JP2002347356A - Method for laser thermal transfer recording and image receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for laser thermal transfer recording in which conveying of an image receiving sheet is smoothly executed and which can record an image of a good quality having no image fault or the like due to a foreign matter adhered due to a cause of charging or the like of a flexible plate. SOLUTION: The method for laser thermal transfer recording comprises the steps of supplying the image receiving sheet onto the flexible plate mounted on a recording medium fixing member having suction holes, superposing the thermal transfer sheet on the image receiving sheet to hold the sheets so that the image receiving layer of the receiving sheet is opposed to the image forming layer of the thermal transfer sheet, and irradiating the support side of the transfer sheet with a laser beam in response to image information to record image data. In this method, the flexible plate is conductive, and a surface electric resistance SR of a back layer of the receiving sheet is 1×10<12> Ω or less under the conditions of 23 deg.C and 50% RH.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In the field of graphic arts, a printing plate is printed using a set of color separation films prepared from a color original by using a lithographic film. In order to check for errors in the color separation process and the necessity of color correction, a color proof is made from the color separation film. A color proof is required to have high resolution which enables high reproducibility of a halftone image, and high performance such as high process stability. In addition, in order to obtain a color proof similar to an actual printed matter, as a material used for the color proof, a material used for an actual printed matter, for example, a printing paper as a base material and a pigment as a coloring material are used. Is preferred.

Further, as a method of producing a color proof, there is a strong demand for a dry method using no developer, and as a method of producing a color proof, an electronic system in a recent pre-printing process (prepress field) has been widely used. Accordingly, recording systems for directly producing a color proof from digital signals have been developed. Such an electronic system is
In particular, the purpose is to produce a high-quality color proof, and generally, a halftone image of 150 lines / inch or more is reproduced. In order to record a proof of high image quality from a digital signal, a laser beam that can be modulated by the digital signal and that can narrow down the recording light is used as a recording head. For this reason, it is necessary to develop a recording material that exhibits high recording sensitivity to laser light and high resolution that enables high-definition halftone dots to be reproduced.

A transfer image recording method using laser light involves a thermal transfer method comprising, as a recording medium, a light-to-heat conversion layer that absorbs laser light to generate heat and an image forming layer containing a color material on a support in this order. A sheet and an image receiving sheet having an image receiving layer on a support are used. The bonding force between the image forming layer and the image receiving layer in the region that has been irradiated with the laser beam is increased, and the image is transferred to an image receiving sheet having the image forming layer in the region laminated thereon and an image is recorded. According to this image recording method, a printing paper having an image receiving layer (adhesive layer) attached thereto can be used as an image receiving sheet material, and a multicolor image can be easily obtained by transferring images having different colors onto the image receiving sheet one after another. This has the advantage that a high-definition image can be easily obtained, and is useful for producing a color proof (DDCP: direct digital color proof) or a high-definition mask image.

Image recording is performed by a recording apparatus as shown in FIG. The recording apparatus is provided with a recording head 2 for performing laser exposure, and the recording head 2 reciprocates in a direction parallel to a rotation axis of a recording drum 4 of a recording medium fixing member. A laser beam Lb is emitted from the recording head 2 and is irradiated as a plurality of spots. On the recording drum 4, an image receiving sheet as a recording medium is fixed by suction with the image receiving layer facing outward, and a thermal transfer sheet also as a recording medium is fixed thereon such that the image forming layer faces the image receiving layer of the image receiving sheet. You. By combining the rotational movement (main scanning direction) of the recording drum 4 and the reciprocating movement (sub-scanning direction) of the recording head 2, a desired image corresponding to the image data is transferred to the image receiving sheet.

[0006]

The recording drum of the above-mentioned recording apparatus has image defects due to irregularities on the surface of the recording drum (cutting marks during processing of the recording drum, cutting streaks, grooves and holes of a recording medium fixing release mechanism, etc.). In order to avoid the problem, or to be able to cope with recording media of various sizes, a flexible plate is mounted. However, there are many recording drums made of a conductive material, so that the flexible plate on the recording drum is easily charged. When the flexible plate is charged,
Foreign matter, such as dust and dirt, adheres to the surface, and this foreign matter causes the image receiving sheet and the transfer sheet to be displaced in the direction perpendicular to the rotation axis of the recording drum, defocusing the recording laser light, and obtaining sufficient energy density. In some cases, the image was thinned and the density was reduced, resulting in image defects. In addition, static electricity is also generated at the time of discharging an image receiving sheet as a recording medium fixed on a flexible plate, which causes problems such as jamming in the discharge conveyance path and inability to accurately accumulate the image receiving sheets. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a laser capable of recording an image of good quality without causing image defects or the like due to smooth transfer of an image receiving sheet and charging of a flexible plate. It is an object to provide a thermal transfer recording method.

[0008]

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

The means for solving the above-mentioned problems are as follows. (1) An image receiving sheet is supplied onto a flexible plate mounted on a recording medium fixing member having a suction hole, and the image receiving layer is placed on the image receiving sheet such that the image receiving layer of the image receiving sheet and the image forming layer of the thermal transfer sheet face each other. In the laser thermal transfer recording method of superposing and holding the thermal transfer sheet and recording image data by irradiating laser light according to image information from the support side of the thermal transfer sheet, the flexible plate is conductive and said image-receiving surface resistivity SR of the seat back layer under conditions RH 23 ℃ / 50% 1 × 10 12 Ω
A laser thermal transfer recording method characterized by the following. (2) The laser thermal transfer recording method according to (1), wherein the static friction coefficient of the back layer surface of the image receiving sheet is 0.5 or less. (3) The surface roughness Rz of the back layer surface of the image receiving sheet is 3 μm or less (1) or (2).
The laser thermal transfer recording method described in 1. (4) The laser thermal transfer recording method according to any one of (1) to (3), wherein the material of the conductive flexible plate is metallic. (5) The laser thermal transfer recording method according to any one of (1) to (4), wherein the material of the conductive flexible plate is a plastic material. (6) A conductive flexible plate is mounted on a recording medium fixing member having a suction hole, a recording medium is supplied onto the flexible plate, and a laser beam corresponding to the image information is irradiated to the image data. In the image receiving sheet used in the laser thermal transfer recording apparatus for recording the image, the surface electric resistance SR of the back layer of the image receiving sheet is 1 × 1 under the condition of 23 ° C./50% RH.
An image receiving sheet having a resistivity of 0 ¹² Ω or less.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention realizes a thermal transfer image with sharp halftone dots, and transfers the paper and B2 size recording (515 mm × 728 mm, but B2 size is 543 mm).
mm x 765 mm). The thermal transfer image obtained by the present invention is 2400 dpi
With the above resolution, a halftone image corresponding to the number of print lines can be obtained. Since each halftone dot has very little bleeding or chipping and a very sharp shape, a high range of halftone dots from highlights to shadows can be formed clearly. As a result, it 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 gradation with good print similarity.

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

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

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

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

[0015] Usually, the image forming layer is also heated to about 500 ° C or more at the time of printing by laser exposure. This can be prevented by adopting it in the image forming layer. And, by high heat at the time of printing,
When the infrared-absorbing dye migrates from the light-to-heat conversion layer to the image forming layer, the light-to-heat conversion layer is combined with a strong holding power of the infrared-absorbing dye / binder as described above to prevent the hue from being changed. It is preferable to design. Generally, in high-speed printing, energy is insufficient, and a gap corresponding to the interval between laser sub-scans is generated. As described above, increasing the concentration of the dye in the light-to-heat conversion layer and reducing the thickness of the light-to-heat conversion layer / image forming layer can increase the efficiency of heat generation / transmission. Further, it is preferable to add a low-melting substance to the image forming layer for the purpose of increasing the effect of slightly flowing the image forming layer upon heating and filling the gap and the adhesiveness to the image receiving layer. Further, in order to increase the adhesiveness between the image receiving layer and the image forming layer and to sufficiently impart the strength of the transferred image, it is preferable to employ, for example, the same polyvinyl butyral as the image forming layer as the binder of the image receiving layer.

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

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

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

FIG. 2 shows a configuration example of the present apparatus. A sequence in the present apparatus as described above 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.
A conductive flexible plate is mounted on the recording drum 4. 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-sucked on the recording drum 4 via a suction hole provided in the recording drum 4 and fixed. 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.

FIG. 3 is a perspective view showing the periphery of the recording drum 4. The recording drum 4 is provided to avoid image defects due to irregularities on the drum surface (cutting marks, cutting streaks, grooves and holes of a recording medium fixing release mechanism during recording drum processing), or for recording media of various sizes. A flexible plate 23 is provided for enabling the response.

The flexible plate 23 is made of a conductive material, and is a thin plate having portability so that it can be wound around the outer peripheral surface of the recording drum 4. Specifically, a metal plate (thickness of about 0.1 to 0.6 mm) such as aluminum, aluminum alloy, or stainless steel;
Alternatively, a conductive plastic (about 0.1 to 0.6 mm) is used. As the conductive plastic, any material may be used as long as it is a well-known conductive plastic, but the surface resistivity is 1 × 10 ⁴ Ω / cm ^2.
~ 1 × 10 ¹⁰ Ω / cm ² , volume resistivity 1 × 10-1 ×
Those having a resistivity of 10 ⁸ Ωcm are preferred. For example, a carbon-containing vinyl chloride plastic is preferable, and more specifically, Evilon CM (trade name: Taihei Chemical Products Co., Ltd.), which is a plastic mixed with carbon, is suitably used.

As shown in FIG. 4, the flexible plate 23 is supplied to and mounted on the outer peripheral surface of the recording drum 4 before the image receiving sheet 20 is supplied onto the recording drum 4. The flexible plate 23 is wound around the outer periphery of the recording drum 4 by the rotation of the recording drum 4, and is fixed in the circumferential direction of the recording drum 4 by a fixing / releasing clamp 25 or the like shown in FIG. Both ends are fixed. here,
At least one of the front end fixing portion 25a and the rear end fixing portion 25b of the fixing / releasing clamp 25 is provided so that recording media of various lengths can be fixed on the recording drum 4.
Is preferably movable in the circumferential direction on the outer circumference.

The flexible plate 23 has holes (through grooves,
It is also possible to open a through hole (or slit) 27. If the flexible plate 23 can be conveyed to the correct recording drum position, it is desirable to open a hole 27 in the flexible plate 23 corresponding to an intake hole (not shown) of the recording drum 4. The hole 27 does not need to completely correspond to the intake hole on the recording drum 4, or may be thinned out to form the hole 27. In this case, the original recording medium is
It is necessary to provide the holes 27 so as not to drop or slip off from the recording drum 4 when they are supplied and fixed, or to provide a minimum number of holes 27 so as to coincide with the intake holes. In this manner, by forming the holes 27 in the flexible plate 23, in addition to the suction holes at the upper, lower, left and right ends, which will be described later, provided on the recording drum 9, a portion for sucking the recording medium is increased. 4 can be fixed by suction.

In the vicinity of the recording drum 4, an adhesive roller 2 rotatable about a rotation axis in the same direction as the rotation axis of the recording drum 4.
9 are provided. The rotation axis of the adhesive roller 29 can be moved in parallel by a moving mechanism (not shown), and the outer peripheral surface can contact the outer peripheral surface of the recording drum. The adhesive roller 29 has a cored bar, and an adhesive rubber provided around the cored bar to remove foreign substances on the recording medium by adhesiveness. The foreign substances adhering to the surface can be removed by adhesion.

The hollow portion of the recording drum 4 communicates with, for example, an intake pipe 36 also serving as a rotating shaft. The intake pipe 36 is a blower (not shown) which is a suction device for fixing a recording medium (not shown) for performing vacuum suction. Alternatively, a vacuum pump or the like is connected. On the other hand, on the outer peripheral surface of the recording drum 4, a number of intake holes (not shown) for sucking air are formed. Therefore, when the recording medium is mounted on the outer peripheral surface of the recording drum 4 and the blower is driven, the recording medium is attracted to the outer peripheral surface of the recording drum 4, and the image receiving sheet 20 and the thermal transfer sheet 10 as the recording medium are fixed to the recording drum 4. Is done. Similarly, by mounting the flexible plate 23 on the recording drum before these recording media are fixed,
Can be fixed to the recording drum 4. When the air blower, which is the suction source, starts the suction operation, the air inside the recording drum 4 is sucked through the suction pipe 36 and the internal pressure of the recording drum 4 decreases. The flexible plate 23 and the recording medium are sucked from the large number of intake holes, and these are securely held and fixed on the recording drum 4.

Specifically, first, when the flexible plate 23 is supplied to the recording drum 4, the fixing / release clamp 25
Thereby, the flexible plate 23 is fixed to the recording drum 4. Further, the flexible plate 23 may be suction-fixed to the recording drum 4 by a number of intake holes located below the flexible plate 23. Next, the image receiving sheet 20 is
, The image receiving sheet 20 is fixed on the recording drum 4 by the holes 27 of the flexible plate 23 located below the image receiving sheet 20. Next, the thermal transfer sheet 10 is supplied onto the image receiving sheet 20. The thermal transfer sheet 10
Since it is cut larger than the image receiving sheet 20,
The four sides of the thermal transfer sheet 10 protrude from the image receiving sheet 20, and the thermal transfer sheet 10 is sucked by the holes 27 located below the protruding portion and fixed on the recording drum 4.

In the above-described apparatus, a cylindrical recording drum was used as the recording medium fixing member. However, the recording medium fixing member is not limited to the recording drum, and can be applied to various shapes. FIG. 7 shows another embodiment of the recording apparatus according to the present invention, which employs a flat recording medium fixing member. The recording unit 40, which is an exposure unit,
A light source 41 that emits laser light in a narrow band wavelength range according to the spectral sensitivity characteristics of the recording medium, first and second lenses (cylindrical lenses) 42 and 43, a polygon mirror 44 serving as an optical deflector, an fθ lens 45, It has a lowering mirror 46. In the exposure unit 40, known members such as a collimator lens and a beam expander for shaping laser light emitted from the light source, a surface tilt correction optical system, and a mirror for adjusting an optical path are arranged, although not shown. You. The laser light emitted from the recording unit 40 is in the main scanning direction on the recording medium. The recording medium fixing member 47 has a planar shape, and a flexible plate 48 is placed thereon. The flat recording medium fixing member 47, the flexible plate 48, and the recording medium further fixed on the flexible plate are conveyed by driving means such as a conveying roller (not shown). Has become.

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

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

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

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

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

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

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

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

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

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

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

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

Next, the 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 the support 1
2, on it, the light-to-heat conversion layer 14, and further thereon
The image receiving layer 20 includes an image forming layer 16 and a support 22.
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 beam to be used can be used without particular limitation as long as it is a multi-beam, and is a gas laser beam such as an argon ion laser beam, a helium neon laser beam, a helium cadmium laser beam, or a solid laser beam such as a YAG laser beam. Light, semiconductor laser light, dye laser light,
Direct laser light such as excimer laser light is used. Alternatively, light obtained by converting these laser lights to half the wavelength through a second harmonic element can be used. In the multicolor image forming method, it is preferable to use a semiconductor laser beam in consideration of output power, ease of modulation, and the like. In the multicolor image forming method, the laser beam has a beam diameter on the photothermal conversion layer of 5 to 50 μm (particularly 6 to 30 μm).
μm), and the scanning speed is 1 m / sec or more (especially 3 m / sec or more).
It is preferable that

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

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

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

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

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

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

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

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

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

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

The support of the thermal transfer sheet may be 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 preferably less than 0.3.
When B / A is 0.3 or more, slipperiness and powder dropping of the back layer tend to be deteriorated.

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

Examples of the antistatic agent used 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_TwoTi₆O₁₃,
NaCaP_TwoO₁₈, MgB_TwoO _FiveOxides such as CuS, Z
Sulfides such as nS; SiC, TiC, ZrC, VC, Nb
Carbides such as C, MoC and WC; Si_ThreeN_Four, TiN, Zr
N, VN, NbN, Cr_TwoNitride such as N; TiB_Two, Zr
B_Two, NbB_Two, TaB_Two, CrB, MoB, WB, La
B_FiveBorides such as TiSi_Two, ZrSi_Two, NbSi_Two, T
aSi_Two, CrSi_Two, MoSi_Two, WSi_TwoSilicides such as;
BaCO_Three, CaCO_Three, SrCO_Three, BaSO_Four, CaS
O_FourMetal salts such as SiN_Four-SiC, 9Al_TwoO_Three-2B_Two
O_ThreeAnd the like. One of these compounds may be used alone or in combination.
More than one species may be used in combination. Of these, SnO_Two, Z
nO, Al_TwoO_Three, TiO_Two, In_TwoO_Three, MgO, BaO
And MoO_ThreeAre preferred, and SnO_Two, ZnO, In_TwoO_ThreePassing
And TiO_TwoIs more preferable, and SnO_TwoIs particularly preferred.

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

When a conductive metal oxide is used as an antistatic agent, the particle size is preferably as small as possible 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 slip 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, acrylates and methacrylates. , 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.

[0066]

Embedded image

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

[0068]

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[0069]

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

[0071]

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[0072]

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

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

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

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

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 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 decreases, 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 at the time of 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), Symul
er Lake Red (Shimla Lake Red) C
conc (manufactured by Dainippon Ink and Chemicals, Inc.) 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 SOCIETY OF
DYES & COLOURIST, THIRD EDITION, 1987 "
The product can be selected as appropriate by referring to the table.

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

As the binder for the image forming layer, an amorphous organic high molecular polymer having a softening point of 40 to 150 ° C. is preferable. 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 suitable. In addition, the said wax-type compound can be used individually or suitably in combination as needed.

Plasticizer As the plasticizer, an ester compound is preferable, and dibutyl phthalate, di-n-octyl phthalate, di (2-ethylhexyl) phthalate, dinonyl phthalate, dilauryl phthalate, butyl lauryl phthalate, Phthalates such as butylbenzyl phthalate, and di (2-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.

The acrylic acid 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 addition effect and difficulty in diffusing under storage conditions. Examples of the polyester include sebacic acid-based polyester and adipic acid-based polyester. The additives to be contained in the image forming layer are not limited to these. The plasticizer may be used alone or in combination of two or more.

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

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

For the image forming layer, a coating solution prepared by dissolving or dispersing the pigment and the binder and the like is prepared, and the solution is coated on the light-to-heat conversion layer (when the heat-sensitive release layer described below is provided 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 is decomposed or deteriorated by heat to generate a gas include a self-oxidizing polymer such as nitrocellulose, chlorinated polyolefin, chlorinated rubber, polyvinyl chloride, polyvinyl chloride, and polyvinylidene chloride. Such halogen-containing polymers, acrylic compounds such as polyisobutyl methacrylate in which volatile compounds such as water are adsorbed, cellulose esters such as ethyl cellulose in which volatile compounds such as water are adsorbed, and volatile compounds such as water. Natural polymer compounds such as adsorbed gelatin can be exemplified. Examples of the low molecular weight compound which decomposes or degrades by heat to generate a gas include a compound which generates a gas upon exothermic decomposition such as a diazo compound or azide. In addition, the decomposition or deterioration of the heat-sensitive material due to heat as described above preferably occurs at 280 ° C. or lower, particularly preferably at 230 ° C. or lower.

When a low molecular 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 the image forming layers are laminated in this order, the heat-sensitive release layer decomposes and degrades by the 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 preferred that the coefficient of static friction of the outermost layer on the side of the thermal transfer sheet on which the image forming layer is coated be 0.35 or less, more 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.
The method described in paragraph (0011) is followed. The smoother value of the surface of the image forming layer is 0.5 to 50 mmHg (≒ 0.06
65 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.). The surface hardness of the image forming layer is preferably 10 g or more with a sapphire needle. After the thermal transfer sheet is charged according to US Federal Government Test Standard 4046, the charge potential of the image forming layer 1 second after the thermal transfer sheet is grounded is preferably -100 to 100V. The surface 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. Further, the support has a back layer on the surface 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 preferred because of their good crystallinity, good stretchability and easy void formation. It is preferable to use the polyolefin resin or the polyethylene terephthalate resin as a main component, and appropriately use a small amount of another thermoplastic resin in combination. As the inorganic pigment used as the filler, those having an average particle diameter of 1 to 20 μm are preferable, and calcium carbonate, clay, diatomaceous earth, titanium oxide, aluminum hydroxide, silica and the like can be used. When polypropylene is used as the thermoplastic resin as the incompatible resin used as the filler, it is preferable to combine polyethylene terephthalate as the filler. The details of the support having minute voids (voids) are described in Japanese Patent Application No. 11-290570. The content of the filler such as an inorganic pigment in the support is 2 to 30 by volume.
% Is common.

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

(Image-Receiving Layer) In order to transfer the image-forming layer to the surface of the image-receiving sheet and fix it, it is preferable to provide one or more image-receiving layers on the support. 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., 55% R
Preferably, H is 0.5 to 50 mmHg (≒ 0.0665 to 6.65 kPa), and Ra is preferably 0.05 to 0.4 μm. Micro gaps can be reduced, transfer,
Further, it is preferable in terms of image quality. The Ra value can be measured based on JIS B0601 using a surface roughness measuring device (Surfcom, manufactured by Tokyo Seiki Co., Ltd.) or the like. After the image receiving sheet is charged according to the US Federal Government Test Standard 4046, the charging potential of the image receiving layer 1 second after the image receiving sheet is grounded is preferably -100 to 100 V. It is preferable that the surface resistance of the image receiving layer is 10 ⁹ Ω or less at 23 ° C. and 55% RH. The coefficient of static friction of the surface of the image receiving layer is preferably 0.2 or less. The surface energy of the surface of the image receiving layer is preferably 23 to 35 mg / m ² .

In the case where an image is once formed on the image receiving layer and then 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 less than 0.3 μm, the film strength is insufficient at the time of retransfer to the printing paper, and the film is easily broken. If it is too thick, the gloss of the image after retransfer of the paper increases, and the closeness to the printed matter decreases.

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

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

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

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

The image receiving sheet combined with the thermal transfer sheet may have a structure in which the image receiving layer also serves as a cushion layer. In this case, the image receiving sheet may be a support / cushion 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, on the image receiving sheet, a back layer is provided on the surface of the support opposite to the surface on which the image receiving layer is provided,
Improves the transportability of the image receiving sheet. In the back layer,
It is preferable to add a surfactant, an antistatic agent such as tin oxide fine particles, and a matting agent such as silicon oxide and PMMA particles in terms of improving transportability in the recording apparatus. From the viewpoint of improving transportability, the coefficient of static friction of the back layer is preferably 0.5 or less, particularly preferably 0.4 or less. The surface roughness Rz of the back layer surface is preferably 3 μm or less, more preferably 1 μm or less. 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%.

The binder used in the back layer includes gelatin, polyvinyl alcohol, methylcellulose, nitrocellulose, acetylcellulose, 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 take any one or a 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.

Organic or inorganic fine particles can be used as a matting agent preferably added to the back layer. As an organic matting agent, polymethyl methacrylate (PMM
A), polystyrene, polyethylene, polypropylene,
Other examples include fine particles of a radical polymerizable polymer, and fine particles of a condensation polymer such as polyester and polycarbonate. The back layer is preferably provided with a coverage of about 0.5 to 5 g / m ² . If it is less than 0.5 g / m ² , the coating properties are unstable and problems such as powder dropping of the matting agent are likely to occur.
Further, when the coating is applied more than 5 g / m ² , the particle size of the suitable matting agent becomes very large, and the image receiving layer surface is embossed by the back layer during storage, and especially the thermal transfer for transferring the thin image forming layer. In this case, missing or unevenness of a recorded image is likely to occur. The matting agent preferably has a number average particle size that is larger by 2.5 to 20 μm than the layer thickness of only the binder in the back layer. Among the matting agents, 5 mg / m ² or more of particles having a particle size of 3 μm or more is required, and preferably 6 to 600 mg / m ^2.
a m ^2. This improves, in particular, foreign object failure.
The value σ / r is obtained by dividing the standard deviation of the particle size distribution by the number average particle size.
By using a material having a narrow particle size distribution such that n (= coefficient of variation of the particle size distribution) is 0.3 or less, defects caused by particles having an abnormally large particle size can be improved.
Desired performance can be obtained with a smaller amount of addition. This coefficient of variation is more preferably 0.15 or less.

The back layer includes a flexible plate and a transport row.
Charging to prevent foreign matter from adhering due to frictional charging with the
Preferably, an inhibitor is added. As antistatic agent
Is a cationic surfactant, an anionic surfactant,
Ionic surfactant, polymer antistatic agent, conductive fine particles
And "11290 Chemical Products", Chemical Daily, 87
The compounds described on pages 5 to 876 and the like are widely used.
Antistatic agents that can be used in combination with the back layer include the above substances
Among them, carbon black, zinc oxide, titanium oxide,
Metal oxides such as tin oxide, conductive fine particles such as organic semiconductors
A child is preferably used. In particular, use conductive fine particles
This means that there is no dissociation of the antistatic agent from the back layer,
It is preferable because a stable antistatic effect can be obtained regardless of
No. In the present invention, the surface resistance SR of the back layer is 23 ° C., 5
1 × 10 at 0% RH ¹²Ω or less, more preferably 1
× 10⁹Anti-static agent in various surface active
It is appropriately selected from a conductive agent and a conductive agent. Back layer
By setting SR within the above range, it is possible to prevent foreign matter from adhering.
In both cases, jamming etc. in the transport path is prevented to improve transportability
It can be good.

The back layer may be added with various activators, silicone oils, release agents such as fluororesins, etc. in order to impart coating properties and release properties. The back layer is a cushion layer and a TMA (Thermomechan) of an image receiving layer.
ical analysis) is particularly preferred when the softening point is 70 ° C. or lower.

The TMA softening point is determined by raising the temperature of an object to be measured at a constant rate of temperature increase 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.

[0127]

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.

—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 (Julima ET410, solid content 20% by mass, Nippon Pure Chemical Industries, 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 (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] Biaxially stretched polyethylene terephthalate support having a thickness of 75 μm (both sides) Ra is 0.01μ
m) is subjected to a corona treatment on one side (back side),
After applying the one-layer coating solution so that the dry layer thickness is 0.03 μm
After drying at 180 ° C. for 30 seconds, the first bag layer was formed. The Young's modulus of the support in the longitudinal direction 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). F-5 in the longitudinal direction of the support
The value was 10 kg / mm ² (≒ 98 MPa), and the F-5 value in the support width direction was 13 kg / mm ² (2127.4 MPa).
The heat shrinkage of the support at 100 ° C. for 30 minutes is 0.3% in the longitudinal direction and 0.1% in the width direction. The breaking strength is 20 kg / mm ² (ｇ196 MPa) in the longitudinal direction.
The width direction is 25 kg / mm ² (≒ 245 MPa), and the 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]
After applying the layer coating solution so that the dry layer thickness becomes 0.03 μm, 170
It dried at 30 degreeC for 30 second, and formed the back 2nd layer.

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

[0131]

Embedded image

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

[0133]

Embedded image

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

[0135]

Embedded image

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

Matting agent dispersion ・ N-methyl-2-pyrrolidone (NMP) 69 parts ・ Methyl ethyl ketone 20 parts ・ Styrene acrylic resin 3 parts (“Johncryl 611”, manufactured by Johnson Polymer Co., Ltd.) ・ SiO ₂ particles 8 parts ("Sea Hostar KEP150": silica particles, manufactured by Nippon Shokubai Co., Ltd.)

2) Formation of a light-to-heat conversion layer on the surface of the support The above-mentioned coating solution for a light-to-heat conversion layer was coated on one surface of a polyethylene terephthalate film (support) having a thickness of 75 μm using a wire bar. 120 ° C
After drying in an oven for 2 minutes, a light-to-heat conversion layer was formed 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, the OD 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.

3) Preparation of Coating Solution for Black Image Forming Layer The following components were put into a kneader mill, and pre-dispersion treatment was performed by applying a shearing force while adding a small amount of a solvent. A solvent was further added to the dispersion, and the dispersion was finally adjusted to have the following composition, followed by sand mill dispersion for 2 hours to obtain a pigment dispersion mother liquor. [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 while stirring with a stirrer to prepare a coating solution for a black image forming layer. [Coating liquid 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.) 1.7 parts ・ Rosin 11.4 parts (“KE -311 ", Arakawa (Components: resin acid 80-97%; resin acid component: abietic acid 30-40%, neoabietic acid 10-20%, dihydroabietic acid 14%, tetrahydroabietic acid 14%) Agent 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 Co., Ltd.) 1050 parts of n-propyl alcohol. 295 parts of methyl ethyl ketone. The particles in the obtained coating solution for the black image forming layer were measured using a laser scattering type particle size distribution analyzer. 25 μm, and the ratio of particles having a size of 1 μm or more was 0.5%.

4) Formation of Black Image Forming Layer on Surface of Light-to-Heat Conversion Layer The above-mentioned coating solution for a 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. After drying in an 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 K) in which a light-to-heat conversion layer and a black image forming layer are provided on the support in this order. Similarly, a yellow image forming layer and an image forming layer are also provided. The heat transfer sheet Y, the sheet provided with the magenta image forming layer is referred to as a heat transfer sheet M, and the sheet provided with the cyan image forming layer is referred to as a thermal transfer sheet C). The optical density (optical density: OD) of the black image forming layer of the thermal transfer sheet K was measured using a Macbeth densitometer “TD-90”.
4 "(W filter), OD = 0.9
It was one. 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. Surface smoother value is 0.5-50mmHg at 23 ℃, 55% RH (≒
0.0665-6.65 kPa), specifically 9.3 m
mHg (≒ 1.24 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08.

-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 the coating solution for the yellow 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 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 liquor composition] Yellow pigment composition 1: 7.1 parts of polyvinyl butyral ("S-lec B BL-SH", manufactured by Sekisui Chemical Co., Ltd.) Pigment Yellow 180 (C.I.N.) 12.9 parts (“Novoperm Yellow (Novo Palm Yellow) P-HG”, manufactured by Clariant Japan K.K.) ・ 0.6 parts of dispersing aid (“Solsperse S-20000”, ICI Corporation)・ N-propyl alcohol 79.4 parts [Yellow pigment dispersion mother liquor composition] Yellow pigment composition 2: ・ Polyvinyl butyral 7.1 parts (“ESLEC B BL-SH”, manufactured by Sekisui Chemical Co., Ltd.) ・ Pigment Yellow (Pigment Yellow) 139 (CINO 56298) 12.9 parts ("Novoperm Yellow (Novo Palm Yellow) M2R 70", Clariant Japan K.K.)-0.6 parts of dispersing aid ("Solsperse S-20000", ICI K.K.)-n-propyl alcohol 79.4 Department

[Composition of Yellow Image Forming Layer Coating Solution] 126 parts of the above-mentioned yellow pigment dispersion mother liquor Yellow pigment composition 1: yellow pigment composition 2 = 95: 5 (parts) 4.6 parts of polyvinyl butyral (S-LEC B BL-1 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 acid amide "Diamid O-200", manufactured by Nippon Kasei Co., Ltd.) World Activator 0.4 part ("Chemistat 1100", manufactured by Sanyo Chemical Co., Ltd.) 2.4 parts of rosin ("KE-311", manufactured by Arakawa Chemical Co., Ltd.) (Ingredient: resin acid 80-97%; resin) Acid component: abietic acid 30-40%, neoabietic acid 10-20%, dihydroabietic acid 14%, tetrahydroabietic acid 14%)-Surfactant 0.8 part ("MegaFac F-176PF", solid content 20) %, Manufactured by Dainippon Ink and Chemicals, Inc.)-793 parts of n-propyl alcohol-198 parts of methyl ethyl ketone

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. Surface smoother value is 0.5-50mmHg at 23 ℃, 55% RH (≒
0.0665 to 6.65 kPa), specifically, 2.3 m
mHg (≒ 0.31 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.1.

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

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. Surface smoother value is 0.5-50mmHg at 23 ℃, 55% RH (≒
0.0665 to 6.65 kPa), specifically 3.5 m
mHg (≒ 0.47 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08.

-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 Dispersion Mother Liquid Composition] Cyan Pigment Composition 1: 12.6 parts of polyvinyl butyral ("ESLEC B BL-SH", manufactured by Sekisui Chemical Co., Ltd.)-Pigment Blue 15: 4 (CI. No. 74160) 15.0 parts (“Cyanine Blue (Cyanine Blue) 700-10FG”, manufactured by Toyo Ink Mfg. Co., Ltd.) 0.8 parts of dispersing aid (“PW-36”, Kusumoto Kasei Co., Ltd. 110 parts of n-propyl alcohol [Cyan pigment dispersed mother liquor composition] Cyan pigment composition 2: 12.6 parts of polyvinyl butyral ("ESLEC B BL-SH", manufactured by Sekisui Chemical Co., Ltd.) Pigment Blue ( Pigment Blue) 15 (CI No. 74 160) 15.0 parts ("Lionol Blue" Chromatography) 7027 ", Toyo Ink Manufacturing Co., Ltd.) Dispersion aid 0.8 parts (" PW-36 ", manufactured by Kusumoto Kasei Co.), n-propyl alcohol 110 parts

[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 (Eslek B BL- SH, manufactured by Sekisui Chemical Co., Ltd.) 1.3 parts of inorganic pigment "MEK-ST" 1.0 parts of wax-based compound (stearic acid amide "Neutron 2" manufactured by Nippon Seika Co., Ltd.) 1.0 part (lauric amide "Diamid Y", manufactured by Nippon Kasei Co., Ltd.) 1.0 part (palmitic acid amide "Diamind KP", manufactured by Nippon Kasei Co., Ltd.) Nippon Kasei Co., Ltd.) 1.0 part (erucamide "Diamid L-200" (Nippon Kasei Co., Ltd.) 1.0 part (oleic amide "Diamid O-200", Nippon Kasei Co., Ltd.) )) 1.0 part ・ Rosin 2.8 parts (“KE-311”, manufactured by Arakawa Chemical Co., Ltd.) (Component: resin acid 80 to 97%; resin acid component: abietic acid 30 to 40%, neoavietin) Acids 10 to 20%, dihydroabietic acid 14%, tetrahydroabietic acid 14%) 1.7 parts of pentaerythritol tetraacrylate ("NK ester A-TMMT", manufactured by Shin-Nakamura Chemical Co., Ltd.) Surfactant 1. 7 parts (“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. Surface smoother value is 0.5-50mmHg at 23 ℃, 55% RH (≒
0.0665 to 6.65 kPa) is preferable, and specifically, 7.0 m
mHg (≒ 0.93 kPa). The coefficient of static friction of the surface is preferably 0.2 or less, specifically 0.08.

-Preparation of Image Receiving Sheet- 1) Formation of Back Layer Transparent polyethylene terephthalate (P) having a thickness of 100 μm
ET) A back layer was formed on one surface (back surface) of the support with the same formulation as the back layer of the thermal transfer sheet. However, three types of back layer coating liquids according to Table 1 below were prepared.

[0153]

[Table 1]

A coating solution for a cushion layer and a coating solution for an image receiving layer having the following compositions were prepared. 2) Cushion layer coating liquid-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

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

The above-mentioned coating solution for forming a cushion layer is applied to the surface of the support opposite to the back layer using a small-width coating machine, the coating layer is dried, and then the coating solution for an image receiving layer is applied. And dried. The coating amount was adjusted such that the layer thickness of the cushion layer after drying was about 20 μm and the layer thickness of the image receiving layer was about 2 μm.
The physical properties of the obtained image receiving layer were as follows. Surface roughness
Ra is preferably 0.4 to 0.01 μm, specifically 0.02 μm.
m. The undulation on the surface of the image receiving layer was preferably 2 μm or less, specifically 1.2 μm. The smoother value of the surface of the image receiving layer is 0.5 to 50 mmHg (≒ 0.06
65 to 6.65 kPa), 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.

-Formation of Transfer Image- A flexible plate is mounted on a rotating drum having a diameter of 38 cm in which a vacuum section hole having a diameter of 1 mm (one surface density is provided in an area of 3 cm x 8 cm) is provided. The above-prepared image receiving sheet (56 cm × 79 cm) was wrapped around and vacuum-adsorbed. Next, the thermal transfer sheet K (black) cut into a size of 61 cm × 84 cm was overlapped so as to evenly protrude 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 with the section hole closed is -150 mmHg (≒
81.13 kPa). Rotate the drum,
Wavelength 808 nm from outside on the surface of the laminate on the drum
The semiconductor laser 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 a direction perpendicular to the rotation direction (main scanning direction) of the rotating drum (sub-scanning) to form a laminate. Laser image (image) recording was performed. 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 23 ° C. 50% The diameter of the exposure drum is preferably 360 mm or more, and specifically, the one having 380 mm was used. The image size is 5
The size is 15 mm × 728 mm, and the resolution is 2600 dpi.

When the laminate on which the laser recording was completed was removed from the drum and the thermal transfer sheet K was peeled off from the image receiving sheet by hand, only the light-irradiated area of the image forming layer of the thermal transfer sheet K received the image from the thermal transfer sheet K. Transferring to the sheet was confirmed. In the same manner as described above, the thermal transfer sheet Y, thermal transfer sheet M, and thermal transfer sheet C
From each of the thermal transfer sheets, an image was transferred onto an image receiving sheet.

The transferred images obtained in this example are Example 1 and Comparative Examples 1 to 5 shown in Table 2 below.

[0160]

[Table 2]

The following evaluation was performed on the obtained transferred image. Table 3 shows the evaluation results. 1) Image defects due to foreign matter Image defects per 1 m ² were visually counted and evaluated. ：: The number of image defects is 1 or less Δ: The number of image defects is 2 to 10 ×: The number of image defects is 11 or more 2) Resolution: An image having 2,98% halftone dots is recorded and a desired halftone dot is recorded.点: Reproduce dot images (both 2, 98%) ×: Do not reproduce (either 2, 98% do not reproduce) 3) Conveyance of image receiving sheet When 30 continuous transfer images are recorded, The occurrence of jamming was examined when the image receiving sheet was discharged. ○: No jamming occurred ×: Jamming occurred

[0162]

[Table 3]

According to the recording method of the present invention, it can be seen that the image receiving sheet can be stably conveyed, the number of image defects considered to be caused by the attachment of foreign matter such as dust and dirt is extremely small, and an image having excellent resolution can be obtained. Considering that the evaluation results of image defects are Δ in Comparative Examples 1-4, by providing a conductive flexible plate or suppressing the surface resistance of the back layer of the image receiving sheet, a certain amount of foreign matter adheres. Although it can be prevented, it can be said that a sufficient effect can be obtained only by combining both.

[0164]

According to the present invention, the image receiving sheet can be stably conveyed without causing jamming or the like, and an image defect caused by the attachment of dust or other foreign matter due to charging of the flexible plate or the like. It is possible to provide a laser thermal transfer recording method capable of recording an image of good image quality without the like. In addition, we can provide proofs and contract proofs that can replace analog color proofs in response to filmlessness in the CTP era. This proof has color reproducibility that matches prints and analog color proofs for customer approval. 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 provide a large-size (A2 / B2) digital direct color proof system that can transfer to a real paper, uses the same pigment-based coloring material as the printing ink, and has high print similarity. The present invention
This is a system in which actual halftone dot recording is performed by using the thin film thermal transfer system, using a pigment colorant, and transferring to a real paper. Under different temperature and humidity conditions, even when laser recording is performed with high energy using a multi-beam two-dimensional laser beam,
It is possible to provide a multicolor image forming method capable of forming an image having good image quality and a stable transfer density on an image receiving sheet.

[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 perspective view of a peripheral portion of a recording drum of the recording apparatus shown in FIG.

FIG. 4 is a perspective view of a recording drum peripheral portion where a flexible plate is mounted on the recording drum.

FIG. 5 is a side view showing a fixing / releasing mechanism of a flexible plate.

FIG. 6 is a perspective view of a peripheral portion of a recording drum of a conventional recording apparatus.

FIG. 7 is a main part configuration diagram of another embodiment of the recording apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording device 2 Recording head 3 Sub scanning rail 4 Recording drum 5 Thermal transfer sheet loading unit 6 Image receiving sheet roll 7 Conveyance roller 8 Squeeze roller 9 Cutter 10 Thermal transfer sheet 10K, 10C, 10M, 10Y Thermal transfer sheet roll 12 Support body 13 Frame 14 Light heat Conversion layer 15 Recording medium 16 Image forming layer 20 Image receiving sheet 22 Image receiving sheet support 23 Flexible plate 24 Image receiving layer 25 Fixing / releasing clamp 25a Front end fixing portion 25b Rear end fixing portion 29 Adhesive roller 30 Laminated body 31 Discharge stand 32 Waste port 33 Discharge port 34 Air 35 Waste box 36 Intake pipe 40 Recording unit 41 Light source 42, 43 First and second lenses 44 Polygon mirror 45 fθ lens 46 Start-up mirror 47 Recording medium fixing member 48 Flexible plate Lb Laser light

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C065 AF01 CA03 CA07 CA13 2H111 AA15 AA35 CA05 CA33 CA41 CA46

Claims (6)

[Claims] 1. An image receiving sheet is supplied onto a flexible plate mounted on a recording medium fixing member having a suction hole, and the image receiving sheet is placed such that an image receiving layer of the image receiving sheet and an image forming layer of the thermal transfer sheet face each other. In a laser thermal transfer recording method of superposing and holding the thermal transfer sheet on a sheet and recording image data by irradiating a laser beam corresponding to image information from a support side of the thermal transfer sheet, the flexible plate may be made of a conductive material. And the surface electric resistance SR of the back layer of the image receiving sheet is 1 × 1 at 23 ° C./50% RH.
A laser thermal transfer recording method characterized by being at most 0 ¹² Ω. 2. The laser thermal transfer recording method according to claim 1, wherein the static friction coefficient of the back layer surface of the image receiving sheet is 0.5 or less. 3. The laser thermal transfer recording method according to claim 1, wherein the surface roughness Rz of the back layer surface of the image receiving sheet is 3 μm or less. 4. The laser thermal transfer recording method according to claim 1, wherein the material of said conductive flexible plate is metallic. 5. A material according to claim 1, wherein said conductive flexible plate is made of a plastic material.
The laser thermal transfer recording method according to any one of the above. 6. A conductive flexible plate is mounted on a recording medium fixing member having a suction hole, and a recording medium is supplied onto the flexible plate and irradiated with a laser beam according to image information. An image receiving sheet used in a laser thermal transfer recording apparatus for recording image data, wherein a surface electric resistance SR of a back layer of the image receiving sheet is 1 × 10 ¹² Ω or less at 23 ° C./50% RH. Sheet.