JP3207518B2 - Thermal transfer sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer sheet, and more particularly, to a thermal transfer sheet particularly suitable for forming a high-quality image on a thermal transfer image receiving sheet by performing heating printing according to image information using a thermal head or a laser. Regarding the sheet.

[0002]

2. Description of the Related Art Conventionally, thermosensitive coloring paper has been mainly used to form an image in accordance with image information using a thermal printing means such as a thermal head or a laser. In this thermosensitive coloring paper, a colorless or pale-colored leuco dye provided at room temperature and a developer provided on a base paper are brought into contact by heating to obtain a coloring image. As such a developer, a phenolic compound, a zinc salicylate derivative, rosin and the like are generally used. However, the heat-sensitive coloring paper as described above has a fatal disadvantage that the obtained color image is erased when stored for a long period of time, and color printing is limited to two colors, and continuous gradation is not possible. Color image could not be formed.

On the other hand, in recent years, heat-sensitive transfer paper having a heat-meltable wax layer in which a pigment is dispersed on a base paper has begun to be used. When the thermal transfer paper and the thermal transfer image receiving sheet are overlapped and heated printing is performed from the back surface of the binder resin, the wax layer containing the pigment is transferred onto the thermal transfer image receiving sheet to obtain an image. According to such a printing method, a durable image can be obtained, and a multicolor image can be obtained by performing printing a plurality of times using a binder resin containing three primary color pigments. It is not possible to form a photograph-like image having various gradations. In recent years, there has been an increasing demand for obtaining an image such as a color photograph directly from an electric signal, and various attempts have been made. One of such attempts is to project an image on a CRT and photograph the image with a silver halide film. However, when the silver halide film is an instant film, the running cost is increased. When the silver halide film is a 35 mm film, there is a drawback that the film is not instantaneous because a developing process is required after photographing.

As another method, an impact ribbon method or an ink jet method has been proposed, but the former method has a drawback that the image quality is poor, and the latter method requires image processing. There is a disadvantage that it is difficult to form an image. In order to solve such a drawback, a thermal transfer sheet provided with a sublimable dye layer having a property of being transferred by heating is used in combination with a thermal transfer image receiving sheet, and the dye is formed on the thermal transfer image receiving sheet while controlling the sublimable dye. Has been proposed to form an image such as a photograph with gradation (see Journal of Image Electronics Society, Vol. 12, No. 1, 1983). According to the above method, an image having continuous gradation can be obtained from a television signal by simple processing, and the apparatus used at that time has attracted attention because the apparatus used is not complicated. As one of the prior arts close to such a method, there is a dry transfer printing method of polyester fiber. In the dry transfer printing method, a dye such as a sublimable disperse dye is dispersed or dissolved in a synthetic resin to form an ink. This ink is applied to a thin paper or the like in a pattern and dried to form a thermal transfer sheet. This thermal transfer sheet is superimposed on a polyester cloth which is a thermal transfer image receiving sheet and heated in close contact to dye a dye on the polyester cloth to form an image. It is a method of forming.

[0005]

However, it is difficult to form a high-density color image even if a thermal transfer sheet conventionally used in a dry transfer printing method for a polyester fabric is used as it is and heated and printed by a thermal head or the like. It is. This is mainly because the thermal transfer sheet does not have high thermal sensitivity and the thermal transfer image-receiving sheet has low dyeing ability. Of these drawbacks, those attributable to the thermal transfer image-receiving sheet side are -100 ° C to 2 ° C.
A dye-receiving layer in which island portions each having a glass transition temperature of 0 ° C. and made of a synthetic resin having a polar group and sea portions made of a synthetic resin having a glass transition temperature of 40 ° C. or more are formed in a sea-island shape; It has been found that the problem can be solved by a thermal transfer image receiving sheet having the following (Japanese Patent Application No. 58-135627), but the problem caused by the thermal transfer sheet has not yet been solved. This is because, in the conventional printing method for fabric or the like, transfer and dyeing of the dye are achieved by heating at 200 ° C. for about 1 minute, for example, whereas heating by a thermal head is performed at about 400 ° C. for several milliseconds. . The reason is that the degree and shortness have a cause.

The present inventors use a thermal transfer image-receiving sheet, particularly a thermal transfer image-receiving sheet described in Japanese Patent Application No. 58-135627, in order to form a color photographic image by heating and printing with a thermal head or the like. As a result of conducting various studies to obtain a thermal transfer sheet suitable for printing, the following facts were found. That is, in a generally used thermal transfer sheet, the dye is in a state of being dispersed in the binder resin in the form of particles. In order to heat and sublimate the dye molecules in such a state, the interaction within the crystal is required. Defeat,
Furthermore, since thermal energy exceeding the interaction with the binder resin must be applied to the dye molecules and sublimated to be dyed on the thermal transfer image receiving sheet, high energy is required, and in order to obtain a high density color image. If the dye is contained in a high proportion with respect to the binder resin, an image with a certain high density can be obtained, but the adhesive force between the dye layer of the thermal transfer sheet and the base sheet becomes weak. When the thermal transfer sheet is peeled off after printing with a thermal head or the like overlaid on the thermal transfer image receiving sheet, a phenomenon that not only the dye but also the entire dye layer is peeled off on the thermal transfer image receiving sheet easily occurs, and the dye is expensive in price. From the standpoint of OA equipment and home use, it is economically disadvantageous to contain a dye more than necessary.

On the other hand, if it is possible to hold the dye in the binder resin in the form of a molecular dispersion instead of a particle, it is possible to improve the thermal sensitivity as much as there is no interaction within the crystal unlike the case where the dye is dispersed. There is expected. However, simply achieving such a state in the binder resin does not provide a practical thermal transfer sheet. That is, the dye molecule having a heat sublimation has a relatively small molecular weight of about 150 to 550, and easily moves in the binder resin forming the dye layer. Therefore, for example, when a binder resin having a low glass transition temperature (Tg) is used, the dye develops such that the dye agglomerates and folds out in the dye layer over time, and eventually the dye is dispersed in the form of particles as described above. The dye may bleed out to the surface of the dye layer or the surface of the dye layer, and the dye may adhere to the area around the heated portion due to the pressure between the thermal head and the platen (platen) during recording. This causes background stains and significantly degrades image quality. Further, even if the glass transition temperature (Tg) of the binder resin is high, the dye molecules cannot be retained unless the molecular weight of the binder resin is large to some extent. Furthermore, even if a dye is dissolved in a molecular state in a binder resin having a high glass transition temperature (Tg) and a certain degree of molecular weight, a dye molecule and a binder resin must be used to achieve a state that is stable over time. Is required. In view of the above, various thermal transfer sheets for improving image quality have been proposed. For example, as described in JP-A-63-151484, by using a specific polyvinyl acetoacetal resin as a binder resin component in a dye layer ink, it is possible to improve print quality and stability over time. It is known that you can do it.

However, these conventional thermal transfer sheets are not always satisfactory in terms of sensitivity. Ethylhydroxyethylcellulose and ethylcellulose are known as binder resins having excellent sensitivity, but these binder resins have a drawback that storage stability is inferior in terms of prevention of aggregation and precipitation of dyes. In general, as conditions required for a thermal transfer sheet, it is important to preserve the thermal transfer sheet itself as well as various characteristics relating to image quality such as printing sensitivity and resolution. However, printing sensitivity and storability tend to cancel each other out, and it is difficult to improve both of these characteristics. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art,
An object of the present invention is to provide a thermal transfer sheet which has excellent properties relating to image quality such as printing sensitivity and resolution, and also has excellent storage stability of the thermal transfer sheet itself and excellent releasability of the thermal transfer sheet during image formation.

[0009]

The above object is achieved by the present invention described below. That is, the present invention is a thermal transfer sheet in which a dye layer containing a dye that is transferred by heating and transferred onto a thermal transfer image receiving sheet is laminated on a base material sheet, wherein the binder component of the dye layer is consisting of polystyrene, polyvinyl toluene, polyacrylate, polyvinyl acetal, polyvinyl butyral, a mixture of nitrocellulose, at least one resin selected from the group consisting of ethyl hydroxyethyl cellulose and ethyl cellulose, and compatibilizing agent represented by the following structural formula It is a thermal transfer sheet characterized by the above.

[0010]

By adopting a composition comprising a specific binder resin and a specific compatibilizer as a binder component constituting a dye layer, various properties relating to image quality such as printing sensitivity and resolution are excellent, and thermal transfer is performed. It is possible to provide a thermal transfer sheet that is excellent in the storage stability of the sheet itself and the releasability of the thermal transfer sheet during image formation.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail hereinafter with reference to preferred embodiments illustrated in the drawings. As shown in FIG. 1, a thermal transfer sheet 1 according to the present invention
A dye layer 3 is provided thereon. Examples of the base sheet 2 include a condenser paper, a polyester film, a polystyrene film, a polysulfone film, a polyimide film, a polyvinyl alcohol film, an aramid film such as cellophane, a polyetherimide film,
Paper or a film such as a polyetheretherketone film or a polypalvanic acid film is used, and its thickness is 1.5 to 50 μm, preferably 2 to 9 μm.
When these papers or films require heat resistance in the price and unprocessed state, condenser paper is used.On the other hand, it has mechanical strength and is used for handling when creating a thermal transfer sheet or in a thermal printer. Polyester film is preferably used when emphasis is placed on not breaking when running and having a smooth surface.

The dye layer 3 mainly comprises a dye and a specific binder component. The dye used in the present invention is a dye which is transferred by melting, diffusing or sublimating by heat, and a disperse dye is particularly preferably used. These dyes have a molecular weight of about 150 to 550, and are selected in consideration of sublimation (melting) temperature, hue, light resistance, ink formation, solubility in a binder resin, and the like. , ヂ aryl methane, triaryl methane,
Typical dyes include thiazole, methine, azomethine, xanthine, oxazine, thiazine, azine, acridine, azo, spirodipyran, indolinospiropyran, fluoran, rhodamine lactam, and anthraquinone dyes. Specifically, the following dyes can be preferably used. C. I. (Color Inde
x) Yellow 51, 3, 54, 79, 60, 23, 7,
141; I. Disperse Blue 24, 56, 1
4, 301, 334, 165, 19, 72, 87, 28
7, 154, 26; I. Disperse thread 13
5, 146, 59, 1, 73, 60, 167; I.
Disperse Violet 4, 13, 26, 36, 5
6, 31; I. Solvent Violet 13; C.I.
I. Solvent Black 3; I. Solvent Green 3; I. Solvent Yellow 56, 14, 16,
29; I. Solvent Blue 70, 35, 63, 3
6, 50, 49, 111, 105, 97, 11;
I. Solvent Red 135, 81, 18, 25, 1
9, 23, 24, 143, 146, 182 and the like.

More specifically, for example, 3,3'-diethyloxathiocyanine iodide astrazone pink FG (CI.48015, manufactured by Bayer AG);
2,2'-carbocyanine (CI.808), Astraphyloxine FF (CI.48070), Astrazone Yellow 7GLL (CI. Basic Yellow 21), Eisen Katilon Yellow 3GLH (Hodogaya Chemical) Methine (cyanine) -based basic dyes such as monomethine, dimethine, and trimethine, such as Aizen Katilon Red 6BH (CI.48020); Auramine (CI.655); Diphenylmethane-based basic dyes such as malachite
Green (CI.42000), Brilliant Green (CI.42040), Magenta (CI.4)
2510), metal violet (CI. 4253)
5), Crystal Violet (CI. 4255)
5), triphenylmethane-based basic dyes such as methyl green (CI.684) and Victoria blue B (CI.44045); pyronin G (CI.739);
Rhodamine B (CI. 45170), Rhodamine 6G
Xanthene-based basic dyes such as (CI. 45160);
Acridine Yellow G (CI. 785), Leonin AL (CI. 46075), Benzoflavin (C.I.
I. Acridine base dyes such as Affine (CI.46045); Neutral Red (C.I.
I. 50040), Astrazon Blue BGE / x1
Quinone imine-based basic dyes such as 25% (CI. 50005) and methylene blue (CI. 52015); and other basic dyes such as anthraquinone-based basic dyes having a quaternary ammonium group. . These dyes can be used as they are or in a form obtained by treating these dyes with alkali, and a counter ion exchanger or a leuco form of these dyes can also be used. When a colorless or light-colored leuco dye or the like is used in a normal state, a developer may be included in the thermal transfer image-receiving sheet.

Further preferred dyes are exemplified.

Embedded image (In the above general formula, R ₁ represents a substituted or unsubstituted alkyl group or an alkoxy group, and R ₂ represents an alkoxycarbonyl group, an alkylaminocarbonyl group, an alkoxy group, an alkoxyalkoxy group, an alkyl group, a cycloalkyl group or a heteroalkyl group. A ring group, R ₃ and R ₄ are a substituted or unsubstituted alkyl group, R ₅ is a substituted or unsubstituted aryl group or a substituted or unsubstituted aromatic heterocyclic group, and R ₆ is a substituted or unsubstituted R ₁₁ and R ₁₂ represent a substituted or unsubstituted alkyl group, cycloalkyl group, vinyl group or aryl group, R ₉ represents CONHR, NHCOR, SO ₂ NHR,
NHSO ₂ R (R represents a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group or aromatic heterocyclic group), R ₁₀ is a substituted or unsubstituted alkyl group, alkoxy group, alkylcarbonylamino group, Represents an alkylsulfonylamino group, a carbamoyl group, a sulfamoyl group, a hydrogen atom or a halogen atom. )

The binder resin used in the present invention is at least one resin selected from the group consisting of polystyrene, polyvinyl toluene, polyacrylate, polyvinyl acetoacetal, polyvinyl butyral, nitrocellulose, ethyl hydroxyethyl cellulose and ethyl cellulose. As long as the object of the present invention is not hindered, another binder resin can be used in an amount of 50% by weight or less of the entire binder resin.

The present invention is characterized in that a compatibilizer comprising a part compatible with the binder resin and a part compatible with the dye is used as one component of the binder component. According to the compatibilizing agent, the properties involved in the image quality such as printing sensitivity and the resolution is excellent, to provide excellent thermal transfer sheet storability of the thermal transfer sheet itself kills with <br/>. One preferred example of such a compatibilizer is a copolymer generally represented by the following structural formula, which has excellent compatibility with both the binder resin and the dye.

Embedded image The compatibilizer is obtained by copolymerization of a vinyl compound having a polyoxyalkylene glycol chain, an acid anhydride group, a phenyl ring and the like in the skeleton thereof, the composition of the polyoxyalkylene glycol chain, the substituent of the phenyl ring and By changing the ratio of the constituent components, a compatibilizer ranging from water-soluble to oil-soluble can be obtained. Further, by introducing a reactive functional group into an acid anhydride group, a polyoxyalkylene glycol chain or a phenyl ring in the skeleton, it becomes possible to obtain various derivatives or to form a crosslinked structure.

[0017] Another is such compatibilizers on than that obtained by the ternary polymerization of a monomer of the three components, for example, market or llama rear <br/> rim AFB-1521, AKM-1511 ( CAS N
O. 136959-57-4), 0530 (CAS N
O. 138184-87-9), 1510 (CAS N
O. 138789-65-8), 0531, AKS-1
215, under the trade names such as AAB-0850,0851, for example, can be used in the present invention to obtain NOF stock company or et al. The amount of these compatibilizers used is 1 to 99%, preferably 3 to 8%, based on the total amount of the binder resin.
0% or less is desirable for improving storage stability and printing characteristics.

The ratio of the dye contained in the dye layer depends on the sublimation (melting) temperature of the dye and the magnitude of the covering power (color rendering) in the color-developed state. (Dye / binder resin ratio) is preferably 0.3 or more, more preferably 0.3 to 3.0.
And most preferably 0.55 to 2.5. If the dye / binder resin ratio is less than 0.3, image quality such as print density and thermal sensitivity is not preferable, while 3.0
If it exceeds 300, the adhesiveness to the film and the storability tend to decrease. In order to provide the dye layer 3 on the base sheet 2, a dye, a binder resin and a compatibilizer are dissolved together with a suitable solvent to form an ink for the dye layer, which is then printed by a suitable printing method or coating method. 2 may be applied and dried. Alternatively, the dye and the binder resin may be dissolved together with a suitable solvent and applied as a dye layer ink, and then a compatibilizer dissolved in a suitable solvent may be overcoated to form a dye layer. It is preferable that the dye is substantially dissolved in the binder resin. Incidentally, an optional additive may be added to the dye layer ink as required.

The basic structure of the thermal transfer sheet of the present invention is as described above. However, when the surface of the substrate sheet is directly heated by a contact-type heating means such as a thermal head, it is shown in FIG. In this manner, by providing a slipping layer 4 containing a lubricant such as wax or a release agent on the side of the base sheet 2 where the dye layer 3 is not provided, a heating means such as a thermal head can be connected to the base sheet. It is possible to prevent fusion and improve the slipperiness. The thermal transfer sheet of the present invention may be a sheet-like sheet cut to a required size, may be a continuous form or a rolled-up form, or may be a tape form having a smaller width. When the dye layer 3 is provided on the base sheet 2, a dye layer ink containing the same dye may be applied to the entire surface of the base sheet 2, but in some cases, different dyes may be used. A plurality of dye layer inks may be formed in different areas on the surface of the base sheet 2 respectively. For example, as shown in FIG. 3, a thermal transfer sheet in which a black dye layer 5 and a red dye layer 6 are laminated in parallel on the base sheet 2, or a yellow dye layer 7, as shown in FIG. It may be a thermal transfer sheet in which a red dye layer 8, a blue dye layer, and a black dye layer 10 are repeatedly provided on the base sheet 2.

By using such a thermal transfer sheet provided with a plurality of dye layers having different hues, there is an advantage that a multicolor image can be obtained by one thermal transfer sheet. The use of the thermal transfer sheet can be facilitated by forming perforations or providing detection marks for detecting the positions of areas having different hues. The thermal transfer sheet of the present invention and the optional thermal transfer image-receiving sheet constructed as described above are combined with the dye layer 3 of the thermal transfer sheet 1 and the dye-receiving layer 13 on the base sheet 12 of the thermal transfer image-receiving sheet as shown in FIG. The heat is applied to the interface between the dye layer 3 and the dye receiving layer 13 by a heat applying means such as a thermal head 14 in accordance with image information, so that the dye in the dye layer 3 is 1
3, the desired image can be formed in the dye receiving layer 13.

As a heat source for giving thermal energy, laser light, infrared flash,
A known device such as a hot pen can be used. The thermal energy may be applied from the thermal transfer sheet side, from the thermal transfer image receiving sheet side, or from both sides, but preferably from the thermal transfer sheet side from the viewpoint of effective use of thermal energy. . However, applying thermal energy from the thermal transfer image receiving sheet side controls the applied thermal energy to express the gradation of the image,
Alternatively, it is preferable in terms of promoting the diffusion of the dye on the thermal transfer image-receiving sheet and thereby ensuring the continuous tone expression of the image. In the method of applying thermal energy from both sides, the advantages of both methods are simultaneously used. You can enjoy.
When the thermal head 14 is used as a heat source for applying thermal energy, the applied thermal energy can be changed continuously or in multiple steps by modulating the voltage or pulse width applied to the thermal head.

When laser light is used as a heat source for applying heat energy, the applied heat energy can be changed by changing the amount of laser light or the irradiation area. If a dot generator having an acousto-optic element is used, heat energy corresponding to the size of a halftone dot can be applied. When using laser light,
It is preferable that the thermal transfer sheet and the thermal transfer image receiving sheet are sufficiently adhered to each other, and the surface to be irradiated with laser light is preferably colored black, for example, to improve the absorption of laser light. Alternatively, if a substance that absorbs non-sublimable laser light and converts it into heat is added to the dye layer 3, heat is more efficiently transferred to the dye and the resolution of the image is increased. When using an infrared flash lamp as a heat source for applying heat energy, it is preferable to perform the same operation as when using a laser beam, or through a pattern or a halftone pattern that continuously expresses the shading of an image, such as black. This may be performed, or a combination of a color layer such as black on one surface and a negative pattern corresponding to the negative of the above pattern may be performed.

When heat energy is applied to the interface between the dye layer and the dye receiving layer as described above, the dye in the dye layer is transferred to and received by the dye receiving layer 13 in an amount corresponding to the applied heat energy. To form a desired image. By the thermal transfer recording as described above, the dye corresponding to the thermal energy is thermally transferred to the dye receiving layer, and a one-color image can be recorded. By replacing the thermal transfer sheet with the above method, for example,
By sequentially replacing the yellow, red, indigo and, if necessary, black thermal transfer sheets and performing thermal transfer according to each color, a photographic color image composed of a combination of each color can also be formed. Instead of using the thermal transfer sheet of each color as described above, a thermal transfer sheet having areas previously formed by applying different colors to each other as shown in FIG. 4 is used. First, a yellow color separation image is thermally transferred using the yellow area. Then, thermal transfer is performed using the red area of the thermal transfer sheet, and thereafter, a method of thermally transferring yellow, red, indigo, and, if necessary, black color separation images by repeating thermal transfer sequentially, the thermal transfer sheet There is an advantage that the replacement of the battery becomes unnecessary. The quality of the obtained image can be improved by appropriately adjusting the size of the heat source used for applying the heat energy, the adhesion between the heat transfer sheet and the heat transfer image receiving sheet, and the heat energy.

By using the thermal transfer sheet of the present invention in combination with a thermal transfer image receiving sheet, printing using various types of thermal printing printers, facsimile or magnetic recording, making prints of photographs, and printing from television screens. It can be used for making. For example, one screen of the received television is stored in a recording medium such as a magnetic tape or a magnetic disk as a signal of each color separation pattern of yellow, red, indigo and, if necessary, black, and is stored. When a signal of each color separation pattern is output, heat energy corresponding to this signal is applied to a superimposed body of a thermal transfer sheet and a thermal transfer image receiving sheet by the above-described heat source such as a thermal head, and thermal transfer is sequentially performed for each color. A television screen can be reproduced as a sheet-like hard print. When a combination of the thermal transfer image-receiving sheet and the thermal transfer sheet of the present invention is used for printing out such a television screen, a white dye-receiving layer alone or a colorless and transparent dye-receiving layer is usually used as the thermal transfer image-receiving sheet. Is used to form a reflection image when a base material sheet such as paper or a white dye receiving layer is backed with a base sheet such as paper is used.

The same operation as described above can be performed when a combination of characters, graphics, symbols, colors, and the like formed on a CRT screen by operating a computer, and a graphic pattern are used as an original image. When the original image is a fixed image such as a painting, photograph, or printed matter, or an actual object such as a person, still life, or landscape, an image is formed in the same manner as described above by using an appropriate means such as a video camera. You can do it. Further, in producing signals of each color separation pattern from the original image, an electronic plate making machine (color scanner) used for photomechanical printing may be used.

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the description, parts and% are based on weight unless otherwise specified. <Examples 1 to 7 > An ink for a dye layer having the following composition was prepared, and coated and dried on a 6 μm-thick polyethylene terephthalate film having a heat-treated rear surface so that the dry coating amount was 1.0 g / m ^2. Thus, a thermal transfer sheet of the present invention was obtained. (Ink composition) Dye a part Binder resin b part Compatibilizer c part Methyl ethyl ketone (100-abc) / 2 parts Toluene (100-abc) / 2 parts However, Reseda series among the compatibilizers Is manufactured by Toa Gosei Chemical Industry Co., Ltd., and Modiper and Maria Rim series are manufactured by NOF Corporation. If the dye is insoluble in the solvent in the above composition, DMF as a solvent,
Dioxane or chloroform was used as appropriate.

Next, a synthetic paper (Yupo FPG # 150, manufactured by Oji Yuka Co., Ltd.) was used as a base sheet, and a coating solution having the following composition was applied to one surface of the synthetic paper at a rate of 10.0 g / m ² when dried. And dried at 100 ° C. for 30 minutes to form a dye-receiving layer to obtain a thermal transfer image-receiving sheet. Polyester binder resin (Vylon 200, manufactured by Toyobo) 11.5 parts Vinyl chloride / vinyl acetate copolymer (VYHH, manufactured by UCC) 5.0 parts Amino-modified silicone (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 1.2 parts Epoxy-modified Silicone (X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.) 1.2 parts Methyl ethyl ketone / toluene / cyclohexane (weight ratio 4: 4: 2) 102.0 parts

Thermal transfer recording test The above-mentioned thermal transfer sheet of the present invention and the above-mentioned thermal transfer image-receiving sheet were superposed on each other with the respective dye layers and the dye-receiving surface facing each other, and a voltage applied to the head of 11 V and a printing time of 10 msec. . Recording was performed with a thermal head under the conditions described above, and the results shown in Tables 1 to 4 below were obtained. Storage test The thermal transfer sheet of the present invention was stored at 60 ° C for 60 hours. The surface condition of the dye layer after storage was observed, and the storage property was determined according to the following criteria. …: No precipitation of dye was observed. Δ: Some precipitation of dye was observed. ×: precipitation of a large amount of dye was observed. The reflection density of the thermal transfer image receiving sheet on which the density measurement was recorded was measured using an optical densitometer R.
It measured using D-918 (made by Macbeth).

<Comparative Examples 1 to 9> The results shown in Table 4 below were obtained in the same manner as in Example except that the materials for forming the dye layer were changed as follows. (Ink composition) Dye having the following structure a part Binder resin b part Methyl ethyl ketone (100-ab) / 2 parts Toluene (100-ab) / 2 parts

Embedded image

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

([Table 4] is deleted.)

[0033]

[Table 5]

[0034]

According to the present invention as described above, by adopting a composition comprising a specific binder resin and a specific compatibilizer as a binder component constituting a dye layer, image quality such as printing sensitivity and resolution can be improved. It is possible to provide a thermal transfer sheet that is excellent in various properties involved, and excellent in the preservability of the thermal transfer sheet itself and the releasability of the thermal transfer sheet during image formation.

[0035]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a thermal transfer sheet of the present invention.

FIG. 2 is a cross-sectional view of the thermal transfer sheet of the present invention.

FIG. 3 is a perspective view of the thermal transfer sheet of the present invention.

FIG. 4 is a perspective view of the thermal transfer sheet of the present invention.

FIG. 5 is an explanatory view illustrating a method of transferring using the thermal transfer sheet of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Thermal transfer sheet 2 ... Base sheet 3 ... Thermal transfer layer 11 ... Heat transfer sheet 12 ... Base sheet 13 ... Receptive layer 14 ... Thermal head 15 ... Platen roll

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Yusuke Nakamura 1-1-1, Ichigaya-Kaga-cho, Shinjuku-ku, Tokyo Inside Dai Nippon Printing Co., Ltd. (56) References JP-A-61-262189 (JP, A) JP-A-3-61087 (JP, A) JP-A-4-113889 (JP, A) JP-A-4-163092 (JP, A) JP-A-4-201494 (JP, A) JP-A-2-128889 ( JP, A) JP-A-4-22686 (JP, A) JP-A-2-229076 (JP, A) JP-A-3-256795 (JP, A) JP-A-2-3384 (JP, A) (58) ) Surveyed field (Int.Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (3)

(57) [Claims] 1. A thermal transfer sheet comprising a substrate sheet and a dye layer containing a dye which is transferred by heating and transferred onto a thermal transfer image receiving sheet, and wherein the binder component of the dye layer is polystyrene. , Polyvinyl toluene,
At least one resin selected from the group consisting of polyacrylate, polyvinyl acetoacetal, polyvinyl butyral, nitrocellulose, ethyl hydroxyethyl cellulose and ethyl cellulose, and represented by the following structural formula
Thermal transfer sheet characterized by comprising a mixture of compatibilizing agent. 2. The weight ratio of the compatibilizer to the binder resin (binder resin / compatibilizer) is from 1/99 to 99/99.
The thermal transfer sheet according to claim 1, which is 1 . 3. The weight ratio of the dye to the binder resin in the dye layer (dye / binder resin + compatibilizer) is 0.3.
The thermal transfer sheet according to claim 1, which is as described above.