As described in JP-A-8-238858, a method in which a hydroxyl group is reacted with a hydrophobic group, a method in which two or more hydroxyl groups are crosslinked with a hardener, and the like are mentioned.

A third characteristic of the material technology is that the approximation of the hue to printed matter is improved. Thermal head color proof (for example, FirstPr manufactured by Fuji Photo Film Co., Ltd.)
In addition to the color matching of the pigment of the method (of) and the stable dispersion technique, the following problems newly generated in the laser thermal transfer system have been solved. That is, the technique 1 for improving the approximation of the printed matter of the hue is that a highly heat-resistant pigment is used. Normally, when printing by laser exposure, the image forming layer also receives heat of about 500 ° C or more, and some pigments used conventionally decompose thermally, but pigments with high heat resistance are used for the image forming layer. By doing so, this can be prevented. The second technique for improving the closeness of the printed matter to the hue is prevention of diffusion of the infrared absorbing dye. As described above, in order to prevent the hue from being changed when the infrared absorbing dye migrates from the light-to-heat conversion layer to the image forming layer due to high heat at the time of printing, as described above, the infrared absorbing dye / binder having a strong coercive force is used. It is preferable to design the light-to-heat conversion layer in combination.

The fourth characteristic of the material technology is to increase the sensitivity.
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 point 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 with 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 fifth characteristic of the material technology is improvement in vacuum adhesion. 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.

The first technique for improving the vacuum adhesion is to make the surface of the thermal transfer sheet uneven. Irregularities were formed on the thermal transfer sheet so that the effect of vacuum adhesion could be sufficiently exerted even when printing two or more colors. 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 preferred 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.

Next, the features of the systemization technology of the system of the present invention will be described. Feature 1 of the systematization technology is the configuration of the recording device. 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. In this configuration, a recording head equipped with a plurality of high-power lasers irradiates a laser to a thermal transfer sheet and an image receiving sheet fixed on a drum, and performs recording.
This is a so-called heat mode outer drum recording system. Among them, the following embodiments are preferred configurations. The first configuration of the recording apparatus is to avoid mixing of dust. The supply of the image receiving sheet and the thermal transfer sheet is a fully automatic roll supply. Since a small number of sheets are supplied with a large amount of dust generated from the human body, roll supply was adopted. Since the thermal transfer sheet has one roll for each of the four colors, the loading unit rotates to switch the roll for each color.
Each film is cut into a predetermined length by a cutter during loading, and then fixed to a drum. The second configuration of the recording apparatus is to strengthen the adhesion between the image receiving sheet and the thermal transfer sheet on the recording drum. The image receiving sheet and the thermal transfer sheet are fixed to the recording drum by vacuum suction. Since the adhesive force between the image receiving sheet and the thermal transfer sheet cannot be increased by mechanical fixing, vacuum suction is employed. 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.

The third configuration of the recording apparatus is to stably accumulate a plurality of sheets on a discharge table. In this apparatus, it is assumed that many sheets having a large area of B2 size or more can be stacked and stacked on the discharge table. Already integrated film A with thermal adhesion
When the next sheet B is discharged onto the image receiving layer, both may be stuck. If sticking, the next sheet will not be properly ejected and a jam will occur, which is a problem. It is best to prevent the films A and B from contacting each other to prevent sticking. Several methods are known as contact prevention measures. (A) a method in which a gap is formed between the films by providing a step on the discharge table to make the film shape non-planar; (C) There is a method in which air is blown out between both films so that a film discharged later is floated. In this system, since the sheet size is very large as B2, (a) and (b)
Since the structure becomes very large in the method of,
The air ejection method (c) was adopted. For this purpose, a method is employed in which air is blown out between the two sheets to float the sheet discharged later.

FIG. 2 shows an example of the configuration of the present apparatus. A sequence of forming a full-color image by applying the image forming material to the present apparatus as described above (hereinafter, referred to as an image forming sequence of the present system) will be described. 1) The sub-scanning axis of the recording head 2 of the recording apparatus 1 is returned to the origin by the sub-scanning rail 3, and the main scanning rotation axis of the recording drum 4 and the thermal transfer sheet loading unit 5 are returned to the origin. 2) The image receiving sheet roll 6 is unwound by the transport roller 7, and the leading end of the image receiving sheet is vacuum-suctioned and fixed on the recording drum 4 via a suction hole provided in the recording drum. 3) The squeeze roller 8 descends onto the recording drum 4 and stops while the image receiving sheet is further conveyed by a specified amount by rotation of the drum while holding down the image receiving sheet, and is cut to a specified length by the cutter 9. 4) The recording drum 4 further makes one revolution, and the loading of the image receiving sheet is completed. 5) Next, in the same sequence as the image receiving sheet, the first color-black thermal transfer sheet K is fed out from the thermal transfer sheet roll 10K, cut, and loaded. 6) Next, the recording drum 4 starts rotating at a high speed, the recording head 2 on the sub-scanning rail 3 starts to move, and when the recording head reaches a recording start position, the recording head 2 irradiates the recording laser onto the recording drum 4 according to the recording image signal. Is done. The irradiation ends at the recording end position, and the sub-scanning rail operation and the drum rotation stop. Return the recording head on the sub-scanning rail to the origin. 7) With the image receiving sheet left on the recording drum, only the thermal transfer sheet K is peeled off. Therefore, the front end of the thermal transfer sheet K is hooked with a nail and pulled out in the discharge direction, and is discarded from the discard port 32 to the discard box 35. 8) Repeat steps 5) to 7) for the remaining three colors. The recording order is black, followed by cyan, magenta, and yellow. That is, the second color-cyan thermal transfer sheet C is sequentially from the thermal transfer sheet roll 10C, the third color-magenta thermal transfer sheet M is from the thermal transfer sheet roll 10M, and the fourth color-yellow thermal transfer sheet Y is sequentially from the thermal transfer sheet roll 10Y. It is paid out. This is the opposite of the general printing order, because the color order on the paper is reversed by the paper transfer in a later step. 9) When the four colors are completed, the recorded image receiving sheet is finally discharged to the discharge table 31. The method of peeling off from the drum is the same as that of the thermal transfer sheet of 7), but unlike the thermal transfer sheet, it is not discarded. When the sheet is discharged to the discharge table, air 34 is blown from below the discharge port 33 to enable stacking of a plurality of sheets.

The transport roller 7 at any one of the supply portion and the transport portion of the thermal transfer sheet roll and the image receiving sheet roll.
It is preferable to use an adhesive roller having an adhesive material disposed on the surface.

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

Examples of the adhesive material provided on the surface of the adhesive roller include ethylene-vinyl acetate copolymer and ethylene-vinyl acetate copolymer.
Ethyl acrylate copolymer, polyolefin resin, polybutadiene resin, styrene-butadiene copolymer (S
(BR), styrene-ethylene-butene-styrene copolymer (SEBS), acrylonitrile-butadiene copolymer (NBR), polyisoprene resin (IR), styrene-isoprene copolymer (SIS), acrylic ester copolymer , Polyester resin, polyurethane resin, acrylic resin, butyl rubber, polynorbornene and the like.

The surface of the adhesive roller can be cleaned by contacting the surfaces 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 roller is 50 kg / mm ² (# 490
It is preferable that the pressure be equal to or less than (MPa) because dust as foreign matter can be sufficiently removed and image defects can be suppressed.

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

Hardness Hv = 1.854 P / d ² (kg / m
m ² ) ≒ 18.1692 P / d ² (MPa) where P: magnitude of the load (kg), d: diagonal length of the square of the hollow (mm).

In the present invention, the elasticity at 20 ° C. of the adhesive material used for the adhesive roller is 200 kg / cm ² (≒ 19.6 MPa) or less. This is preferable because certain dust can be sufficiently removed and image defects can be suppressed.

The feature 2 of the systematization technique is the configuration of the thermal transfer device. The image receiving sheet on which the image is printed by the recording device,
A thermal transfer device is used to perform the process of transferring to printing paper (called “book paper”). This process is called First P
It is exactly the same as roofofTM. When the image receiving sheet and the paper are overlapped and heat and pressure are applied, they adhere to each other, and then when the image receiving film is peeled off from the paper, only the image and the adhesive layer remain on the paper, and the image receiving sheet support and the cushion layer are peeled off. Therefore, practically, the image is transferred from the image receiving sheet to the actual paper. In First Proof ™, the original paper and the image receiving sheet are superimposed on an aluminum guide plate, and are transferred by being passed between heat rollers. The use of the aluminum guide plate is to prevent the paper from being deformed. However, if this is adopted for the present system of B2 size, an aluminum guide plate larger than B2 is required, and there is a problem that the installation space of the apparatus becomes large. Therefore, this system does not use an aluminum guide plate, and adopts a structure in which the transport path is further rotated by 180 degrees and discharged to the insertion side, so that the installation space is extremely compact (FIG. 3). However, since the aluminum guide plate was not used, there was a problem that the paper was deformed. Specifically, the pair of the discharged paper and the image receiving sheet curls with the image receiving sheet inside, and rolls on the discharge table. It is very difficult to peel off the image receiving sheet from the curled book.

Therefore, as described above, in the present invention, as a method for preventing rounding, it is preferable to insert the image receiving sheet so as to be below the book sheet. It utilizes the ironing effect of a structure that can be wound around a heat roller. When the image receiving sheet is inserted on top of the actual paper as in the past, the thermal shrinkage of the image receiving sheet in the insertion direction is larger than the thermal shrinkage of the actual paper. Since the direction of the ironing effect is the same, the curl becomes severe due to the synergistic effect. However, if the image receiving sheet is inserted so as to be below the paper, the curl of the bimetal effect is downward and the curl of the iron effect is upward, so that the curl is canceled and no problem occurs.

The sequence of the actual paper transfer is as follows (hereinafter, the actual paper transfer method used in the present system). The thermal transfer device 41 shown in FIG. 3 used in this method is a manual device unlike the recording device. 1) First, according to the type of the book paper 42, the heat roller 4
The temperature (100 to 110 ° C.) and the transfer speed during transfer are set with a dial (not shown). 2) Next, the image receiving sheet 20 is placed on the insertion table with the image facing up, and dust on the image is removed with a charge removing brush (not shown). The real paper 42 from which dust has been removed is laid thereon. At this time, since the size of the book paper 42 placed above the image receiving film 20 placed below is larger, the position of the image receiving sheet 20 becomes invisible and positioning is difficult. In order to improve the workability, a mark 45 indicating the placement position of each of the image receiving sheet and the book sheet is provided on the insertion table 44. The reason why the paper is larger is to prevent the image receiving sheet 20 from being displaced and protruding from the paper 42 and contaminating the heat roller 43 with the image receiving layer of the image receiving sheet 20. 3) When the image receiving sheet and the actual paper are pushed into the insertion slot while being overlapped, the insertion roller 46 rotates and sends both toward the heat roller 43. 4) When the leading end of the paper reaches the position of the heat roller 43, the heat roller is nipped and starts transfer. The heat roller is a heat-resistant silicone rubber roller. Here, by simultaneously applying pressure and heat, the image-receiving sheet and the paper are bonded. A guide 47 made of a heat-resistant sheet is installed downstream of the heat roller, and the image receiving sheet / book sheet pair passes between the upper heat roller and the guide 47,
The sheet is conveyed upward while applying heat, is peeled off from the heat roller at the position of the peeling claw 48, and is guided to the discharge port 50 along the guide plate 49. 5) The image receiving sheet / book pair coming out of the discharge port 50 is discharged onto the insertion table while being bonded. Thereafter, the image receiving sheet 20 is peeled off from the main paper 42 by hand.

The feature 3 of the systematization technique is the system configuration. By connecting the above-described apparatus on a plate making system, a function as a color proof can be exhibited. It is necessary that a printed matter having an image quality as close as possible to the printed matter output from certain platemaking data be output from the proof. As described above, the multicolor image forming method of the present invention has a color matching step. Therefore, as an actual system, software for bringing colors and halftone dots closer to the printed matter is required. A specific connection example will be introduced below.
When proofing printed matter from a plate making system called Celebra ™ manufactured by Fuji Photo Film Co., Ltd., the system connection is as shown in FIG. 4 as shown below. C
elebra with CTP (Computer To Pl)
ate) Connect the system. By applying the printing plate thus output to a printing machine, a final printed matter is obtained. C
Luxel FINALPRO manufactured by Fuji Photo Film Co., Ltd.
OF 5600 (hereinafter also referred to as FINALPROOF) is connected, and a PD system TM manufactured by Fuji Photo Film Co., Ltd. is connected as proof drive software for bringing colors and halftone dots closer to the printed matter. In the system shown in FIG. 4, the plate making system Cell
The bra and PD system will be responsible for the color matching process. The contone (continuous tone) data (image data) converted into raster data by Celebra of the plate making system is converted into binary data for halftone dots and CTP.
It is output to the system and finally printed. On the other hand, the same contone data (image data) is converted into image data for a proof output device, and further converted into raster data.
It is also output to the system. The PD system converts the received data according to a four-dimensional (black, cyan, magenta, yellow) table so that the colors match 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 is output to FINALPROOF. The four-dimensional table is created experimentally in advance and stored in the system. The experiment for making is as follows. Important color data can be printed via CTP system and printed via PD system.
The image output to the LPROOF is prepared, the colorimetric values are compared, and a table is created so that the difference is minimized.
As described above, according to the present invention, a system configuration capable of sufficiently exerting the ability of a material having a high resolution can be realized.

Next, the thermal transfer sheet which is a material used in the system of the present invention will be described. Surface roughness Rz of the surface of the image forming layer of the thermal transfer sheet and surface roughness R of the surface of the backside layer
The absolute value of the difference z is 3.0 or less, and the surface roughness Rz of the image receiving layer surface of the image receiving sheet and the surface roughness Rz of the back surface layer surface thereof
Is preferably 3.0 or less. 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 as J
A ten-point average surface roughness corresponding to Rz (maximum height) of IS. The average surface of a portion extracted from the curved surface of the roughness by a reference area is used as a reference surface, and the highest to fifth peaks are determined. The distance between the average value of the altitude and the average value of the depth of the valley bottom from the deepest to the fifth is input and converted. For the measurement, a probe-type three-dimensional roughness meter (Surfcom 570) manufactured by Tokyo Seimitsu Co., Ltd.
A-3DF). The measurement direction was the vertical direction, the cutoff value was 0.08 mm, and the measurement area was 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 1.0 or less, and the surface roughness of the surface of the image receiving layer of the image receiving sheet. It is preferable that the absolute value of the difference between the surface roughness Rz and the surface roughness Rz of the back surface layer be 1.0 or less from the viewpoint of further improving the above effect.

In another embodiment, the surface roughness of the surface of the image forming layer of the thermal transfer sheet and the surface of the back layer thereof and / or the surface roughness Rz of the front and back surfaces of the image receiving sheet are preferably 2 to 30 μm. 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 further improved.

The glossiness of the image forming layer of the thermal transfer sheet is preferably from 80 to 99.

The glossiness greatly 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 of 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 includes a support 12
And a light-to-heat conversion layer 14 thereon, and an image forming layer 16 thereon.
And an image receiving layer 24 thereon, and the image receiving layer 24 is laminated on the surface of the image forming layer 16 of the thermal transfer sheet 10 so as to be in contact with the surface (FIG. 1A). 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.
And the adhesive strength with the film is reduced (FIG. 1B). After that, 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
0 is transferred onto the image receiving layer 24 (FIG. 1C).

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 light to be used can be used without any particular limitation. Gas laser light such as argon ion laser light, helium neon laser light, helium cadmium laser light, solid laser light such as YAG laser light, semiconductor laser light Direct laser light such as dye laser light and 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, it is preferable to irradiate the laser beam under the condition that the beam diameter on the light-to-heat conversion layer is in the range of 5 to 50 μm (particularly, 6 to 30 μm), and the scanning speed is 1 m / sec. It is preferable to set it as above (especially 3 m / sec or more).

In the multicolor image formation, the thickness of the image forming layer in the black thermal transfer sheet is larger than the thickness of the image forming layer in each of the yellow, magenta, and cyan thermal transfer sheets, and is 0.5 to 0.5 mm. 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. By setting the thickness of the image forming layer in the black thermal transfer sheet to 0.5 μm or more, when recording with high energy, the image density is maintained without transfer unevenness, and the image density required as a proof of printing is achieved. can do. This tendency becomes more remarkable under high humidity conditions, so that a change in concentration due to the environment can be suppressed. On the other hand, when the layer thickness is 0.7 μm or less, transfer sensitivity can be maintained during laser recording, and small dots and fine lines can be improved. This tendency is more pronounced under low humidity conditions. In addition, the resolution can be improved. 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,
By setting the thickness of the image forming layer in each of the thermal transfer sheets of cyan and cyan to 0.2 μm or more, the density can be maintained without transfer unevenness during laser recording. On the other hand, by setting the thickness to 0.5 μm or less, the transfer sensitivity and The resolution can be improved. More preferably, it is 0.3 to 0.45 μm.

The image forming layer of 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.

Dilution Compound Preparation Conditions LDPE resin 58.3 g Calcium stearate 0.2 g Carbon black 40% by mass blended resin 1.5 g Slit width 0.3 mm 65 ± 3μm
Into a film.

As a method for forming a multicolor image, as described above, the thermal transfer sheet is used to repeatedly overlap a large number of image layers (image forming layers on which images are formed) 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 color materials having mutually different hues is prepared, and an image forming laminate in which this is combined with an image receiving sheet is independently made of four types (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 sheet using laser beam irradiation is
It is preferable to form an image on an image receiving sheet by converting a laser beam into heat and using the thermal energy to form an image forming layer containing a pigment on an image receiving sheet by a thin film transfer method. The technology used in the development of the sheet-forming image forming material can be appropriately applied to the development of a thermal transfer sheet and / or an image receiving sheet such as a fusion transfer method, an ablation transfer method, and a sublimation transfer method. The inventive system can also include the imaging materials used in these systems.

Hereinafter, the thermal transfer sheet and the image receiving sheet will be described in detail. [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,
Examples include synthetic resin materials such as polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, styrene-acrylonitrile copolymer, polyamide (aromatic or aliphatic), polyimide, polyamideimide, and polysulfone. 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 preferably from 25 to 130 μm, particularly preferably from 50 to 120 μm. Center line average surface roughness Ra of the support on the image forming layer side
(Surface roughness measuring device (Surfcom, Tokyo Seiki Co., Ltd.)
Is preferably less than 0.1 μm. 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
It is preferably 1600 kg / mm ² (≒ 2.5 to 16 GPa). The F-5 value in the longitudinal direction of the support is preferably 5 to 50 kg / mm ² (≒ 49 to 490 MP
a) The F-5 value in the width direction of the support is preferably 3 to 30.
kg / mm ² (≒ 29.4 to 294 MPa), and the F-5 value in the support longitudinal direction is generally higher than the F-5 value in the support width direction. This is not the case when it is necessary to raise it. The heat shrinkage of the support in the longitudinal and width directions at 100 ° C. for 30 minutes is preferably 3% or less, more preferably 1.5% or less, and 80 ° C.
The heat shrinkage in 30 minutes is preferably 1% or less, more preferably 0.5% or less. The breaking strength is 5-1 in both directions
^{00kg / mm 2 (≒ 49~980MPa)} , modulus 100~2000kg / mm ² (≒ 0.98~19.6
GPa) is preferred.

The support of the thermal transfer sheet is subjected to a surface activation treatment and / or 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 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. Further, the layer 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 in 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_TwoTi₆O
₁₃, NaCaP_TwoO₁₈, MgB _TwoO_FiveOxides, etc .; Cu
Sulfides such as S and ZnS; SiC, TiC, ZrC, V
Carbides such as C, NbC, MoC and WC; Si_ThreeN_Four, Ti
N, ZrN, VN, NbN, Cr_TwoNitride such as N; Ti
B_Two, ZrB_Two, NbB_Two, TaB_Two, CrB, MoB, W
B, LaB_FiveBorides such as TiSi_Two, ZrSi_Two, Nb
Si_Two, TaSi_Two, CrSi_Two, MoSi_Two, WSi_Twoetc
Silicide; BaCO_Three, CaCO_Three, SrCO_Three, BaS
O_Four, CaSO_FourMetal salts such as SiN_Four-SiC, 9Al_Two
O_Three-2B_TwoO_ThreeAnd the like.
They may be used alone or in combination of two or more. Of these, S
nO_Two, ZnO, Al_TwoO_Three, TiO_Two, In_TwoO_Three, Mg
O, BaO and MoO_ThreeAre preferred, and SnO_Two, ZnO,
In_TwoO_ThreeAnd TiO_TwoIs more preferable, and SnO_TwoIs particularly good
Good.

When the thermal transfer material of the present invention is used in a laser thermal transfer recording system, the antistatic agent used for 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 in order 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 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.

Examples of the binder used for forming the first and second back layers include homopolymers and copolymers of acrylic acid monomers such as acrylic acid, methacrylic acid, acrylic acid esters and methacrylic acid esters. , 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 substance, 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 an organic solvent, 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.

[0089]

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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.

[0091]

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[0092]

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

[0094]

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[0095]

Embedded image

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

As a guide for judging whether or not the resin is soluble in an organic solvent, the resin is dissolved at 25 ° C. in an amount of 10 parts by mass or more based on 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.

Examples of the matting agent contained in the light-heat conversion layer include 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 .

The light-to-heat conversion layer may further contain a surfactant, a thickener, an antistatic agent and the like, 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 to which a matting agent and other components are added if necessary, coating the coating 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.

When 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 (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 SOCI
ETY OF DYES & COLOURIST, T
HIRD EDITION, 1987 "and the like, and a product can be appropriately selected.

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 0.03 μm or more, the dispersion cost does not increase, and the dispersion does not cause gelation or the like,
On the other hand, when the thickness is 1 μm or less, coarse particles do not exist in the pigment, so that the adhesion between the image forming layer and the image receiving layer is good, and the transparency of the image forming layer can be improved.

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 the 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 may 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 acrylic or methacrylic acid ester compounds include polyethylene glycol dimethacrylate, 1,2,4-butanetriol trimethacrylate, trimethylolethane triacrylate, pentaerythritol acrylate, pentaerythritol tetraacrylate, and dipentaerythritol. And polyacrylate.

The plasticizer may be a polymer, and among them, polyester is preferred because of its large effect of addition 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 includes 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 is prepared on the light-to-heat conversion 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 decomposes or degrades by heat to generate a gas include self-oxidizing polymers such as nitrocellulose, chlorinated polyolefin, chlorinated rubber, polyvinyl chloride, polyvinyl chloride, and polyvinylidene chloride. Such halogen-containing polymers, acrylic polymers such as polyisobutyl methacrylate in which volatile compounds such as moisture 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 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.

On a support, 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.

It is preferable that the coefficient of static friction of the outermost layer on the side where the image forming layer of the thermal transfer sheet is coated is 0.35 or less, preferably 0.20 or less. By setting the coefficient of static friction of the outermost layer to 0.35 or less, it is possible to eliminate roll contamination when the thermal transfer sheet is conveyed, and to improve the quality of the formed image. The method for measuring the coefficient of static friction is described in Japanese Patent Application No. 2000-85759.
According to paragraph (0011). The smoother value of the surface of the image forming layer is 0.5 to 5 at 23 ° C. and 55% RH.
0 mmHg (≒ 0.0665 to 6.65 kPa) is preferred, and more preferably 2.2 to 50 mmHg (≒ 0.2
93 to 6.65 kPa) and Ra is 0.05 to 0.4 μm.
m is preferable, whereby a large number of microscopic voids where the image receiving layer and the image forming layer cannot contact each other on the contact surface can be reduced, which is preferable in terms of transfer and further image quality. The R
The a value can be measured based on JIS B0601 using a surface roughness measuring device (Surfcom, manufactured by Tokyo Seiki Co., Ltd.) or the like. The surface hardness of the image forming layer is preferably 10 g or more with a sapphire needle. After charging the thermal transfer sheet 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-
It is preferably 100 to 100V. The surface resistance of the image forming layer is preferably 10 ⁹ Ω or less at 23 ° C. and 55% RH.

Next, an image receiving sheet which 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 JP-A-2001-105752. still,
The content of the filler such as an inorganic pigment in the support is generally about 2 to 30% by volume.

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 surface of the image receiving layer is 23 ° C., 5
0.5 to 50 mmHg at 5% RH ($ 0.0665 to
6.65 kPa) and Ra is 0.05 to
Preferably, the thickness is 0.4 μm, whereby a large number of microscopic voids where the image receiving layer and the image forming layer cannot contact each other at the contact surface can be reduced, which is preferable in terms of transfer and further image quality. The Ra value is measured by a surface roughness measuring device (Surfcom,
It can be measured based on JIS B0601 using, for example, Tokyo Seiki Co., Ltd.). US Federal Exam Standard 40
After the image receiving sheet is charged by 46, 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 23 ° C., 55
% RH is preferably 10 ⁹ Ω or less. The coefficient of static friction of the surface of the image receiving layer is preferably 0.2 or less.
The surface energy of the image receiving layer surface is preferably 23 to 35 mg / m ² .

In the case where an image is once formed on the image receiving layer and then re-transferred to printing paper or the like, at least one of the image receiving layers is preferably 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 0.3 μm or more, the film strength can be ensured at the time of retransfer to the printing paper. By setting the thickness to 4 μm or less, the gloss of the image after the re-transfer of the paper is suppressed,
The closeness to printed matter is improved.

(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 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 a material which is 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 the 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 releasable 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 the binder of the release layer is selected in accordance with the above physical properties, polycarbonate, acetal and ethyl cellulose are preferred in terms of preservability. Further, when an acrylic resin is used for the image receiving layer, the release after retransfer of the image after laser thermal transfer is performed. This is particularly preferable because the properties are good. Separately, a layer having extremely low adhesion 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 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.

Further, it is preferable to provide a back layer 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 the antistatic agent, the surface resistance of the layer is 23 ° C., 50
10 ¹² Ω or less, more preferably 10 ⁹ Ω under the condition of% RH
As described below, it can be appropriately selected and used from various surfactants and conductive agents.

Examples of the binder used in 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 the 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 in 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 tend to occur. Further, when the coating is applied in an amount exceeding 5 g / m ² , the particle size of a suitable matting agent becomes very large, and the image receiving layer surface is embossed by the back layer during storage, and in particular, thermal transfer for transferring a 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, 5 mg / m ² or more of particles having a particle size of 8 μm or more is required, and preferably 6 to 6 μm.
00 mg / m ² . This improves, in particular, foreign object failure. Further, by using a material having a narrow particle size distribution such that the value σ / rn (= coefficient of variation of the particle size distribution) obtained by dividing the standard deviation of the particle size distribution by the number average particle size is 0.3 or less, Defects caused by particles having an abnormally large particle size can be improved, and 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 foreign matter from adhering 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, various activators, silicone oils, release agents such as fluorine-based resins, and the like can be added to the back layer in order to impart coating properties and release properties. The back layer is a TMA (Thermomechanical) of the cushion layer and the image receiving layer.
It is particularly preferred when the softening point measured by the method (Analysis) is 70 ° C. or lower.

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.

[0149]

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.

Example 1-1 —Preparation of Thermal Transfer Sheet K (Black) — [Formation of Back Layer] [Preparation of Coating Solution for Back First Layer] Aqueous dispersion of acrylic resin 2 parts (Jurimar ET410, solid content 20 mass) %, Nippon Junyaku Co., Ltd.) Antistatic agent (water dispersion of tin oxide-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, manufactured by Sumitomo Chemical Co., Ltd.) Distilled water was prepared so that the total amount was 100 parts.

[Formation of Back First Layer] 75 μm thick 2
A corona treatment is applied to one surface (back surface) of the axially stretched polyethylene terephthalate support (Ra on both surfaces is 0.01 μm), and the back layer first layer coating solution is dried to a thickness of 0.03 μm.
And dried at 180 ° C. for 30 seconds to form a back first layer. The Young's modulus in the longitudinal direction of the support is 450 kg / mm ² (≒ 4.4 GPa), and the Young's modulus in the width direction is 500 kg / mm ² (≒ 4.9 GPa). 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 25 kg /
mm ² (≒ 245 MPa), elastic modulus is 400 kg / mm ²
(≒ 3.9 GPa).

[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] A back second layer coating solution was applied on the back first layer so that the dry layer thickness became 0.03 μm, and then dried at 170 ° C. for 30 seconds. A layer was formed.

[Formation of Light-to-Heat Conversion Layer] [Preparation of Light-to-Heat Conversion Layer Coating Solution] The following components were mixed while stirring with a stirrer to prepare a light-to-heat conversion layer coating solution. [Composition of coating solution for photothermal conversion layer]-7.6 parts of infrared absorbing dye ("NK-2014" manufactured by Hayashibara Biochemical Laboratory Co., Ltd., cyanine dye having the following structure)

[0155]

Embedded image

[0156] (wherein, R is CH _3, X- is ClO ₄ -. Shown), 29.3 parts of a polyimide resin having the following structure ( "RIKACOAT SN-20F", New Japan Chemical Co., Ltd., thermal decomposition (Temperature: 510 ° C)

[0157]

Embedded image

(Wherein, R ₁ represents SO _2. R ₂ represents

[0159]

Embedded image

Is shown. Exonnaphtha 5.8 parts N-methylpyrrolidone (NMP) 1500 parts Methyl ethyl ketone 360 parts Surfactant 0.5 part ("MegaFac F-176PF", manufactured by Dainippon Ink and Chemicals, F-system interface) Activator) 14.1 parts of a matting agent dispersion having the following composition

Preparation of Matting Agent Dispersion 10 parts of true spherical silica fine particles (Seahoster KE-P150 manufactured by Nippon Shokubai Co., Ltd.) having an average particle size of 1.5 μm, and a dispersing agent polymer (acrylate styrene copolymer polymer, Johnson polymer) Junkryl 611 manufactured by Co., Ltd.)
2 parts, 16 parts of methyl ethyl ketone and 64 parts of N-methylpyrrolidone were mixed with glass beads 3 having a diameter of 2 mm.
0 parts were placed in a polyethylene container having a capacity of 200 ml and dispersed with a paint shaker (manufactured by Toyo Seiki) for 2 hours to obtain a dispersion of silica fine particles.

[Formation of Light-to-Heat Conversion Layer on Support Surface] The above-mentioned coating solution for a light-to-heat conversion layer was applied to one surface of a 75 μm-thick polyethylene terephthalate film (support) using a wire bar. The coated material was dried in an oven at 120 ° C. for 2 minutes to form a light-to-heat conversion layer on the support. The optical density of the obtained photothermal conversion layer at a wavelength of 808 nm was measured using a UV-spectrophotometer UV-24 manufactured by Shimadzu Corporation.
When measured at 0, OD _LH was 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. In the present invention, the optical density (OD _LH ) of the light-to-heat conversion layer of the thermal transfer sheet refers to the absorbance of the light-to-heat conversion layer at the peak wavelength of the laser light used when recording the image forming material of the present invention. The measurement can be performed using a spectrophotometer. As a spectrophotometer, in the present invention, a UV-spectrophotometer UV-240 manufactured by Shimadzu Corporation was used as described above. The optical density (OD _LH ) was a value obtained by subtracting the value of the support alone from the value including the support.

[Formation of Image Forming Layer] [Preparation of Coating Solution for Black Image Forming Layer] The following components were put into a kneader mill, and a shearing force was applied while adding a small amount of a solvent to perform a pre-dispersion treatment. Was. The dispersion was further added with a solvent, and finally prepared to have the following composition,
Sand mill dispersion was performed for 2 hours to obtain a pigment dispersion mother liquor. [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

Next, the following components were mixed with stirring with a stirrer to prepare a coating solution for a black image forming layer. [Coating solution composition for black image forming layer]-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・ Wax-based compound (Stearic acid amide “Neutron 2”, manufactured by Nippon Seika Co., Ltd.) 1.7 parts (Behenic acid amide “Diamid BM”, manufactured by Nippon Kasei Co., Ltd.) 1 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 (Ercamidamide) 1.7 parts (Diamid L-200, manufactured by Nippon Kasei Co., Ltd.) 1.7 parts (oleamide amide "Diamid O-200", manufactured by Nippon Kasei Co., Ltd.) 11.4 parts of rosin ("KE -311 ", Arakawa (Component: resin acid 80-97%; resin acid component: abietic acid 30-40%, neo abietic acid 10-20%, dihydroabietic acid 14%, tetrahydroabietic acid 14%) Activator 2.1 parts ("MegaFac F-176PF", solid content 20%, manufactured by Dainippon Ink and Chemicals, Inc.) 7.1 parts of inorganic pigment ("MEK-ST", 30% methyl ethyl ketone solution, Nissan Chemical (・ N-propyl alcohol 1050 parts ・ Methyl ethyl ketone 295 parts The particles in the obtained coating solution for a black image forming layer were measured using a laser scattering type particle size distribution analyzer. .25 μm, and the ratio of particles of 1 μm or more was 0.5%.

[Formation of Black Image Forming Layer on Surface of Light-to-Heat Conversion Layer] The coating solution for the black 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. Dried in the oven for 2 minutes,
A black image forming layer was formed on the light-to-heat conversion layer. Through the above steps, a heat transfer sheet (hereinafter, referred to as a heat transfer sheet) in which a light-to-heat conversion layer and a black image forming layer are provided on a support in this order.
This is referred to as a thermal transfer sheet K. Similarly, a sheet provided with the yellow image forming layer and the image forming layer is referred to as a thermal transfer sheet Y, a sheet provided with the magenta image forming layer is referred to as a thermal transfer sheet M, and a sheet provided with the cyan image forming layer is referred to as a thermal transfer sheet C).
Was prepared. The optical density of the black image forming layer of the thermal transfer sheet K was measured as a transmission density (transmission optical density) with a Macbeth densitometer “TD-904” (W filter), and was found to be 0.91. When the thickness of the black image forming layer was measured, it was 0.60 μm on average.

The physical properties of the obtained image forming layer were as follows. Surface hardness of image forming layer is 10 g with sapphire needle
The above was preferable, and specifically 200 g or more. The surface smoother value is 0.5-5 at 23 ° C and 55% RH.
0 mmHg ($ 0.0665-6.65 kPa) is preferable, and specifically, 9.3 mmHg ($ 1.24 kPa).
Met. The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08. Surface energy is 2
It was 9 mJ / m ² . The contact angle of water was 94.8 °. The deformation ratio of the light-to-heat conversion layer was 168% when recording was performed with a laser beam having a light intensity of 1000 W / mm ² or more on the exposed surface at a linear velocity of 1 m / sec or more.

—Preparation of Thermal Transfer Sheet Y— The preparation of the thermal transfer sheet K was the same as the preparation of the thermal transfer sheet K except that a coating liquid for a yellow image forming layer having the following composition was used instead of the coating liquid for a black image forming layer. In the same manner as in the above, a thermal transfer sheet Y was produced. The layer thickness of the image forming layer of the obtained thermal transfer sheet Y was 0.42 μm. [Yellow Pigment Dispersion Mother Liquid Composition] Yellow Pigment Composition 1: 7.1 parts of polyvinyl butyral (“ESLEC 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 Solution] 126 parts of the above-mentioned yellow pigment dispersion mother liquor Yellow pigment composition 1: yellow pigment composition 2 = 95: 5 (parts) Polyvinyl butyral 4.6 parts (“ESLEC B BL- 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 0.7 parts (oleic acid amide "Diamid L-200", manufactured by Nippon Kasei Co., Ltd.) 0.7 parts (oleic amide "Diamid O-200", manufactured by Nippon Kasei Co., Ltd.) World Surfactant 0.4 part (“Chemistat 1100”, manufactured by Sanyo Chemical Co., Ltd.) ・ Rosin 2.4 parts (“KE-311”, Arakawa Chemical Co., Ltd.) ・ Surfactant 0.8 part (“Mega FAC-176PF ", solid content 20%, manufactured by Dainippon Ink and Chemicals, Inc.)-793 parts of n-propyl alcohol-198 parts of methyl ethyl ketone

The physical properties of the obtained image forming layer were as follows. Surface hardness of image forming layer is 10 g with sapphire needle
The above was preferable, and specifically 200 g or more. The surface smoother value is 0.5-5 at 23 ° C and 55% RH.
0 mmHg (≒ 0.0665 to 6.65 kPa) is preferable, and specifically, 2.3 mmHg (≒ 0.31 kPa).
Met. The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.1. Surface energy is 24
mJ / m ² . The contact angle of water was 108.1 °. The deformation ratio of the photothermal conversion layer was 150% when recording was performed at a linear velocity of 1 m / sec or more with a laser beam having a light intensity of 1000 W / mm ² or more on the exposed surface.

-Preparation of Thermal Transfer Sheet M- The preparation of the thermal transfer sheet K was the same as the preparation of the thermal transfer sheet K except that a coating solution for the magenta image forming layer having the following composition was used instead of the coating solution for the black image forming layer. In the same manner as in the above, a thermal transfer sheet M was produced. The layer thickness of the image forming layer of the obtained thermal transfer sheet M was 0.38 μm. [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 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 KK, 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 acid amide "Diamid O-200", Nippon Kasei Co., Ltd.) )) 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.) -2.5 parts of pentaerythritol tetraacrylate ("NK ester A-TMMT", manufactured by Shin-Nakamura Chemical Co., Ltd.)-1.3 parts of surfactant ("Megafac F-176PF", solid content 20%, Dainippon Japan) Ink Chemical Industry Co., Ltd.) ・ 848 parts of n-propyl alcohol ・ 246 parts of methyl ethyl ketone

The physical properties of the resulting image forming layer were as follows. Surface hardness of image forming layer is 10 g with sapphire needle
The above was preferable, and specifically 200 g or more. The surface smoother value is 0.5-5 at 23 ° C and 55% RH.
0 mmHg (≒ 0.0665 to 6.65 kPa) is preferable, and specifically, 3.5 mmHg (≒ 0.47 kPa).
Met. The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08. Surface energy is 2
It was 5 mJ / m ² . The contact angle of water was 98.8 °. The deformation ratio of the photothermal conversion layer was 160% when recording was performed at a linear velocity of 1 m / sec or more with a laser beam having a light intensity of 1000 W / mm ² or more on the exposed surface.

-Preparation of Thermal Transfer Sheet C- Preparation of the thermal transfer sheet K, except that a coating solution for a cyan image forming layer having the following composition was used instead of the coating solution for the black image forming layer in the preparation of the thermal transfer sheet K In the same manner as in the above, a thermal transfer sheet C was produced. The layer thickness of the image forming layer of the obtained thermal transfer sheet C was 0.45 μm. [Cyan pigment dispersed mother liquor 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 (C.I. 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

[Composition of Cyan Image Forming Layer Coating Solution] 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, manufactured by Sekisui Chemical Co., Ltd.) 1.3 parts of inorganic pigment "MEK-ST" 1.0 parts of wax compound (stearic acid amide "Neutron 2" manufactured by Nippon Seika Co., Ltd.) Behenic acid amide "Diamid BM", manufactured by Nippon Kasei Co., Ltd. 1.0 part (Lauramide amide "Diamid Y", manufactured by Nippon Kasei Co., Ltd.) 1.0 part (palmitic acid amide "Diamind KP", Nippon Kasei Co., Ltd.) 1.0 part (Erucamide "Diamid L-200" (Nippon Kasei Co., Ltd.) 1.0 part (Oleic acid amide "Diamid O-200", Nippon Kasei Co., Ltd. 1.0 part ・ Rosin 2.8 parts (“KE-311”, Arakawa Chemical Co., Ltd.) 1.7 parts Pentaerythritol tetraacrylate (“NK ester A-TMMT”, 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

The physical properties of the obtained image forming layer were as follows. Surface hardness of image forming layer is 10 g with sapphire needle
The above was preferable, and specifically 200 g or more. The surface smoother value is 0.5-5 at 23 ° C and 55% RH.
0 mmHg ($ 0.0665-6.65 kPa) is preferable, and specifically, 7.0 mmHg ($ 0.93 kPa).
Met. The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08. Surface energy is 2
It was 5 mJ / m ² . The contact angle of water was 98.8 °. The deformation ratio of the light-to-heat conversion layer when recorded with a laser beam having a light intensity of 1000 W / mm ² or more at a linear velocity of 1 m / sec or more was 165%.

-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 and Chemicals, Inc.) ・ n-propyl alcohol 20 parts ・ Methanol 20 parts ・ 1-methoxy-2- 50 parts of propanol

Using a small width coater, 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 is 0.4-
0.01 μm was preferred, and specifically 0.02 μm. The undulation of the surface of the image receiving layer is preferably 2 μm or less,
Specifically, it was 1.2 μm. The smoother value of the surface of the image receiving layer is 0.5 to 50 mmHg at 23 ° C. and 55% RH.
(≒ 0.0665 to 6.65 kPa) is preferable, and specifically 0.8 mmHg (≒ 0.11 kPa).
The coefficient of static friction of the surface of the image receiving layer is preferably 0.8 or less, and specifically 0.37. The surface energy of the surface of the image receiving layer was 29 mJ / m ² . Water contact angle is 85.0 °
Met.

-Formation of Transferred Image- The image forming system of the present system including the above-described color matching step using the Luxel FINALPROOF 5600 (manufactured by Fuji Photo Film Co., Ltd.) as a recording device in the system shown in FIG. The image transferred to the paper was obtained by the paper transfer method used in the sequence and the present system. 1mm diameter vacuum section hole (3cm × 8
diameter 3 with one area density in the area of cm
On the rotating drum of 8 cm, the image receiving sheet (5
(6 cm × 79 cm) was wound and vacuum-adsorbed. Next, the thermal transfer sheet K cut into 61 cm × 84 cm
(Black) was 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 in a state where the section holes were closed was -150 mmHg (ｋ81.13 kPa) with respect to 1 atm. The drum is rotated, and a semiconductor laser beam having a wavelength of 808 nm is applied to the surface of the stacked body on the drum from the outside,
The light is focused so as to form a spot of 7 μm on the surface of the light-to-heat conversion layer, and is moved in the direction perpendicular to the rotating direction (main scanning direction) of the rotating drum (sub-scanning). ) Recording was done. Laser irradiation conditions are as follows. The laser beam used in this embodiment was a multi-beam two-dimensional laser beam consisting of five parallel lines in the main scanning direction and three parallel lines in the sub-scanning direction. Laser power 110 mW Drum rotation speed 500 rpm Sub-scanning pitch 6.35 μm Ambient temperature and humidity 20 ° C. 40%, 23 ° C. 50%, 2
3 conditions of 6 ° C and 65%. The diameter of the exposure drum is preferably 360 mm or more, and specifically, the diameter was 380 mm.
The image size is 515 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 K 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 K was transferred from the thermal transfer sheet K to the image receiving sheet. It was confirmed that it was.

In the same manner as described above, the thermal transfer sheets Y,
From each of the thermal transfer sheets M and C, an image was transferred onto an image receiving sheet. The transferred four-color image was further transferred to recording paper to form a multi-color image.
Even when laser recording was performed with high energy using a laser beam having a dimensional array, a multicolor image having good image quality and a stable transfer density could be formed. For the transfer to the paper, a thermal transfer device having a dynamic friction coefficient of 0.1 to 0.7 with respect to polyethylene terephthalate of the material of the insertion table and a transport speed of 15 to 50 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.

The reflection optical density was obtained by transferring the original paper onto Tokishi art paper using a densitometer X-write 938 (X-write 938).
(Manufactured by the company) in Y, M, C, and K modes, respectively. Table 1 shows the reflection optical density and the reflection optical density / image forming layer thickness of each color.

[0182]

[Table 1]

Example 1-2 A proof recording device manufactured by CreoScitex
A transferred image was formed in the same manner as in Example 1-1, except that ProofSetterSpectrum was used.

Reference Examples 1-1 and 1-2 Instead of the thermal transfer sheet and the image receiving sheet used in Example 1-1, reference examples 1-1 and Approval Digital Colo manufactured by Kodak Co., Ltd. were used.
r Proofing Film (sublimation type thermal transfer material), MAT manufactured by Imation Corporation as Reference Example 1-2
CHPRINTTM DIGITAL HALFTON
A transfer image was formed in the same manner as in Example 1-1, except that E (ablation type thermal transfer material) was used.

Example 1-3 The procedure of Example 1-1 was repeated except that the thermal transfer sheet and the image receiving sheet used in Example 1-1 were replaced with a Konica Corporation Color-Decision I material (fused type thermal transfer material). A transfer image was formed in the same manner.

Comparative Example 1-1 Except that the color matching step was not performed in Example 1-1,
A transfer image was formed in the same manner as in Example 1-1.
It was set to -1.

Comparative Example 1-2 Except that the color matching step was not performed in Example 1-3,
A transfer image was formed in the same manner as in Example 1-3.
-2.

Table 2 shows the results of Examples, Reference Examples and Comparative Examples.
It was shown to. The evaluation of each image was visually performed according to the following criteria. ：: good △: slightly insufficient ×: poor

[0189]

[Table 2]

The Transfer Images of Examples 1-1 to 1-3 and Comparative Example 1
As a result of comparing each of the transferred images 1 and 2, the color reproduction was significantly deteriorated without going through the color matching step. None of the products of the reference examples had a sharp recording dot shape. In each of the laser sublimation type and laser ablation type methods, the color material is sublimated or scattered, so that the outline of a halftone dot is blurred. On the other hand, in the laser heat-melting type, a clear contour is not produced because the melt flows. However, good color reproduction is realized because of the color matching process. In the embodiment, the color reproduction is good, and at the same time, the image quality is high and sharp.

(1) Line width reproducibility The two-dimensional energy distribution of the laser beam spot is integrated in the main scanning direction, and the half-width a of the energy distribution in the sub-scanning direction is taken. The ratio (b / 2a) of the line width b of the transferred image to 2a was taken.

(2) Dot Shape The image obtained in Example 1-1 is 2400 to 2540 dp.
A dot image corresponding to the number of print lines was formed at a resolution of i. 1
Since each halftone dot has almost no bleeding or chipping and is very sharp in shape, halftone dots in a high range from highlight to shadow can be clearly formed as shown in FIGS. . 5 to 12 show Example 1-1.
Shows the dot shape of the image obtained in the above, and the distance between the dot centers is 125 μm. As a result, a high-quality halftone dot output was possible at the same resolution as that of the image setter and the CTP setter, and as shown in FIGS. 13 and 14, halftone dots and gradation with good print similarity were reproduced. . FIG.
3 (b) shows a halftone dot of the image obtained in Example 1-1,
The distance between the dot centers is 125 μm. (A)
Is an enlarged view of the printed halftone dot, and it can be confirmed that the dot shape of (b) is very similar to the printed halftone dot of (a). FIG. 14 shows the dot reproducibility of the image obtained in Example 1-1, where the vertical axis represents the dot area ratio calculated from the reflection density, and the horizontal axis represents the dot area ratio of the input signal. The dotted line is a printed matter, and the solid line is a characteristic curve according to the first embodiment. In addition, the product obtained good results even at a resolution of 2600 dpi or more.

(3) Repeat Reproducibility Since the product of the present invention obtained in Example 1-1 has a sharp halftone dot shape, it can faithfully reproduce a halftone dot corresponding to a laser beam, and has a recording characteristic of an environmental temperature. Since the humidity dependency is very small, as shown in FIGS. 15 and 16, stable repetitive reproducibility can be obtained in both hue and density. FIG. 15 shows the repetition reproducibility of the image obtained in Example 1-1 as L * a * b.
* Shown on the a * b * plane of the color system. FIG. 16 shows the reproducibility of the image obtained in the first embodiment. The results shown in FIG. 16 indicate that the environmental temperature and humidity of the system were 19 ° C. and 37% RH, using the image forming material of Example 1-1.
7 ° C 37% RH, 19 ° C 74% RH, 27 ° C 74% RH
And the laser irradiation energy is 180 to 290 mJ /
A paper-transferred image was obtained in the same manner as in Example 1-1, except that the OD was changed to cm ² , and the OD was shown on the vertical axis. From this figure, it can be seen that the present invention can obtain a constant image over a wide range of environmental temperature and humidity even if the energy load by the laser fluctuates somewhat.

(4) Color Reproduction The thermal transfer sheet of Example 1-1 uses the coloring pigment used in the printing ink as a coloring material, and has good repetition reproducibility, thereby realizing high-precision CMS. . Japan
almost matches the hue of the printed part of an-Color,
When the light source such as a fluorescent lamp or an incandescent lamp was changed, the color appearance was the same as that of the printed matter.

(5) Character Quality Since the image obtained in Example 1-1 had a sharp dot shape, fine lines of fine characters could be reproduced clearly as shown in FIGS. FIG. 17 is a positive image showing the character quality of two points of the image obtained in Example 1-1, and FIG. 18 is a negative image showing the character quality of two points of the image obtained in Example 1-1. In each case, it can be seen that fine lines of fine characters were clearly reproduced.

Example 2-1 Preparation of Thermal Transfer Sheet The thermal transfer sheets K (black), Y (yellow), M (magenta) and C (cyan) were prepared in the same manner as in the following except that the composition of the coating solution was as follows. Was produced in the same manner as in Example 1-1.

[Composition of Black Image Forming Layer Coating Solution] Black pigment dispersed mother liquor as in Example 1-1 185.7 parts Composition 1: Composition 2 = 70: 30 (parts) Polyvinyl butyral 11.9 parts ( "ESLEC B BL-SH", manufactured by Sekisui Chemical Co., Ltd.)-Wax-based compound (stearic amide "Neutron 2", manufactured by Nippon Seika Co., Ltd.) 1.7 parts (behenamide "Diamid BM") 3.4 parts (palmitic acid amide "Diamid KP", manufactured by Nippon Kasei Co., Ltd.) 1.7 parts (erucic acid amide "Diamid L-200", Nippon Kasei Co., Ltd.) )) 3.4 parts ・ Rosin 11.4 parts ("KE-311", manufactured by Arakawa Chemical Co., Ltd.) (Component: resin acid 80 to 97%; resin acid component: abietic acid 30 to 40%, neoavietin 10-20% acid, dihydroavier -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, manufactured by Nissan Chemical Co., Ltd.) n-propyl alcohol 1050 parts methyl ethyl ketone 295 parts [The particles in the obtained black image forming layer coating solution are subjected to laser scattering particle size analysis. As a result of measurement using a distribution meter, the average particle size was 0.25 μm, and the ratio of particles having a size of 1 μm or more was 0.5%. ]

[Composition of Yellow Image Forming Layer Coating Solution] 126 parts of a yellow pigment dispersion mother liquor similar to that in Example 1-1 Yellow pigment composition 1: Yellow pigment composition 2 = 95: 5 (parts) Polyvinyl butyral 4.6 Part (“ESLEC B BL-SH”, manufactured by Sekisui Chemical Co., Ltd.) ・ Wax-based compound (stearic amide “Neutron 2” manufactured by Nippon Seika Co., Ltd.) 0.7 part (behenamide “ "Diamid BM", manufactured by Nippon Kasei Co., Ltd.) 1.4 parts (palmitic acid amide "Diamit KP", manufactured by Nippon Kasei Co., Ltd.) 0.7 parts (erucic acid amide "Diamid L-200", Japan 1.4 parts ・ Nonionic surfactant 0.4 part (“Chemistat 1100”, manufactured by Sanyo Chemical Co., Ltd.) 2.4 parts rosin (“KE-311”, Arakawa Chemical Co., Ltd.) )) ・Surface active agent 0.8 parts ( "Megafac F-176PF", 20% solids, manufactured by Dainippon Ink and Chemicals, Inc.), n-propyl alcohol 793 parts Methyl ethyl ketone 198 parts

[Composition of Magenta Image Forming Layer] Magenta pigment dispersed mother liquor as in Example 1-1 163 parts Magenta pigment composition 1: Magenta pigment composition 2 = 95: 5 (parts) Polyvinyl butyral 4.0 (“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 "Diamid BM", manufactured by Nippon Kasei Co., Ltd.) 2.0 parts (palmitic acid amide "Diamid KP" manufactured by Nippon Kasei Co., Ltd.) 1.0 part (erucamide "Diamind L" -200 ", Nippon Kasei Co., Ltd.) 1.0 part (Oleic acid amide" Diamid O-200 ", Nippon Kasei Co., Ltd.) 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.)-2.5 parts of pentaerythritol tetraacrylate ("NK ester A-TMMT", new -Nakamura Chemical Co., Ltd.-1.3 parts of surfactant ("Megafac F-176PF", solid content 20%, manufactured by Dainippon Ink & Chemicals, Inc.)-848 parts of n-propyl alcohol-246 parts of methyl ethyl ketone

[Composition of Cyan Image Forming Layer Coating Solution] 118 parts of cyan pigment dispersed mother liquor as in Example 1-1 Cyan pigment composition 1: cyan pigment composition 2 = 90: 10 (parts) polyvinyl polyvinyl butyral 5.2 Part (“ESLEK B BL-SH”, manufactured by Sekisui Chemical Co., Ltd.) 1.3 parts of inorganic pigment “MEK-ST” ・ Wax-based compound (stearic amide “Neutron 2”, 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 (palmitine Acid amide “Diamind KP”, manufactured by Nippon Kasei Co., Ltd.) 1.0 part (Erucamide “Diamid L-200” (manufactured by Nippon Kasei Co., Ltd.) 2.0 parts ・ Rosin 2.8 parts (“KE -311 ", Arakawa -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 20%, manufactured by Dainippon Ink and Chemicals, Inc.) ・ 890 parts of n-propyl alcohol ・ 247 parts of methyl ethyl ketone

The obtained thermal transfer sheets K, Y, M, and C
The physical properties of the image forming layer of each thermal transfer sheet were as follows. [Physical properties of image forming layer of thermal transfer sheet K] The layer thickness is 0.60
μm. The surface hardness of the image forming layer was preferably 10 g or more, specifically 200 g or more, with a sapphire needle. The surface smoother value is 0.2 at 23 ° C. and 55% RH.
5 to 50 mmHg ($ 0.0665 to 6.65 kPa) is preferable, and specifically, 9.3 mmHg ($ 1.24 kP)
a). The coefficient of static friction of the surface is preferably 0.8 or less, specifically 0.08. The surface energy was 29 mJ / m ^2. The contact angle of water was 94.8 °. The deformation ratio of the light-to-heat conversion layer was 168% when recording was performed with a laser beam having a light intensity of 1000 W / mm ² or more on the exposed surface at a linear velocity of 1 m / sec or more.

[Physical Properties of Image Forming Layer of Thermal Transfer Sheet Y] The layer thickness was 0.42 μm. The surface hardness of the image forming layer is preferably 10 g or more with a sapphire needle, and specifically 200 g.
g or more. Surface smoother value 23 ° C, 55
% RH 0.5 to 50 mmHg ($ 0.0665 to 6.6)
5 kPa), specifically, 2.3 mmHg (≒
0.31 kPa). The coefficient of static friction of the surface is 0.
It was preferably 8 or less, specifically 0.1. The surface energy was 24 mJ / m ^2. Water contact angle is 10
It was 8.1 °. The light intensity on the exposed surface is 1000 W / mm
The deformation ratio of the photothermal conversion layer when recording at a linear velocity of 1 m / sec or more with ^two or more laser beams was 150%.

[Physical Properties of Image Forming Layer of Thermal Transfer Sheet M] The layer thickness was 0.38 μm. The surface hardness of the image forming layer is preferably 10 g or more with a sapphire needle, and specifically 200 g.
g or more. Surface smoother value 23 ° C, 55
% RH 0.5 to 50 mmHg ($ 0.0665 to 6.6)
5 kPa), specifically, 3.5 mmHg (≒
0.47 kPa). The coefficient of static friction of the surface is 0.
8 or less, and specifically 0.08. The surface energy was 25 mJ / m ^2. Water contact angle is 9
8.8 °. The light intensity on the exposed surface is 1000 W / mm
The deformation ratio of the light-to-heat conversion layer when recording with a linear velocity of 1 m / sec or more with ^two or more laser beams was 160%.

[Physical Properties of Image Forming Layer of Thermal Transfer Sheet C] The layer thickness was 0.45 μm. The surface hardness of the image forming layer is preferably 10 g or more with a sapphire needle, and specifically 200 g.
g or more. Surface smoother value 23 ° C, 55
% RH 0.5 to 50 mmHg ($ 0.0665 to 6.6)
5 kPa) is preferred, and specifically, 7.0 mmHg (≒
0.93 kPa). The coefficient of static friction of the surface is 0.
8 or less, and specifically 0.08. The surface energy was 25 mJ / m ^2. Water contact angle is 9
8.8 °. The light intensity on the exposed surface is 1000 W / mm
The deformation ratio of the photothermal conversion layer when recording at a linear velocity of 1 m / sec with ^two or more laser beams was 165%.

-Preparation of Image Receiving Sheet- An image receiving sheet was prepared in the same manner as in Example 1-1. The physical properties of the image receiving layer of the obtained image receiving sheet were as follows.
The layer thickness was 2 μm. Surface roughness Ra is 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 at 23 ° C. and 55% RH (≒ 0.0
665 kPa to 6.65 kPa), specifically, 0.1 kPa.
It was 8 mmHg (≒ 0.11 kPa). The coefficient of static friction of the surface of the image receiving layer is preferably 0.8 or less.
37. The surface energy of the image receiving layer surface is 29 mJ
/ M ² . The water contact angle was 85.0 °.

-Formation of Transferred Image- The image forming system of the present system including the above-described color matching step using the Luxel FINALPROOF 5600 (manufactured by Fuji Photo Film Co., Ltd.) as a recording device in the system shown in FIG. The image transferred to the paper was obtained by the paper transfer method used in the sequence and the present system. 1mm diameter vacuum section hole (3cm × 8
diameter 3 with one area density in the area of cm
On the rotating drum of 8 cm, the image receiving sheet (5
(6 cm × 79 cm) was wound and vacuum-adsorbed. Next, the thermal transfer sheet K cut into 61 cm × 84 cm
(Black) was 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 in a state where the section holes were closed was -150 mmHg (ｋ81.13 kPa) with respect to 1 atm. The drum is rotated, and a semiconductor laser beam having a wavelength of 808 nm is applied to the surface of the stacked body on the drum from the outside,
The light is focused so as to form a spot of 7 μm on the surface of the light-to-heat conversion layer, and is moved in the direction perpendicular to the rotating direction (main scanning direction) of the rotating drum (sub-scanning). ) Recording was done. Laser irradiation conditions are as follows. The laser beam used in this embodiment was a multi-beam two-dimensional laser beam consisting of five parallel lines in the main scanning direction and three parallel lines in the sub-scanning direction. Laser power 110 mW Drum rotation speed 500 rpm Sub-scanning pitch 6.35 μm Ambient temperature and humidity 20 ° C. 40%, 23 ° C. 50%, 2
3 conditions of 6 ° C and 65%. The diameter of the exposure drum is preferably 360 mm or more, and specifically, the diameter was 380 mm. 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 K 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 K was transferred from the thermal transfer sheet K to the image receiving sheet. It was confirmed that it was.

In the same manner as described above, the thermal transfer sheets Y,
From each of the thermal transfer sheets M and C, an image was transferred onto an image receiving sheet. The transferred four-color image was further transferred to recording paper to form a multi-color image.
Even when laser recording was performed with high energy using a laser beam having a dimensional array, a multicolor image having good image quality and a stable transfer density could be formed. At the time of transfer of the paper, the image receiving sheet and the paper were conveyed so as to be wound around a heat roller so that the image receiving sheet was outside the paper. As a result, the curl at the laminator outlet is 4
The average of the sides was 10 mm. The transfer to the paper is performed by a material having a dynamic friction coefficient of 0.1 to 0.7 with respect to polyethylene terephthalate, which is a material of the insertion table, and a transport speed of 15 to 50 mm / s.
The ec thermal transfer device was used. The Vickers hardness of the heat roller material of the thermal transfer device is preferably from 10 to 100, and specifically, a material having a Vickers hardness of 70 was used.
The obtained image was good in all three environment temperature and humidity.

The reflection optical density was obtained by transferring the original paper to Tokishi Art Paper using a densitometer X-write 938 (X-write 938).
(Manufactured by the company) in Y, M, C, and K modes, respectively. The reflection optical density and the reflection optical density / image forming layer thickness of each color were as shown in Table 3 below.

[0209]

[Table 3]

Reference Example 2-1 The same procedure as in Example 2-1 was carried out except that the image receiving sheet and the paper were superposed and conveyed so that the image receiving sheet was wound around a heat roller so as to be inside the paper at the time of transferring the paper. A transfer image was formed. As a result, the curl at the laminator discharge port during the transfer of the paper was rounded to an unmeasurable degree. Table 4 summarizes the results of Example 2-1 and Reference Example 2-1.

[0211]

[Table 4]

Here, the curl was determined by placing the sheet on a flat table so that the upper surface would be concave when the upper surface was curled, and measuring the lift amounts of the four corners, and calculating the average value.

Further, when other performances (dot shape, repetition reproducibility, color reproducibility, character quality) of Example 2-1 were evaluated, they were as good as Example 1-1.

Example 3-1 -Preparation of Thermal Transfer Sheet- Thermal transfer sheets K (black), Y (yellow), M (magenta) and C (cyan) were prepared except that the composition of the following coating liquid was changed as follows. Was produced in the same manner as in Example 1-1.

[Composition of Back Second Layer Coating Solution] Polyolefin 3.0 parts (Chemipearl S-120, 27% by mass, manufactured by Mitsui Petrochemical Co., Ltd.) Antistatic agent 2.0 parts (tin oxide-oxidation Aqueous dispersion of antimony, 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 parts (Dinacol) Ex614B, manufactured by Nagase Kasei Co., Ltd.) ・ Sodium polystyrene sulfonate 0.1 part ・ Distilled water Prepared so that the total becomes 100 parts

The resulting thermal transfer sheets K, Y, M, and C
The physical properties of the image forming layer of each thermal transfer sheet were as follows. [Physical properties of the image forming layer of the thermal transfer sheet K] The surface hardness of the image forming layer is preferably 10 g or more, specifically 200 g or more, with a sapphire needle. Surface smoother value is 2
0.5 to 50 mmHg at 3 ° C. and 55% RH (≒ 0.06
65 to 6.65 kPa), specifically 9.3.
mmHg (≒ 1.24 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08. The surface energy was 29 mJ / m ^2. The contact angle of water was 94.8 °. Reflective optical density (OD)
Was 1.82, the layer thickness was 0.60 μm, and the OD / layer thickness was 3.03. The light intensity on the exposed surface is 1000 W / m
The deformation ratio of the light-to-heat conversion layer when recorded with a laser beam of m ² or more at a linear velocity of 1 m / sec or more was 168%.

[Physical Properties of Image Forming Layer of Thermal Transfer Sheet Y] The surface hardness of the image forming layer is preferably 10 g or more, specifically 200 g or more, with a sapphire needle. The surface smoother value is 0.5-50mmHg at 23 ° C and 55% RH.
(≒ 0.0665 to 6.65 kPa), more specifically, 2.3 mmHg (≒ 0.31 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.1. The surface energy was 24 mJ / m ^2. The contact angle of water was 108.1 °. The reflection optical density (OD) is 1.01, the layer thickness is 0.42 μm,
OD / layer thickness was 2.40. The light intensity on the exposed surface is 10
The deformation ratio of the light-to-heat conversion layer when recorded with a laser beam of 00 W / mm ² or more at a linear velocity of 1 m / sec or more was 150%.

[Physical Properties of Image Forming Layer of Thermal Transfer Sheet M] The surface hardness of the image forming layer is preferably 10 g or more, specifically 200 g or more, with a sapphire needle. The surface smoother value is 0.5-50mmHg at 23 ° C and 55% RH.
(≒ 0.0665 to 6.65 kPa), more specifically, 3.5 mmHg (≒ 0.47 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08. The surface energy was 25 mJ / m ^2. The contact angle of water was 98.8 °. The reflection optical density (OD) is 1.51, the layer thickness is 0.38 μm,
OD / layer thickness was 3.97. The light intensity on the exposed surface is 10
The deformation ratio of the photothermal conversion layer when recording with a laser beam of 00 W / mm ² or more at a linear velocity of 1 m / sec or more was 160%.

[Physical Properties of Image Forming Layer of Thermal Transfer Sheet C] The surface hardness of the image forming layer was preferably 10 g or more, specifically 200 g or more, with a sapphire needle. The surface smoother value is 0.5-50mmHg at 23 ° C and 55% RH.
(≒ 0.0665 to 6.65 kPa), specifically, 7.0 mmHg (≒ 0.93 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08. The surface energy was 25 mJ / m ^2. The contact angle of water was 98.8 °. The reflection optical density (OD) is 1.59, the layer thickness is 0.45 μm,
OD / layer thickness was 3.53. The light intensity on the exposed surface is 10
The deformation ratio of the photothermal conversion layer when recording with a laser beam of 00 W / mm ² or more at a linear velocity of 1 m / sec or more was 165%.

-Preparation of Image Receiving Sheet- An image receiving sheet was prepared in the same manner as in Example 1-1. The physical properties of the image receiving layer of the obtained image receiving sheet were as follows.
The layer thickness was 2 μm. Surface roughness Ra is 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 at 23 ° C. and 55% RH (≒ 0.0
665 kPa to 6.65 kPa), specifically, 0.1 kPa.
It was 8 mmHg (≒ 0.11 kPa). The coefficient of static friction of the surface of the image receiving layer is preferably 0.8 or less.
37. The surface energy of the image receiving layer surface is 29 mJ
/ M ² . The water contact angle was 85.0 °.

-Formation of Transfer Image- A transfer image was formed in the same manner as in Example 1-1, except that the above-described thermal transfer sheet and image receiving sheet were used. The transfer order to the image receiving sheet was black, cyan, magenta, and yellow.

Here, the method of measuring the reflection optical density and the measurement result will be described. The reflection optical density was obtained by transferring the original paper to Tokishi Art Paper using a densitometer X-rite 938 (X-ri
te company) Y, M, C, K colors Y, M, C,
It was measured in K mode. The reflection optical density of each color and the reflection optical density / the thickness of the image forming layer were as shown in Table 3 below.

[0223]

[Table 5]

The evaluation of the image obtained by the above system configuration was performed as follows. (1) Measurement of Reflection Density (OD) of Black Image Area and Calculation of Image Transfer Rate Using the thermal transfer sheet K, the image density of a transfer image obtained under each temperature and humidity condition is measured using a reflection Macbeth densitometer “RD”. −
918 "(W filter), the reflection density (OD) was as follows. The thermal transfer sheet K was transferred onto an image receiving sheet without laser recording using a thermal transfer apparatus, and the reflection density (OD) of the obtained black image was measured by the above method.
The image transfer rate by laser recording was 18 ° C.
Under the respective temperature and humidity conditions of 30%, 23 ° C 50%, and 26 ° C 65%, they were 98.4%, 96.8%, and 96.3%, respectively.

<Evaluation of Black Image Quality> Using the thermal transfer sheet K, a solid portion and a line drawing portion of a transfer image obtained under each temperature and humidity condition were observed with an optical microscope. No gap was observed in the solid portion, the resolution of the line drawing was a good result, and a black transfer image less dependent on environmental conditions could be obtained.
The evaluation of the image quality was visually performed according to the following criteria. -Solid part-A: No gap or defective transfer during recording. Δ: There are gaps and poor transfer at the time of recording. X: A gap at the time of recording or transfer failure exists on the entire surface. -Line drawing part-A: The edge of the line drawing is sharp and has good resolution. △: The edge of the line drawing is very slightly jagged, but no bridging has occurred. Δ ○: The edge of the line drawing is jagged, but no bridging has occurred. Δ: The edge of the line drawing is jagged, and bridging occurs partially. ×: Bridging has occurred entirely.

Next, the following evaluation was further performed on a color image created at a temperature and humidity of 23 ° C. and 50% RH. The results are also shown in Table 6.

<Evaluation of Color Tone of Black Portion> The color tone of the black portion of the color image transferred to the recording paper was visually evaluated and divided into the following three ranks. ：: The part which is transferred by overlapping with other colors is also good without yellow or reddish tinge. Δ: The portion transferred and overlapped with another color has a slight yellow or red tint, but is practically acceptable. X: The part which is transferred with being overlapped with another color has a yellowish or reddish color and is not practically acceptable. As a result, good color tone was obtained in Example 3-1 and Reference Example 3-5, but all of Reference Examples 2-1 to 4 were defective.

<Evaluation of white spots> Size 515 mm × 72
The number of white spots having a diameter of 1 mm or more in the color image transferred to the 8 mm recording paper was counted.

Further, when other performances (dot shape, repetition reproducibility, color reproducibility, character quality) of Example 3-1 were evaluated, they were as good as Example 1-1.

Reference Examples 3-1 to 4-4 Reference Example 3 was performed in the same manner as in Example 3-1 except that the same sample as in Example 3-1 was used and the order of image formation was changed as shown in Table 6. 1-4 were performed.

Reference Example 3-5 Reference Example 3-5 was carried out in the same manner as in Example 3-1 except that the pigment of each of the image forming layers for yellow, magenta, cyan, and black was 0.5 times. However, the optical density of the image forming layer was the same as in Example 3-1.

Example 3-2 The same sample as in Example 3-1 was used to reduce the image size to 594 m.
Example 3-2 was performed in the same manner as in Example 3-1 except that the size was set to mx841 mm.

Example 3-3 Example 3-3 was carried out in the same manner as in Example 3-1 except that the amount of the pigment added to the image forming layer was 0.85 times that of Example 3-1.

Example 3-4 Example 3-4 was carried out in the same manner as in Example 3-1 except that the amount of the pigment added to the image forming layer was 1.15 times that of Example 3-1.

The samples of Reference Examples 3-1 to 5 and Examples 3-2 to 4 were subjected to an ambient temperature and humidity of 23 ° C. in the same manner as in Example 3-1.
The image was prepared at 50% RH, and the image quality of the black image, the color tone of the black part, and the white spot were evaluated. Table 6 shows the above results.
It was shown to.

[0236]

[Table 6]

[0237]

The proof product developed in the present invention is based on the thin film transfer technology, and incorporates the various technologies described above in order to solve new problems in the laser thermal transfer system and to achieve higher image quality. Realized sharp halftone dots by thin film thermal transfer method, real paper transfer, actual halftone output, pigment type, B2
We have developed a laser thermal transfer recording system for DDCP which consists of a size image forming material, an output machine and high quality CMS software. As described above, according to the present invention, a system configuration capable of sufficiently exerting the ability of a material having a high resolution can be realized. Specifically, we can provide a contract proof that replaces proofs and analog color proofs in response to filmlessness in the CTP era. Can be reproduced. 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, it is possible to transfer a real paper, use the same pigment-based coloring material as the printing ink, and use a large size (A2 / B
(2 or more) 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. Further, when the image receiving sheet on which the multicolor image is formed is transferred to the actual paper, it is possible to prevent the pair of the actual paper and the image receiving sheet discharged from the laminator from being curled with the image receiving sheet inside and the original paper being deformed. .

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a mechanism of forming a multicolor image by thin-film thermal transfer using a laser.

FIG. 2 is a diagram illustrating a configuration example of a recording apparatus for laser thermal transfer.

FIG. 3 is a diagram illustrating a configuration example of a thermal transfer device.

FIG. 4 FINALPROO recording device for laser thermal transfer
1 is a diagram illustrating a configuration example of a system using F. FIG.

FIG. 5 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 6 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 7 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 8 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 9 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 10 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 11 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 12 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 13 shows a dot shape of an image obtained in Example 1-1. The distance between the dot centers is 125 μm.

FIG. 14 shows the dot reproducibility of the image obtained in Example 1-1. The vertical axis is the dot area ratio calculated from the reflection density,
The horizontal axis indicates the dot area ratio of the input signal.

FIG. 15 shows the repetition reproducibility of the image obtained in Example 1-1 on the a * b * plane of the L * a * b * color system.

FIG. 16 shows the repetition reproducibility of the image obtained in Example 1-1.

FIG. 17 shows two points of character quality of an image obtained in Example 1-1. Shows a positive image.

FIG. 18 shows two points of character quality of an image obtained in Example 1-1. Shows a negative image.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 recording apparatus 2 recording head 3 sub-scanning rail 4 recording drum 5 thermal transfer sheet loading unit 6 image receiving sheet roll 7 transport roller 8 squeeze roller 9 cutter 10 thermal transfer sheet 10K, 10C, 10M, 10Y thermal transfer sheet roll 12 support 14 photothermal conversion layer Reference Signs List 16 image forming layer 20 image receiving sheet 22 image receiving sheet support 24 image receiving layer 30 laminated body 31 discharge stand 32 waste port 33 discharge port 34 air 35 waste box 42 book paper 43 heat roller 44 insertion table 45 mark indicating placement position 46 insertion Roller 47 Guide made of heat-resistant sheet 48 Peeling nail 49 Guide plate 50 Discharge port

Continuation of the front page (72) Inventor Toshiharu Tanaka 200 Onakazato, Fujinomiya-shi, Shizuoka Fuji Photo Film Co., Ltd. F-term (reference) 2C065 AA01 AB02 AC01 AF03 CA03 CA08 CA10 CA13 CZ01 CZ13 CZ14 5C074 AA02 BB13 DD14 DD24 DD28 EE02 FF07 FF15

Claims (12)

[Claims] A thermal transfer sheet comprising: an image receiving sheet having at least an image receiving layer on a support; and at least four or more different color thermal transfer sheets having at least a light-to-heat conversion layer and an image forming layer on the support. The image forming layer and the image receiving layer of the image receiving sheet are superposed facing each other, and a laser beam is irradiated, and the laser light irradiation area of the image forming layer is transferred onto the image receiving layer of the image receiving sheet to form a multicolor image. In the forming method, the ratio OD / layer thickness of the optical density (OD) of the image forming layer of each thermal transfer sheet to the layer thickness (μm unit) is 1.
50 or more, and the resolution of the transferred image is 2400 dp
a multicolor image forming method, wherein a color matching step is performed before recording the thermal transfer image on the image receiving sheet. 2. A color image data conversion processing step of converting color image data for creating a print into color image data for a proof output device, and a color and / or halftone of the print. 2. The color / dot matching conversion processing step of performing data conversion processing for matching a point with a color and / or a halftone dot of a color image output by the proof output device. The multicolor image forming method described in the above. 3. A thermal transfer sheet comprising: an image receiving sheet having at least an image receiving layer on a support; and at least four or more different color thermal transfer sheets having at least a photothermal conversion layer and an image forming layer on the support. The image forming layer and the image receiving layer of the image receiving sheet are superposed facing each other, and a laser beam is irradiated, and the laser light irradiation area of the image forming layer is transferred onto the image receiving layer of the image receiving sheet to form a multicolor image. In the forming method, the recording area of the multicolor image of each of the thermal transfer sheets is a size of 515 mm × 728 mm or more, and the image receiving sheet is wound around a heat roller so that the image receiving sheet is outside the actual paper at the time of actual paper transfer. Color image forming method. 4. The multicolor printing method according to claim 1, wherein the order of transferring the image forming layer of each of the thermal transfer sheets onto the image receiving layer of the image receiving sheet is black, cyan, magenta, and yellow. Image forming method. 5. The image forming layer on the image receiving sheet is formed in the order of yellow, magenta, cyan, cyan,
5. The multicolor image forming method according to claim 4, wherein the paper is transferred in the order of forming the black image forming layer. 6. The multicolor image forming method according to claim 1, wherein the image forming layer in the laser light irradiation area is transferred to the image receiving sheet in a thin film state. 7. The contact angle of water between the image forming layer of each of the thermal transfer sheets and the image receiving layer of the image receiving sheet is 7.0-1.
The angle is in the range of 20.0 °.
The multicolor image forming method according to any one of the above. 8. The ratio (OD / layer thickness) between the optical density (OD) and the layer thickness (μ unit) of the image forming layer of each thermal transfer sheet is 1.8.
0 or more, and the contact angle of the image receiving sheet with water is 8
The multicolor image forming method according to claim 1, wherein the angle is 6 ° or less. 9. A thermal transfer sheet comprising: an image receiving sheet having at least an image receiving layer on a support; and at least four or more different color thermal transfer sheets having at least a photothermal conversion layer and an image forming layer on the support. The image forming layer and the image receiving layer of the image receiving sheet are superposed facing each other, and a laser beam is irradiated thereon, and the laser light irradiation area of the image forming layer is transferred onto the image receiving layer of the image receiving sheet to form a multicolor image. In the forming material, the ratio OD / layer thickness of the optical density (OD) and the layer thickness (in μm) of the image forming layer of each thermal transfer sheet is 1.
50 or more, and the resolution of the transferred image is 2400 dp
a multicolor image forming material, which is subjected to a color matching step before recording a thermal transfer image on the image receiving sheet. 10. The multicolor image recording area of each of the thermal transfer sheets has a size of 515 mm × 728 mm or more, and the image receiving sheet is wound around a heat roller so that the image receiving sheet is outside the actual paper at the time of actual paper transfer. Claim 9
2. The multicolor image forming material according to item 1. 11. The thermal transfer sheet comprises at least four types of thermal transfer sheets including at least yellow, magenta, cyan and black, and the image forming layers of each thermal transfer sheet are transferred in the order of black, cyan, magenta and yellow. The multicolor image forming material according to claim 9, further comprising an image receiving sheet. 12. The image transfer layer according to claim 1, wherein the image forming layer on the image receiving sheet is transferred onto the paper in the order of yellow, magenta, cyan, and black image forming layers in the order from the support on the paper. 12. The multicolor image forming material according to item 11.