JP6028482B2 - Thermal transfer sheet - Google Patents

Description

  The present invention relates to a thermal transfer sheet.

  As a general thermal transfer sheet used in a printer, a thermal transfer sheet in which a dye layer is provided on one side of a substrate and a back layer is provided on the other side of the substrate is known. According to this thermal transfer sheet, after the transfer target such as the thermal transfer image receiving sheet and the dye layer of the thermal transfer sheet are stacked so as to face each other, the back layer and the heating device such as a thermal head are brought into contact with each other, By applying energy corresponding to image information to the heating device in such a manner as to rub on the back layer, an image can be formed on the transfer medium.

  By the way, when image formation is performed using a thermal transfer sheet having a back layer having low slipperiness, wrinkles are generated in the thermal transfer sheet during image formation, and printing wrinkles are also generated in the image formed accordingly. It becomes. Therefore, it is necessary to use a thermal transfer sheet provided with a back layer having sufficient slipperiness so as not to cause printing wrinkles in the formed image. Various proposals have been made for thermal transfer sheets focusing on the slipperiness of the back layer. For example, Patent Document 1 includes a back layer containing a phosphate ester compound and a reactive modified silicone oil as a lubricant component. Thermal transfer sheets have been proposed. Patent Document 2 proposes a thermal transfer sheet containing metal soap as a lubricant component in the back layer.

  The thermal transfer sheet is generally stored and used in a wound state. In the state where the thermal transfer sheet is wound, the dye layer and the back layer are in direct contact with each other. Therefore, when the back layer contains components that are easily dyed by the dye of the dye layer, the thermal transfer sheet A so-called kick occurs in which the dye in the dye layer moves to the back surface layer during winding. The phosphate ester, silicone oil, etc. proposed in Patent Document 1 are liquid lubricants, and are lubricant components that are particularly easily dyed by the dyes in the dye layer. Therefore, a thermal transfer sheet having a back layer containing a liquid lubricant such as phosphate ester or silicone oil has a high degree of kick generation. On the other hand, solid lubricants such as metal soaps proposed in Patent Document 2 are less likely to be dyed by dyes in the dye layer than liquid lubricants, and although the degree of kick generation is low, sufficient lubricity is exhibited. In the case where a solid lubricant is contained in the back layer, the degree of kick generation increases as in the case where a liquid lubricant is used. In other words, there is a trade-off between the effect of improving lubricity and the effect of preventing the occurrence of kicks, and if the focus is on improving the lubricity, the degree of occurrence of kicks will increase, while the occurrence of kicks will be prevented. When the main focus is on, sufficient slipperiness cannot be imparted to the back layer.

  Further, when the thermal transfer sheet having the dye layer kicked on the back layer is rolled back, a so-called back is formed in which the kicked dye re-transfers to the dye layer, causing various problems. For example, in a thermal transfer sheet in which dye layers of different colors are repeatedly provided in the surface order on the base material, when the dye kicked to the back layer backs to another dye layer containing a dye of a hue different from the dye Will cause a reduction in color development characteristics. In addition, in the integrated thermal transfer sheet in which the dye layer and the transferable protective layer are provided in the surface order on the base material, when the dye kicked to the back layer is back on the transferable protective layer, the transferable protective layer The transferability of the toner onto the transfer medium is inhibited, and the quality of the printed material after the transfer of the transferable protective layer is lowered.

JP 2008-188902 A JP 2004-90594 A

  The present invention has been made in view of such a situation, and when the thermal transfer sheet is wound up, it is possible to effectively prevent the occurrence of a kick in which the dye in the dye layer moves to the back layer, and the back layer is slipped. The main object is to provide a thermal transfer sheet having excellent properties.

The present invention for solving the above problems is a thermal transfer sheet in which a dye layer is provided on one surface of a substrate and a back layer is provided on the other surface of the substrate, wherein the back layer is a binder. A first lubricant and a second lubricant, wherein the first lubricant is diacylglycerol, the second lubricant is a solid lubricant having a melting point of 80 ° C. or higher, and the total solid content of the back layer On the other hand, the first lubricant is contained in a range of 2 to 20% by mass, and the second lubricant is contained in a range of 1 to 15% by mass .

Further, the thermal transfer sheet of one embodiment is a thermal transfer sheet in which a dye layer is provided on one surface of a substrate and a back layer is provided on the other surface of the substrate, and the back layer is a binder, A first lubricant and a second lubricant, wherein the first lubricant is at least one selected from the group consisting of sorbitan fatty acid ester, triacylglycerol, and diacylglycerol; The lubricant is a solid lubricant having a melting point of 80 ° C. or higher.
In the thermal transfer sheet according to the embodiment, the first lubricant is contained in a range of 2% by mass to 20% by mass with respect to the total solid content of the back layer, and the second lubricant is 1% by mass to 15% by mass. % Or less may be contained.

  According to the present invention, it is possible to effectively prevent the occurrence of a kick in which the dye of the dye layer shifts to the back layer when the thermal transfer sheet is wound up while providing sufficient slip to the back layer.

It is a schematic sectional drawing which shows an example of the thermal transfer sheet of this invention. It is a schematic sectional drawing which shows an example of the thermal transfer sheet of this invention. It is a schematic sectional drawing which shows an example of the thermal transfer sheet of this invention.

  Hereinafter, the thermal transfer sheet of the present invention will be specifically described with reference to the drawings. 1 to 3 are schematic cross-sectional views showing an example of the thermal transfer sheet of the present invention.

  As shown in FIGS. 1 to 3, the thermal transfer sheet 10 of the present invention has a configuration in which a dye layer 3 is provided on one surface of a substrate 1 and a back layer 5 is provided on the other surface of the substrate 1. Take. In the thermal transfer sheet 10 of the present invention, the back layer 5 contains a binder, a first lubricant, and a second lubricant, and the first lubricant is composed of sorbitan fatty acid ester, triacylglycerol, and diacylglycerol. One or two or more selected from the group, and the second lubricant is a solid lubricant having a melting point of 80 ° C. or higher. In the present invention, any other configuration of the thermal transfer sheet 10 is not limited as long as the back layer 5 has this requirement. For example, as shown in FIG. 2, a dye primer layer 7 may be provided between the substrate 1 and the dye layer 3, and a release layer (not shown) is provided between the substrate 1 and the dye layer 3. It may be done. A back primer layer (not shown) may be provided between the base material 1 and the back layer 5. Moreover, as shown in FIG. 3, the dye layer 3 may have a configuration in which a plurality of dye layers (3Y, 3M, 3C) having different hues are provided in the surface order. In addition, the dye primer layer 7, the release layer, and the back primer layer are arbitrary configurations in the thermal transfer sheet 10 of the present invention. Hereinafter, each configuration of the thermal transfer sheet 10 will be specifically described.

(Base material)
The substrate 1 is an essential component in the thermal transfer sheet 10 of the present invention, and is provided to hold a dye layer 3 and a back layer 5 described later. The material of the substrate 1 is not particularly limited, but it is desirable that the material has mechanical characteristics that can withstand heat applied by the thermal head when the dye layer 3 is transferred onto the transfer target and does not hinder handling. Examples of such base materials include polyesters such as polyethylene terephthalate, polyarylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivatives, polyethylene, ethylene / vinyl acetate copolymer, polypropylene, polystyrene, acrylic, and polyvinyl chloride. , Polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyether sulfone, tetrafluoroethylene / perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene / hexafluoro Various plastic fills such as propylene, polychlorotrifluoroethylene, and polyvinylidene fluoride Or it can be given a seat. Moreover, the thickness of the base material 1 can be appropriately set according to the material so that the strength and heat resistance are appropriate, and is generally about 2 to 100 μm, preferably 1 to 10 μm.

(Back layer)
As shown in the drawing, a back layer 5 is provided on the other surface of the substrate 1 (in the case of FIGS. 1 to 3, the lower surface of the substrate 1). The back layer 5 is an essential component in the thermal transfer sheet 10 of the present invention.

  The back layer 5 contains a binder, a first lubricant, and a second lubricant. The first lubricant contained in the back layer 5 is one or more selected from the group of sorbitan fatty acid ester, triacylglycerol, and diacylglycerol, and the second lubricant has a melting point of 80 ° C. It is the above solid lubricant. Hereinafter, each component contained in the back layer 5 will be described in detail.

<< first lubricant >>
The back layer 5 contains one or more selected from the group of sorbitan fatty acid ester, triacylglycerol, and diacylglycerol as the first lubricant. Sorbitan fatty acid ester, triacylglycerol, and diacylglycerol have the property of being difficult to be dyed by the dye of the dye layer 3 while serving as a lubricant that imparts lubricity to the back layer. Therefore, according to the back layer 5 containing the first lubricant, the occurrence of print wrinkles during image formation can be prevented by the lubricity imparted to the back layer 5, and the thermal transfer sheet 10 of the present invention can be used as the dye layer. 3 and the back layer 5 are wound so that they face each other, it is possible to effectively prevent the occurrence of a kick in which the dye of the dye layer 3 moves to the back layer 5.

<Sorbitan fatty acid ester>
The sorbitan fatty acid ester is an ester of sorbitan and a fatty acid represented by RCOOH (general formula (1)), and the sorbitan fatty acid ester includes a linear or branched fatty acid residue. In addition, the fatty acid residue said in this specification means "RCOO" in the said General formula (1). There is no particular limitation on the fatty acid residue contained in the sorbitan fatty acid ester. For example, lauric acid residue, palmitic acid residue, stearic acid residue, isostearic acid residue, oleic acid residue, caprylic acid residue, myristic acid residue Group, behenic acid residue and the like.

  Specific examples of sorbitan fatty acid esters containing these fatty acid residues include, for example, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan sesquistearate, sorbitan dilaurate. Sorbitan dipalmitate, sorbitan distearate, sorbitan dioleate, sorbitan trilaurate, sorbitan tripalmitate, sorbitan tristearate, sorbitan trioleate and the like. These sorbitan fatty acid esters may be used alone or in combination of two or more.

  As described above, there is no particular limitation on the fatty acid residue contained in the sorbitan fatty acid ester. In addition, it has the property of being excellent in lubricity. Accordingly, it is preferable that the sorbitan fatty acid ester contains a fatty acid residue having a long carbon chain length. Specifically, the sorbitan fatty acid ester may contain a fatty acid residue having a carbon chain length of 18 or more. preferable. More specifically, the sorbitan fatty acid ester preferably contains a stearic acid residue, an oleic acid residue, a behenic acid residue and the like as the fatty acid residue.

  When the sorbitan fatty acid ester is other than sorbitan monofatty acid ester, the fatty acid residues contained in the sorbitan fatty acid ester may be the same or different. When fatty acid residues are different, at least one fatty acid residue is preferably a fatty acid residue having a carbon chain length of 18 or more, and all fatty acid residues are fatty acids having a carbon chain length of 18 or more. A residue is particularly preferred. In the present specification, when the fatty acid residue having a carbon chain length of 18 or more is included, the carbon chain of at least one fatty acid residue among one or two or more fatty acid residues contained in the sorbitan fatty acid ester It means that the length is 18 or more. Hereinafter, the same applies to triacylglycerol and diacylglycerol.

<Triacylglycerol>
Triacylglycerol is a compound represented by the following general formula (2).

In the above general formula (2), “R ₁ COO”, “R ₂ COO”, and “R ₃ COO” are linear or branched fatty acid residues, respectively. The fatty acid residues (“R ₁ COO”, “R ₂ COO”, “R ₃ COO”) may be the same or different.

There is no particular limitation on the fatty acid residues (“R ₁ COO”, “R ₂ COO”, “R ₃ COO”) contained in triacylglycerol, and the same fatty acid residues as those described for the sorbitan fatty acid ester described above, For example, lauric acid residue, palmitic acid residue, stearic acid residue, isostearic acid residue, oleic acid residue, caprylic acid residue, myristic acid residue, behenic acid residue and the like can be mentioned.

  Specific examples of triacylglycerols containing these fatty acid residues include glycerol trioleate, glycerol tristearate, glycerol tribehenate, glycerol tricaprylate, and glycerol trimyristate. These triacylglycerols can be used alone or in combination of two or more.

  Triacylglycerol has a low HLB value because all three hydroxyl groups of glycerin are esterified. It is presumed that the kick prevention effect improves as the HLB value decreases. Therefore, according to the triacylglycerol in which all of the three hydroxyl groups of glycerin are esterified, the back layer 5 is given lubricity regardless of the carbon chain length of the fatty acid residue contained in the triacylglycerol. However, a sufficient kick prevention effect can be achieved. For the purpose of further preventing the occurrence of kicks, the triacylglycerol preferably contains a fatty acid residue having a carbon chain length of 18 or more. In other words, triacylglycerol preferably contains a fatty acid residue having a carbon chain length of 18 or more, such as a stearic acid residue, an oleic acid residue, and a behenic acid residue. In particular, it is preferable that all fatty acid residues contained in triacylglycerol are fatty acid residues having a carbon chain length of 18 or more.

<Diacylglycerol>
Diacylglycerol is a compound represented by the following general formula (3) or general formula (4).

In the above general formulas (3) and (4), “R ₁ COO” and “R ₂ COO” are linear or branched fatty acid residues, respectively. The fatty acid residues (“R ₁ COO” and “R ₂ COO”) may be the same or different.

The fatty acid residue (“R ₁ COO”, “R ₂ COO”) contained in diacylglycerol is not particularly limited, and is the same as the fatty acid residue described for sorbitan fatty acid ester and triacylglycerol described above, for example, Examples thereof include a lauric acid residue, a palmitic acid residue, a stearic acid residue, an isostearic acid residue, an oleic acid residue, a caprylic acid residue, a myristic acid residue, and a behenic acid residue.

  Specific examples of diacylglycerol compounds containing these fatty acid residues include glycerol dilaurate, glycerol dipalmitate, glycerol dioleate, glycerol distearate, glycerol dibehenate, glycerol dicaprylate, and glycerol dimyristate. Can be mentioned. These diacylglycerols may be used alone or in combination of two or more.

  Diacylglycerol preferably contains a fatty acid residue having a carbon chain length of 18 or more, and all fatty acid residues (“R1COO” and “R2COO”) contained in diacylglycerol have a carbon chain length of 18 The above fatty acid residues are preferable. Diacylglycerol has a smaller number of esterified three hydroxyl groups of glycerin than triacylglycerol described above, and tends to have a higher HLB value than triacylglycerol. By including 18 or more fatty acid residues, it is possible to achieve a very excellent kick prevention effect as in the case of triacylglycerol.

  The content of the first lubricant with respect to the total solid content of the back layer 5 is not particularly limited, but when the content of the first lubricant is less than 2% by mass with respect to the total solid content of the back layer 5, There exists a tendency for the improvement effect of the lubricity of the back layer 5 brought about by 1 lubricant to fall. On the other hand, if it exceeds 20% by mass, the effect of preventing kick generation and the effect of further improving the lubricity of the back layer 5 cannot be expected, and the content of the binder is reduced correspondingly. Tend to decrease. Therefore, considering this point, the content of the first lubricant is preferably in the range of 2% by mass or more and less than 20% by mass with respect to the total solid content of the back layer 5. In addition, content of the 1st lubricant said here means the total mass of the lubricant used as a 1st lubricant.

  Further, sorbitan fatty acid ester containing a fatty acid residue having a carbon chain length of 18 or more, triacylglycerol containing a fatty acid residue having a carbon chain length of 18 or more, and a carbon chain length of 18 or more with respect to the total solid content of the first lubricant. The total mass of the diacylglycerol containing the fatty acid residues is preferably 80% by mass or more. By making the content of sorbitan fatty acid ester, triacylglycerol, and diacylglycerol containing a fatty acid residue having a carbon chain length of 18 or more within this range, the effect of preventing the occurrence of kick and the improvement of the slipperiness of the back layer 5 are achieved. The effect can be further enhanced.

<< Second lubricant >>
The back layer 5 contains a solid lubricant having a melting point of 80 ° C. or higher as the second lubricant. In the present invention, the second lubricant acts as a role of improving the lubricity of the back layer 5. Specifically, the second lubricant acts as a role of improving the lubricity when forming an image in a high gradation region. In addition, melting | fusing point of the 2nd lubricant in this invention is melting | fusing point measured based on JISK0064 (1992).

  When the back layer 5 does not contain the second lubricant or contains a solid lubricant having a melting point of less than 80 ° C., the lubricity at the time of image formation in the high gradation region becomes insufficient, and the image in the high gradation region At the time of formation, wrinkles may occur in the formed image. On the other hand, in the back layer containing only the second lubricant, to the extent that sufficient lubricity can be imparted, in other words, until the back layer 5 containing the first lubricant and the second lubricant becomes the same slipperiness, When the content of the second lubricant is increased, the occurrence of kick cannot be prevented. Furthermore, the slipperiness below the melting point of the second lubricant cannot be satisfied. On the other hand, when the back layer containing only the first lubricant is used, the occurrence of kick can be sufficiently prevented, but the slipperiness above the melting point of the second lubricant is lowered, and the back layer 5 of the thermal transfer sheet 10 of the present invention is reduced. The slipperiness of the high gradation region is lower than the slipperiness of.

  That is, the present invention is characterized in that sufficient lubricity is imparted to the back layer 5 by the synergistic effect of the first lubricant and the second lubricant. In addition, the presence of the first lubricant component having lubricity can reduce the content of the second lubricant, which has a lower kick prevention effect than the first lubricant, and prevents the occurrence of kick as the entire back layer 5. be able to.

  The second lubricant need only satisfy the following conditions: (1) it is a solid lubricant, and (2) the melting point is 80 ° C. or higher, and there are no particular limitations on other requirements. Examples of solid lubricants that satisfy such conditions include metal soaps having a melting point of 80 ° C. or higher, fatty acid amides that are fatty acid derivatives, and the like.

  Examples of the metal soap include polyvalent metal salts of alkyl phosphates, polyvalent metal salts of fatty acids, metal salts of alkyl carboxylic acids, and more specifically, zinc stearyl phosphate and zinc stearate. be able to. Examples of the fatty acid amide include ethylene bisoleic acid amide, methylene bis stearic acid amide, and stearic acid amide.

  Note that the second lubricant is a solid lubricant and is hard to be dyed by the dye of the dye layer 3 compared to the liquid lubricant, but is more easily dyed by the dye of the dye layer 3 than the first lubricant, and the solid content of the back layer 5 When the content of the solid lubricant having a melting point of 80 ° C. or higher with respect to the total amount exceeds 15% by mass, the back layer 5 tends to be dyed with the dye of the dye layer, and the effect of preventing the occurrence of kick tends to be lowered. Therefore, in consideration of this point, the content of the solid lubricant having a melting point of 80 ° C. or higher with respect to the total solid content of the back layer 5 is preferably 15% by mass or less. Moreover, from the point of the further improvement effect of the lubricity in a high gradation area | region, it is preferable that it is 1 mass% or more. In addition, when a liquid lubricant having a melting point of less than 80 ° C. is used instead of the second lubricant, the back layer is likely to be dyed with the dye of the dye layer by the liquid lubricant, and the occurrence of kick cannot be prevented. . Note that this does not prohibit the back layer 5 from containing a liquid lubricant having a melting point of less than 80 ° C., but is allowed to be contained within a range that does not impede the gist of the present invention.

  Moreover, the back surface layer 5 may contain a lubricant component other than this within the range not impeding the gist of the present invention. Examples of other lubricant components include phosphate esters, graphite powder, fluorine-based graft polymers, silicone oils, silicone-based graft polymers, acrylic silicone graft polymers, silicone polymers such as acrylic siloxane and aryl siloxane, and polyethylene. it can. In addition, since these other lubricant components reduce the effect of preventing the occurrence of kicks, it is necessary to have a content of 5% by mass or less with respect to the total solid content of the back layer 5.

<< Binder >>
The back surface layer 5 contains a binder together with the first lubricant and the second lubricant.

  The binder contained in the back layer 5 is not particularly limited, and examples thereof include polyester resins, polyacrylate resins, polyvinyl acetate resins, styrene acrylate resins, polyurethane resins, polyethylene resins, and polypropylene resins. Polyolefin resin, polystyrene resin, polyvinyl chloride resin, polyether resin, polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, polyacrylamide resin, polyvinyl chloride resin, polyvinyl butyral resin, polyvinyl aceto Thermoplastic resins such as polyvinyl acetal resins such as acetal resins, silicone modified products thereof, and the like can be used.

  The binder may be a curable binder. According to the back layer 5 containing a curable binder, the coating strength and heat resistance can be improved. As a curing agent for making a curable binder, polyisocyanate is suitable, and it is particularly desirable to use an adduct body of aromatic isocyanate. As the aromatic polyisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, Examples include p-phenylene diisocyanate, trans-cyclohexane-1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, and tris (isocyanatophenyl) thiophosphate, particularly 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. Or, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is preferable.

  There is no limitation in particular about content of a binder, It can determine suitably according to content of the sorbitan fatty acid ester and triacylglycerol which are the essential components mentioned above. Preferably, it is the range of 40 mass% or more and 90 mass% or less with respect to the solid content total amount of the back surface layer 5.

The method for forming the back layer 5 is not particularly limited, and the first lubricant, the second lubricant, the binder, and other components added as necessary are dispersed or dissolved in an appropriate solvent. By applying the liquid on the opposite surface of the dye layer 3 of the substrate 1 by a known means such as a gravure printing method, a screen printing method, a reverse roll coating printing method using a gravure plate, and drying. Can be formed. The coating amount of the back layer 5, from the viewpoint of improvement of such as heat resistance, it is preferable that the coating amount after drying is 3 g / m ² or less, and particularly preferably 0.1-2 g / m ² .

(Back primer layer)
Further, a back primer layer (not shown) for improving the adhesion between the base material 1 and the back layer 5 may be provided between the base material 1 and the back layer 5. Examples of the material for the back primer layer include those showing adhesiveness such as polyester resin and acrylic resin.

(Dye layer)
As shown in the drawing, a dye layer 3 that is an essential component of the thermal transfer sheet 10 of the present invention is formed on one surface of the substrate 1 (the upper surface of the substrate 1 in the case shown in FIGS. 1 to 3). Yes. The thermal transfer sheet 10 of the present invention is characterized in that the back layer 5 contains the first lubricant, the second lubricant, and the binder described above, and the dye layer 3 is not limited in any way. There is nothing.

  The dye layer 3 contains a dye binder and a dye. The dye layer 3 may be formed as a single color layer selected as appropriate when the desired image is monochromatic, or as shown in FIG. 3 when the desired image is a full color image. A plurality of dye layers 3Y, 3M, and 3C including dyes having different hues, such as yellow dye, magenta dye, cyan dye, and black dye as necessary, are repeatedly formed on the same surface of the same substrate in the surface order. Also good. In the thermal transfer sheet including a plurality of dye layers 3 containing dyes having different hues, the dye kicked to the back layer, for example, the yellow dye kicked to the back layer is the kicked dye when the thermal transfer sheet is rolled back. When backing to another dye layer having a different hue, for example, a cyan dye layer, color development characteristics may be caused when an image is formed using the cyan dye layer, or image quality may be reduced when an image is formed using the cyan dye layer. In the present invention, since the occurrence of kick is prevented in the back layer 5 as described above, the present invention is a case where the thermal transfer sheet is provided with a plurality of dye layers having different hues. In addition, the effect of preventing the deterioration of the image quality can be achieved.

  When the thermal transfer sheet 10 of the present invention is a sublimation type thermal transfer sheet, the dye layer 3 contains a sublimable dye. When the thermal transfer sheet 10 of the present invention is a thermal melt type thermal transfer sheet, a hot melt ink or the like is contained. included.

  As the sublimable dye, those having a sufficient color density and not discolored by light, heat, temperature, etc. are preferable. For example, diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolones Dyes, methine dyes, indoaniline dyes, acetophenone azomethine, pyrazoloazomethine, imidazole azomethine, imidazoazomethine, pyridone azomethine and other azomethine dyes, xanthene dyes, oxazine dyes, dicyanostyrene, tricyanostyrene and other cyano Styrene dyes, thiazine dyes, azine dyes, acridine dyes, benzene azo dyes, pyridone azo, thiophenazo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo Azo dye of the disazo, etc., spiropyran dyes, India Linos Piropi run dyes, fluoran dye, rhodamine lactam-based dyes, naphthoquinone dyes, anthraquinone dyes, quinophthalone dyes, and the like. Specifically, red dyes such as MSRedG (manufactured by Mitsui Toatsu Chemical Co., Ltd.), Macrolex Red Violet R (manufactured by Bayer), CeresRed 7B (manufactured by Bayer), Samalon Red F3BS (manufactured by Mitsubishi Chemical), and holon brilliant yellow Yellow dyes such as 6GL (manufactured by Clariant), PTY-52 (manufactured by Mitsubishi Kasei), Macrolex Yellow 6G (manufactured by Bayer), Kayaset Blue 714 (manufactured by Nippon Kayaku Co., Ltd.), Waxoline Blue AP-FW ( ICI), Holon Brilliant Blue SR (Sand), MS Blue 100 (Mitsui Toatsu Chemical), C.I. I. Blue dyes such as Solvent Blue 22 are listed.

  As the dye binder for supporting the dye, generally, a binder having heat resistance and having an appropriate affinity with the dye can be used. Examples of the dye binder include cellulose resins such as nitrocellulose, ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and butyric acid cellulose; polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetoacetal, Examples thereof include vinyl resins such as polyvinyl pyrrolidone; acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide; polyurethane resins; polyamide resins; polyester resins;

  The sublimable dye is preferably 50% by mass or more and 350% by mass, and more preferably 80% by mass or more and 300% by mass with respect to the total solid content of the dye binder of the dye layer 3. When the content of the sublimation dye is less than the above range, the printing density may be lowered, and when it exceeds the above range, the storage stability and the like may be deteriorated.

  Further, the dye layer 3 of the sublimation type thermal transfer sheet 10 may contain additives such as a release agent, inorganic fine particles, and organic fine particles, if desired. Examples of the release agent include silicone oil and phosphate ester, examples of the inorganic fine particles include carbon black, aluminum, and molybdenum disulfide. Examples of the organic fine particles include polyethylene wax.

  The heat-meltable ink contained in the dye layer 3 of the heat-melting type thermal transfer sheet 10 can be appropriately selected from known organic or inorganic pigments or dyes, and has, for example, a sufficient color density. Those which do not discolor or fade due to light, heat, or the like are preferable. The color of the hot-melt ink is not limited to cyan, magenta, yellow, and black, and various colorants can be used.

  Examples of the dye binder contained in the dye layer 3 of the heat melting type thermal transfer sheet 10 include, for example, ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer, polyethylene, polystyrene, polypropylene, polybutene, petroleum resin, and chloride. Vinyl resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol, vinylidene chloride resin, acrylic resin, methacrylic resin, polyamide, polycarbonate, fluororesin, polyvinyl formal, polyvinyl butyral, acetyl cellulose, nitrocellulose, polyvinyl acetate, poly Examples include isobutylene, ethyl cellulose, and polyacetal.

  The hot-melt dye layer 3 includes microcrystalline wax, carnauba wax, paraffin wax, and the like. Furthermore, Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, whale wax, ibota wax, wool wax, shellac wax, candelilla wax, petrolactam, polyester wax, partially modified wax, fatty acid ester, fatty acid amide and other waxes Ingredients may be included.

  The formation method of the dye layer 3 is not particularly limited, and a gravure printing method is performed by dispersing or dissolving the dye, the dye binder, and any components added as necessary in an appropriate solvent. It is formed by applying and drying on the opposite surface of the back layer 5 of the substrate 1 by a conventionally known coating means such as a reverse roll coating method using a gravure plate, a roll coater or a bar coater. Can do.

  Although there is no limitation in particular about the thickness of the dye layer 3, It is preferable that it is about 0.3 micrometer-1.5 micrometers in the thickness at the time of drying.

(Dye primer layer)
When the thermal transfer sheet of the present invention is a sublimation type thermal transfer sheet, a dye primer layer 7 is preferably provided between the substrate 1 and the dye layer 3 as shown in FIG. By providing the dye primer layer, the adhesion between the substrate 1 and the dye layer 3 can be improved, and the dye layer 3 can be prevented from being abnormally transferred during image formation.

  The resins constituting the dye primer layer include polyester resins, polyvinyl pyrrolidone resins, polyvinyl alcohol resins, hydroxyethyl cellulose, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylamide resins. Examples thereof include resins, polyamide resins, polyether resins, polystyrene resins, polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral, and the like.

  The dye primer layer can also be composed of colloidal inorganic pigment ultrafine particles. This not only prevents abnormal transfer of the dye layer 3 to the thermal transfer image receiving sheet at the time of thermal transfer, but also prevents migration of the dye from the dye layer 3 to the dye primer layer at the time of image formation, to the receiving layer side of the thermal transfer image receiving sheet. Dye diffusion can be performed effectively and the print density can be increased.

  As the colloidal inorganic pigment ultrafine particles, conventionally known compounds can be used. For example, silica (colloidal silica), alumina or alumina hydrate (alumina sol, colloidal alumina, cationic aluminum oxide or its hydrate, suspect boehmite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, magnesium oxide, oxidation Examples include titanium. In particular, colloidal silica and alumina sol are preferably used. These colloidal inorganic pigment ultrafine particles have a primary average particle size of 100 nm or less, preferably 50 nm or less.

For the dye primer layer, the resin exemplified above and the coating solution for the dye primer layer in which the colloidal inorganic pigment ultrafine particles are dissolved or dispersed in an appropriate solvent are used as a gravure coating method, a roll coating method, a screen printing method, and a gravure plate. It can be formed by coating and drying by a conventionally known forming means such as the reverse roll coating method used. The coating amount of the dye primer layer coating solution is preferably about 0.02 to 1.0 g / m ² .

  On the other hand, when the thermal transfer sheet of the present invention is a thermal melting type thermal transfer sheet, a release layer is preferably provided between the substrate 1 and the dye layer 3. Examples of the resin forming the release layer include waxes, silicone wax, silicone resin, silicone-modified resin, fluorine resin, fluorine-modified resin, polyvinyl alcohol, acrylic resin, heat-crosslinkable epoxy-amino resin, and heat-crosslinkable alkyd. -Amino resin etc. are mentioned. Further, the release layer may be composed of one kind of resin or may be composed of two or more kinds of resins. The release layer may be formed by using a cross-linking agent such as an isocyanate compound, a catalyst such as a tin-based catalyst, and an aluminum-based catalyst in addition to the releasable resin. The thickness of the release layer is generally about 0.5 to 5 μm. The release layer is formed by dissolving or dispersing the resin in a suitable solvent to prepare a release layer coating solution, which is then applied to the substrate 1 by a gravure printing method, a screen printing method or a gravure plate. It can be formed by coating and drying by a conventionally known means such as a reverse coating method using a bismuth.

  The thermal transfer sheet 10 of the present invention has been specifically described above, but various modifications can be made without departing from the spirit of the present invention. For example, in the configuration shown in FIGS. 1 to 3, an integrated thermal transfer sheet in which the dye layer 3 and a transferable protective layer (not shown) are provided in the surface order on the same surface of the substrate 1 may be used. A release layer can also be provided between the substrate 1 and the transferable protective layer.

  Next, an Example is given and this invention is demonstrated further more concretely. Hereinafter, unless otherwise specified, “part” and “%” are based on mass. Further, unless otherwise specified, “parts” and “%” indicate solid content values.

( Reference Example 1)
A 4.5 μm thick polyethylene terephthalate film having a thickness of 4.5 μm was used as the base material, and the back layer coating solution 1 having the following composition was applied to one side of the base material, and the coating amount when dried was 1.0 g / m. It was coated using a bar coater so as to be ^2, and dried at 80 ° C. for 1 minute to form a back layer. Also, apply the coating solution for the dye layer having the following composition on the other side of the substrate (the surface that is easily treated) using a bar coater so that the coating amount when dried is 0.6 g / m ^2. The thermal transfer sheet of Reference Example 1 was obtained by forming a dye layer.

<Back layer coating liquid 1>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Sorbitan monooleate (HLB value: 4.3) 10.0 parts (Rheodor SP-O10V Kao Corporation)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

<Coating liquid for dye layer>
・ Disperse dye (disperse thread 60) 1.5 parts ・ Disperse dye (dispers violet 26) 2.0 parts ・ Polyvinyl acetal resin 4.5 parts (Eslex KS-5 Sekisui Chemical Co., Ltd.)
・ Polyethylene wax 0.1 part ・ Toluene 45.0 parts ・ Methyl ethyl ketone 45.0 parts

( Reference Example 2)
A thermal transfer sheet of Reference Example 2 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 2 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 2>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Sorbitan monooleate (HLB value: 4.3) 10.0 parts (Rheodor SP-O10V Kao Corporation)
-Ethylene bis stearic acid amide (melting point: 145 ° C) 5.0 parts (Sripacks E Nippon Kasei Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 3)
A thermal transfer sheet of Reference Example 3 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 3 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 3>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Sorbitan monooleate (HLB value: 4.3) 10.0 parts (Rheodor SP-O10V Kao Corporation)
・ Stearic acid amide (melting point: 101 ° C.) 5.0 parts (Amide AP-1 Nippon Kasei Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 4)
A thermal transfer sheet of Reference Example 4 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 4 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 4>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
-Sorbitan monostearate (HLB value: 4.7) 10.0 parts (Rheidol SP-S10V Kao Corporation)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 5)
A thermal transfer sheet of Reference Example 5 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 5 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 5>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Sorbitan trioleate (HLB value: 1.8) 10.0 parts (Rheodor SP-O30V Kao Corporation)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 6)
A thermal transfer sheet of Reference Example 6 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 6 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 6>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
-Sorbitan tristearate (HLB value: 2.1) 10.0 parts (Rheidol SP-S30V Kao Corporation)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Example 7)
A thermal transfer sheet of Example 7 was obtained in the same manner as in Reference Example 1 except that the back layer coating solution 7 having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid 7>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl dioleate 10.0 parts (NIKKOL DGO-80 Nikko Chemicals Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Example 8)
A thermal transfer sheet of Example 8 was obtained in the same manner as in Reference Example 1 except that the back layer coating solution 8 having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid 8>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl dioleate 10.0 parts (NIKKOL DGO-80 Nikko Chemicals Co., Ltd.)
-Ethylene bis stearic acid amide (melting point: 145 ° C) 5.0 parts (Sripacks E Nippon Kasei Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

Example 9
A thermal transfer sheet of Example 9 was obtained in the same manner as in Reference Example 1 except that the back layer coating solution 9 having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid 9>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl dioleate 10.0 parts (NIKKOL DGO-80 Nikko Chemicals Co., Ltd.)
・ Stearic acid amide (melting point: 101 ° C.) 5.0 parts (Amide AP-1 Nippon Kasei Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Example 10)
A thermal transfer sheet of Example 10 was obtained in the same manner as Reference Example 1 except that the back layer coating solution 10 having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid 10>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl distearate 10.0 parts (NIKKOL DGS-80 Nikko Chemicals Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 11)
A thermal transfer sheet of Reference Example 11 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 11 having the following composition was used instead of the back layer coating liquid 1.

<Back surface layer coating solution 11>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Tri (caprylic acid / capric acid) glyceryl 10.0 parts (NIKKOL Triester F-180 Nikko Chemicals Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 12)
A thermal transfer sheet of Reference Example 12 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 12 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 12>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Tri (caprylic acid / capric acid) glyceryl 10.0 parts (NIKKOL Triester F-180 Nikko Chemicals Co., Ltd.)
-Ethylene bis stearic acid amide (melting point: 145 ° C) 5.0 parts (Sripacks E Nippon Kasei Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 13)
A thermal transfer sheet of Reference Example 13 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 13 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 13>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Tri (caprylic acid / capric acid) glyceryl 10.0 parts (NIKKOL Triester F-180 Nikko Chemicals Co., Ltd.)
・ Stearic acid amide (melting point: 101 ° C.) 5.0 parts (Amide AP-1 Nippon Kasei Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 14)
A thermal transfer sheet of Reference Example 14 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 14 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 14>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl trioleate 10.0 parts (Triolein Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 15)
A thermal transfer sheet of Reference Example 15 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 15 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating solution 15>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl tristearate 10.0 parts (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 16)
A thermal transfer sheet of Reference Example 16 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 16 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 16>
・ 47.1 parts of polyvinyl acetal resin (SREC KS-1 Sekisui Chemical Co., Ltd.)
・ Polyisocyanate 22.9 parts (Bernock D750 DIC Corporation)
・ Glyceryl tristearate 20.0 parts (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 17)
A thermal transfer sheet of Reference Example 17 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 17 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 17>
・ 47.1 parts of polyvinyl acetal resin (SREC KS-1 Sekisui Chemical Co., Ltd.)
・ Polyisocyanate 22.9 parts (Bernock D750 DIC Corporation)
・ Glyceryl tristearate 10.0 parts (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 15.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 18)
A thermal transfer sheet of Reference Example 18 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 18 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 18>
-43.7 parts of polyvinyl acetal resin (S-REC KS-1 Sekisui Chemical Co., Ltd.)
・ Polyisocyanate 21.3 parts (Bernock D750 DIC Corporation)
・ Glyceryl tristearate 10.0 parts (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 20.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 19)
A thermal transfer sheet of Reference Example 19 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 19 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 19>
-Polyvinyl acetal resin 59.2 parts (SREC KS-1 Sekisui Chemical Co., Ltd.)
・ Polyisocyanate 28.8 parts (Bernock D750 DIC Corporation)
・ Glyceryl tristearate 2.0 parts (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 20)
A thermal transfer sheet of Reference Example 20 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 20 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating solution 20>
-Polyvinyl acetal resin 59.9 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
-Polyisocyanate 29.1 parts (Bernock D750 DIC Corporation)
・ 1.0 parts of glyceryl tristearate (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 5.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 21)
A thermal transfer sheet of Reference Example 21 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 21 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 21>
-Polyvinyl acetal resin 56.5 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ Polyisocyanate 27.5 parts (Bernock D750 DIC Corporation)
・ Glyceryl tristearate 10.0 parts (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 1.0 part (LBT-1830 purification Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

( Reference Example 22)
A thermal transfer sheet of Reference Example 22 was obtained in the same manner as Reference Example 1 except that the back layer coating liquid 22 having the following composition was used instead of the back layer coating liquid 1.

<Back layer coating liquid 22>
・ Polyvinyl acetal resin 56.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ Polyisocyanate 27.7 parts (Bernock D750 DIC Corporation)
・ Glyceryl tristearate 10.0 parts (Tristearin Tokyo Chemical Industry Co., Ltd.)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 0.5 part (LBT-1830 purification Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Comparative Example 1)
A thermal transfer sheet of Comparative Example 1 was obtained in the same manner as Reference Example 1 except that the back layer coating solution A having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid A>
-Polyvinyl acetal resin 56.3 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
-Polyisocyanate 28.7 parts (Bernock D750 DIC Corporation)
・ Glyceryl dioleate 10.0 parts (NIKKOL DGO-80 Nikko Chemicals Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Comparative Example 2)
A thermal transfer sheet of Comparative Example 2 was obtained in the same manner as Reference Example 1 except that the back layer coating solution B having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid B>
-Polyvinyl acetal resin 56.3 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
-Polyisocyanate 28.7 parts (Bernock D750 DIC Corporation)
・ Glyceryl distearate 10.0 parts (NIKKOL DGS-80 Nikko Chemicals Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Comparative Example 3)
A thermal transfer sheet of Comparative Example 3 was obtained in the same manner as in Reference Example 1 except that the back layer coating solution C having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid C>
-Polyvinyl acetal resin 56.3 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
-Polyisocyanate 28.7 parts (Bernock D750 DIC Corporation)
・ Zinc stearyl phosphate (melting point: 230 ° C.) 10.0 parts (LBT-1830 purification, Sakai Chemical Industry Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Comparative Example 4)
A thermal transfer sheet of Comparative Example 4 was obtained in the same manner as in Reference Example 1 except that the back layer coating solution D having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid D>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl dioleate 10.0 parts (NIKKOL DGO-80 Nikko Chemicals Co., Ltd.)
・ N-stearyl erucic acid amide (melting point: 69 ° C.) 5.0 parts (Nikka Amide SE Nippon Kasei Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Comparative Example 5)
A thermal transfer sheet of Comparative Example 5 was obtained in the same manner as Reference Example 1 except that the back layer coating solution E having the following composition was used instead of the back layer coating solution 1.

<Back layer coating liquid E>
-Polyvinyl acetal resin 53.8 parts (ESREC KS-1 Sekisui Chemical Co., Ltd.)
・ 26.2 parts of polyisocyanate (Bernock D750 DIC Corporation)
・ Glyceryl dioleate 10.0 parts (NIKKOL DGO-80 Nikko Chemicals Co., Ltd.)
・ Phosphate 5.0 parts (Pricesurf A-208F Daiichi Kogyo Seiyaku Co., Ltd.)
-Talc 5.0 parts (MICRO ACE P-3 Nippon Talc Industry Co., Ltd.)
・ Toluene 200 parts ・ Methyl ethyl ketone 200 parts

(Evaluation of printing wrinkles)
Sublimation type thermal transfer printer (manufactured by ALTECH ADS Co., Ltd.) Model: CW-01) Media set CW-MS46 Y area, M area, C area in each of the examples, reference examples, and comparative example thermal transfer sheets, respectively After the printer and the media set genuine thermal transfer image-receiving sheet were left in a low-temperature and low-humidity environment (5 ° C., 20%) for 3 hours, (1) white solid (0 (/ 255 gradation) image, (2) 30/255 gradation gray solid image, (3) 60/255 gradation gray solid image, (4) 90/255 gradation gray solid image, (1) black solid ( 255/255 gradation) image, (2) 210/255 gradation gray solid image, (3) 180/255 gradation gray solid image, and (4) 150/255 gradation gray solid image. 20 sheets) and printed, were evaluated in the print wrinkles based on the following evaluation criteria. The evaluation results are shown in Table 1.

"Evaluation criteria"
... No wrinkle generated in all images ((1) to (4))... Wrinkle generated in any one of the images (1) to (4). Wrinkles occur in 2 to 3 types of images among (1) to (4).
X: Wrinkles occur in all the images (1) to (4).

(Kick evaluation)
The back layer and the dye layer of the thermal transfer sheets of each Example, Reference Example, and Comparative Example were opposed to ^each other, applied with a load of 15 kg / cm ² , and stored for 96 hours in a 40 ° C. and 90% humidity environment. The dye in the dye layer was transferred (kick). The hues of the back and front layers before and after facing were measured using Gretag Spectrolino (D65 light source, viewing angle 2 °) manufactured by Gretag, and the color difference (ΔE ^* ) was calculated by the following formula and evaluated based on the following criteria. The evaluation results are also shown in Table 1.
ΔE ^* = ((difference between L ^* values before and after facing) ² + (difference between a ^* values before and after facing) ² + (difference between b ^* values before and after facing) ² ) ^1/2

"Evaluation criteria"
A: Color difference ΔE ^* is less than 2.5 B: Color difference ΔE ^* is 2.5 or more and less than 3.0 Δ: Color difference ΔE ^* is 3.0 or more and less than 5.0 ^* Is 5.0 or more

  As is clear from Table 1, according to the thermal transfer sheet of the example satisfying all the matters specific to the invention of the present invention, the occurrence of printing wrinkles is prevented at the time of printing in both the high gradation region and the low gradation region. It was confirmed that it was possible to prevent kicks from occurring. On the other hand, in the thermal transfer sheet of the comparative example that does not satisfy all the matters specific to the invention of the present invention, the occurrence of printing wrinkles or the occurrence of kicks cannot be prevented. Also from this, the superiority of the present invention is clear.

DESCRIPTION OF SYMBOLS 1 ... Base material 3 ... Dye layer 5 ... Back layer 7 ... Dye primer layer 10 ... Thermal transfer sheet

Claims (1)

A thermal transfer sheet provided with a dye layer on one side of a substrate and a back layer on the other side of the substrate,
The back layer contains a binder, a first lubricant, and a second lubricant;
The first lubricant is diacylglycerol;
The second lubricant is a solid lubricant having a melting point of 80 ° C. or higher,
The first lubricant is contained in the range of 2% by mass or more and 20% by mass or less, and the second lubricant is contained in the range of 1% by mass or more and 15% by mass or less with respect to the total solid content of the back layer. thermal transfer sheet, characterized in that there.

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