JP2006281602A - Thermal transfer sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel thermal transfer sheet with no deterioration in the coloring density. <P>SOLUTION: The sheet has thermal transfer dye layers 2, 3 and 4 on one side of a base 1. One of the thermal transfer dye layers 2, 3 and 4 contains at least one kind of indoaniline dye. A heat-resistant lubricative layer 6 is provided on the other side of the base 1. This layer 6 has a laminated structure and a lower layer 6a of the layer 6 that is in contact with the base 1 contains at least one kind of acid type phosphoric ester, while an upper layer 6b formed on the lower layer 6a contains specific polyglycerin fatty acid ester or specific glycerin fatty acid ester. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thermal transfer sheet, and more particularly to a thermal transfer sheet having excellent storage stability.

  The thermal transfer method using sublimation dyes, which has been widely adopted in recent years, transfers a large number of color dots to a transfer material by heating in an extremely short time, and reproduces a full color image of an original with these multicolored color dots. . Heating at this time is performed by a thermal head on the back side of the thermal transfer sheet, but a thermal transfer dye layer is provided in order to prevent the thermal transfer sheet from fusing to the thermal head and to impart smooth running properties to the thermal transfer sheet. A heat resistant slipping layer is provided on the opposite side of the surface.

  When printing a thermal transfer sheet on photographic paper, heat is applied from the thermal head to the heat-resistant slipping layer to transfer the dye in the thermal transfer dye layer on the opposite side to the photographic paper, but the color density is proportional to the amount of heat and the thermal head The surface temperature varies in the range of several hundred degrees. Therefore, when the thermal transfer sheet moves on the thermal head, the friction coefficient between the thermal head and the heat-resistant slipping layer is likely to change due to temperature change. If the coefficient of friction between the thermal head and the heat-resistant slip layer changes, the thermal transfer sheet becomes difficult to move at a constant speed, and a clear image cannot be obtained.

  For example, when the friction is large, the movement of the thermal transfer sheet is temporarily delayed, and linear printing unevenness called “sticking” in which the density is increased only in that portion occurs. In order to prevent such “sticking”, it is necessary to reduce the coefficient of friction particularly at high temperatures. Acid type phosphate esters are known as lubricants that reduce the coefficient of friction at high temperatures (for example, (See Patent Document 1).

  On the other hand, various dyes such as azo, anthraquinone, and methine are used in the thermal transfer dye layer to obtain a good color reproduction range, but indoaniline dyes are widely used as cyan dyes. It has become. When using an indoaniline dye as cyan in the thermal transfer dye layer, if a high acidity lubricant such as phosphate ester is used in the heat resistant slipping layer at the same time, it decomposes under acidity due to the contact of both layers in the wound layer state. The indaniline dyes that are easily damaged deteriorate and the color density decreases.

In order to solve this problem, a new thermal transfer sheet has been developed (for example, see Patent Document 2). This is a thermal transfer sheet having a thermal transfer dye layer on one side of the base sheet and a heat resistant slipping layer on the other side, and the heat resistant slipping layer contains a mixture of glycerin fatty acid ester and phosphate ester. is doing. Glycerin fatty acid esters and phosphate esters exhibit excellent lubricity and achieve a low coefficient of friction. Moreover, the bad influence to a dye layer becomes small by using these together.
Japanese Patent Laid-Open No. 06-155940 Japanese Patent Laid-Open No. 11-58989

However, in the conventional thermal transfer sheet described above, since the heat-resistant slipping layer contains a mixture of glycerin fatty acid ester and phosphate ester, it is unavoidable to be affected by the phosphate ester. That is, when using an indoaniline dye as cyan for the thermal transfer dye layer, if a mixture of glycerin fatty acid ester and phosphate ester is used for the heat-resistant slipping layer, both layers are in contact with each other in the wound layer state. There is a problem that the indaniline dyes which are easily decomposed are slightly deteriorated and the color density is lowered.
For these reasons, development of a new thermal transfer sheet that solves this problem is desired.

  The present invention has been made in view of such problems, and an object thereof is to provide a novel thermal transfer sheet.

  In order to solve the above problems and achieve the object of the present invention, the thermal transfer sheet of the present invention has a thermal transfer dye layer on one surface of a substrate, and the thermal transfer dye layer contains a dye that decomposes under acidic conditions. In the thermal transfer sheet having the heat resistant slipping layer on the other surface of the base material, the heat resistant slipping layer has a laminated structure, and the lower layer in contact with the base material of the heat resistant slipping layer is an acid-type phosphorus. The upper layer which contains an acid ester and is formed on the lower layer of the previous period contains a neutral lubricant.

  According to the thermal transfer sheet of the present invention, even if the thermal transfer sheet is in a wound layer state and the thermal transfer dye layer is in contact with the heat resistant slipping layer, the upper layer containing a neutral lubricant is formed on the lower layer. The acid type phosphate ester contained in the lower layer is prevented from exuding to the surface of the heat-resistant active layer.

  The thermal transfer sheet of the present invention has a thermal transfer dye layer on one surface of a substrate, the thermal transfer dye layer contains at least one kind of indoaniline dye (Chemical Formula 4), and on the other surface of the substrate. In the thermal transfer sheet having a heat-resistant slip layer, the heat-resistant slip layer has a laminated structure, and the lower layer in contact with the base material of the heat-resistant slip layer contains at least one acid-type phosphate ester, The upper layer formed on the first lower layer contains at least one polyglycerin fatty acid ester (Chemical Formula 5) or glycerin fatty acid ester (Chemical Formula 6).

  According to the thermal transfer sheet of the present invention, at least one polyglycerin fatty acid ester (Chemical Formula 5) or glycerin fatty acid ester (Chemical Formula 6) is used even when the thermal transfer sheet is in a wound layer state and the thermal transfer dye layer and the heat-resistant slipping layer are in contact with each other. Since the seed-containing upper layer is formed on the lower layer, the acid type phosphate ester contained in the lower layer is prevented from oozing out to the surface of the heat-resistant active layer.

The present invention has the following effects.
The present invention provides a thermal transfer sheet having a thermal transfer dye layer on one side of a substrate, the thermal transfer dye layer containing a dye that decomposes under acidity, and a heat resistant slipping layer on the other side of the substrate. The heat resistant slipping layer has a laminated structure, and the lower layer in contact with the base material of the heat resistant slipping layer contains an acid-type phosphate ester, and the upper layer formed on the lower layer is the middle layer. Therefore, a novel thermal transfer sheet can be provided.

  The present invention has a thermal transfer dye layer on one surface of a substrate, the thermal transfer dye layer contains at least one indoaniline dye (Chemical Formula 4), and heat-resistant slipping on the other surface of the substrate. In the thermal transfer sheet having a layer, the heat resistant slipping layer has a laminated structure, and the lower layer in contact with the substrate of the heat resistant slipping layer contains at least one acid-type phosphate ester, Since the upper layer formed above contains at least one polyglycerol fatty acid ester (Chemical Formula 5) or glycerin fatty acid ester (Chemical Formula 6), a novel thermal transfer sheet can be provided.

  Hereinafter, the best mode for carrying out the invention relating to a thermal transfer sheet will be described.

  FIG. 1 schematically shows a cross section of the thermal transfer sheet of the present invention, and FIGS. 2 to 6 are top views thereof. Here, there are thermal transfer dye layers 2, 3, and 4 on one side of the substrate 1. The thermal transfer dye layer is composed of at least a dye and a binder. In addition to the thermal transfer dye layer, a detection mark 9 for detecting the sheet position may be provided. On the other hand, the heat resistant slipping layer 6 is provided on the other surface of the substrate 1. The heat-resistant slip layer 6 has a laminated structure (two-layer structure). The lower layer 6 a of the heat-resistant slip layer 6 is in contact with the substrate 1. An upper layer 6b is formed on the lower layer 6a.

  The thermal transfer dye layers 2, 3, and 4 correspond to yellow, magenta, and cyan, but the order of yellow, magenta, and cyan does not necessarily have to be the same. Further, as shown in FIG. 3, the thermal transfer dye layer may be black only, and further, four colors of yellow, magenta, cyan, and black may be used as shown in FIG.

  In addition to the thermal transfer dye layer, a transparent transfer protective layer 8 may be provided for protecting the print screen by transferring it to the print screen after printing as shown in FIG. Further, as shown in FIG. 6, a thermal transfer receiving layer 10 for transferring to plain paper may be provided.

  At least one of the thermal transfer dye layers of the thermal transfer sheet contains a dye that decomposes under acidic conditions. Examples of the dye that decomposes under acid conditions include indoaniline-based dyes. The thermal transfer dye layer contains at least one kind of indoaniline dye (Chemical Formula 4).

  In this case, a single or a plurality of indoaniline dyes may be used as the cyan dye, and in addition to the indoaniline dyes, conventionally known dyes such as anthraquinone, naphthoquinone, and heterocyclic azo dyes may be used. May be.

  The dye that decomposes under acidic conditions is not limited to indoaniline dyes. Other dyes that decompose under acidic conditions can be used.

  In general, yellow and magenta colors other than cyan are used for the thermal transfer dye layer. However, the dyes contained in the yellow and magenta thermal transfer dye layers are conventionally known various dyes, for example, yellow dyes such as azo and disazo dyes. As methine dyes, methine dyes, styryl dyes, pyridone / azo dyes, and mixtures thereof, and magenta dyes, azo dyes, anthraquinone dyes, styryl dyes, heterocyclic azo dyes, and the like, and mixtures thereof can be used.

  As the substrate 1, various conventionally known substrates can be used. For example, polyester film, polystyrene film, polypropylene film, polysulfone film, polycarbonate film, polyimide film, aramid film, and the like.

  The thickness of the substrate is preferably in the range of 1 to 30 μm. Further, the thickness of the base material is more preferably in the range of 2 to 10 μm.

  When the thickness of the substrate is 1 μm or more, there is an advantage that heat wrinkles can be prevented from occurring due to the elongation of the substrate. This effect becomes more remarkable when the thickness of the substrate is 2 μm or more.

  When the thickness of the substrate is 30 μm or less, there is an advantage that heat from the thermal head can be appropriately transmitted and a decrease in the color density of the image can be prevented. This effect becomes more remarkable when the thickness of the substrate is 10 μm or less.

  The heat-resistant slip layer 6 is a resin containing a lubricant in both the lower layer 6a and the upper layer 6b, and various fillers and polyisocyanate compounds can be added as necessary.

  Preferred binder resins for the lower layer 6a and the upper layer 6b of the heat resistant slip layer 6 include, for example, polyester resins, polyacrylate resins, polyvinyl acetate resins, styrene acrylate resins, polyurethane resins, polyolefin resins, Polystyrene resin, polyvinyl chloride resin, polyether resin, polyamide resin, polycarbonate resin, polyethylene resin, polypropylene resin, polyacrylate resin, polyacrylamide resin, polyvinyl chloride resin, polyvinyl butyral resin, acetal resin, etc. Among these, particularly preferred resins are polyvinyl butyral resin and acetal resin. Furthermore, the lower layer 6a and the upper layer 6b do not need to be the same resin.

  The lower layer of the heat resistant slipping layer contains at least one acid-type phosphate ester. Here, the acid-type phosphate ester is a compound having at least one active hydroxyl group in which —OH is directly bonded to P.

  Examples of the acid type phosphoric acid ester include “PHOSPANOL” series manufactured by Toho Chemical Industry Co., Ltd. and “Plisurf” series manufactured by Daiichi Kogyo Seiyaku Co., Ltd.

  The upper layer 6b of the heat resistant slip layer 6 contains a neutral lubricant. Examples of neutral lubricants include polyglycerol fatty acid esters and glycerol fatty acid esters. The upper layer 6b of the heat-resistant slip layer 6 contains at least one polyglycerin fatty acid ester (Chemical Formula 5) or glycerin fatty acid ester (Chemical Formula 6).

  Polyglycerin fatty acid esters and glycerin fatty acid esters include the “NIKKOL” series manufactured by Nikko Chemicals, the “Lunac” series manufactured by Kao Corporation, the “Emulsy” series manufactured by Takeda Kirin Foods Co., Ltd., and the “SY Glister” manufactured by Sakamoto Pharmaceutical Co., Ltd. ”Series.

  As the lubricant contained in the lower layer 6a and the upper layer 6b of the heat-resistant slip layer 6, in addition to the above, organic silicon, polyethylene phenyl polysiloxane, fatty acid amide, fatty acid ester, long chain aliphatic compound, low molecular weight polypropylene and the like are added. May be.

  The content of the acid-type phosphate ester in the lower layer 6a of the heat-resistant slip layer 6 is X parts by mass with respect to 100 parts by mass of the resin in the lower layer 6a, and the content of the polyglycerol fatty acid ester and glycerol fatty acid ester in the upper layer 6b is When the mass ratio is Y parts by mass with respect to 100 parts by mass of the resin of the upper layer 6b, the mass ratio Y / X is preferably in the range of 0.1 to 2.0. The mass ratio Y / X is more preferably in the range of 0.2 to 1.0.

  When the mass ratio Y / X is 0.1 or more, even if the thermal transfer sheet is in a wound layer state and the thermal transfer dye layer is in contact with the heat-resistant slipping layer, the surface of the heat-resistant active layer of the acid type phosphate ester contained in the lower layer There is an advantage that exudation to the water is suppressed. This effect becomes more remarkable when the mass ratio Y / X is 0.2 or more.

  When the mass ratio Y / X is 2.0 or less, when the heat-resistant active layer comes into contact with a high-temperature thermal head, the acid type phosphoric acid ester under the heat-resistant active layer oozes out to the surface of the heat-resistant active layer and serves as a lubricant. The advantage is that it works well. This effect becomes more remarkable when the mass ratio Y / X is 1.0 or less.

  The content of the acid phosphate in the lower layer 6a of the heat-resistant slip layer 6 is preferably in the range of 3 to 60 parts by mass with respect to 100 parts by mass of the resin of the lower layer 6a. Moreover, it is further more preferable that content of acid type phosphate ester exists in the range of 5-40 mass parts with respect to 100 mass parts of resin of the lower layer 6a.

  When the content of the acid-type phosphate ester is 3 parts by mass or more with respect to 100 parts by mass of the resin of the lower layer 6a, the acid type of the lower layer of the heat-resistant active layer when the heat-resistant active layer comes into contact with the high-temperature thermal head There is an advantage that the phosphate ester oozes out on the surface of the heat-resistant active layer and functions sufficiently as a lubricant. This effect becomes more prominent when the content of the acid-type phosphate is 5 parts by mass or more with respect to 100 parts by mass of the resin of the lower layer 6a.

  When the content of the acid type phosphate ester is 60 parts by mass or less with respect to 100 parts by mass of the resin of the lower layer 6a, even if the thermal transfer sheet is in a wound layer state and the thermal transfer dye layer and the heat-resistant slipping layer are in contact with each other, There is an advantage that the acid type phosphate ester contained in the lower layer is prevented from exuding to the surface of the heat-resistant active layer. This effect becomes more conspicuous when the content of the acid-type phosphate ester is 40 parts by mass or less with respect to 100 parts by mass of the resin of the lower layer 6a.

  Examples of the filler contained in the lower layer 6a and the upper layer 6b of the heat-resistant slip layer 6 include inorganic fillers such as silica, talc, clay, zeolite, titanium oxide, zinc oxide, carbon, silicon resin, fluororesin, benzoguanamine resin, and the like. An organic filler consisting of can be used.

  The polyisocyanate compound contained in the lower layer 6a and the upper layer 6b of the heat-resistant slip layer 6 is not particularly limited as long as it is an isocyanate compound having at least two isocyanate groups in the molecule. For example, tolylene diisocyanate, 4, 4 '-Diphenylmethane diisocyanate, 4,4'-xylene diisocyanate, hexamethylene diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methylcyclohexane-2,4 (or 2,6) -diisocyanate, 1,3-diisocyanate (Isocyanate methyl) cyclohexane, isophorone diisocyanate, trimethyl hexamethylene diisocyanate, etc., and polyisocyanate adducts obtained by partial addition reaction of diisocyanate and polyol (polyisocyanate) Prepolymer), for example, it can be used adduct obtained by reacting tolylene diisocyanate with trimethylol propane.

  Each thickness of the lower layer 6a and the upper layer 6b of the heat-resistant slip layer 6 is preferably in the range of 0.1 to 5.0 μm. Further, it is more preferable that the thicknesses of the lower layer 6a and the upper layer 6b are in the range of 0.2 to 1.0 μm.

  When the thickness of the lower layer 6a and the upper layer 6b is 0.1 μm or more, there is an advantage that the friction between the heat resistant slipping layer and the thermal head can be reduced during printing. This effect becomes more remarkable when the thickness of the lower layer 6a and the upper layer 6b is 0.2 μm or more.

  When the thickness of the lower layer 6a and the upper layer 6b is 5.0 μm or less, there is an advantage that heat from the thermal head can be appropriately transmitted and a reduction in the color density of the image can be prevented. This effect becomes more remarkable when the thickness of the lower layer 6a and the upper layer 6b is 1.0 μm or less.

  From the above, according to the best mode for carrying out the present invention, a thermal transfer dye layer is provided on one surface of a substrate, and the thermal transfer dye layer contains a dye that decomposes under acidic conditions, In the thermal transfer sheet having a heat-resistant slip layer on the other surface of the material, the heat-resistant slip layer has a laminated structure, and the lower layer in contact with the base material of the heat-resistant slip layer is an acid-type phosphate ester. Since the upper layer formed on the lower layer contains a neutral lubricant, even if the thermal transfer sheet is in a wound layer state and the thermal transfer dye layer and the heat resistant slipping layer are in contact, the acid contained in the lower layer Exudation of the type phosphate ester to the surface of the heat-resistant active layer is suppressed. As a result, a novel thermal transfer sheet can be provided.

  Further, according to the best mode for carrying out the present invention, the substrate has a thermal transfer dye layer on one side of the substrate, and the thermal transfer dye layer contains at least one kind of indoaniline dye (Chemical Formula 4). In the thermal transfer sheet having the heat resistant slipping layer on the other surface of the base material, the heat resistant slipping layer has a laminated structure, and the lower layer in contact with the base material of the heat resistant slipping layer is an acid-type phosphorus. Since the upper layer that contains at least one acid ester and is formed on the lower layer contains at least one polyglycerin fatty acid ester (Chemical Formula 5) or glycerin fatty acid ester (Chemical Formula 6), the thermal transfer sheet is in a wound layer state Even if the thermal transfer dye layer and the heat-resistant slipping layer are in contact with each other, exudation of the acid-type phosphate ester contained in the lower layer to the surface of the heat-resistant active layer is suppressed. As a result, a novel thermal transfer sheet can be provided.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, specific examples of the present invention will be described. However, it goes without saying that the present invention is not limited to these examples.

Examples 1-7
A method for producing a thermal transfer sheet will be described.
First, a polyester film having a thickness of 6 μm (Lumirror, manufactured by Toray Industries, Inc.) was used as a base material, and the following ink composition was applied to one surface of the base material so as to have a dry thickness of 1 μm.

Ink composition 100 and indoaniline dyes of Tables 1 and 2 100 parts by mass BX-1 100 parts by mass (polyvinyl butyral resin manufactured by Sekisui Chemical Co., Ltd.)
900 parts by weight of methyl ethyl ketone 900 parts by weight of toluene

  Next, on the other surface of the above-mentioned base material, a heat resistant slipping layer comprising the following composition is applied so that the lower layer has a dry thickness of 0.5 μm and the upper layer has a dry thickness of 0.5 μm. A thermal transfer sheet was obtained.

Lower layer Resin of Table 2 100 parts by weight Coronate-L 10 parts by weight (made by Nippon Polyurethane Industry Co., Ltd., isocyanate)
Acid type phosphoric acid ester of Table 2 X part by mass Nipsil E-200A 10 parts by mass (made by Nippon Silica Kogyo Co., Ltd.)
Methyl ethyl ketone 940-X / 2 parts by mass Toluene 940-X / 2 parts by mass

Upper layer Resin of Table 2 100 parts by weight Coronate-L 10 parts by weight (Nippon Polyurethane Industry Co., Ltd., isocyanate)
Polyglycerin fatty acid ester of Table 2, etc. Y parts by mass Nipsil E-200A 10 parts by mass (made by Nippon Silica Kogyo Co., Ltd.)
Methyl ethyl ketone 940-Y / 2 parts by mass Toluene 940-Y / 2 parts by mass

Comparative Examples 1-7
Thermal transfer sheets for evaluation of Comparative Examples 1 to 7 shown in Table 2 were obtained in the same manner as in Examples.

  In Table 2, polyglycerin fatty acid esters and the like are manufactured by NIKKOL: Nikko Chemicals Co., Ltd. and Lunac: Kao Corporation. The acid type phosphoric acid ester is PHOSPANOL: manufactured by Toho Chemical Industry Co., Ltd. The resin is Denkabu Chiral: manufactured by Denki Kagaku Kogyo Co., Ltd., and ESREC: manufactured by Sekisui Chemical Co., Ltd. Here, among the resins, Denka Butyral 6000AS and Eslek KS-5 are acetal resins, and those other than these two are polyvinyl butyral resins.

  For Examples 1 to 7 and Comparative Examples 1 to 7, the obtained thermal transfer sheets were printed on UP-D7000 (manufactured by Sony, full-color printer) and printed on UPC7010 (manufactured by Sony, print media for UP-7000). Tone printing (16 STEP) was performed, and sticking was examined visually.

  As for dye storage stability, the thermal transfer dye layer and the heat-resistant slipping layer of the two obtained thermal transfer sheets are overlapped (20 × 20 cm), sandwiched between two glass plates, and a load of 5 kg is applied from above. It was put in an oven at 50 ° C. (PHH-200, manufactured by Tabai Corporation) and stored for 48 hours. The obtained thermal transfer sheet is printed with gradation (16 STEP) on photographic paper of UPC7010 (manufactured by Sony, UP-7000) by UP-D7000 (manufactured by Sony, full color printer), and before and after storage. The dye preservability was evaluated by measuring the reflection density with a Macbeth densitometer TR-924 (Red filter) at the highest cyan density.

  The evaluation results are as shown in Table 3. In the evaluation of sticking, the case where sticking did not occur was marked with ◯, and the case where sticking occurred was marked with ×. Here, it was assumed that “good” was satisfied.

In the evaluation of dye storage stability, dye storage stability was defined by the following formula.
Dye storage stability (%) = (maximum density after storage / maximum density before storage) × 100
A dye having storability of 90% or more was rated as ◯, and a dye having less than 90% was rated as x. Here, it was assumed that “good” was satisfied.

  From the results of Table 3, in all of Examples 1 to 7, no sticking accompanying an increase in friction was confirmed, and clear images were obtained. Further, the dye storage stability was hardly observed, and all the values were 90% or more.

  On the other hand, in Comparative Examples 1 and 2, since the content of the acid type phosphoric ester is as small as 4.0 parts by mass with respect to 100 parts by mass of the lower layer resin, the heat-resistant active layer is in contact with the high-temperature thermal head. In addition, the acid type phosphoric acid ester under the heat-resistant active layer cannot sufficiently ooze out to the surface of the heat-resistant active layer, and does not function sufficiently as a lubricant. As a result, sticking has occurred.

  In Comparative Examples 3 and 4, fatty acid ester or fatty acid was used for the upper layer, but sticking occurred. Therefore, it turns out that fatty acid ester and a fatty acid do not fully function as a lubricant.

  In Comparative Example 5, since the mass ratio Y / X between the polyglycerin fatty acid ester and the like and the acid type phosphate ester is as high as 1.05, when the heat resistant active layer comes into contact with the high temperature thermal head, the lower layer of the heat resistant active layer The acid type phosphoric acid ester cannot sufficiently ooze out to the surface of the heat-resistant active layer and does not function sufficiently as a lubricant. As a result, sticking has occurred. In Comparative Example 2, the mass ratio Y / X between the polyglycerin fatty acid ester and the like and the acid-type phosphate ester is as high as 1.25, so the same result as in Comparative Example 5 is obtained.

  In Comparative Example 6, the mass ratio Y / X between the polyglycerin fatty acid ester and the like and the acid-type phosphate ester is as low as 0.15, so that the thermal transfer sheet is in a wound layer state and the thermal transfer dye layer and the heat-resistant slipping layer are in contact with each other. When it exists, it is difficult to suppress the acid type phosphate ester contained in the lower layer from exuding to the surface of the heat-resistant active layer. As a result, satisfactory dye storage stability cannot be obtained.

  In Comparative Example 7, the content of the acid type phosphate ester is as high as 45 parts by mass with respect to 100 parts by mass of the lower layer resin, so that the thermal transfer sheet is in a wound layer state and the thermal transfer dye layer and the heat-resistant slipping layer are in contact with each other. In such a case, it is difficult to suppress the acid type phosphoric acid ester contained in the lower layer from exuding to the heat-resistant active layer surface. As a result, satisfactory dye storage stability cannot be obtained.

  As described above, according to the present embodiment, the thermal transfer sheet moves on the thermal head at a constant speed to obtain a clear image, and provides a thermal transfer sheet that does not cause a decrease in density due to dye deterioration in the wound layer state. be able to.

It is sectional drawing which represented typically the thermal transfer sheet of this invention. It is the top view which represented typically the thermal transfer sheet of this invention. It is the top view which represented typically the thermal transfer sheet of this invention. It is the top view which represented typically the thermal transfer sheet of this invention. It is the top view which represented typically the thermal transfer sheet of this invention. It is the top view which represented typically the thermal transfer sheet of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Base material, 2-4 ... Thermal transfer dye layer, 6 ... Heat-resistant slipping layer, 6a ... Lower layer, 6b ... Upper layer, 7 ... Thermal transfer dye layer, 8 ... Transfer protective layer, 9 ... Detection mark, 10 ... Thermal transfer receiving layer

Claims (4)

Having a thermal transfer dye layer on one side of the substrate,
The thermal transfer dye layer contains a dye that decomposes under acidic conditions,
In the thermal transfer sheet having a heat resistant slipping layer on the other surface of the substrate,
The heat-resistant slip layer has a laminated structure,
The lower layer in contact with the substrate of the heat-resistant slip layer contains an acid-type phosphate ester,
A thermal transfer sheet, wherein the upper layer formed on the lower layer contains a neutral lubricant. Having a thermal transfer dye layer on one side of the substrate,
The thermal transfer dye layer contains at least one kind of indoaniline dye (Chemical Formula 1),
In the thermal transfer sheet having a heat resistant slipping layer on the other surface of the substrate,
The heat-resistant slip layer has a laminated structure,
The lower layer in contact with the substrate of the heat-resistant slip layer contains at least one acid-type phosphate ester,
The thermal transfer sheet, wherein the upper layer formed on the lower layer contains at least one polyglycerin fatty acid ester (Chemical Formula 2) or glycerin fatty acid ester (Chemical Formula 3).

The content of the acid type phosphate ester in the lower layer is X parts by mass with respect to 100 parts by mass of the lower layer resin,
The content of the polyglycerol fatty acid ester and glycerol fatty acid ester in the upper layer is Y parts by mass with respect to 100 parts by mass of the resin in the upper layer,
Mass transfer ratio Y / X exists in the range of 0.2-1.0. The thermal transfer sheet of Claim 2 characterized by the above-mentioned. 4. The thermal transfer sheet according to claim 3, wherein the content of the acid phosphate in the lower layer is in the range of 5 to 40 parts by mass with respect to 100 parts by mass of the resin in the lower layer.

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