JP6756128B2 - Thermal transfer sheet - Google Patents

Description

The present invention relates to a thermal transfer sheet, and more particularly to a thermal transfer sheet having high organic solvent resistance, fine line printability and blocking resistance.

Conventionally, a thermal transfer sheet in which a colored layer in which a colorant such as a pigment or a dye is dispersed in a wax or a resin is supported on a base material such as a plastic film is used to respond to image information by a heating device such as a thermal head. A heat-melt transfer method is known in which a colored layer is transferred onto an object to be transferred such as paper or a plastic sheet by applying energy. The printed image formed by the heat-melt transfer method has high density and excellent sharpness, and is suitable for recording binary images such as characters and line art.
Further, according to the thermal fusion transfer method, variable information represented by attribute information such as address, customer information, numbering, and barcode is easily output and recorded on the transfer target using a computer and a thermal transfer printer. can do.

Such a thermal transfer sheet is required to have high adhesiveness to the transferred body. In order to satisfy this requirement, Patent Document 1 includes a release layer, a colored layer, and an adhesive layer on the support in this order, and the adhesive layer contains a polyester resin having a glass transition temperature of 70 ° C. or higher and 80 ° C. or lower. A thermal transfer sheet consisting of is disclosed.

Further, when such a thermal transfer sheet is used in an environment where an organic solvent such as isopropyl alcohol (IPA) is used, characters and the like formed by transferring the colored layer are not erased by the organic solvent. Is required.
However, the conventional thermal transfer sheet including the thermal transfer sheet disclosed in Patent Document 1 does not have sufficient adhesiveness between the adhesive layer and the transferred body and the adhesive layer and the colored layer, and an organic solvent is provided between them. Soaked in, and there was room for improvement in its organic solvent resistance.

Japanese Unexamined Patent Publication No. 11-321116

The present invention has been made in view of the above problems, and an object of the present invention is to provide a thermal transfer sheet having high organic solvent resistance.

The thermal transfer sheet according to the present invention
A thermal transfer sheet comprising a base material, a colored layer, and an adhesive layer in this order.
The colored layer contains a colorant and a polyester resin,
The adhesive layer is a water-based coating layer containing a polyester-based resin having a glass transition temperature of 50 ° C. or higher and 80 ° C. or lower.

In the above aspect, it is preferable that the colored layer contains the polyester resin A having a number average molecular weight of 15,000 or more and the polyester resin B having a number average molecular weight of 5,000 or less as the polyester resin.

In the above aspect, the thickness of the colored layer is preferably 0.2 μm or more and 0.8 μm or less.

In the above aspect, the thickness of the adhesive layer is preferably 0.1 μm or more and 0.6 μm or less.

In the above aspect, the glass transition temperature of the polyester resin contained in the adhesive layer is preferably 52 ° C. or higher and 67 ° C. or lower.

In the above aspect, it is preferable that a release layer is further provided between the base material and the colored layer.

According to the present invention, it is possible to provide a thermal transfer sheet having high organic solvent resistance, in which characters and the like formed by transferring a colored layer are not erased by an organic solvent.
Further, according to the present invention, it is possible to provide a thermal transfer sheet capable of printing fine lines without fading or crushing, that is, having high fine line printability.
Furthermore, according to the present invention, it is possible to provide a thermal transfer sheet in which ink or the like does not set off (blocking) on the back surface of the thermal transfer sheet during storage, that is, it has high blocking resistance.

It is a schematic sectional drawing which shows one Embodiment of the thermal transfer sheet of this invention. It is a figure which shows the printing pattern used in the organic solvent resistance evaluation of an Example. It is a figure which shows the print pattern used in the thin line printability evaluation of an Example.

(Thermal transfer sheet)
As shown in FIG. 1, the thermal transfer sheet 10 according to the present invention includes a base material 1, a colored layer 2, and an adhesive layer 3 in this order.
Further, in one embodiment, the thermal transfer sheet 10 may include a release layer 4 between the base material 1 and the coloring layer 2.
Further, in one embodiment, the thermal transfer sheet 10 may have a back surface layer 5 on a surface opposite to the surface of the base material 1 on which the colored layer 2 is provided.
Hereinafter, each layer included in the thermal transfer sheet according to the present invention will be described.

(Base material)
The base material may be any conventionally known material having a certain degree of heat resistance and strength, for example, polyethylene terephthalate (PET) film, 1,4-polycyclohexylene methylene terephthalate film, and polyethylene naphthalate. (PEN) film, polyphenylene sulfide film, polystyrene (PS) film, polypropylene (PP) film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose derivatives such as cellulose acetate, polyethylene (PE) film, Examples thereof include resin films such as polyvinyl chloride film, nylon film, polyimide film and ionomer film.

The base material may be surface-treated in order to improve the adhesion with the adjacent layer. As the surface treatment, known resin surface modification techniques such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, roughening treatment, chemical treatment, plasma treatment, and grafting treatment shall be applied. Can be done. The above surface treatment may be performed by only one type or two or more types.

In the present invention, among the above-mentioned surface treatments, corona treatment or plasma treatment is preferable in terms of low cost. Further, if necessary, the base material may be provided with an undercoat layer (primer layer) on one surface or both surfaces thereof. The above-mentioned primer treatment can be carried out, for example, by applying a primer solution to an unstretched film at the time of film formation by melt extrusion of a plastic film, and then stretching the unstretched film. It is also possible to form a primer layer (adhesive layer) by coating between the base material and the heat-resistant slippery layer described above. The primer layer is, for example, a polyester resin, a polyacrylic acid ester resin, a polyvinyl acetate resin, a polyurethane resin, a styrene acrylate resin, a polyacrylamide resin, a polyamide resin, a polyether resin, or a polystyrene resin. , Polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyvinyl alcohol resin, vinyl resin such as polyvinylidene chloride resin, polyvinyl acetal resin such as polyvinyl acetacetal and polyvinyl butyral, cellulose resin, etc. be able to.

The thickness of the base material is not particularly limited, and is preferably 2 μm or more and 25 μm or less, and more preferably 3 μm or more and 10 μm or less.

(Colored layer)
The colored layer comprises a colorant and a polyester resin.
In the present specification, the "polyester-based resin" means a polymer containing an ester group obtained by polycondensing a polyvalent carboxylic acid and a polyvalent alcohol, and for example, PET, polyethylene isophthalate, polybutylene. Examples thereof include terephthalate, polypropylene terephthalate, polycyclohexanedimethylene terephthalate and PEN.
Examples of the polyvalent carboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, decandicarboxylic acid, azelaic acid, dodecadicarboxylic acid, cyclohexanedicarboxylic acid and the like. Can be mentioned.
Examples of the polyhydric alcohol include ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, decanediol, and 2-ethyl-butyl-1-propanediol. , Bisphenol A and the like.
Further, the polyester resin may be obtained by copolymerizing three or more of the above-mentioned polyhydric carboxylic acids and polyhydric alcohols, and may be copolymerized with monomers and polymers such as diethylene glycol, triethylene glycol and polyethylene glycol. It may be a polymer.
Further, in the present specification, the polyester resin also includes a modified product thereof. Examples of the modified product of the polyester-based resin include urethane-modified polyester-based resin.

The colored layer may contain two or more polyester resins, preferably a polyester resin A having a number average molecular weight (Mn) of 15,000 or more (hereinafter, sometimes referred to as a high molecular weight polyester resin) and a number. It contains a polyester resin B having an average molecular weight of 5000 or less (hereinafter, may be referred to as a low molecular weight polyester resin).
More preferably, the number average molecular weight of the polyester resin A is 15,000 or more and 40,000 or less, and even more preferably 15,000 or more and 25,000 or less.
More preferably, the number average molecular weight of the polyester resin B is 2000 or more and 5000 or less.
Since the colored layer contains the polyester-based resin A and the polyester-based resin B having a number average molecular weight as described above, it is possible to prevent the occurrence of tailing during thermal transfer and the organic resistance of the thermal transfer sheet. The solvent property can be improved.
The number average molecular weight is a value obtained in terms of polystyrene by gel permeation chromatography (GPC) in accordance with JIS K 7252-1 (2008).
The colored layer may contain two or more types of polyester resin A, or may contain two or more types of polyester resin B.

When the colored layer contains a high molecular weight polyester resin A and a low molecular weight polyester resin B, the content ratio of the polyester resin A to the polyester resin B (polyester resin A / polyester resin B) is On a mass basis, it is preferably 2/9 or more and 3 or less, and more preferably 1/4 or more and 1 or less.
By the colored layer containing the high molecular weight polyester resin and the low molecular weight polyester resin in the above proportions, it is possible to prevent the occurrence of tailing during thermal transfer and the thermal transfer sheet. The organic solvent resistance can be further improved.

The glass transition temperature (Tg) of the polyester resin contained in the colored layer is preferably 20 ° C. or higher and 90 ° C. or lower, and more preferably 50 ° C. or higher and 80 ° C. or lower.
By setting the glass transition temperature of the polyester resin contained in the colored layer within the above numerical range, it is possible to improve the blocking resistance while improving the transferability of the thermal transfer sheet.
The glass transition temperature can be determined based on the measurement of calorific value change (DSC method) by DSC (Differential Scanning Calorimetry) in accordance with JIS K 7121 (2012).

The total content of the polyester resin in the colored layer is preferably 30% by mass or more and 90% by mass or less, and more preferably 40% by mass or more and 70% by mass or less.
By setting the total content of the polyester-based resin contained in the colored layer within the above numerical range, the adhesion to the adhesive layer can be further enhanced, so that the organic solvent resistance can be improved. It is also possible to improve scratch resistance and print density.

The colored layer may contain other resins as long as the effects of the present invention are not impaired. Examples of such resins include acrylic resins, polyurethane resins, vinyl resins, cellulose resins, melamine resins, polyamide resins, polyolefin resins, and styrene resins.
From the viewpoint of achieving high organic solvent properties, the content of the other resin in the colored layer is preferably 20% by mass or less, more preferably 5% by mass or less, and most preferably not contained. ..

The colorant contained in the colored layer can be appropriately selected from carbon black, inorganic pigments, organic pigments and dyes according to the required color tone and the like. For example, in the case of barcode printing, it is preferable that the barcode has a particularly sufficient black density and does not discolor or fade due to light, heat, or the like. Examples of such a colorant include carbon black such as lamp black, graphite, and niglosin dye. Further, when color printing is required, other chromatic dyes or pigments are used.

The colored layer may contain additives such as inorganic fine particles, organic fine particles, a mold release agent, a dispersant, and an antistatic agent as long as the effects of the present invention are not impaired.

The thickness of the colored layer is preferably 0.2 μm or more and 0.8 μm, and more preferably 0.3 μm or more and 0.6 μm.
By setting the thickness of the colored layer within the above numerical range, the fine line printability can be improved.

For the colored layer, if necessary, the above materials are dissolved in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, xylene, or water to prepare a coating liquid for the colored layer, which is used as a gravure coater, roll coater, wire bar, etc. It can be formed by coating on a substrate by a conventional suitable printing method and coating method, and then drying by heating to a temperature of 30 ° C to 80 ° C.

(Adhesive layer)
The adhesive layer is an aqueous coating film provided on the colored layer and containing a polyester resin having a glass transition temperature of 50 ° C. or higher and 80 ° C. or lower.
When the adhesive layer contains the polyester resin as in the colored layer, the adhesiveness to the transferred body and the colored layer can be improved, and the organic solvent resistance can be improved. In addition, fine line printability and blocking resistance can be improved.
Further, since the adhesive layer is a water-based coating film, it is possible to improve the stability of the coating amount when printing is continued for a long time.

The glass transition temperature of the polyester resin contained in the adhesive layer is 50 ° C. or higher and 80 ° C. or lower, but more preferably 52 ° C. or higher and 67 ° C. or lower.
By setting the glass transition temperature of the polyester resin within the above numerical range, the organic solvent resistance, fine line printability and blocking resistance can be further improved.

The number average molecular weight of the polyester resin contained in the adhesive layer is preferably 2000 or more and 25,000 or less, and more preferably 3000 or more and 20000 or less.
By setting the number average molecular weight of the polyester resin contained in the adhesive layer within the above numerical range, it is possible to improve the organic solvent resistance while maintaining the transferability of the thermal transfer sheet. In addition, scratch resistance can be improved.

The content of the polyester resin in the adhesive layer is preferably 50% by mass or more and 100% by mass or less, and more preferably 70% by mass or more and 100% by mass or less.
By setting the content of the polyester resin in the adhesive layer within the above numerical range, the adhesiveness to the transferred body and the adhesiveness to the colored layer can be further improved, and the organic solvent resistance can be improved. ..

The adhesive layer may contain other resins as long as the effects of the present invention are not impaired. Examples of such resins include acrylic resins, polyurethane resins, vinyl resins, cellulose resins, melamine resins, polyamide resins, polyolefin resins, and styrene resins.

The thickness of the adhesive layer is preferably 0.1 μm or more and 0.6 μm, and more preferably 0.2 μm or more and 0.5 μm.
By setting the thickness of the adhesive layer within the above numerical range, the fine line printability can be improved.

In the adhesive layer, the above-mentioned material is dispersed in water to prepare a water-based coating liquid for the adhesive layer, which is applied onto the base material by a conventional appropriate printing method or coating method such as a gravure coater, a roll coater, or a wire bar. It is an aqueous coating film formed by coating and then drying by heating to a temperature of 30 ° C to 80 ° C. By using an aqueous coating film as the adhesive layer, stable coating can be performed without invading the underlying colored layer.

(Peeling layer)
The release layer is a layer that is optionally arranged between the base material and the colored layer and is transferred onto the transferred object together with the colored layer and the like during thermal transfer.

The release layer may contain, for example, a cellulosic resin, a vinyl resin, a polyurethane resin, a silicone resin, a fluorine resin, a silicone wax, a fluorine-modified resin, a wax, or the like. Examples of waxes include microcrystalin wax, carnauba wax, paraffin wax, fisher tropsh wax, various low molecular weight polyethylenes, wood wax, beeswax, whale wax, ibota wax, wool wax, cellac wax, candelilla wax, petrolactam, and some. Examples include modified waxes, fatty acid esters and fatty acid amides.

The thickness of the release layer is preferably 0.4 μm or more and 1.2 μm, and more preferably 0.5 μm or more and 1.0 μm. By setting the thickness of the release layer within the above numerical range, it is possible to improve the printability on the transferred body having irregularities on the surface and prevent the occurrence of tailing.

For the release layer, if necessary, the above materials are dissolved in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, xylene, or water to prepare a coating solution for the release layer, which is used as a gravure coater, roll coater, wire bar, etc. It can be formed by coating on a substrate by a conventional suitable printing method and coating method, and then drying by heating to a temperature of 30 ° C to 80 ° C.

(Back layer)
In the present invention, the back surface layer is optionally provided in order to prevent adverse effects such as sticking and wrinkles due to heating from the back surface side of the base material (the side where the colored layer of the base material is not provided) during thermal transfer. It is a layer. By providing the back layer, it is possible to perform thermal transfer without sticking even on a thermal transfer sheet based on a plastic film with inferior heat resistance, and the plastic film has difficulty in cutting, ease of processing, etc. You can take advantage of.

The back layer may contain a binder resin, and examples thereof include cellulose-based resin, vinyl-based resin, polyester-based resin, polyurethane-based resin, silicone-modified urethane-based resin, fluorine-modified urethane-based resin, and acrylic resin.
Further, a two-component curable resin that can be cured by using an isocyanate compound or the like may be contained as the binder resin. Examples of such a resin include polyvinyl acetal-based resins and polyvinyl butyral-based resins.
As the isocyanate compound, conventionally known compounds can be used without particular limitation, but among them, it is desirable to use an adduct of aromatic isocyanate. Examples of the aromatic polyisocyanate include 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, and trizine diisocyanate. Examples thereof include p-phenylene diisocyanate, trans-cyclohexane-1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate and tris (isocyanisocyanene phenyl) 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.

In addition to the above-mentioned components, inorganic or organic fine particles may be added to the back layer for auxiliary adjustment of slipperiness. Examples of the inorganic fine particles include clay minerals such as talc and kaolin, carbonates such as calcium carbonate and magnesium carbonate, hydroxides such as aluminum hydroxide and magnesium hydroxide, sulfates such as calcium sulfate, and oxides such as silica. , Inorganic fine particles such as graphite, sulphate, and boron hydroxide. The organic fine particles include acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenol resin, acetal resin, polystyrene resin, nylon resin, and other organic resin fine particles, or a crosslinked resin obtained by reacting these with a crosslinking agent. Examples include fine particles. Among the above-mentioned inorganic or organic fine particles, talc can be preferably used.

The thickness of the back layer is preferably 0.03 μm or more and 1.0 μm or less, and more preferably 0.05 μm or more and 0.5 μm or less. By setting the thickness of the back layer within the above numerical range, it is possible to prevent adverse effects such as sticking and wrinkles while maintaining heat transfer from the thermal head at a sufficient print density.

For the back layer, the above material is dissolved in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, xylene or water to prepare a coating liquid for the back layer, which is commonly used as a gravure coater, a roll coater, a wire bar or the like. It can be formed by coating on a substrate by an appropriate printing method and coating method, and then drying by heating to a temperature of 30 ° C. to 110 ° C.

(Other layers)
In one embodiment, the thermal transfer sheet according to the present invention may include a release layer between the base material and the release layer. The release layer is a layer that stays on the substrate during thermal transfer.
Further, in one embodiment, the thermal transfer sheet according to the present invention may include an intermediate layer for improving the adhesiveness between arbitrary layers.

In the present invention, the thickness of each layer provided in the thermal transfer sheet was measured by using the resin embedding method.
Specifically, after embedding a cut thermal transfer sheet (test piece) with epoxy resin, a cut surface is formed in the thickness direction of the test piece by an ultrathin section method (cutting with a microtome and a diamond cutter). This cut surface is ion-sputtered (manufactured by Hitachi High-Technologies, trade name: E-1045, target: Pt, current: 15 mA, 10 seconds), and then a scanning electron microscope (manufactured by Hitachi High-Technologies, trade name: S-). By using 4800TYPE I, accelerating voltage: 3.0 kv, emission current: 10 μA, working distance: 8 mm, detector: Mix), a cross-sectional image of the test piece was obtained and measured from this image.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, parts or% are based on mass.

Example 1
On one surface of the base sheet of the easy-adhesion-treated PET film with a thickness of 4.5 μm, apply the coating liquid for the back layer having the following composition so that the coating amount is 0.3 g / m ^{2 in} terms of solid content. The back layer was formed by applying and drying. The thickness of the back layer was 0.3 μm.
<Coating liquid for back layer>
・ Styrene-acrylonitrile copolymer resin 11 parts ・ Linear saturated polyester resin 0.3 parts ・ Zincstearyl phosphate 6 parts ・ Melamine resin powder 3 parts ・ Methyl ethyl ketone 80 parts

Next, a coating liquid for a release layer having the following composition is applied to a part of the base sheet opposite to the side on which the back layer is provided so that the dry coating amount is 0.6 g / m ^2. , Dryed to form a release layer. The thickness of the formed release layer was 0.6 μm.
<Coating liquid for release layer>
・ Carnauba wax 100 copies ・ Water 450 copies ・ IPA 450 copies

On the release layer formed as described above, a coating liquid for a colored layer having the following composition was applied so that the dry coating amount was 0.45 g / m ² , and dried to form a colored layer. The compounding ratio (A: B) of the high molecular weight polyester resin (A) and the low molecular weight polyester resin (B) was 1: 1. The thickness of the formed colored layer was 0.4 μm.
<Coating liquid for colored layer>
-Carbon black 33.4 parts-Polyester resin A 33.3 parts (Mn: 17000, Tg: 67)
-Polyester resin B 33.3 parts (Mn: 3000, Tg: 53)
-Toluene / methyl ethyl ketone (1/1) 900 parts

On the colored layer formed as described above, a coating liquid for an adhesive layer having the following composition is applied and dried so that the dry coating amount is 0.3 g / m ² , and the adhesive layer is formed by thermal transfer. A sheet was prepared. The thickness of the formed adhesive layer was 0.3 μm.
<Coating liquid for adhesive layer>
-Polyester resin X1 100 parts (Mn: 18000, Tg: 67)
・ 450 copies of water ・ 450 copies of IPA

Examples 2-11 and Comparative Examples 1-17
A thermal transfer sheet was produced in the same manner as in Example 1 except that the polyester resins A and B contained in the colored layer and the polyester resins X contained in the adhesive layer were changed as shown in Tables 1 to 6.

The following tests were performed on the thermal transfer sheets obtained in Examples and Comparative Examples and evaluated. The evaluation results of each test were as shown in Tables 1-6.

<< Organic solvent resistance (IPA resistance) >>
Using the thermal transfer sheets of Examples and Comparative Examples, a Zebra 105SL printer, a printing speed of 4IPS, a printing energy of 26, a PET label (manufactured by Avery Co., Ltd., trade name: 72825) as a white PET label to be transferred, and a picket barcode (see FIG. 2). Is printed, and a dyed fastness friction tester FR-2S type (manufactured by Suga Test Instruments Co., Ltd., conforming to JIS L 0849 (2013) friction tester type II) is used to apply isopropyl alcohol (IPA). Using a cotton cloth impregnated with 0.5 cc, scratching was performed 100 times back and forth under a load of 800 g, and the organic solvent resistance was evaluated.
Evaluation was performed using a barcode checker Quick Check 850 (manufactured by Honeywell), and the evaluation criteria were as follows. After confirming that all the evaluation results of the barcode checker before rubbing were judged as A, the organic solvent resistance evaluation was carried out.
(Evaluation criteria)
A: The judgment result by the barcode checker after rubbing is A judgment.
B: The judgment result by the barcode checker after rubbing is B judgment.
C: The determination result by the barcode checker after rubbing is the C determination.
D: The judgment result by the barcode checker after rubbing is D judgment or less.

<< Fine line printability >>
As a printer, a label printer Zebra96XiIII (thermal head 600 dpi (dot per inch)) manufactured by Zebra was used, and printing speed was 4 IPS (inch per second) and printing energy was printed one step at a time in the range of 20 to 30. A silver PET label (manufactured by Avery Co., Ltd., trade name: 72826) was used as the transfer material, and a picket barcode (see FIG. 3) including 1 dot of thin lines was printed as a print pattern. The printed matter was visually evaluated. The evaluation criteria were as follows.
(Evaluation criteria)
A: The printable energy range is wide, and with three or more printing energies, fine line printing without blurring or crushing is possible.
B: The printable energy range is wide, and with two printing energies, fine line printing without blurring or crushing is possible.
C: The printable energy range is wide, and fine line printing without blurring or crushing is possible with one printing energy.
D: There is no printable energy range, blurring and crushing occur, and fine line printing is not possible.

<< Blocking resistance >>
Two of each of the thermal transfer sheets obtained in Examples and Comparative Examples were superposed so that the surface on the adhesive layer side and the surface on the back layer side faced each other, and a pressure of 12 kgf / cm ² was applied to 24 at 45 ° C. I left it for a while. The adhesive layer and the back surface layer were peeled off after standing, and the blocking resistance was evaluated from the ease of peeling off. The evaluation criteria were as follows.
(Evaluation criteria)
A: The adhesive layer and the back surface layer can be easily peeled off.
B: There is a slight sticking between the adhesive layer and the back layer, but there is no problem in practical use.
C: Adhesive layer and back layer stick together, but there is no problem in practical use.
D: Adhesion between the adhesive layer and the back surface occurs, which is problematic in practical use.

1 Base material 2 Colored layer 3 Adhesive layer 4 Peeling layer 5 Back layer 10 Transfer sheet

Claims (5)

A thermal transfer sheet comprising a base material, a colored layer, and an adhesive layer in this order.
The colored layer contains a colorant and a polyester resin.
The adhesive layer is an aqueous coating layer containing a polyester resin having a glass transition temperature of 50 ° C. or higher and 80 ° C. or lower.
The colored layer, as the polyester resin, Ri number average molecular weight of the polyester resin A and a number average molecular weight of more than 15,000 na contains 5000 following polyester resin B,
The glass transition temperature of the polyester resin B is, 50 ° C. or more, and the Der Rukoto below 80 ° C., the thermal transfer sheet. The thermal transfer sheet according to claim 1, wherein the thickness of the colored layer is 0.2 μm or more and 0.8 μm or less. The thermal transfer sheet according to claim 1 or 2, wherein the thickness of the adhesive layer is 0.1 μm or more and 0.6 μm or less. The thermal transfer sheet according to any one of claims 1 to 3, wherein the glass transition temperature of the polyester resin contained in the adhesive layer is 52 ° C. or higher and 67 ° C. or lower. The thermal transfer sheet according to any one of claims 1 to 4, further comprising a release layer between the base material and the colored layer.