JPH1178256A - Sublimation type thermal transfer material and sublimation type thermal transfer recording method using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sublimation type thermal transfer material prevented from the generation of wrinkles or the generation of the fusion or sticking with an image receiving sheet even when reheating treatment is performed by an n-time mode method in a thermal transfer material provided with a region containing a colorant and a region containing no colorant. SOLUTION: In a sublimation type thermal transfer material wherein a region (A) composed of a layer containing a colorant and a region (B) containing no colorant are provided on a substrate, the difference between the coefficient of dynamic friction to the image receiving sheet of the region (A) and that to the image receiving sheet of the region (B) is set to 0.25 or less. Or, the thickness difference between both of them is set to 3 μm or less or the surface roughness difference between both of them is set to 0.06 μm (Ra) or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer member used for a printer or the like employing a sublimation type thermal transfer method and a thermal transfer recording method using the same.

[0002]

2. Description of the Related Art In recent years, demand for full-color printers has been increasing year by year. As a recording method of the full-color printer, there are an electrophotographic method, an ink jet method, a thermal transfer method, and the like. Among these, the thermal transfer method is often used because of easy maintenance and no noise.

In the thermal transfer method, a colorant is dispersed on a substrate in a hot-melt substance or a heat-transferable dye (sublimable dye) is used.
Is placed on a colorant layer surface of a thermal transfer body (sometimes referred to as an “ink sheet”) having a colorant layer in which is dispersed in a resin binder, and is placed on the recording medium (thermal transfer body) side. This is a recording method in which thermal energy controlled by an electric signal from a laser beam or a thermal head or the like is applied, and the colorant in that portion is thermally melt-transferred or heat-transferred onto an image receiving sheet to form an image.

[0004] The thermal transfer recording method is roughly classified into a heat melting type and a heat transfer type (sublimation type) as described above, depending on the type of recording medium to be used. Since the dye is transferred to the image receiving sheet in a monomolecular state in response to heat energy from a thermal head or the like, it has an advantage that a halftone can be easily obtained, and is considered to be a method most suitable for a full-color printer.

However, unlike the electrophotographic method and the ink-jet method, the heat transfer type thermal transfer recording method requires an auxiliary member such as a base material in addition to a colorant directly contributing to image formation. However, even if unused portions remain after performing selective thermal printing, the unused portions are collected and discarded without being reused, so that the running cost is high.

In recent years, instead of using one ink sheet repeatedly for printing many times, the speed of the image receiving sheet is set to n times (n times) the speed of the ink sheet.
An n-fold mode method has been proposed in which the printing is repeatedly performed while both sheets are running in the condition of > 1). In the n-times mode method, printing is performed a number of times by a relative speed method in which the overlap with the used portion of the previous color material layer is slightly shifted, and the larger the value of n, the more advantageous in cost. is there.

As an ink sheet for multiple recordings, there is an ink sheet having two colorant layers in which a colorant layer is functionally separated into a dye supply layer and a dye transfer contributing layer. On the other hand, in the sublimation type thermal transfer recording by the usual one-time method, various improvements are made for the purpose of improving the durability of the image, in which, after printing, the dye is further deepened by reheating the image. There are a method of pressing in, a method of further laminating a protective layer on an image, and the like.

Here, the reheating process is a process for heating the formed image again, and is carried out by leaving the printer from the printing section and passing it through a heat press or a heat roll, or using a thermal head in the printing section. It can be carried out. When using a thermal head, there are cases where the thermal head is brought into direct contact with the image and heating, and cases where heating is carried out via a film. It is preferable from the point of view.

However, when the above-mentioned reheating process is to be performed on an image formed by the n-times mode method, the ink sheet is formed by forming the respective colorant layers of Y, M, and C in a plane-sequential manner. If the reheating region is formed in a plane sequence, the reheating process can be performed using the energy applied to the thermal head (without using another device). Here, the region of the colorant layer is called (A), and the region used for reheating is called (B).

In the case of lamination, a laminate film having an area equal to that of an image is required. In the case of reheating, a region (B) containing no dye is sufficient.
If the reheating is performed by the double mode method, the area of the region (B) can be 1 / n of the image as in the case of the region (A).

However, if the blank area (B) is simply provided after the area (A), the heat resistance of (A) and (B) cannot be obtained.
Since areas having different properties such as adhesion, friction, and shrinkage are continuously formed, after the image forming process in (A),
If heating is attempted using the same thermal head in the reheating step in (B), wrinkles are likely to be formed in the ink sheet in the reheating step in (B), or fusion or sticking to the image receiving sheet may occur. There has been a problem that the running speed (1: n) of the ink sheet and the image receiving sheet becomes unstable.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has high durability even when the image is reheated by the n-fold mode method. It is an object of the present invention to provide a sublimation-type thermal transfer member free from occurrence of an abnormal image, a conveyance failure, and the like.

[0013]

According to the present invention, first, sublimation in which a region (A) composed of a layer containing a colorant and a region (B) composed of a layer not containing a colorant are provided on a substrate. A sublimation type thermal transfer member, wherein a difference between a dynamic friction coefficient of the region (A) with respect to the image receiving sheet and a dynamic friction coefficient of the region (B) with respect to the image receiving sheet is 0.25 or less. .

Second, in a sublimation type thermal transfer member having a region (A) composed of a layer containing a colorant and a region (B) composed of a layer not containing a colorant on a substrate, the thickness of the region (A) is reduced. And a difference in thickness between the first and second regions (B) is 3 μm or less.

Third, in a sublimation-type thermal transfer member provided with a region (A) composed of a layer containing a colorant and a region (B) composed of a layer not containing a colorant on a substrate, the surface of the region (A) is provided. A sublimation type thermal transfer member is provided, wherein the difference between the roughness and the surface roughness of the region (B) is 0.06 μm (Ra) or less.

Fourth, in the sublimation-type thermal transfer member according to any one of the first to third aspects, the region (A) comprises two or more layers including a layer containing a colorant, and the region (B) )), A sublimation-type thermal transfer member is provided in which layers other than the layer containing the colorant in the region (A) are laminated in the same order as in the region (A).

Fifth, in the sublimation-type thermal transfer member according to any one of the first to third aspects, the region (B) is
(A) provides a sublimation-type thermal transfer member having at least one layer that is not laminated.

Sixth, in the sublimation-type thermal transfer member according to any one of the first to third aspects, the region (B) includes at least a layer containing pigment particles which is not transferred to an image receiving sheet by heat. A sublimation-type thermal transfer member having one layer is provided.

Seventh, in the sublimation-type thermal transfer member according to any one of the first to third aspects, the region (A) and the region (B) are repeatedly formed in a plane-sequential manner. Is provided.

Eighth, using the sublimation-type thermal transfer member and the image receiving sheet described in any one of the first to third aspects,
The image is formed in (A), and the second formed image is
(B) A sublimation type thermal transfer recording method characterized by reheating is provided.

Hereinafter, the present invention will be described in detail. As described above, the present invention relates to a thermal transfer body having a colorant-containing layer (colorant layer) on a substrate, the thermal transfer body having a colorant-free reheat-treating region in a surface-sequential manner with the colorant layer. is there. Describing with reference to FIG. 1, FIG. 1- (1) shows a plane of the ink sheet, and a region (A) composed of a layer containing a colorant and a region (B) composed of a layer not containing a colorant. Are formed face-sequentially. FIG. 1- (2) is a sectional view corresponding to FIG. 1- (1).

First, the region (A) will be described. As the colorant layer according to the present invention, a conventionally known colorant layer can be used, and a single layer structure of a colorant layer containing a sublimable dye and a binder, or a dye supply layer and a transfer contributing layer are sequentially laminated from the substrate side. Configurations are included.

The sublimable dye used in the colorant layer includes:
It is a dye that sublimates or vaporizes at 60 ° C. or higher, and may be any dye used in thermal transfer printing, such as a disperse dye or an oil-soluble dye. I. Disperse Yellow 1,3,8,9,16,41,54,60,77,11
6, C.I. I. Disperse Red 1,4,6,1
1, 15, 17, 55, 59, 60, 73, 83, etc.
C. I. Disperse Blue 3,14,19,26,
C. 56, 60, 64, 72, 99, 108; I.
Solvent Red 23, 25, 27, C.I. I. Solvent Blue 36, 83, 105 and the like. These dyes can be used singly, but a mixture of several kinds can also be used.

As the binder used for the colorant layer, a thermoplastic resin or a thermosetting resin is used. Among the resins having a relatively high glass transition point or high softening property, for example, vinyl chloride resin, acetic acid Vinyl resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, epoxy resin, silicone resin, fluororesin, butyral resin, melamine resin, natural rubber,
Examples include synthetic rubber, polyvinyl alcohol, and cellulose resin. These resins can be used singly, but several kinds may be mixed or a copolymer may be used.

The thickness of the colorant layer is 0.5 to 10 μm, preferably 3 to 7 μm.

For multiple recordings, a laminated structure of a dye supply layer, a dye transfer contributing layer, and a surface layer (low dyeing layer) is preferred in order from the substrate side. The dye supply layer is preferably a layer in which the dye is dispersed in the resin in the form of particles, and the thickness is 2 to 7 μm.
m, the dye / resin ratio (weight) is preferably 2 to 4. The dye transfer contributing layer is preferably formed by coating a resin layer on the dye supply layer, and has a thickness of 0.2 to 2 μm, and the resin is preferably the same or a cross-linked reactant of the same resin as the dye supply layer. . The low dyeing layer is preferably formed by coating a resin layer on the dye transfer contributing layer, and has a thickness of 0.1 to 0.6 μm, and the resin is preferably an acrylic resin, a silicone resin, or the like. And known additives such as release agents, surfactants, particles, and antistatic agents.

Next, as a substrate, a film such as a condenser paper, a polyester film, a polystyrene film, a polysulfone film, a polyimide film, a polyaramid film, etc. is used. An adhesive layer (also referred to as an intermediate adhesive layer) or the like may be provided, and a conventional heat-resistant lubricating layer (also referred to as a heat-resistant layer) may be provided on the back side of the substrate.

Next, the region (B) of the present invention will be described. The substrate and the back surface of the ink sheet are common to the region (A). It is preferable to form a pseudo colorant layer containing no colorant to be transferred in a portion corresponding to the colorant layer. The pseudo colorant layer preferably has the same coefficient of dynamic friction during heating, the same thickness, and the same surface roughness as the colorant layer in the region (A).

The kinetic friction coefficient during heating was measured by a prototype measuring device. The measuring device acts on a normal thermal transfer printer, and operates on the ink sheet, the image receiving sheet, and the thermal head for measuring the coefficient of friction, and a drive control unit for separately varying the transport speed of the image receiving sheet. It has a configuration in which a measuring unit for measuring the tension to be applied is added. The coefficient of kinetic friction during printing tends to increase according to the applied energy.If the coefficient exceeds the limit value, the fusion of the ink sheet and the image receiving sheet occurs and the transport speed cannot be controlled. This is the characteristic.

If the difference in the friction coefficient between the area (A) and the area (B) is large, it is necessary to use the apparatus under different transport conditions and application conditions during image formation and during reheating. For example, the tension of the ink sheet take-up drive unit, the tension of the supply drive unit, the sheet conveyance speed, the head voltage, the head pressure, and the like must be set to different values between when forming an image and when reheating. ,
Since the control becomes too complicated for the printer to handle, it is preferable that the characteristics of the area (A) and the area (B) are equal in terms of printer control.

In a normal one-time ink sheet, since the colorant layer is as thin as 1 to 2 μm, regions having different thicknesses are not formed in a plane-sequential manner. Since the pseudo colorant layer is not formed in the region (B) because of the thickness of about 7 μm, a film thickness difference corresponding to the thickness of the colorant layer in the region (A) occurs. For this reason, when the difference in film thickness is large, problems such as peeling of the colorant layer when the thermal head comes into contact with the edge portion of the colorant layer and fusion of the ink sheet and the image receiving sheet are likely to occur.

The material for forming the pseudo colorant layer is not particularly limited as long as it is a material capable of forming an equivalent thickness in addition to the same resin as the colorant layer. , Polycarbonate resin, acrylic resin, urethane resin, butyral resin and the like are preferable.

In order to make the surface of the pseudo colorant layer the same surface roughness as that of the colorant layer, a method of adding particles, a method of containing two or more resins, and a combination of a solvent and a low molecular additive are used. There are methods. Normally, the printer conditions are optimally set according to the surface condition of the colorant layer. Therefore, when the area (B) is smoother than the area (A), fusion or conveyance failure is likely to occur, and conversely, When the size is large, there are problems such as scratching the image. As the particles to be added, known inorganic pigments and organic pigments can be used, and the particle size is 0.1 to 1.0.
μm is preferred.

As described above, a layer that is not provided in the region (A) is provided in the region (B), and the difference in the dynamic friction coefficient, the film thickness, and the surface roughness from the region (A) can be eliminated.

[0035]

The present invention will be described more specifically with reference to the following examples. In addition, the amount (part) of each component in the following description is part by weight.

Example 1 << Preparation of Ink Sheet >> A dye supply layer was formed on an aromatic polyamide film having a thickness of about 6 μm having a silicone resin-based heat-resistant layer having a thickness of about 1 μm on the rear surface by using a screen printing machine according to the following formulation. Liquid (layer thickness after drying: about 6.0 μm) and pseudo-colorant layer forming liquid (layer thickness after drying: about 4.0 μm)
A 25 mm surface of each color was formed in the order of M, C, and pseudo colorant layer. <Dye supply layer forming liquid> Polyvinyl butyral resin (trade name: BX1 / manufactured by Sekisui Chemical Co., Ltd.) 7.5 parts Sublimable dye 22.5 parts Here, the following sublimable dye was used for each color transfer member. . For yellow: Yellow VP (manufactured by Mitsui Toatsu Dye Co., Ltd.) For magenta: Magentanta VP (manufactured by Mitsui Toatsu Dye Co., Ltd.) For cyan: Cyan VP (manufactured by Mitsui Tosho Dye Co., Ltd.) n-hexanol: 70 parts <Pseudo-colorant layer forming liquid>> 10 parts of polyvinyl butyral (BX1) 90 parts of n-hexanol Then, a dye transfer contributing layer forming liquid and a surface layer forming liquid having the following formulation were added to the above-mentioned colorant layer using a wire bar.
Coating was performed to a thickness of 6 μm to produce a sublimation type thermal transfer member. <Dye transfer contributing layer forming liquid> Polyvinyl butyral (BX1) 10 parts Diisocyanate (manufactured by Takeda Pharmaceutical Company: TDH703) 5 parts Ethyl alcohol 95 parts Butyl alcohol 95 parts <Surface layer forming liquid> Acrylic-silicone copolymer (LDL615 / Natco) Paint) 45 parts Silicone cross-linking agent (HC400 / Natco Vint) 6 parts Isopropyl alcohol 15 parts

<< Preparation of Image Receiving Sheet >> On a synthetic paper having a thickness of about 150 μm (Yupo FP-150 manufactured by Oji Yuka Synthetic Paper Co., Ltd.), a coating solution for a receiving layer and a surface layer having the following compositions were sequentially applied. Then, it was stored and cured at 60 ° C. for 24 hours to prepare a test image receiving sheet. <Liquid for Forming Receptive Layer> Vinyl chloride = vinyl acetate = vinyl alcohol copolymer (Denka Vinyl # 1000GKT / Denki Kagaku Kogyo) 9.38 parts Isocyanate (D140N / Takeda Pharmaceutical) 3.2 parts Toluene 21.4 Part Methyl ethyl ketone 64.3 parts <Surface layer forming liquid> Silicone resin (SR2411 / Toray Silicone Co., Ltd.) 18.5 parts Silicone oil (SF8427 / Toray Silicone Co., Ltd.) 0.37 part Isopropyl alcohol 81.5 parts

Comparative Example 1 Example 1 except that the pseudo colorant layer of the ink sheet was not formed.
In the same manner as in the above, a sublimation-type thermal transfer member was produced.

Example 2 A sublimation type thermal transfer member was prepared in the same manner as in Example 1 except that the thickness of the pseudo colorant layer of the ink sheet was changed to 6 μm.

Comparative Example 2 A sublimation-type thermal transfer member was produced in the same manner as in Example 1 except that the thickness of the pseudo colorant layer of the ink sheet was changed to 2 μm.

Example 3 A sublimation type thermal transfer member was produced in the same manner as in Example 1 except that the liquid for forming a pseudo colorant layer of an ink sheet was changed as follows. <Pseudo-colorant layer forming solution> Polyvinyl butyral (BX1) 10 parts Silicone filler (Tospearl 108 / manufactured by Toshiba Silicone Co., Ltd.) 5 parts n-hexanol 90 parts

<< Evaluation >> The evaluation was performed as follows for the purpose of comparing the performance of the anti-fusing and sticking properties during the reheating treatment. By changing the speed ratio between the thermal transfer member and the image receiving sheet under the following conditions, printing of three colors of YMC and reheating treatment in the area (B) were performed, and the ability to prevent fusion and sticking was visually evaluated. Table 1 shows a difference in thickness, a difference in surface roughness, and a difference in dynamic friction coefficient between the region (A) and the region (B) of each thermal transfer member. Table 2 shows the results of the fusion evaluation at the time of reheating. (Printing conditions) Thermal head resolution 12 dots / mm Applied power 0.16 W / dot (Feeding speed during recording) 3 times speed: image receiving sheet 8.4 mm / sec Ink sheet 2.8 mm / sec 7 times speed: image receiving sheet 8.4 mm / Sec Ink sheet 1.2 mm / sec 10 times speed: Image receiving sheet 8.4 mm / sec Ink sheet 0.84 mm / sec 15 times speed: Image receiving sheet 8.4 mm / sec Ink sheet 0.56 mm / sec

[0043]

[Table 1] Thickness of region (A): 13.8 μm Surface roughness of region (A): 0.19 μm (Ra) Dynamic friction coefficient of region (A): 0.20 (n = 15, highest image density portion)

[0044]

[Table 2]

[0045]

As described above, in the sublimation type thermal transfer body having the region (A) composed of the layer containing the colorant for forming an image on the substrate and the region (B) composed of the layer not containing the colorant,
By making the dynamic friction coefficient, the thickness or the surface roughness during printing of the area (A) and the area (B) equal, the image formation in the area (A) and the reheating processing in the area (B) are the same. Machine conditions (head pressure, winding tension, supply tension,
(Transport speed) and applied energy conditions (head type, head voltage, pulse time, correction conditions).
In addition, both the image formation in the area (A) and the reheating in the area (B) can be printed in green by a large number of recordings by the speed difference mode method.

[Brief description of the drawings]

FIG. 1 is a plan view of an ink sheet according to the present invention (FIG. 1);
1) and a corresponding cross section (FIG. 1-2), all of which are schematic views.

[Explanation of symbols]

 Reference Signs List 1 colorant layer 2 substrate 3 back layer 4 pseudo colorant layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shingo Suzuki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Chiharu Nogawa 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Hideo Sakurai 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd.

Claims (8)

[Claims] 1. A sublimation-type thermal transfer member having a substrate and a region (A) comprising a layer containing a colorant and a region (B) comprising a layer not containing a colorant, wherein the region (A) corresponds to the image receiving sheet. A sublimation type thermal transfer member, wherein a difference between a coefficient of dynamic friction and a coefficient of dynamic friction with respect to the image receiving sheet in the region (B) is 0.25 or less. 2. In a sublimation-type thermal transfer member having a region (A) composed of a layer containing a colorant and a region (B) composed of a layer not containing a colorant on a substrate, the thickness of the region (A) A sublimation-type thermal transfer member, wherein the difference in the thickness of the region (B) is 3 μm or less. 3. In a sublimation-type thermal transfer member provided with a region (A) composed of a layer containing a colorant and a region (B) composed of a layer not containing a colorant on a substrate, the surface roughness of the region (A) is reduced. A sublimation-type thermal transfer member, wherein a difference in surface roughness of the region (B) is not more than 0.06 μm (Ra). 4. The sublimation-type thermal transfer member according to claim 1, wherein the region (A) is composed of two or more layers including a layer containing a colorant, and the region (B) A sublimation-type thermal transfer body, wherein layers other than the layer containing the colorant in the region (A) are laminated in the same order as in the region (A). 5. The sublimation-type thermal transfer member according to claim 1, wherein the region (B) has at least one layer that is not laminated on the region (A). Mold heat transfer body. 6. The sublimation type thermal transfer member according to claim 1, wherein the region (B) has at least one layer containing pigment particles that are not transferred to an image receiving sheet by heat. A sublimation type thermal transfer member characterized by the following. 7. The sublimation-type thermal transfer body according to claim 1, wherein the area (A) and the area (B) are repeatedly formed in a plane-sequential manner. body. 8. An image is first formed in the area (A) using the sublimation-type thermal transfer body and the image receiving sheet according to claim 1, and the second formed image is formed in the area (A). A sublimation type thermal transfer recording method, wherein reheating is performed in B).