JPH02233295A - Sublimation type thermal transfer recording method - Google Patents

Abstract

PURPOSE:To prevent the color turbidity and ghost due to reverse transfer from an image receiving layer to an ink layer by forming a thin transparent layer to the dye receiving layer of an image receiving body after each color recording. CONSTITUTION:As the thin transparent layer 5 formed on the dye receiving surface of an image receiving body 1, a transparent resin film having good dyeability is pref. and a vinyl chloride/vinyl acetate copolymer film and a polyester resin film are especially pref. The thin transparent layer 5 is formed according to a method wherein a thin transparent layer forming solution prepared by mixing a release agent such as silicone oil with a resin having good dyeability if necessary is applied to a proper substrate composed of polyester or the like at first to form a thin transparent layer forming member which is, in turn, superposed on the image receiving body having a transfer image so as to bring the thin transparent layer into contact therewith to be heated by a hot roller while thermally fused to the image while the thin transparent layer is released from the substrate or a method wherein an aqueous emulsion of the aforementioned resin having good dyeability is applied or sprayed to the surface of the image to form the thin transparent layer.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a sublimation thermal transfer recording method.

[Prior art]

The sublimation type thermal transfer recording method can obtain a full-color image on a dye molecule basis comparable to silver salt, but it requires four recording sheets of yellow, magenta, cyan, and black to obtain one full-color image.

In this method, because of the diffusion transfer of dye molecules,
When printing the next color, the previous dye that has been transferred to the image-receiving paper is reversely transferred from the image-receiving layer to the ink layer (4th Non-Impact Printing Ink Technology Symposium Proceedings 2-6).

In this way, when a full-color image is formed using a recording sheet that can be used many times, there is no problem with the image on the jth sheet, but on the second and subsequent sheets, the original color tone is changed due to the dye of a different tone mixed into the ink layer due to retransfer. It has been reported that there is a drawback that the image is distorted due to slight deviation from the image.

That is, the thermal transfer recording method using a sublimable dye involves thermal diffusion of the sublimable dye from an ink layer to an image-receiving layer, and both are brought into close contact by the pressing force between a thermal head and a platen roller.

During full color formation, when forming secondary and tertiary colors, the dye that was previously transferred to the image-receiving layer returns from the image-receiving layer to the ink layer when forming the secondary and tertiary colors (this is reversed). (called photo). If the ink layer containing this reverse-transferred dye is used for one-time use, it will be discarded and no problem will occur. However, if the ink layer is used many times, it will be transferred to the image-receiving layer during the next recording, causing color turbidity and Gose 1- of the picture pattern is closed and the next recording is adversely affected. This adverse effect can be visually reduced by changing the color recording order, but the effect is insufficient.

In the technology disclosed in JP-A-61-293891, etc., each color is formed on a separate transparent image-receiving layer, and full colors are formed by overlapping them, so reverse transfer does not occur, but unlike the conventional technology, special Since an image receiving paper (layer) is required and three sheets of image receiving paper are used to form a full color image, the entire image receiving paper is thick and the cost is 1.

Furthermore, when three images are stacked, there is a risk that the image will become blurred due to slight positional deviation of /h, resulting in image deterioration.

〔the purpose〕

The present invention overcomes the conventional drawbacks, prevents color turbidity, ghosting, etc. due to reverse transfer of sublimable dye of a different color from the image receiving layer to the ink layer, and allows good images to be received in the same manner as in the conventional one-time image receiving layer. The purpose of the present invention is to provide a sublimation type thermal transfer recording method for forming on paper.

〔composition〕

As a result of intensive research to achieve the above object, the inventors of the present invention have sequentially installed an image receptor and a sublimation type thermal transfer recording medium that separately supports sublimable dyes of each full color on the dye-receiving surface of the image receptor. Dye sublimation thermal transfer, in which the dye-bearing surfaces of the transfer recording medium are stacked so that they are facing each other, and a thermal energy key is applied from at least one side to transfer the dye of the transfer recording medium to the dye-receiving surface of the image receptor to record a full-color image. It has been found that the above object can be achieved by providing a sublimation thermal transfer recording method, which is characterized in that a transparent thin layer is formed on the dye-receiving surface of the image receptor after each color recording.

Reverse transfer is when sublimation dye on the receiving surface of a recording medium, which cannot be diffused into the receiving layer and is attached to the surface, is used when forming secondary and tertiary colors. This is thought to occur because some of the dye on the receiving surface returns to the ink layer due to the softening of the binder material in the receiving layer and ink layer during heating.

Therefore, the separation layer between the dye and the ink layer on the receiving surface after forming each color for preventing reverse transfer may be a thin layer as long as it prevents direct contact between the two.

FIG. 1 is an explanatory diagram showing one embodiment of the thermal transfer recording method of the present invention. Here, 1 is an image receptor, and any recording material that has dyeability may be used. 2 is a platen roller, 3
4 is a thermal transfer recording medium, 4 is a thermal head, 5 is a transparent thin layer, 6 is a heat roller, and 7 is a transferred image.

The transparent thin layer 5 is preferably a transparent resin film with good dyeability, such as polyester, polycarbonate, polysulfone, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, vinyl chloride/vinyl acetate, etc. Examples include films of polymers, polyamides, polyurethanes, styrene/acrylic copolymers, etc., and vinyl chloride/vinyl acetate copolymer resins and polyester resin films are particularly preferred.

The transparent thin layer 5 can be formed by the following methods.

(i) First, on a suitable known substrate such as polyester,
A transparent thin layer forming liquid obtained by mixing a resin with good dyeability as described above with a release agent such as silicone oil as necessary is applied to prepare a member for forming a transparent thin layer. next,
As shown in Fig. 1, the transparent thin layer is placed on the image receptor having the transferred image so that it is in contact with the image receiving body, and the transparent thin layer is peeled off from the substrate while being heated with a heat roller (or thermal head), etc., and the image is transferred. or (ii) a method of forming a water-based emulsion from the above-mentioned resin with good dyeability and coating or spray coating it on the image surface to form a transparent thin layer.

As described in Japanese Patent Application No. 62-280434, the sublimation type heat-sensitive transfer recording medium 4 for multi-time recording used in the present invention has an ink layer that functions as a dye transfer contributing layer (a layer that contributes to image formation). Laminated type type with functionally separated dye supply layer (layer that supplies dye to contributing layer) and patent application 1986-
A single layer type formed by dispersing particulate dye as described in US Pat. No. 3,169,979 can be used.

Printing and recording methods include a constant speed mode method in which printing is repeated while the ink sheet 1 and the image receiving sheet are running at a constant speed, and a method in which the speed of the image receiving sheet is increased by n times the speed of the ink sheet (
There are two methods including an n-fold mode method in which printing is performed repeatedly with both seams 1 running with n > 1). The latter n-fold mode method uses a relative speed method that gradually shifts the overlap between the part of the ink layer used in the previous time and the part used in the next time.
This type of printing is performed multiple times using the -type.

That is, the ink layer of the sublimation type thermal transfer recording medium used in the present invention includes, in order from the substrate side, a dye supply layer consisting of at least an undissolved particulate sublimable dye and an organic binder, and a dye supply layer consisting of at least an undissolved particulate sublimable dye and an organic binder; It may consist of a plurality of laminated dye transfer contributing layers consisting of a dispersed sublimable dye and an organic binder, or an IK layer consisting of an undissolved particulate sublimable dye and an organic binder. But it's okay.

When the ink layer has a multilayer structure, when setting the material formulation M1 of the dye supply layer and transfer contribution layer, it is necessary to form the same amount of adhesion on the substrate as a single layer with each formulation of the dye supply layer and transfer contribution layer. Then, when each is overlapped with a separate image-receiving layer and a certain sublimation temperature is applied, the appropriate dye supply layer,
It is preferable to provide a concentration gradient and/or a diffusion coefficient gradient between the dye transfer contributing layers. In that case, the thickness of the transfer contributing layer is generally 0.05 to 5 μn1, preferably 0.
．． It is 1 to 2 μm. The thickness of the dye supply layer is generally 0.1 to 20 μm, preferably 0.5 to 10 μm.
It is.

Furthermore, known sublimable dyes, binders, etc. used in the ink layer can be used.

Sublimable dyes are dyes that sublimate or vaporize at 60°C or higher, and are mainly used in thermal transfer printing such as disperse dyes and oil-soluble dyes, such as C.I. I. Disverse yellow 1, 3, 8, 9, 16, 41, 5
4, 60, 77, 116, etc., C. I. Dispersed thread 1.4, 6, 11, 15, 17, 55, 59,
60, 73.83, etc., C. I. Disperse blue 3.14, 19, 26, 56, 60, 64, 72, 9
9, 1.08, etc., C. ■． Solvent Yellow 7
7,116 etc., C. I. Solvent Red 23.
25.27 etc., C. I. Solvent Bull No. 63,
83, 105, etc., and these dyes can be used alone or in combination.

Thermoplastic or thermosetting resins are used as the binder, and examples of resins with relatively high glass transition points or high softening properties include vinyl chloride resins, vinyl acetate resins,
Examples include polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, epoxy resin, silicone resin, fluorocarbon resin, butyral resin, melamine resin, natural rubber, synthetic rubber, polyvinyl alcohol, cellulose resin, etc. . These resins can be used alone, but several types may be mixed or a copolymer may be used.

Furthermore, when the ink layer has a multilayer structure, and when a difference is made in the glass transition or softening temperature between the dye transfer contribution layer and the dye supply layer, a resin with a glass transition temperature of 0°C or lower or a softening temperature of 60°C or lower or Natural and synthetic rubbers, and waxes are preferred, and polyethylene oxide, polycaprolactone polyol, and waxes are particularly useful for practical use, and the above-mentioned thermoplastic or thermosetting resins and one or more of the above are preferred. It is preferable to use 101 in a mixed form.

The dye concentration of the transfer contributing layer is usually 5 to 80%, preferably
It is about 10 to 60%.

Regarding the dye depth of the dye supply layer, a dye concentration of 5 to 80% is preferable, but when creating a dye concentration gradient between the dye transfer contribution layer and the dye supply layer, the dye concentration of the dye transfer contribution layer is 1.1 to 5 times, preferably 1.5-Y3 times.

In addition, as the base sheet, films such as capacitor paper, polyester film, polystyrene film, polysulfone film, polyimide film, and polyamide film are used, and if necessary, a conventionally used film is used between the base sheet and the dye supply layer. An adhesive layer etc. may be provided,
Furthermore, a conventional heat-resistant lubricating layer may be provided on the back surface of the base sheet, if necessary.

The present invention will be explained in more detail with reference to Examples below.

Example 1 <Prescription for multi-layer yellow ink layer> 11 Parts by weight of the first layer Prescription Solvent ethyl alcohol Butyl alcohol [Prescription of the second layer] Parts by weight Solvent Toluene 100 Methyl ethyl carbone 100 Composition of the above formulation 24 things
After dispersing in a ball mill for an hour, the ink composition for the second layer was applied to an 8.5 μm polyimide film with a film thickness of 3.5 μm using a wire bar.
After coating to a thickness of 0.00 μm, a second M ink composition was further applied thereon to a thickness of 0.84 μm to form a sublimation type thermal transfer recording medium 4 (ribbon).

Similarly, in the yellow ink layer formulation, M
S Red G and Macrolex Red Viol
et R to create a magenta recording medium (ribbon).

Similarly, in the yellow ink layer formulation, the sublimable dye is
A recording medium (ribbon) for cyan was created instead of AYASET Blue 714.

Prescription of image-receiving layer and transparent thin layer> Parts by weight: Methyl ethyl chloride 1-40 Toluene 40 The composition of the above formulation was synthesized to a thickness of about 150 μm using a wire bar! (Yupo FPG-150, Oji Yuka Synthetic Paper) Film thickness 6.0μ
The image receptor 1 was formed by coating and drying to obtain a coating film of m.

Furthermore, the composition described above was coated on a 6.0 μm polyethylene terephthalate film support with a thickness of 0.3 μm as a transparent thin M5.
The coating was applied to a thick thickness to form a member for forming a transparent thin layer.

Here, yellow was formed at a recording density of 1.20 on the image receiving layer using a thermal head with a resolution of 6 dots/IIwI1.

Next, the transparent thin layer 5 was placed on the image receptor for 200 minutes while peeling it off from the polyethylene terephthalate film support.
The entire surface was coated with a heated roller at ℃.

Then, place a magenta ribbon on the image receptor 1. 3
．． As a result of recording with the printing energy of OOmj/dot,
The difference in density of the yellow component between the yellow recorded area and the overlapping area and the non-overlapping area was ○.

Example 2 As in Example 1, magenta was recorded at a recording density of 1.40, and cyan ribbon was recorded at a recording density of 3.40. As a result of recording in the same manner at OOmj/dat, the density difference of the magenta component was =14-0.

Example 3 (Formulation for single-layer yellow ink layer) Part by weight Macrolex Yellow 6G
10 Curing Agent CVL A-Donor NCI 10 0. 8 Solvent toluene 20 Ethyl acetate
20 isoprobyl alcohol
After dispersing 10 in a Pall mill for 24 hours, 8.
A 7.0 μm yellow ink layer was formed on a 5 μm polyimide film.

Similarly, in the yellow ink layer formulation, M
S Red G and Macrolex Red Viol
I changed it to et R and created a recording medium for evening use.

Similarly, in the formulation for the yellow ink layer, K
A cyan recording medium was created instead of ASET Blue 714.

Using these recording media, different patterns were recorded five times in the order of yellow, magenta, and cyan.

At this time, after recording each yellow, magenta, and cyan,
A transparent thin layer 5 was formed at 200° C. with a heated roller.

As a result, the ghost of the previous pattern in each recording by reverse transfer could not be visually determined. The recorded density was measured using a Macbeth densitometer RD-918.

[Effect] By interposing a transparent thin layer between the image-receiving layer and the ink layer for each color recording, the two do not come into contact with each other, so reverse transfer from the image-receiving layer to the ink layer can be completely prevented and color turbidity can be prevented. , it is possible to prevent the occurrence of ghosts in the previous pattern.

Furthermore, conventional image receiving paper can be used, image blurring due to positional deviation and increase in image receiving paper thickness can be ignored, and good images can be obtained in multiple recordings.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an embodiment of the thermal transfer recording method of the present invention. 1. Image receptor 2. Platen roller 3. Thermal transfer recording medium 4. Thermal head 5. Transparent thin layer 6. Heat roller 7. Transfer image

Claims (1)

[Claims] 1. An image receptor and a sublimation type thermal transfer recording medium that separately supports sublimable dyes of each full color are sequentially connected so that the dye-receiving surface of the image receptor and the dye-bearing surface of the transfer recording medium are connected to each other. In the sublimation thermal transfer recording method, in which a full-color image is recorded by stacking the recording medium facing each other and applying thermal energy from at least one side to transfer the dye from the transfer recording medium to the dye-receiving surface of the image receptor, each color is . A sublimation thermal transfer recording method, characterized in that a transparent thin layer is formed on the dye-receiving surface of the image receptor. 2. The method according to claim 1, wherein the transparent thin layer has a thickness of 1.0 μm or less. 3. The method according to claim 1, wherein the transparent thin layer has a thickness of 0.5 μm or less.