JP2013226806A - Thermal transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer sheet capable of exhibiting excellent antistatic performance without disturbing a function required for a back layer.SOLUTION: A thermal transfer sheet includes a back layer formed on one surface of a base material, and at least one kind of layer selected from a dye layer, a protective layer and a receiving layer, on the other surface of the base material. The back layer contains binder resin and an ionic liquid whose melting point is 5°C or lower.

Description

  The present invention relates to a thermal transfer sheet.

  As a method of forming an image using thermal transfer, a thermal transfer sheet in which a sublimation dye is supported on a substrate such as a plastic film and a thermal transfer image receiving sheet in which a dye receiving layer is provided on another substrate such as paper or plastic film A sublimation type thermal transfer method is known in which a full-color image is formed by superimposing them on each other. Since this method uses sublimation dyes as color materials, it is excellent in halftone reproducibility and gradation, and a full color image as it is on the original can be clearly displayed on the image receiving sheet. It is applied to color image formation for computers.

  By the way, in such a thermal transfer sheet, when printing is performed by directly contacting the thermal head with the substrate, sticking occurs during scanning due to the frictional force generated between the substrate and the thermal head, resulting in poor printing. May end up. Further, the base material is fused to the thermal head by heat at the time of printing, which prevents the thermal transfer sheet from running and causes sticking, and in some cases, may cause sheet breakage. Therefore, in the field of thermal transfer sheets, a back layer is usually provided on one side of a substrate for the purpose of improving heat resistance and running stability by imparting slipperiness.

  Since the back layer of the thermal transfer sheet is generally an electrical insulator, friction is caused when the thermal transfer sheet is conveyed in contact with a thermal transfer sheet conveyance system, i.e., a thermal head, a thermal head cover, a conveyance roller, or the like. The thermal transfer sheet is charged. Further, the thermal transfer sheet is charged even when the thermal transfer sheet roll is rewound and wound. When the thermal transfer sheet is charged, it causes a conveyance failure due to sticking to the thermal transfer image receiving sheet, an ejection failure of the image receiving sheet, and the like. In addition to this, it also has an electrical effect on electronic parts used for electrical control of thermal transfer printers, etc., which may cause malfunctions and malfunctions. Further, since the charged thermal transfer sheet adsorbs dust, print defects caused by the adsorbed dust are generated, and thus it is a very important issue to prevent charging of the thermal transfer sheet.

  Under such circumstances, various attempts have been made to prevent the thermal transfer sheet from being charged by adding an antistatic agent to any layer constituting the thermal transfer sheet. For example, Patent Document 1 discloses a thermal transfer sheet in which an antistatic agent is contained in a back primer layer provided between a base material and a back layer.

JP 2000-272254 A

  However, a conductive polymer widely known as an antistatic agent for the back primer layer is very expensive and is not a preferable material in terms of cost. Further, as a generally known antistatic agent, there are a surfactant type and a conductive fine particle type, but these cannot exhibit a sufficient antistatic effect in the back primer layer serving as an intermediate layer. Therefore, it is considered to add a surfactant type or conductive fine particle type antistatic agent to the outermost layer of the thermal transfer sheet. However, since it is difficult to sufficiently exert the antistatic effect with a small amount of the surfactant type, it is necessary to add a large amount of the antistatic agent. Various problems occur. On the other hand, the conductive fine particle type needs to be added in a large amount in order to exert the antistatic effect, so that the smoothness of the outermost layer of the thermal transfer sheet is lost and the glossiness of the printed matter is reduced. The conductive fine particles protruding from the surface layer may cause the thermal head to wear.

  The present invention has been made in such a situation, and a main object is to provide a thermal transfer sheet capable of exhibiting excellent antistatic performance without interfering with functions required for the back layer.

  In order to solve the above problems, the present invention provides a back layer on one surface of a substrate, and at least one layer selected from the group consisting of a dye layer, a protective layer and a receiving layer on the other surface of the substrate. The back layer contains a binder resin and an ionic liquid having a melting point of 5 ° C. or lower.

  Moreover, the said ionic liquid may be contained in the range of 0.1 mass% or more and 12 mass% or less among all the structural components of the said back surface layer.

  Further, the thermal transfer sheet may be a thermal transfer sheet in which one or both of the dye layer and the protective layer are provided on the other surface of the substrate. The thermal transfer sheet may be an intermediate transfer medium in which the protective layer and the receiving layer are laminated in this order on the other surface of the substrate.

  According to the thermal transfer sheet of the present invention, excellent antistatic performance can be exhibited without interfering with the function required for the back layer.

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

  Hereinafter, the thermal transfer sheets 10 and 100 of the present invention will be specifically described. In the thermal transfer sheet of the present invention, the back layer 5 is provided on one surface of the substrate 1, and at least 1 selected from the group of the dye layer 2, the protective layer 3 and the receiving layer 4 on the other surface of the substrate 1. It takes a configuration in which a seed layer is provided. FIG. 1 shows a thermal transfer sheet 10 having a structure in which a dye layer 2 and a protective layer 3 are provided in the surface order on the other surface of the base material 1, and FIG. The thermal transfer sheet 100 has a configuration in which the protective layer 3 and the receiving layer 4 are laminated in this order. Both of the thermal transfer sheets 10 and 100 are provided with a back layer 5 on one surface of the substrate 1. The thermal transfer sheet 10 of the present invention is not limited to the illustrated form, and may be a thermal transfer sheet in which the dye layer 2 is provided on the other surface of the substrate 1. It may be a thermal transfer sheet provided with a protective layer 3 on its surface. Hereinafter, each configuration of the thermal transfer sheet 10 will be specifically described.

(Base material)
The substrate 1 is not particularly limited as long as it has a certain degree of heat resistance and strength, and a conventionally known material can be appropriately selected and used. As such a substrate 1, for example, a polyethylene terephthalate film, a 1,4-polycyclohexylenedimethylene terephthalate film, a polyethylene naphthalate film, a polyphenylene sulfide having a thickness of about 0.5 μm to 50 μm, preferably about 1 μm to 10 μm. Film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose derivatives such as cellulose acetate, polyethylene film, polyvinyl chloride film, nylon film, polyimide film, ionomer film, etc. . Furthermore, each of these materials can be used alone, but may be used as a laminate in combination with other materials.

(Back layer)
A back layer 5 is provided on one surface of the substrate 1. In the present invention, the back layer 5 contains a binder resin and an ionic liquid having a melting point of 5 ° C. or lower. An ionic liquid having a melting point of 5 ° C. or less can exhibit an antistatic effect with a small addition amount as compared with a conventionally known antistatic agent. Therefore, excellent antistatic performance can be imparted to the thermal transfer sheets 10 and 100 without interfering with functions required for the back layer 5, for example, functions such as heat resistance and slipperiness. In addition, when a conventionally known antistatic agent, that is, a solid antistatic agent, is used, there is a problem that the thermal head is worn out by the antistatic agent protruding from the surface of the back layer, or the surface of the back layer protrudes. The antistatic agent causes the surface of the back layer to become rough, and as a result, the surface of the resulting image or printed matter becomes rough. However, the melting point contained in the back layer 5 is an ion having a melting point of 5 ° C. or less. Since the liquid exists in a liquid state at the time of image formation using the thermal transfer sheet, the back layer is not roughened and the thermal head is not worn.

  Also, the guaranteed operating temperature of printers generally used in the sublimation thermal transfer system is often set between 5 ° C and 40 ° C, and the thermal transfer sheet is good in the range of 5 ° C to 40 ° C. Antistatic performance is required. In the present invention, since the melting point of the ionic liquid contained in the back layer 5 is specified to be 5 ° C. or lower, the ionic liquid exists in the liquid state within the range of the operation guarantee temperature, in other words, good. It exists in a state where it can exhibit excellent antistatic performance. As a result, it is possible to give the thermal transfer sheet good antistatic performance within the range of the above-mentioned guaranteed operating temperature, and paper feeding or paper discharge failure due to charging of the thermal transfer sheet, charging of the thermal transfer sheet, electronic parts, etc. Can be prevented from causing malfunctions and malfunctions. Further, since the antistatic performance can be imparted in the liquid state, the smoothness of the back surface layer is not lost, and the thermal head is not worn.

  Furthermore, since the ionic liquid is bound to each other by an electrostatic interaction force, even if it is a liquid, there is almost no vapor pressure. Therefore, it can be said that the ionic liquid is not scattered in the atmosphere and is excellent in terms of environment. Hereinafter, the ionic liquid will be specifically described.

<Ionic liquid>
The ionic liquid is generally composed of a cation and an anion, and has a melting point of 100 ° C. or lower, that is, a liquid state at 100 ° C. or lower. In the present invention, the back layer 5 contains an ionic liquid, and the melting point of the ionic liquid contained in the back layer 5 is 5 ° C. or less. In addition, melting | fusing point of an ionic liquid is melting | fusing point measured by the method based on JISK0064.

  Examples of the cation constituting the ionic liquid include triethylpentylammonium, cyclohexyltrimethylammonium, methyltri-n-octylammonium, tetrabutylammonium, tetrabutylphosphonium, tributylhexadecylphosphonium, tributyl (2-methoxyethyl) phosphonium, and tributylmethyl. Ammonium, tributylmethylphosphonium, triethylsulfonium, trimethylpropylammonium, 1-butyl-1-methylpiperidinium, hydroxyethylpiperazine, 2-methylpiperazine, N-ethylmorpholine, N.N.dimethylethanolamine, N.N. Dimethylethanolamine, N-methylethanolamine, N-methyldiethanolamine, N-ethylethanolamine, N-ethyl Tildiethanolamine, N- (β-aminoethyl) ethanolamine, Nn-butyldiethanolamine, Nt-butyldiethanolamine, N, N-diethylisopropanolamine, 1-butyl-2,3-dimethylimidazolium, 1-butyl-3-methylimidazolium, 1,3-dimethylimidazolium, 1,2-dimethyl-3-propylimidazolium, 1-ethyl-2,3-dimethylimidazolium, 1-ethyl-3-methylimidazolium 1-hexyl-3-methylimidazolium, 1-methyl-3-n-octylimidazolium, 1-methyl-3-propylimidazolium, 1-butyl-4-methylpyridinium, 1-butyl-3-methyl Pyridinium, 1-butylpyridinium, 1-ethyl-3- (hydroxymethyl) pyrid Um, 1-ethyl-3-methylpyridinium, 1-ethyl pyridinium, 1-butyl-1-methyl pyrrolidinium, and the like 1-methyl-1-propyl pyrrolidinium.

  The cation is not limited as long as it can constitute an ionic liquid, and the ionic liquid containing the cation and the anion described below has a melting point of 5 ° C. or lower. Other than the cations exemplified above can also be used.

  The anion constituting the ionic liquid is not limited as in the case of the cation, and any limitation is possible as long as the ionic liquid containing the cation and the anion described above has a melting point of 5 ° C. or lower. There is nothing, and anions other than those exemplified below can also be used.

Examples of the anion constituting the ionic liquid include AlCl ₄ −, Al ₂ Cl ₇ −, BF ₄ −, PF ₆ −, F (HF) n−, CF ₃ COO—, and CH ₃ CH ₂ OSO ₃ —CF _{3. SO 3 - (TfO), (} CF 3 SO 2) 2 N- (TFSI), (CF 3 SO 2) 3 C- (TFSM), HN (Tf) 2, NO 3 -, (NC) 2 N-, CH ₃ COO—, Br—, Cl—, I—, (CH ₃ O) ₂ OPO—, linear alkylbenzene sulfonic acid, dialkyl succinate sulfonic acid, α-sulfo fatty acid methyl ester, α-olefin sulfonic acid, alkane Sulfonic acid type (sulfonate type) anion such as sulfonic acid, fatty acid type anion such as higher fatty acid, sulfuric acid ester such as alkyl sulfate ester, glycol ether sulfate ester, alkyl ether sulfate ester Le type (sulfate type) anion, and (mono) phosphoric acid ester type such as alkyl phosphate (phosphate type) anion.

  Examples of ionic liquids include ionic liquids containing N-ethylethanolamine and alkylbenzene sulfonic acid, N-ethylethanolamine and glycol ether sulfate, N-ethylethanolamine and dialkyl succinate sulfonic acid, and melting point An ionic liquid having a temperature of 5 ° C. or lower can be used. The ionic liquid which consists of a cation and an anion and whose melting | fusing point is 5 degrees C or less can use a single thing, and can also mix and use 2 or more types. Further, the ionic liquid may contain two or more kinds of cations and / or two or more kinds of anions.

  The content of the ionic liquid having a melting point of 5 ° C. or lower is not particularly limited, but when the total mass of all components of the back layer is 100% by mass, the ionic liquid is 0.1% by mass to 12% by mass. It is preferable to contain in the range, and it is more preferable to contain in the range of 0.5 mass% or more and 10 mass% or less. When the content of the ionic liquid is less than 0.1% by mass, the antistatic performance tends to deteriorate. When the content exceeds 12% by mass, the balance of the composition ratio of the back layer coating film is lost, and the storage stability and the base material are reduced. There is a tendency for the adhesiveness to decrease.

<Binder resin>
There is no limitation in particular about binder resin contained in the back surface layer 5 with the said ionic liquid, A conventionally well-known thermoplastic resin etc. can be selected suitably and can be formed. Examples of the thermoplastic resin include polyester resins, polyacrylate resins, polyvinyl acetate resins, styrene acrylate resins, polyurethane resins, polyethylene resins, polypropylene resins, and other polyolefin resins, polystyrene resins. Polyvinyl acetal resins such as polyvinyl chloride resins, polyether resins, polyamide resins, polyimide resins, polyamide imide resins, polycarbonate resins, polyacrylamide resins, polyvinyl chloride resins, polyvinyl butyral resins, polyvinyl acetoacetal resins And the like, and these silicone-modified products.

<Lubricant>
The back layer 5 preferably contains a lubricant for improving the slipperiness with the thermal head. The lubricant is an arbitrary configuration in the back layer 5. As the lubricant, for example, phosphoric acid ester, metal soap, Wax, graphite powder, fluorine-based graft polymer, silicone oil, silicone-based graft polymer, acrylic silicone graft polymer, silicone polymer such as acrylic siloxane, aryl siloxane, etc. are appropriately selected. Can be used. Among the above-mentioned lubricant components, phosphate ester, metal soap, and Wax can be particularly preferably used in the present invention.

  Examples of the metal soap include polyvalent metal salts of alkyl phosphate esters, polyvalent metal salts of fatty acids, metal salts of alkyl carboxylic acids, and the like, and known additives for plastics can be used. In the present invention, zinc stearate and / or zinc stearyl phosphate can be preferably used.

  Examples of the phosphate ester include (1) a phosphoric acid monoester or diester of a saturated or unsaturated higher alcohol having 6 to 20 carbon atoms, and (2) a phosphoric acid monoester of a polyoxyalkylene alkyl ether or polyoxyalkylene alkyl allyl ether. Ester or diester, (3) phosphoric acid monoester or diester of the above-mentioned saturated or unsaturated higher alcohol alkylene oxide adduct (average number of added moles of 1 to 8), (4) alkylphenol having an alkyl group of 8 to 12 carbon atoms Alternatively, phosphoric acid monoester or diester of alkyl naphthol can be used. Examples of the saturated or unsaturated higher alcohol in the above (1) and (3) include cetyl alcohol, stearyl alcohol, oleyl alcohol and the like. Examples of the alkylphenol in the above (3) include nonylphenol, dodecylphenol, diphenylphenol and the like.

  The method for forming the back layer 5 is not particularly limited, and a gravure printing method is used in which a coating liquid in which an ionic liquid having a melting point of 5 ° C. or less, a binder resin, a lubricant added as necessary is dissolved or dispersed in an appropriate solvent is used. It can be formed by coating on the substrate 1 using a known coating means such as a screen printing method or a reverse roll coating method using a gravure plate and drying. Examples of the solvent used for preparing the coating liquid include water, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, dimethylformamide, ethyl acetate, butyl acetate, ethylene glycol, dimethylacetamide, Examples thereof include dimethyl sulfoxide.

(Back primer layer)
A back primer layer (not shown) may be provided between the substrate 1 and the back layer 5. The back primer layer is a layer provided in order to improve the adhesion between the substrate 1 and the back layer 5 and is an arbitrary layer. Examples of the back primer layer include polyester resin, polyurethane resin, acrylic resin, polycarbonate resin, polyamide resin, polyimide resin, polyamideimide resin, vinyl chloride / vinyl acetate copolymer, polyvinyl butyral resin, polyvinyl alcohol resin, and polyvinylpyrrolidone resin. Can be mentioned.

  Next, various embodiments of the thermal transfer sheet including the back layer 5 described above will be described. The thermal transfer sheets 10 and 100 according to the present invention require that the back layer 5 described above is provided on one surface of the base material 1, and are on the other surface of the base material 1. There is no limitation in particular about the layer provided in. For example, it is a thermal transfer sheet in which the back layer 5 described above is provided on one surface of the substrate 1 and (1) a dye layer and a protective layer are provided in the surface order on the other surface of the substrate 1. May be. Also, (2) a thermal transfer sheet provided with a dye layer on the other surface of the substrate 1 may be used. (3) a thermal transfer sheet provided with a protective layer on the other surface of the substrate 1 (protection) Layer transfer sheet). Furthermore, (4) a thermal transfer sheet (intermediate transfer medium) in which a protective layer and a receiving layer are laminated in this order on the other surface of the substrate 1 may be used. Hereinafter, these forms will be briefly described.

(1) Thermal transfer sheet in which a dye layer and a protective layer are provided in the surface order on the other surface of the base material. As shown in FIG. The back layer 5 described above is provided on one surface, and the dye layer 2 and the protective layer 3 are provided in the surface order on the other surface of the substrate 1.

(Dye layer)
The dye layer 2 is a dye layer containing a sublimable dye when the thermal transfer sheet of the present invention is a sublimation type thermal transfer sheet, and in the case of a hot melt type thermal transfer sheet, a hot melt composition containing a colorant. A dye layer containing a heat-meltable ink made of Hereinafter, although the case of a sublimation type thermal transfer sheet will be described as a representative example, the present invention is not limited to only a sublimation type thermal transfer sheet.

  As the dye contained in the dye layer 2, conventionally known dyes can be used, but those having good characteristics as a printing material, for example, having a sufficient coloring density and changing depending on light, heat, temperature, etc. Non-fading dyes are preferred, diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, methine dyes such as pyrazolone dyes, pyrazolone methines, pyridone methines, indoaniline dyes, indonaphthol dyes, acetophenone azomethine, Azomethine dyes such as pyrazoloazomethine, pyrazolone azomethine, pyrazolotriazole azomethine, imidazolazomethine, imidazoazomethine and pyridone azomethine, xanthene dyes, oxazine dyes, cyanostyrene dyes such as dicyanostyrene and tricyanostyrene, thia Dyes, azine dyes, acridine dyes, benzene azo dyes, pyridone azo, thiophenazo, thiazole azo, isothiazole azo, pyrrole azo, pyrazole azo, imidazole azo, thiadiazole azo, triazole azo, disazo azo dyes, spiropyran Dyes, indolinospiropyran dyes, fluorane dyes, rhodamine lactam dyes, naphthoquinone dyes, anthraquinone dyes, quinophthalone dyes, aminopyrazole dyes, pyrazolotriazole dyes, styryls such as dicyanostyryl and tricyanostyryl And dyes. 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.

  Examples of the binder resin for supporting the dye include cellulose resins such as ethyl cellulose resin, hydroxyethyl cellulose resin, ethyl hydroxy cellulose resin, methyl cellulose resin, and cellulose acetate resin, polyvinyl alcohol resin, polyvinyl acetate resin, and polyvinyl butyral resin. And vinyl resins such as polyvinyl acetal resin and polyvinyl pyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins and polyester resins. Among these, cellulose-based, vinyl-based, acrylic-based, polyurethane-based, and polyester-based resins are preferable in terms of heat resistance, dye transferability, and the like.

  The dye layer 2 may contain additives such as inorganic fine particles and organic fine particles. Examples of the inorganic fine particles include carbon black, silica, alumina, titanium dioxide, and molybdenum disulfide. Examples of the organic fine particles include polyethylene wax. The dye layer 2 may contain a release agent. Examples of the mold release agent include silicone oil and phosphate ester.

  As a method for forming the dye layer 2, an additive such as a release agent and a filler is added to the dye and the binder resin as necessary, and an appropriate solvent such as toluene, methyl ethyl ketone, ethanol, isopropyl alcohol, cyclohexane, dimethylformamide or the like. The coating liquid dispersed or dissolved in, for example, a gravure printing method, a reverse roll coating method using a gravure plate, a roll coater, a bar coater, or the like is applied onto a substrate and dried. Can be formed.

  In the embodiment shown in FIG. 1, a single dye layer 2 is provided on the substrate 1, but dye layers containing different dyes are repeatedly provided on the same surface of the same substrate in the surface order. It is also possible.

(Underlayer)
In the thermal transfer sheet of the first embodiment, an undercoat layer (not shown) is preferably provided between the substrate 1 and the dye layer 2. By providing the undercoat layer, the adhesion between the substrate 1 and the dye layer 2 can be improved, and the dye layer 2 can be prevented from abnormally transferring to the thermal transfer image receiving sheet side during thermal transfer. The undercoat layer has an arbitrary configuration in the thermal transfer sheet 10.

  As the resin constituting the undercoat layer, polyester resin, polyacrylate resin, polyvinyl acetate resin, polyurethane resin, styrene acrylate resin, polyacrylamide resin, polyamide resin, polyether resin, Examples thereof include polystyrene resins, polyethylene resins, polypropylene resins, vinyl resins such as polyvinyl chloride resins and polyvinyl alcohol resins, and polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral.

  The undercoat layer can also be composed of ultrafine colloidal inorganic pigment particles. This not only prevents abnormal transfer of the dye layer 2 during image formation, but also prevents dye transfer from the dye layer 2 to the undercoat layer and effectively diffuses the dye to the dye receiving layer side of the thermal transfer image receiving sheet. 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 hydrate, pseudoboehmite, 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, particularly preferably 3 nm to 30 nm.

The undercoat layer is a gravure coating method, a roll coating method, a screen printing method, a gravure plate, or a coating solution for the undercoat layer in which the resin exemplified above or colloidal inorganic pigment ultrafine particles are dissolved or dispersed in an appropriate solvent. 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 undercoat layer coating solution is preferably about 0.02 to 1.0 g / m ² .

(Protective layer)
In the thermal transfer sheet of the first embodiment, as shown in FIG. 1, the dye layer 2 and the protective layer 3 described above are provided on a base material 1 in the surface order. The protective layer 3 is configured to be peelable from the substrate 1. The protective layer 3 may have a multilayer structure or a single layer structure. In the case of a multi-layer structure, in addition to the main protective layer serving as a main body for imparting various durability to the image, the protective layer 3 is used to enhance the adhesion between the protective layer 3 and the image receiving surface of the printed material. An adhesive layer disposed on the surface, an auxiliary protective layer, a layer for adding a function other than the function of the protective layer body, or the like may be included. The order of the main protective layer and other layers is arbitrary, but usually other layers are placed between the adhesive layer and the main protective layer so that the main protective layer becomes the outermost surface layer of the image receiving surface after transfer. To do.

  The main protective layer or the single-layer protective layer 3 constituting the multilayer protective layer 3 can be formed of various resins conventionally known as protective layer forming resins. Examples of the resin that forms the protective layer include polyester resins, polystyrene resins, acrylic resins, polyurethane resins, acrylic urethane resins, resins obtained by silicone-modifying these resins, mixtures of these resins, UV curable resins, Examples include EB curable resins and ultraviolet absorbing resins.

  A protective layer containing a UV curable resin or an EB curable resin is particularly excellent in plasticizer resistance and scratch resistance. As the UV curable resin and the EB curable resin, known ones can be used. For example, a radical polymerizable polymer or oligomer is crosslinked and cured by UV irradiation, and a photopolymerization initiator is added if necessary. A polymerized and crosslinked product can be used.

  The main purpose of the protective layer containing the ultraviolet absorbing resin is to impart light resistance to the printed material. As the ultraviolet absorbing resin, for example, a resin obtained by reacting and bonding a reactive ultraviolet absorber to a thermoplastic resin or the above UV curable resin can be used. More specifically, addition-polymerizable double-reactive organic UV absorbers such as salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, nickel chelates, hindered amines, etc. Examples thereof include those in which a reactive group such as a bond (for example, a vinyl group, an acryloyl group, a methacryloyl group), an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, or an isocyanate group is introduced.

  The main protective layer provided in the protective layer 3 having a single layer structure or the protective layer 3 having a multilayer structure usually has a thickness of about 0.5 μm to 10 μm although it depends on the type of resin forming the protective layer. It is preferable.

  An adhesive layer may be formed on the outermost surface of the protective layer 3. The adhesive layer should be formed of a resin having good adhesiveness when heated, such as acrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin, polyester resin, polyamide resin. Can do. The thickness of the adhesive layer is usually about 0.1 μm to 5 μm. Further, a release layer or a release layer may be provided between the protective layer 3 and the substrate 1.

(2) Thermal transfer sheet in which a dye layer is provided on the other surface of the base material The thermal transfer sheet of the second embodiment of the present invention is provided with the back layer 5 described above on one surface of the base material 1. The structure is such that the dye layer 2 is provided on the other surface of the substrate 1. The thermal transfer sheet of the present embodiment is the same as the thermal transfer sheet of the first embodiment except that the protective layer 3 is not provided, and detailed description thereof is omitted.

(3) Thermal transfer sheet provided with a protective layer on the other surface of the substrate The thermal transfer sheet according to the third embodiment of the present invention is provided with the back layer 5 described above on one surface of the substrate 1. In addition, the protective layer 3 is provided on the other surface of the substrate 1. The thermal transfer sheet of this embodiment is the same as the thermal transfer sheet of the first embodiment except that it does not have the dye layer 2, and a detailed description thereof will be omitted.

(4) Thermal transfer sheet in which a protective layer and a receiving layer are laminated in this order on the other surface of the substrate The thermal transfer sheet according to the fourth embodiment of the present invention is one of the substrates 1 as shown in FIG. The back layer 5 described above is provided on the surface, and the protective layer 3 and the receiving layer 4 are provided in this order on the other surface of the substrate 1. That is, the thermal transfer sheet 100 of the fourth embodiment is a thermal transfer sheet 100 that functions as an intermediate transfer medium.

  As the protective layer 3, the protective layer 3 described in the first embodiment can be used as it is, and a detailed description thereof is omitted here.

(Receptive layer)
As shown in FIG. 2, a receiving layer 4 is provided on the protective layer 3. As the material of the receiving layer 4, a conventionally known resin material that can easily receive a heat transferable color material such as a sublimation dye or a heat-meltable ink can be used. For example, polyolefin resin such as polypropylene, halogenated resin such as polyvinyl chloride or polyvinylidene chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer or polyacrylate Vinyl resins, polyester resins such as polyethylene terephthalate or polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene or propylene and other vinyl polymers, cellulose resins such as ionomers or cellulose diastases Polycarbonate and the like, and vinyl chloride resin, acrylic-styrene resin or polyester resin is particularly preferable.

  When the receiving layer 4 is transferred to the transfer medium via the adhesive layer, the adhesiveness of the receiving layer 4 itself is not necessarily required. However, when the receptor layer 4 is transferred to the transfer medium without an adhesive layer, the receptor layer 4 may be formed using an adhesive resin material such as vinyl chloride-vinyl acetate copolymer. preferable.

The receptive layer 4 is a receptive layer coating obtained by adding one or more materials selected from the above materials and various additives as necessary, and dissolving or dispersing them in a suitable solvent such as water or an organic solvent. A working solution is prepared, and this can be formed by coating and drying by means of a gravure printing method, a screen printing method or a reverse coating method using a gravure plate. Its thickness is 1g / m ² ~10g / m ² approximately in a dry state.

  Hereinafter, the present invention will be described with reference to examples and comparative examples. “Part” in the text is based on mass unless otherwise specified.

Example 1
A 4.5 μm-thick polyethylene terephthalate film with an easy adhesion treatment is used as a base material, and a back layer coating solution 1 having the following composition is coated thereon so that the dry coating amount is 0.5 g / m ^2. The work was dried and a back layer was formed. Next, an undercoat layer coating solution having the following composition is applied to a part of the surface of the substrate opposite to the side on which the back layer is provided so that the dry coating amount is 0.10 g / m ^2. The coating was dried to form an undercoat layer. Subsequently, a magenta dye layer coating liquid (M) was applied onto the undercoat layer so that the dry coating amount was 0.6 g / m ² and dried to form a dye layer (M). . As a result, the thermal transfer sheet 1 of Example 1 was obtained in which the back layer was provided on one surface of the substrate, and the undercoat layer and the dye layer (M) were provided in this order on the other surface of the substrate.

<Back layer coating liquid 1>
・ 96 parts of polyvinyl acetal resin (SREC KS-1 manufactured by Sekisui Chemical Co., Ltd.)
・ 9.5 parts of zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.)
-Zinc stearate 9.5 parts (SZ-PF manufactured by Sakai Chemical Industry Co., Ltd.)
・ 5 parts of talc (Microace P-3 manufactured by Nippon Talc Industry Co., Ltd.)
・ Ionic liquid (melting point: 0 ° C. or lower) 1.83 parts (cation: alkanolamine, anion: glycol ether sulfate)
(JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)
・ Methyl ethyl ketone 500 parts ・ Toluene 500 parts

<Coating liquid for undercoat layer>
Colloidal silica (particle diameter 4-6 nm, solid content 10%) 30 parts (Snowtex OXS, manufactured by Nissan Chemical Industries, Ltd.)
・ Polyvinylpyrrolidone resin (K-90, manufactured by ISP) 3 parts ・ Water 50 parts ・ Isopropyl alcohol 17 parts

<Magenta dye layer coating solution (M)>
-Dye represented by the following general formula: 3.0 parts-Polyvinylacetoacetal resin 4.5 parts (KS-5, manufactured by Sekisui Chemical Co., Ltd.)
・ Polyethylene wax 0.1 part ・ Methyl ethyl ketone 50.0 parts ・ Toluene 50.0 parts

(Example 2)
A thermal transfer sheet was obtained in the same manner as in Example 1 except that the back primer layer (1) was provided between the back layer in Example 1 and the substrate. The back primer layer (1) was formed by coating and drying a back primer layer coating solution (1) having the following composition so that the dry coating amount was 0.1 g / m ² .

<Back primer layer coating solution (1)>
・ Polyester resin 50 parts (Polyester WR-961 Nippon Synthetic Chemical Industry Co., Ltd. solid content 30%)
・ 125 parts of water ・ 125 parts of isopropyl alcohol

(Example 3)
A thermal transfer sheet of Example 3 was produced in the same manner as in Example 1 except that the back layer coating solution 1 was changed to the following back layer coating solution 2.

<Back layer coating liquid 2>
・ 96 parts of polyvinyl acetal resin (SREC KS-1 manufactured by Sekisui Chemical Co., Ltd.)
・ 9.5 parts of zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.)
・ 9.5 parts of phosphate ester (Plysurf A-208N, Daiichi Kogyo Seiyaku Co., Ltd.)
・ 5 parts of talc (Microace P-3 manufactured by Nippon Talc Industry Co., Ltd.)
・ Ionic liquid (melting point: 0 ° C. or lower) 1.83 parts (cation: alkanolamine, anion: glycol ether sulfate)
(JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)
・ Methyl ethyl ketone 500 parts ・ Toluene 500 parts

Example 4
A thermal transfer sheet of Example 4 was produced in the same manner as Example 1 except that the back layer coating solution 1 was changed to the following back layer coating solution 3.

<Back layer coating liquid 3>
・ Acrylic resin 96 parts (Dianar BR-85 manufactured by Mitsubishi Rayon Co., Ltd.)
・ 9.5 parts of zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.)
・ 9.5 parts of phosphate ester (Plysurf A-208N, Daiichi Kogyo Seiyaku Co., Ltd.)
・ 5 parts of talc (Microace P-3 manufactured by Nippon Talc Industry Co., Ltd.)
・ Ionic liquid (melting point: 0 ° C. or lower) 1.83 parts (cation: alkanolamine, anion: glycol ether sulfate)
(JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)
・ Methyl ethyl ketone 450 parts ・ Toluene 450 parts

(Example 5)
A thermal transfer sheet of Example 5 was produced in the same manner as Example 1 except that the back layer coating solution 1 was changed to the following back layer coating solution 4.

<Back layer coating liquid 4>
・ 96 parts of cellulose acetate butyrate resin (CAB381-20 manufactured by Eastman Chemical Co., Ltd.)
・ 9.5 parts of zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.)
-Zinc stearate 9.5 parts (SZ-PF manufactured by Sakai Chemical Industry Co., Ltd.)
・ 5 parts of talc (Microace P-3 manufactured by Nippon Talc Industry Co., Ltd.)
・ Ionic liquid (melting point: 0 ° C. or lower) 1.83 parts (cation: alkanolamine, anion: glycol ether sulfate)
(JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)
・ Methyl ethyl ketone 850 parts ・ Toluene 850 parts

(Example 6)
A thermal transfer sheet of Example 6 was produced in the same manner as in Example 1 except that the back layer coating solution 1 was changed to the following back layer coating solution 5.

<Back layer coating liquid 5>
・ 384 parts of polyamideimide resin (HR-15ET, manufactured by Toyobo Co., Ltd., 25%)
・ 9.5 parts of zinc stearyl phosphate (LBT-1830 purification, manufactured by Sakai Chemical Industry Co., Ltd.)
-Zinc stearate 9.5 parts (SZ-PF manufactured by Sakai Chemical Industry Co., Ltd.)
・ 5 parts of talc (Microace P-3 manufactured by Nippon Talc Industry Co., Ltd.)
・ Ionic liquid (melting point: 0 ° C. or lower) 1.83 parts (cation: alkanolamine, anion: glycol ether sulfate)
(JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)
・ Methyl ethyl ketone 450 parts ・ Toluene 450 parts

(Example 7)
1.83 parts of ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the coating liquid 3 for the back layer was added to the ionic liquid (melting point: 5 ° C. or less) ( A thermal transfer sheet of Example 7 was prepared in the same manner as in Example 4 except that the cation was changed to 1.83 parts of 1-hexyl-3-methylimidazolium and anion: bis (trifluoromethanesulfonyl) imide).

(Example 8)
1.83 parts of ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 4 is added to the ionic liquid (melting point: 5 ° C. or less) ( A thermal transfer sheet of Example 8 was produced in the same manner as in Example 5 except that the cation was changed to 1.83 parts of 1-hexyl-3-methylimidazolium, anion: bis (trifluoromethanesulfonyl) imide).

Example 9
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 5 ° C. or less) ( A thermal transfer sheet of Example 9 was produced in the same manner as in Example 1 except that the cation was changed to 1.83 parts of 1-hexyl-3-methylimidazolium, anion: bis (trifluoromethanesulfonyl) imide).

(Example 10)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 5 ° C. or less) ( A thermal transfer sheet of Example 10 was prepared in the same manner as in Example 1 except that the cation was changed to 1.83 parts of 1-butyl-3-methylimidazolium and anion: bis (trifluoromethanesulfonyl) imide.

(Example 11)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 5 ° C. or less) ( A thermal transfer sheet of Example 11 was produced in the same manner as in Example 1 except that the cation was changed to 1.83 parts of 1-n-butyl-3-methylpyridinium, anion: bis (trifluoromethanesulfonyl) imide).

(Example 12)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was added to the ionic liquid (melting point: −75 ° C.) ( A thermal transfer sheet of Example 12 was produced in the same manner as in Example 1 except that 1.83 parts of cation: methyltri-n-octylammonium and anion: bis (trifluoromethanesulfonyl) imide) were changed.

(Example 13)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803, manufactured by Nippon Emulsifier Co., Ltd.) of the coating liquid 1 for the back layer was added to the ionic liquid (melting point: 3 ° C.) (cation : 1-butyl-1-methylpyrrolidinium, anion: trifluoromethanesulfonate) A thermal transfer sheet of Example 13 was produced in the same manner as in Example 1 except that the amount was changed to 1.83 parts.

(Example 14)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 5 ° C. or less) ( A thermal transfer sheet of Example 14 was prepared in the same manner as in Example 1 except that the cation was changed to 1-hexyl-3-methylimidazolium and the anion was changed to 0.61 part of bis (trifluoromethanesulfonyl) imide).

(Example 15)
Except that 1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was changed to 0.61 part. A thermal transfer sheet of Example 15 was produced in the same manner as Example 1.

(Example 16)
Except that 1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was changed to 13.4 parts. A thermal transfer sheet of Example 16 was produced in the same manner as Example 1.

(Example 17)
Except that 1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was changed to 16.4 parts. A thermal transfer sheet of Example 17 was produced in the same manner as Example 1.

(Example 18)
Except that 1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was changed to 21.2 parts. A thermal transfer sheet of Example 18 was produced in the same manner as Example 1.

(Example 19)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 0 ° C. or less) ( A thermal transfer sheet of Example 19 was prepared in the same manner as in Example 1 except that it was changed to 1.83 parts (cation: alkanolamine, anion: dialkyl succinate sulfonic acid) (JNA-10912, manufactured by Nippon Emulsifier Co., Ltd.). .

(Example 20)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 5 ° C. or less) ( A thermal transfer sheet of Example 20 was produced in the same manner as in Example 1 except that the cation: alkanolamine, anion: alkylbenzenesulfonic acid) (JNA-10911, manufactured by Nippon Emulsifier Co., Ltd.) was changed to 1.83 parts.

(Example 21)
Using a polyethylene terephthalate film having a thickness of 4.5 μm as the base material and having been subjected to easy adhesion treatment, a coating solution 1 for the back layer having the above composition is applied thereon so that the dry coating amount is 0.5 g / m ² The work was dried and a back layer was formed. Next, a part of the surface of the substrate opposite to the side on which the back layer is provided is coated with a release layer coating liquid (1) having the following composition so that the dry coating amount is 1.0 g / m ^2. After coating and drying to form the release layer (1), the above undercoat layer coating solution is coated and dried so that the dry coating amount is 0.10 g / m ^2. A protective layer (1) is formed by forming a subbing layer, and further coating and drying the protective layer coating liquid (1) on the undercoat layer so that the dry coating amount is 1.5 g / m ^2. Formed. Thus, the thermal transfer sheet of Example 21 in which the back layer was provided on one surface of the substrate, and the release layer (1) undercoat layer and the protective layer (1) were provided in this order on the other surface of the substrate. (Protective layer transfer sheet) was obtained.

<Peeling layer coating solution (1)>
・ Acrylic resin 20 parts (Dianar BR-87, manufactured by Mitsubishi Rayon Co., Ltd.)
・ Toluene 40 parts ・ Methyl ethyl ketone 40 parts

<Coating liquid for protective layer (1)>
・ Acrylic resin 69.6 parts
(Dianar BR-83, manufactured by Mitsubishi Rayon Co., Ltd.)
17.4 parts of an acrylic copolymer reactively bonded with a reactive ultraviolet absorber (UVA635L, manufactured by BASF Japan)
・ Silica 25 parts (Silicia 310, manufactured by Fuji Silysia)
・ Methyl ethyl ketone 100 parts ・ Toluene 100 parts

(Example 22)
A polyethylene terephthalate film (Lumirror, manufactured by Toray Industries, Inc.) having a thickness of 12 μm is used as a base material, and the back layer coating solution 1 having the above composition is applied thereon with a dry coating amount of 0.5 g / m ^2. And dried to form a back layer. Next, a release layer coating liquid (2) having the following composition is applied on the surface opposite to the side on which the back layer of the substrate is provided, and dried so that the dry coating amount is 1.0 g / m ^2. A release layer (2) was formed. Next, a protective layer coating liquid (2) having the following composition is coated on the release layer (2) and dried so that the dry coating amount is 10.0 g / m ² to form a protective layer (2). did. Further, the receiving layer coating solution having the following composition was applied on the protective layer (2) so that the dry coating amount was 2.0 g / m ² to form a receiving layer. A sheet (intermediate transfer medium) was obtained.

<Peeling layer coating solution (2)>
・ 95 parts acrylic resin (Dianar BR-87, manufactured by Mitsubishi Rayon Co., Ltd.)
・ Polyester resin 5 parts (Byron 200, manufactured by Toyobo Co., Ltd.)
・ Toluene 200 parts ・ MEK 200 parts

<Coating liquid for protective layer (2)>
・ 20 parts of polyester resin (Byron 270, manufactured by Toyobo Co., Ltd.)
・ Toluene 40 parts ・ MEK 40 parts

<Coating liquid for receiving layer>
・ 95 parts of vinyl chloride-vinyl acetate copolymer (CNL, manufactured by Nissin Chemical Industry Co., Ltd.)
・ Epoxy-modified silicone oil 5 parts (KP-1800U, manufactured by Shin-Etsu Chemical Co., Ltd.)
・ Toluene 200 parts ・ MEK 200 parts

(Example 23)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 5 ° C. or less) ( Cation: 1-hexyl-3-methylimidazolium, anion: bis (trifluoromethanesulfonyl) imide) The thermal transfer sheet of Example 23 (protective layer transfer sheet) in the same manner as Example 21, except that it was changed to 1.83 parts ) Was produced.

(Example 24)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 is added to the ionic liquid (melting point: 5 ° C. or less) ( Cation: 1-hexyl-3-methylimidazolium, anion: bis (trifluoromethanesulfonyl) imide) The thermal transfer sheet of Example 24 (intermediate transfer medium) in the same manner as in Example 22 except for changing to 1.83 parts Was made.

(Comparative Example 1)
Except that 1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate) (JNA-08803, manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating solution 1 was omitted, the same procedure as in Example 1 was performed. Thus, a thermal transfer sheet of Comparative Example 1 was produced.

(Comparative Example 2)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was added to the conductive polymer dispersion (CDP-310M Nippon Carlit). A thermal transfer sheet of Comparative Example 2 was prepared in the same manner as in Example 1 except that the solid content was 10%, and that was changed to 18.3 parts.

(Comparative Example 3)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was added to the conductive polymer dispersion (CDP-310M Nippon Carlit). A thermal transfer sheet of Comparative Example 3 was prepared in the same manner as in Example 1 except that the solid content was changed to 134 parts.

(Comparative Example 4)
1.83 parts of ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) Nonionic surfactant (Adekasoap ER-10) A thermal transfer sheet of Comparative Example 4 was produced in the same manner as in Example 1 except that the product was changed to 1.83 parts (manufactured by ADEKA).

(Comparative Example 5)
1.83 parts of ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) Nonionic surfactant (Adekasoap ER-10) A thermal transfer sheet of Comparative Example 5 was produced in the same manner as in Example 1 except that the product was changed to 13.4 parts).

(Comparative Example 6)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)) of the coating liquid 1 for the back layer was coated with conductive fine particles (FSS-10M Ishihara Sangyo ( Co., Ltd. 30% solid content) A thermal transfer sheet of Comparative Example 6 was prepared in the same manner as in Example 1 except that the content was changed to 6.1 parts.

(Comparative Example 7)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)) of the coating liquid 1 for the back layer was coated with conductive fine particles (FSS-10M Ishihara Sangyo ( Co., Ltd. 30% solid content) A thermal transfer sheet of Comparative Example 7 was prepared in the same manner as in Example 1 except that the content was changed to 170 parts.

(Comparative Example 8)
1.83 parts of ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) Nonionic surfactant (Adekasoap ER-10) A thermal transfer sheet (protective layer transfer sheet) of Comparative Example 8 was produced in the same manner as in Example 21 except that the product was changed to 13.4 parts).

(Comparative Example 9)
1.83 parts of ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) Nonionic surfactant (Adekasoap ER-10) A thermal transfer sheet (intermediate transfer medium) of Comparative Example 9 was produced in the same manner as in Example 22 except that the product was changed to 13.4 parts.

(Comparative Example 10)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was made into conductive fine particles (FSS-10M Ishihara Sangyo Co., Ltd.) ) Manufactured: 30% solid content) A thermal transfer sheet (protective layer transfer sheet) of Comparative Example 10 was prepared in the same manner as in Example 21 except that the solid content was changed to 170 parts.

(Comparative Example 11)
1.83 parts of the ionic liquid (cation: alkanolamine, anion: glycol ether sulfate ester) (JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.) of the back layer coating liquid 1 was made into conductive fine particles (FSS-10M Ishihara Sangyo Co., Ltd.) ) Product 30% solid content) A thermal transfer sheet (intermediate transfer medium) of Comparative Example 11 was prepared in the same manner as in Example 22 except that the solid content was changed to 170 parts.

(Comparative Example 12)
A thermal transfer sheet of Comparative Example 12 was obtained in the same manner as Comparative Example 1 except that the back primer layer (2) was provided between the back layer and the substrate. The back primer layer (2) was formed by coating and drying a back primer layer coating solution (2) having the following composition so that the dry coating amount was 0.1 g / m ² .

<Back primer layer coating solution (2)>
・ 15 parts of polyester resin (Byron 200 manufactured by Toyobo Co., Ltd.)
・ Ionic liquid (melting point: 0 ° C. or less) 1.3 parts (cation: alkanolamine, anion: glycol ether sulfate)
(JNA-08803 manufactured by Nippon Emulsifier Co., Ltd.)
・ Toluene 135 parts ・ MEK 135 parts

(Evaluation of surface electrical resistance)
The surface electrical resistance value (Ω / □) on the surface side of the back layer of the thermal transfer sheet of each example and comparative example was measured using a surface electrical resistance meter (Hiresta IP MCP-HT250, manufactured by Mitsubishi Yuka Co., Ltd.) under the following conditions. The surface electrical resistance was evaluated based on the following evaluation criteria. Table 1 shows the evaluation results for the thermal transfer sheets of Examples 1 to 20 and Comparative Examples 1 to 7 and 12, and the thermal transfer sheets of Examples 21 to 24, which are protective transfer sheets or intermediate transfer media, and Comparative Examples Table 2 shows the evaluation results for thermal transfer sheets 8-11. The surface electrical resistance value was measured in an environment of 20 ° C. and 60%.
<Measurement conditions>
PROBE TYPE: HR
SUPPLY VOLTAGE: 500V
TIMER: 10 sec
<Evaluation criteria>
○: 1.0 × 10 11 or less Δ: 1.0 × 10 11 or more, 1.00 × 10 12 or less ×: 1.0 × 10 12 or more

(Roughness evaluation)
The thermal transfer sheets of Examples 1 to 20 and Comparative Examples 1 to 7 and 12 were cut and pasted on the magenta part of a genuine ribbon of a sublimation transfer printer (DS-40 manufactured by DNP Photolcio Co., Ltd.), and a thin magenta image (180/255) (Gradation, 210/255 gradation) was printed on a genuine thermal transfer image receiving paper with a DS-40 printer, and the roughness was visually evaluated based on the following evaluation criteria. The evaluation results are also shown in Table 1. Roughness refers to innumerable extremely small density unevenness observed in the entire colored portion of the printed material.
<Evaluation criteria>
○: No roughening ×: Roughness can be confirmed

(Heat resistance evaluation)
The thermal transfer sheets of Examples 1 to 20 and Comparative Examples 1 to 7 and 12 were cut and pasted on the magenta portion of a genuine ribbon of a sublimation type transfer printer (DS-40, manufactured by DNP Photo Lucio Co., Ltd.), and Max gradation magenta solids. After printing an image (255/255 gradations) on a genuine thermal transfer receiver with a DS-40 printer, the back layer of the ribbon after printing is observed with a digital microscope (digital microscope VHX-500 KEYENCE). The thermal damage level such as resin flow was visually evaluated. The evaluation results are also shown in Table 1.
<Evaluation criteria>
○: No thermal damage is seen ×: Resin is flowing due to thermal damage

(Preservation evaluation)
The back layer and the magenta dye layer of the thermal transfer sheets of Examples 1 to 20 and Comparative Examples 1 to 7 and 12 were made to face each other, and a load of 20 kg / cm ² was applied for storage for 96 hours in an environment of 40 ° C. and 90% humidity. The dye of the dye layer was transferred to the back layer side. The back layer and the protective layer transfer body (1) were made to face each other, applied with a load of 20 kg / cm ² , and stored in an environment of 50 ° C. and 20% humidity for 24 hours. Thereafter, the protective layer transfer body (1) to which the dye of the back layer was transferred and the image receiving surface of the image receiving paper (color ink / paper set KP-36IP, manufactured by Canon Inc.) were superimposed, and a laminating tester (Lamipacker LPD2305PRO, Transfer was performed at 110 ° C. and 4 mm / sec using Fuji Plastics Co., Ltd. Further, the substrate sheet is peeled off from the image receiving paper, and the hue of the transfer part is measured using Gretag Spectrolino (D65 light source, viewing angle 2 °) manufactured by Gretag, and the color difference (ΔE ^* ) is calculated by the following formula. Evaluation was performed based on the evaluation 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 . As the protective layer transfer body (1) used here, the thermal transfer sheet of Example 21 in which the back layer was not coated was used.
<Evaluation criteria>
A: ΔE ^* is plus 15% or less compared to Comparative Example 1. B: ΔE ^* is plus 15-25% compared to Comparative Example 1. Δ: ΔE ^* is plus 25% compared to Comparative Example 1. 35% range x: ΔE ^* is more than 35% compared to Comparative Example 1

(Glossiness evaluation 1)
The thermal transfer sheets (protective layer transfer sheets) of Examples 21 and 23, Comparative Example 8 and Comparative Example 10 were cut and pasted to the protective layer portion of a genuine ribbon of a sublimation transfer printer (DS-40 manufactured by DNP Photolcio Inc.), A solid black image was printed on a genuine thermal transfer image receiving paper with a DS-40 printer. The specular glossiness (light reflection angle is 45 ° condition) of the protective layer surface of the black solid print is measured with a gloss meter (GlossMeter VG2000, manufactured by Nippon Denshoku Industries Co., Ltd.) and evaluated based on the following evaluation criteria. Went. The evaluation results are also shown in Table 2.
<Evaluation criteria>
○: minus 5% or more of the glossiness of Example 21 Δ: range of minus 5 to 10% of the glossiness of Example 21 ×: minus 10% or less of the glossiness of Example 21

(Glossiness evaluation 2)
Using an HDP-600 printer (manufactured by HID), the thermal transfer sheets (intermediate transfer media) of Examples 22 and 24, Comparative Example 9 and Comparative Example 11 were superimposed on a PVC card (manufactured by DNP), respectively. The transfer layer (peeling layer, protective layer, receiving layer) was transferred to form prints of Examples 22 and 24 and Comparative Examples 9 and 11. The surface gloss of the printed material (with a light reflection angle of 45 °) was measured with a gloss meter (GlossMeter VG2000, manufactured by Nippon Denshoku Industries Co., Ltd.) and evaluated based on the following evaluation criteria. The evaluation results are also shown in Table 2.
<Evaluation criteria>
○: minus 5% or more of the glossiness of Example 22 Δ: range of minus 5 to 10% of the glossiness of Example 22 ×: minus 10% or less of the glossiness of Example 22

(Adhesion evaluation)
Examples 21 and 23, Comparative Example 8 and Comparative Example 10 Thermal Transfer Sheet (Protective Layer Transfer Sheet), Examples 22 and 24, Comparative Example 9 and Comparative Example 11 Thermal Transfer Sheet (Intermediate Transfer Medium) Mending on Back Layer A tape (Scotch Mending Tape 3M) was applied, rubbed with the thumb several times from above the adhesive tape, and then peeled off at the same location three times to evaluate the adhesiveness of the back layer. The evaluation results are also shown in Table 2.
<Evaluation criteria>
○: Back layer is not peeled Δ: Back layer is partially peeled ×: Back layer is peeled

DESCRIPTION OF SYMBOLS 10, 100 ... Thermal transfer sheet 1 ... Base material 2 ... Dye layer 3 ... Protective layer 4 ... Receiving layer 5 ... Back layer

Claims (4)

A thermal transfer sheet provided with a back layer on one side of a substrate and at least one layer selected from the group of a dye layer, a protective layer and a receiving layer on the other side of the substrate,
The back transfer layer contains a binder resin and an ionic liquid having a melting point of 5 ° C. or less.   2. The thermal transfer sheet according to claim 1, wherein the ionic liquid is contained in a proportion of 0.1% by mass or more and 12% by mass or less among all components of the back layer.   The thermal transfer sheet is a thermal transfer sheet in which one or both of the dye layer and the protective layer are provided on the other surface of the base material. Thermal transfer sheet.   The thermal transfer sheet according to claim 1 or 2, wherein the thermal transfer sheet is an intermediate transfer medium in which the protective layer and the receiving layer are laminated in this order on the other surface of the substrate.

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