JPH0564980A - Sublimable thermal transfer medium - Google Patents

Abstract

PURPOSE:To provide a sublimable thermal transfer medium which can be used many times repeatedly and does not allow generation of ghost and trailing pheomena due to the reversed transfer of dye during color superimposition process with outstanding sensitivity. CONSTITUTION:The subject sublimable thermal transfer medium consists of a dye supply layer where sublimable dye is dispersed in an organic binder, a dye transfer contribution layer, a non-dyeable resin or a low dyeable resin thin layer provided sequentially from the side of a base, provided on the base.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sublimation type thermal transfer member, particularly a sublimation type thermal transfer member for recording many times.

[0002]

2. Description of the Related Art In recent years, the demand for full-color printers has been increasing year by year, and electrophotographic method, ink jet method, thermal transfer method, etc. are available as recording methods for these full-color printers. The thermal transfer method is often used.

This thermal transfer method is a thermal transfer recording medium (so-called color) in which a colorant is dispersed in a heat-fusible substance or an ink layer in which a sublimable dye is dispersed in a resin binder is provided on a substrate. An image receiving sheet is superposed on the ink layer surface of the (ink sheet), and thermal energy controlled by an electric signal from a laser or a thermal head is applied from the recording medium side to transfer the ink in that portion to the image receiving sheet by thermal fusion transfer or sublimation transfer. This is a method of forming an image.

This thermal transfer recording method is roughly classified into a thermal fusion transfer type and a sublimation transfer type depending on the type of recording medium used. In particular, the latter corresponds in principle to thermal energy from a thermal head or the like. Since the dye is transferred in the form of a single molecule, a halftone can be easily obtained, and the gradation can be adjusted arbitrarily, and it is considered to be the most suitable method for a full-color printer.

However, this sublimation type thermal transfer recording method uses one yellow, magenta, cyan, and (black) ink sheet to obtain one full-color image, and selectively heats each ink sheet. Since the printing is performed and the unused portion is discarded after that, the running cost is high.

Therefore, in order to improve this drawback, a method has been recently used in which the same ink sheet is repeatedly used to print and record many times. Specifically, a constant velocity mode method in which an ink sheet and an image receiving sheet are repeatedly printed at a constant speed, and a speed of the image receiving sheet is n times the speed of the ink sheet (n> 1) Two methods are the n-times mode method, in which printing is repeated in a running state.

The latter n-times mode method prints a large number of times by a relative speed method in which the portion used before the ink layer and the portion used after the ink layer are slightly overlapped while being sent. In the n-fold mode method, the larger the value of n, the more advantageous the cost. In the multi-time recording method using the n-fold mode method, a part of the unused portion of the ink layer is always supplied every time printing is performed, and thus the multi-time recording method using the constant-velocity mode method is merely a repeated use of the used portion. Compared with the method, there is an advantage that it is possible to reduce the variation in the residual ink amount due to the recording history (Journal of the Institute of Electronics, Information and Communication Engineers, Cvol J70-C, No. 11, 1537-1
544, November 1987).

However, in the case of recording a large number of times in these constant velocity and n-fold modes, reverse transfer of the dye from the image receiving layer to the ink layer may cause color turbidity or ghost, which may result in no clear image. However, there is still room for improvement, and the present invention addresses this problem.

That is, the thermal transfer recording method using the sublimable dye is thermal diffusion of the sublimable dye from the ink layer to the image receiving layer, and both are in close contact with each other by the pressing force between the thermal head and the platen roller.

Here, in the case of forming a secondary color and a tertiary color during full color formation, the dye previously transferred to the image receiving layer returns to the ink layer from the image receiving layer during the secondary color and tertiary color formation ( This is called reverse transcription). The ink layer containing the reverse-transferred dye does not cause a problem after being discarded in the one-time use method, but when the ink layer is used many times, it is transferred to the image receiving layer at the time of the next recording, resulting in color turbidity or the previous color. It affects the next recording as a ghost of the picture pattern. This adverse effect is visually
It can be reduced by changing the color recording order, but the effect is insufficient.

In the technique disclosed in Japanese Patent Laid-Open No. 61-293891, each color is formed on another transparent image-receiving layer, and these are superposed to form a full-color image.
Although reverse transfer does not occur, a special image receiving paper (layer) is required, which is different from the conventional one, and since the full color is formed by using three image receiving papers, the entire image receiving paper is thick and the cost is further increased.

Further, when three sheets are overlapped, a slight positional deviation causes blurring of the image, which poses a risk of image deterioration.

[0013]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a sublimation type thermal transfer member having good multiplicity and sensitivity, and free from ghost and tailing at the time of color superposition by dye reverse transfer. ..

[0014]

The constitution of the present invention for solving the above-mentioned problems is a sublimation type thermal transfer member as set forth in the claims.

The operation based on this structure will be described below.

(1) By adopting a two-layer structure of a dye supply layer containing a high dye concentration and a dye transfer contributing layer containing a small dye concentration, the dye consumed from the upper layer for image formation is transferred from the dye supply layer. Replenishment improves the multiplicity of the thermal transfer member.

(2) By incorporating an undissolved particulate dye in the dye supply layer, (i) a dye which flows from the dye supply layer to the transfer contribution layer even when an organic solvent is used in the ink for forming the transfer contribution layer. The amount can be reduced,
A concentration gradient can be provided between both layers.

(Ii) The dye concentration (molecularly dispersed dye amount) in the dye supply layer can be kept constant, and the multiplicity is improved.

That is, the dye concentration is determined by the amount of the molecularly disperse dye in the layer, and the decrease in the amount of the molecularly disperse dye in the dye supply layer due to the supply to the transfer contributing layer is determined by the molecular weight of the undissolved dye in the dye supply layer. Is released and supplied.

(3) By using an organic solvent dye as the dye in the upper layer, a considerable amount of the dye can be dissolved unlike water, and as a result, a molecularly dispersed dye is present in the upper layer. It is possible to prevent a decrease in dye concentration and a decrease in sensitivity.

(4) By providing a non-dyeing thin layer or a low dyeing thin layer on the upper layer, the dye existing on the surface of the image receiving layer hardly reverse-transfers to the surface of the ink layer during color superposition. As a result, the color is ghosted by reverse transfer, ghost,
Image quality does not deteriorate due to tailing.

(5) The dye concentration gradient between the resin thin layer and the image receiving layer is improved by incorporating a dye into the non-dyeing resin or the low dyeing resin (the dye transfer amount is the dye diffusion coefficient and the dye). (Depending on the concentration gradient), the sensitivity deterioration due to the thin layer installation is improved.

The ghost means n times (constant speed mode method)
Then, the dark pattern before is recognized as a ghost.

Further, the tailing means that the ribbon is continuously used in the n-fold (speed difference mode), so that the edge portion of the dark pattern in the previous color is recognized as the tailing (blur).

As means for facilitating the diffusive supply of the sublimable dye from the dye supply layer to the transfer initiation layer, I. The relationship between dye concentration and the dye supply layer> the transfer contribution layer, and / or II. Regarding the diffusion coefficient in each layer, there is a means for making the relationship of dye supply layer> transfer contributing layer. Further above
As a specific method for manipulating the diffusion coefficient for II, for example, Toyoko Sakai et al. 30, No. 12
(1974); Norihiko Kuroki, "Dyeing Theory Chemistry," published by Maki Shoten, p. 503-; Introduced in the 1st non-impact printing technology symposium papers 3-5. With reference to these, as a specific method for realizing the means of the above II, for example, (1) the diffusion coefficient is affected by the energy suppressing effect on the dye diffusion due to hydrogen bond between the dye and the organic binder. A method of using an organic polymer material having a large number of proton-donating groups or proton-accepting groups that are easily hydrogen-bonded to a sublimable dye as a binder of the transfer contributing layer, (2) The diffusion coefficient is determined by dispersing the dye. The organic binder has a glass transition or softening temperature dependency, and the lower the glass transition or softening temperature is, the larger the diffusion coefficient becomes than the temperature rising characteristics of the layer during printing in this process, and therefore the organic binding of the dye supply layer. A method of using a substance having a glass transition temperature or a softening temperature lower than that of the transfer contributing layer as an agent, (3) having a compatibility with at least one organic binder in the dye supplying layer, and having a transfer contributing layer A method of incorporating in the dye-supplying layer a plasticizer which is incompatible with all the organic binders of (4), a method of appropriately combining the methods of (1), (2) and (3) above, However, it goes without saying that the method is not limited to these methods as long as the relationship of the diffusion coefficient is satisfied.

In designing the material formulation of the dye supplying layer and the transfer contributing layer in the present invention, the above means I and / or II are useful, and it is determined whether or not the intended improvement is realized by these effects. As a simple method for confirming, the same amount of coating was formed as a single layer on the substrate in each formulation of the dye supplying layer and the transfer contributing layer, each layer was superposed on a separate image receiving layer, and a constant sublimation temperature was applied. At this time, there is a method of selecting each layer so that the sublimation transfer amount has a relationship of dye supply layer> transfer layer.

Next, the thickness of the transfer contributing layer is generally 0.
It is from 05 to 5 μm, preferably from 0.1 to 2 μm. The thickness of the dye supply layer is generally 0.1 to 20 μm, preferably 0.5 to 10 μm.

Known sublimable dyes and binders may be used in the transfer contributing layer and the dye supplying layer of the present invention.

The sublimable dye is a dye that sublimes or vaporizes at 60 ° C. or higher, and any dye mainly used in thermal transfer printing such as a disperse dye or an oil-soluble dye may be used. I. Disperse Yellow 1,3,8,9,1
6,41,54,60,77,116, etc., C.I. I. Disperse Red 1,4,6,11,15,17,5
5,59,60,73,83, etc., C.I. I. Disperse Blue 3,14,19,26,56,60,64,
72, 99, 108, etc., C.I. I. Solvent Yellow 77, 116, C.I. I. Solvent Red 2
C. 3, 25, 27, etc. I. Solvent blue 36,
83, 105 and the like can be used, and one of these dyes can be used, but a mixture of several dyes can also be used.

A thermoplastic or thermosetting resin is used for the binder used in the dye transfer contributing layer and the dye supplying layer, and as the resin having a relatively high glass transition point or a high softening property, for example, Vinyl chloride resin, vinyl acetate resin,
Examples thereof include polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin, polyester, polyurethane, epoxy resin, silicone resin, fluororesin, butyral resin, melamine resin, natural rubber, synthetic rubber, and cellulose resin. These resins can be used alone, but several kinds may be mixed or a copolymer may be used.

Further, when a difference in glass transition or softening temperature is provided between the dye transfer contributing layer and the dye supplying layer,
A resin having a glass transition temperature of 0 ° C. or lower, or a softening temperature of 60 ° C. or lower, or a natural or synthetic rubber is preferable. Specifically, syndiotactic 1,2-polybutadiene (commercially available as J
SR RB810, 820, 830 Nippon Synthetic Rubber); olefin copolymers and terpolymers containing acid or non-acidic groups (Dexon XEA-7 as a commercial product, Dexon Chemical); ethylene-vinyl acetate copolymer (40 as a commercial product)
0 & 400A, 405, 430, Allied Fibers &Plastics; P-3307 (EV150), P
-2807 (EV250), Mitsui DuPont Polychemical); low molecular weight polyolefin-based polyol and its derivatives (commercially available as Polytail H, HE Mitsubishi Kasei); brominated epoxy resin (YDB-340,400,
500,600 Toto Kagaku); Novolac type epoxy resin (YDCN-701, 702, 703 Tobu Kagaku); Thermoplastic acrylic solution (Dianal LR107)
5,1080,1081,1082,1063,107
9 Mitsubishi Rayon); thermoplastic acrylic emulsion (L
X-400, LX-450, Mitsubishi Rayon); polyethylene oxide (Alcox E-30,45, Alcox R-150,400,1000 Meisei Chemical Industry);
Caprolactone polyol (Plaxel H-1, 4,
7, Daicel Chemical Industries, Ltd.), and the like, and particularly, polyethylene oxide and polycaprolactone polyol are practically useful, and in the form of a mixture of the above-mentioned thermoplastic or thermosetting resin and one or more of the above. It is preferably used.

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

Regarding the concentration of the dye in the dye supply layer,
A dye concentration of 5 to 80% is preferable, but when a dye concentration gradient is provided between the dye transfer contributing layer and the dye supplying layer, it is 1.1 to 5 times, preferably 1 to the dye concentration of the dye transferring contributing layer. 0.5 to 3 times is desirable.

In order to keep the dye supply stable for a long time and maintain good printing characteristics, the dye supply layer preferably contains at least an undissolved particulate sublimable dye. Here, the undissolved particulate dye means a dye that cannot be completely dissolved in the organic binder and is deposited as particles after the ink (organic binder + sublimable dye + solvent) is applied and dried when the ink layer is formed. Then
Even with the same binder and dye, the presence state of the undissolved particulate dye varies depending on the solvent. The presence or absence of undissolved particulate dye can be easily identified by an electron microscope after forming the dye supply layer. The particle size of the undissolved particulate dye varies depending on the layer thickness of the dye supply layer, but is 0.01 μm to 20 μm, preferably 1.0 μm to 5 μm.

Further, the dye state in the dye transfer contributing layer is dispersed in the form of a single molecule that actually contributes to the transfer, preventing unevenness in the transfer density and preventing the dye supplying layer and the dye transfer contributing layer from being dispersed. It is desirable because it keeps the dye concentration gradient between them stable.

Further, as the base sheet, condenser paper, polyester film, polystyrene film,
Films such as polysulfone film, polyimide film, and polyamide film are used, and a conventional adhesive layer or the like may be provided between the base sheet and the dye supply layer, if necessary, and the back surface of the base sheet may be provided. If necessary, a conventional heat-resistant lubricating layer may be provided.

Up to now, an example in which the dye layer is divided into two layers has been described. However, if an appropriate difference in the dye transfer amount is generated and the functional separation intended by the present invention can be achieved, the dye layer is made into a multilayer of two or more layers. It is also possible.

Although the above description has been given of the recording method using a thermal head, the transfer medium of the present invention is a recording method in which recording thermal energy is applied by a method other than the thermal head, for example, a thermal printing plate or laser light. Alternatively, it can be used for a method using Joule heat generated in a medium such as a support. Of these, the so-called energization thermal transfer method, which uses Joule heat generated in the medium, is best known,
For example, USP 4,103,066, JP-A-57-140.
60, JP-A-57-11080, or JP-A-59-
It is described in many documents such as 9096.

When used in this electric transfer method, as a support, polyester, polycarbonate, triacetyl cellulose, nylon, polyimide, which has relatively good heat resistance,
For resins such as aromatic polyamide, aluminum, copper, iron,
Supports in which metal powders such as tin, zinc, nickel, molybdenum, and silver and / or conductive powders such as carbon black are dispersed to adjust the resistance value between an insulator and a good conductor, and these supports are described above. A support obtained by vapor-depositing or sputtering a conductive metal as described above may be used. Considering the Joule heat conduction efficiency, the thickness of these supports is 2
It is desirable to be about 15 microns.

When used in the laser light transfer method, a material that absorbs laser light and generates heat may be selected as the support. For example, a conventional thermal transfer film containing a light absorption conversion material such as carbon, or an absorption layer formed on the front and back surfaces of a support is used.

As for the non-dyeing or low-dyeing resin used for the thin layer, the target resin is evaluated as a resin for an image receiving layer,
A resin having a low recording density will be suitable as the resin for the thin layer.

Specifically, the evaluation was carried out by the following method.

Synthetic paper YUPO FPG # 95 as a base
(Manufactured by Oji Yuka Co., Ltd.) 5 to 20 wt% of a volatile solvent dissolved in each studied resin solution containing 30 wt% of resin solids modified silicone oil SF8417 / SF8411 = 1/1
A liquid containing (Toray Silicone) is dried at 70 ° C. for 1 minute so as to have a dry film thickness of 10 μm, and then dried at room temperature for 1 day or more.
Next, a sheet set CK2LB for Mitsubishi color video copy processor and a cyan ribbon were superposed on the image-receiving layer formed as described above, resolution 6 dots / mm, average resistance 542.
Recording was performed at 2.00 mj / dot using a thermal head KMT-85-6MPD4 (manufactured by Kyocera) of Ω, and the recording density was evaluated by a reflection type densitometer RD-918. As a result, the recording density was 1.2 or less, preferably 1. A value of 0.0 or less is adopted as a non-dyeing or low dyeing resin.

As a result of the above evaluation, as a preferable resin for the thin layer, an aromatic polyester resin, a styrene-butadiene resin, a polyvinyl acetate resin, a polyamide resin, and a particularly preferable resin are a methacrylate resin or a copolymer and styrene-malein. Acid resins, styrene-maleic acid ester resins and ester groups include methyl, ethyl, n-propyl, iso-propyl, n-butyl,
sec-butyl, ter-butyl, n-amyl, n-hexyl, cyclohexyl, allyl, benzyl, phenyl and the like, and further polyimide resin, acetate resin, silicone resin, styrene-acrylonitrile resin,
Examples thereof include polysulfone resin.

Further, the thickness of the thin layer is preferably 0.1 to 2 μm, preferably 1 μm or less, and when it is 0.1 μm or less, the convex portion of the minute unevenness on the surface of the contributing layer becomes too thin, or one of the convex portions. The uncovered portion is generated in the part, and the ghost and the tailing due to the reverse transfer of the dye from the surface of the image receiving layer occur in the uncoated contributing layer portion.

If the thickness of the thin layer is increased, the dye is less likely to diffuse and permeate, and the sensitivity is lowered. Therefore, the thickness is preferably 2 μm or less.

It is preferred to add the dye in the thin layer. The dye in the thin layer is preferably in the form of molecular dispersion rather than particles.
In the case of particles, pinholes are more likely to occur in the thin layer and the surface smoothness of the thin layer is lower than in the case of molecular dispersion.
The dye concentration in the thin layer is 60% or less, preferably 10 to 60
%, Particularly preferably 20 to 50%. When the dye concentration is low, the sensitivity improving effect is low, and when the dye concentration is too high, the effect of preventing reverse transfer of the dye from the receiving paper is lowered.

When the present transfer body is used in the speed difference mode method, the following slipping substances may be contained in the thin layer for the purpose of improving running defects.

Examples of the substance having a slipping property or releasing property (slippery substance) contained in the thin layer are, for example, petroleum-based lubricating oil such as liquid paraffin, hydrogen halide, diester oil, silicone oil, fluorosilicone oil. Synthetic lubricating oil,
Various modified silicone oils (epoxy-modified, amino-modified, alkyl-modified, polyether-modified, etc.), silicone-based lubricants such as copolymers of organic compounds such as polyoxyalkylene glycol and silicone, fluoroalkyl compounds, and various fluorine-based interfaces Activators, fluorine-based lubricating substances such as ethylene trifluoride chloride low polymer, waxes such as paraffin wax and polyethylene wax, higher fatty acids, higher aliphatic alcohols, higher fatty acid amides, higher fatty acid esters, higher fatty acid salts, and The lubricity includes particles having thermal releasability. The content of the substance having slipperiness or releasability in the thin layer is preferably 5 to 30% by weight. The content is 5%
If it is less than 30%, the releasability or the fusion preventing effect is insufficient, while if it exceeds 30%, the sensitivity and the storage stability are deteriorated.

The present invention will be specifically described below with reference to examples.

The amounts (parts) of the respective components described in the examples are parts by weight.

[0052]

Examples (Formulation of Adhesive Layer) Polyvinyl butyral resin BX-1 {manufactured by Sekisui Chemical Co., Ltd.} 10 parts Diisocyanate Coronate L {manufactured by Nippon Polyurethane Industry Co., Ltd.} 5 parts Toluene 95 parts Methyl ethyl ketone 95 parts on the back surface 6 with 1μm thick silicone resin heat resistant layer
A 1 μm thick coating was applied to the surface of a μm aromatic polyamide film to form an adhesive layer. (Prescription of dye supply layer) Polyvinyl butyral resin BX-1 7 parts Polyethylene oxide Alcox R-400 {manufactured by Meisei Chemical Industry Co., Ltd.} 3 parts Sublimation dye Kayaset Blue 714 {Nippon Kayaku Co., Ltd. Made 30 parts Isocyanate Coronate L 3 parts Toluene 95 parts Methyl ethyl ketone 95 parts (Formulation of dye transfer contributing layer) Polyvinyl butyral resin BX-1 10 parts Sublimable dye Kayaset Blue 714 10 parts Diisocyanate Coronate L 3 parts Toluene 95 parts Methyl ethyl ketone 95 After the composition of the above formulation was dispersed in a ball mill, a dye bar was applied onto the adhesive layer with a wire bar so that the thickness was 4.5 μm, and a dye transfer contributing layer was formed on the adhesive layer to a thickness of 1.0 μm. To form an ink layer.
Recording body A was prepared by heat curing at 24 ° C. for 24 hours.

Example I-1 (Formation of low dyeing thin layer) Resin Styrene-maleic acid isopropyl ester 10 parts Carboxyl modified silicone oil SF8418 {made by Toray Silicone} 1.5 parts Epoxy modified silicone oil SF8411 {Toray Silicone} 1.5 parts Solvent Tetrahydrofuran 40 parts The above prescription liquid is 0.7 on the recording material A using a wire bar.
A thermal transfer member was prepared by forming the film with a thickness of μm.

However, styrene-maleic acid isopropyl ester was prepared as follows.

5 g of styrene-maleic acid copolymer powder
Was stirred with 250 ml of isopropanol at 70 ° C. for 2 hours to obtain a colorless and transparent styrene-maleic acid isopropyl ester copolymer. Then, it was added to a large amount of n-hexane to obtain powdery styrene-maleic acid isopropyl ester.

Example I-2 Styrene-maleic acid isopropyl ester (hereinafter referred to as resin component A) in Example I-1 styrene-maleic acid AP-30 (BASF) 20 parts except that the solvent was replaced with tetrahydrofuran 80 parts. A thermal transfer member was prepared in the same manner.

Example I-3 The same as in Example I-1, except that the resin component A was styrene acrylonitrile litac A330-PC (Mitsui Toatsu) 15 parts, and the solvent was tetrahydrofuran 42.5 parts toluene 42.5 parts. Then, a thermal transfer member was prepared.

Example I-4 The same as in Example I-1, except that the resin component A was polymethylmethacrylate Dyanal BR-85 (Mitsubishi Rayon) 10 parts, and the solvent was toluene 42.5 parts methyl ethyl ketone 42.5 parts. Then, a thermal transfer member was prepared.

Example I-5 A thermal transfer member was prepared in the same manner as in Example I-1, except that the resin component A was polysulfone P-1700NT11 (Nissan Chemical Co., Ltd.) 15 parts and tetrahydrofuran 85 parts.

Example I-6 Thermal transfer was performed in the same manner as in Example I-1, except that the resin component A was silicone resin SR-5410 (Toray Silicone) 75 parts, the solvent was toluene 12.5 parts, and benzene 12.5 parts. The body was made.

Comparative Example I-1 A thermal transfer member was obtained by adding 1.5 parts of carboxyl-modified silicone oil SF8418 and 1.5 parts of epoxy-modified silicone oil SF8411 in the contributing layer of the recording medium A without forming a thin layer. .

Comparative Example I-2 In Example I-1, styrene-maleic acid isopropyl ester was used as the polycarbonate resin Panlite C-1400 (Teijin) 5 parts, and the solvent was tetrahydrofuran 47.5 parts Dioxane 47.5 parts. A thermal transfer member was prepared in the same manner.

Comparative Example I-3 In Example I-1, the resin component styrene-maleic acid isopropyl ester is ethylene vinyl chloride copolymer Lulon E-800 (Tosoh) 5 parts Solvent is toluene 47.5 parts Methyl ethyl ketone 47.5 parts A thermal transfer member was prepared in the same manner except that

Comparative Example I-4 In Example I-1, styrene-maleic acid isopropyl ester was used as a resin component, vinyl chloride vinyl acetate copolymer VAGH (union carbide) 15 parts, solvent was toluene 42.5 parts, methyl ethyl ketone 42.5 parts. A thermal transfer member was prepared in the same manner except that

Example II-1 (Formation of low dyeing thin layer) Resin Styrene-maleic acid isopropyl ester 10 parts Kayaset Blue 714 15 parts Diisocyanate Coronate L (manufactured by Nippon Polyurethane) 3 parts Carboxy modified silicone oil SF8418 {Toray Silicone} 1.5 parts Epoxy-modified silicone oil SF8411 {Toray Silicone} 1.5 parts Solvent Tetrahydrofuran 90 parts The above prescription liquid is 1.5 on the recording medium A using a wire bar.
It was formed to a thickness of μm to prepare a thermal transfer member.

However, styrene-maleic acid isopropyl ester was prepared as follows.

5 g of powder of styrene-maleic acid copolymer
Was stirred with 250 ml of isopropanol at 70 ° C. for 2 hours to obtain a colorless and transparent styrene-maleic acid isopropyl ester copolymer. Then, it was added to a large amount of n-hexane to obtain powdery styrene-maleic acid isopropyl ester.

Example II-2 A thermal transfer member was prepared in the same manner as in Example II-1, except that Kayaset Blue 714 was changed to 3.5 parts.

Example II-3 A thermal transfer member was prepared in the same manner as in Example II-1, except that 5 parts of Kayaset Blue 714 was used.

Example II-4 In Example II-1, 10 times of Kayaset Blue 714 was used.
A thermal transfer member was produced in the same manner except that the parts were used.

Reference Example A thermal transfer member was prepared in the same manner as in Example II-1, except that Kayaset Blue 714 was omitted.

Further, a mixture having the following composition was thoroughly mixed and dispersed to prepare a coating liquid for the dye receiving layer {A liquid}.

{Liquid A} Vinyl Chloride / Vinyl Acetate / Vinyl Alcohol Copolymer (trade name VAGH; Union Carbide Co.) 10 parts Isocyanate (trade name Coroneto L; Nippon Polyurethane Industry Co., Ltd.) 5 parts Amino-modified Silicone (trade name SF-8417; Toray Silicone Co., Ltd.) 0.5 part Epoxy-modified silicone (trade name SF-8411; Toray Silicone Co., Ltd.) 0.5 part Toluene 40 parts Methyl ethyl ketone 40 parts Next {A Liquid} using a wire bar to a thickness of about 150μ
m synthetic paper (trade name: YUPO FPG-150; manufactured by Oji Yuka Synthetic Paper Co., Ltd.) and dried at a drying temperature of 75 ° C. for 1 minute to form a dye receiving layer having a thickness of about 5 μm. 8 more
It was stored at 0 ° C. for 3 hours and cured to prepare an image receiving sheet used for the test.

Using this image-receiving sheet, under the conditions of a thermal head resolution of 12 dots / mm, applied energy of 0.64 mj / dot and applied power of 0.16 W / dot, (a) First, Comparative Example I was previously formed on the image-receiving layer. -1 in the sublimation dye MS-Magenta V
The same transfer body was used except for P (manufactured by Mitsui Toatsu Dye Co., Ltd.), and the feed speed during recording was 8.5 mm / sec for the image receiving sheet and 0.6 mm / sec for the ink sheet. Set and use speed difference mode method recording, Figure 1
The block-shaped pattern M in magenta color as shown in FIG.

The magenta density at this time exceeded 2.0 in the Macbeth densitometer.

(B) Next, using the thermal transfer member of Example I-1 and the image receiving sheet on which the pattern M was printed, the same applied energy and feed rate as above, the image receiving sheet of 8.5 mm / sec, the ink The color of the cyan color c was superimposed on the magenta block pattern M by solid image printing as shown in FIG.

As a result, FIG. 3 shows an enlarged view of the edge portion E of the magenta block generated by the reverse transfer of the magenta dye on the surface of the image receiving layer to the ink layer. O is a portion where the magenta dye reversely transferred to the ink layer is retransferred to the image receiving sheet when the cyan color c is printed.

FIG. 5 is a diagram in which the magenta color density is measured by XY (FIG. 4) of the magenta block printed in the above (a), and the density (OD) is plotted.

In FIG. 7, after the cyan color c is overprinted as a solid image by the above (b), the same position as the above XY (6th color) is displayed.
FIG. 4 is a diagram in which the magenta color density is measured in FIG. 2 and the density (OD) is plotted.

FIGS. 5 and 7 show the microphotometer M.
PM-2 (manufactured by Union Optical Co., Ltd.) is a graph in which the microscopic density change of a magenta color block is plotted along XY using a Kodak Ratten filter # 58 as a filter. The tailing length is a value in an actual unit calculated based on 1-m. Tables 1 and 2 show the results of printing (a) and (b) and performing the above measurements on the thermal transfer members of Examples, Comparative Examples, and Reference Example. Table 1
The value of the tailing length in Table 2 is shown as the maximum value among the measured values.

It should be noted that the shorter the trailing length, the less the color transfer and the reverse transfer due to the reverse transfer.

Further, according to the above (a), the image-receiving sheet having the magenta block pattern M and the thermal transfer member of Example I-1 were used, the feeding speed during recording was 8.5 mm / sec for the image-receiving sheet, and the ink sheet 8. 5 mm / sec at a constant speed, solid color cyan printing was overlaid on the magenta color block, and printing was performed using the same portion as the cyan solid printing of the thermal transfer member of Example I-1. A cyan solid image was recorded again on a new image receiving sheet which was not printed under the same conditions, and the McBase densitometer RD-918 was used.
Was used to measure the magenta color density of the cyan image portion where there was no color overlap and the magenta density of the cyan image portion where there was no color overlap, and the ghost density of magenta color was measured from the difference.

FIG. 8 shows an image in which a magenta ghost image (G) is generated (C is a cyan color portion), and FIG. 9 is an image in which no magenta ghost image is present (C is a cyan color portion). Show. Tables 1 and 2 show the ghost concentrations measured in the same manner as described above for each of the examples, each of the comparative examples, and the reference example.

[0084]

[Table 1]

The concentration of the above (A) was obtained by using a base solution (synthetic paper YUPO FPG # 95, manufactured by Oji Yuka Co., Ltd.) with a coating solution having the same formulation as that of the low dyeing thin layer in each of Examples and Comparative Examples. ) Is applied to the above, dried at 70 ° C. for 1 minute, and then dried at room temperature for 1 day or more to form an image receiving layer having a film thickness of 10 μm. Then, on this image receiving layer, sheet set CK2LB for Mitsubishi color video copy processor, cyan Thermal head K with a resolution of 6 dots / mm and an average resistance of 542Ω
Using MT-85-6MPD4 (manufactured by Kyocera Corporation),
Recording is performed at 2.00 mj / dot, and the recording density is a value measured by a Macbeth reflection type densitometer RD-918.

[0086]

[Table 2]

The recording densities shown in Table 2 above are the recording densities of the single cyan color of the cyan image portion having no ghost image.

Also, the surface of the ink layer was observed with a scanning electron microscope.
As a result of confirmation at 000 times, a large number of needle-like crystalline particulate dyes having a diameter of several μm were confirmed only in Example II-1.

[0089]

The effects of the present invention described above are summarized as follows.

1. By further providing a non-dyeing thin layer or a low dyeing thin layer on the dye transfer contributing layer, it is possible to reduce the amount of the reverse transfer dye from the image receiving layer at the time of color superimposition, and the tail in the speed difference mode method can be reduced. The ghost in the constant velocity mode method is reduced.

2. With the resin according to claim 2, the above-mentioned improvement effect is great.

3. By making the supply layer particulate and the contribution layer molecularly dispersed, the dye concentration in the supply layer due to the release of the molecularly disperse dye in the supply layer is made constant, and the multiplicity is improved. Even if an organic solvent is used in the contribution layer, the mulching property is improved due to a good dye concentration gradient. Furthermore, since the dye concentration in the contributing layer increases, the sensitivity does not decrease.

4. By including a lubricant in the thin layer, running defects and sticking do not occur even in the speed difference mode method.

5. According to the inventions of claims 7 to 9, not only the ghost and the tailing are improved but also the sensitivity is reduced.

6. Similarly, since the dye is in a dissolved state, recording density unevenness is eliminated and uniform solid printing is possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a magenta block on an image receiving surface.

FIG. 2 is an explanatory diagram of a state in which cyan is color-overlaid.

FIG. 3 is an enlarged schematic view of an edge portion.

FIG. 4 is a diagram showing magenta color blocks and magenta color density measurement positions.

FIG. 5 is a diagram in which density of magenta color in a magenta color block and its edge portion is plotted.

FIG. 6 is a diagram showing a magenta color block portion after printing a cyan solid image on the magenta color block and a magenta color density measurement position.

FIG. 7 is a diagram in which density of magenta color in a magenta color block in which tailing has occurred and its edge portion is plotted.

FIG. 8 is an explanatory diagram of cyan solid image printing in which a magenta ghost image is generated.

FIG. 9 is an explanatory diagram of cyan solid image printing in a state where no image is generated.

[Explanation of symbols]

 M Magenta block image C Cyan solid image E Edge part G Magenta ghost part l Tail length O Tail part

Claims (9)

[Claims] 1. A sublimation-type thermal transfer member comprising a substrate and a dye supply layer and a dye transfer-contributing layer each comprising a sublimable dye dispersed in an organic binder in this order from the substrate side. A sublimation type thermal transfer member, further comprising a thin layer made of a non-dyeing resin or a low dyeing resin on the transfer contributing layer. 2. The sublimation property according to claim 1, wherein the dye supply layer contains at least an undissolved particulate sublimation dye, and the dye transfer contributing layer contains at least a molecular dispersion sublimation dye. Thermal transfer body. 3. The sublimation type thermal transfer member according to claim 1, wherein the thickness of the thin layer made of a non-dyeing resin or a low dyeing resin is in the range of 0.1 to 2 μm. 4. The sublimation type thermal transfer member according to claim 1, wherein the non-dyeing or low-dyeing resin used for the thin layer is a resin soluble in an organic solvent. .. 5. The sublimation type thermal transfer member according to claim 1, wherein the thin layer made of non-dyeing or low-dyeing resin contains a lubricant. 6. The non-staining resin or the low-staining resin is any one of silicone resin, styrene maleic acid resin, styrene maleic acid ester resin, styrene acrylonitrile resin, polysulfone resin and polymethacrylate resin. The sublimable thermal transfer member according to any one of claims 1 to 5, wherein 7. The sublimation type thermal transfer member according to claim 1, wherein the non-dyeing resin or the low dyeing resin contains a sublimation dye. 8. The sublimation type thermal transfer member according to claim 7, wherein the sublimation dye in the non-dyeing resin or the low dyeing resin is present in a dissolved state. 9. The sublimation type thermal transfer member according to claim 7, wherein the sublimation dye concentration in the non-dyeing resin or the low dyeing resin is 20 to 50%.