JP2020001225A - Thermal transfer sheet - Google Patents

Abstract

To provide a thermal transfer sheet capable of maintaining high transferability of a transfer layer and having high blocking resistance even if the content rate of a coloring material in a colored layer is increased.SOLUTION: There is provided a thermal transfer sheet which comprises a substrate and a transfer layer having a colored layer and an adhesion layer, wherein the colored layer contains an ethylene-vinyl acetate copolymer, a terpene resin and a coloring material and the adhesion layer contains an ethylene-vinyl acetate copolymer, a terpene resin and a filler.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal transfer sheet.

Conventionally, energy is applied to a thermal transfer sheet provided with a base material such as a resin film and a transfer layer provided with a coloring layer containing a coloring material using a thermal head or the like to transfer a paper or a plastic sheet or the like. 2. Description of the Related Art A hot-melt transfer system for producing a print by transferring a transfer layer onto a body and forming an image is known.
Since an image formed by the hot-melt transfer method has high density and excellent sharpness, this method is suitable for recording binary images such as characters and line drawings. Further, according to the thermal fusion transfer method, variable information such as address, customer information, numbering, and barcode can be recorded on the transfer-receiving body using a computer and a thermal transfer printer.

  When a high density is required for an image to be formed, usually, the content of the coloring material in the colored layer is adjusted. In particular, it is difficult to increase the image density (whiteness) of a white image formed using a white pigment such as titanium oxide, and thus it was necessary to further increase the content of the white pigment in the colored layer.

  By increasing the content of the coloring material in the coloring layer, the adhesiveness of the transfer layer to the object to be transferred is reduced, and the transferability of the transfer layer is reduced. Therefore, Patent Literature 1 and the like have proposed providing an adhesive layer on a colored layer.

However, there is room for improvement in the transferability of the transfer layer provided in the thermal transfer sheet proposed in Patent Document 1 and the like.
In addition, the provision of the adhesive layer has caused a new problem that adhesion (blocking) occurs between the back surface of the thermal transfer sheet and the adhesive layer during winding storage.

JP 2016-22722 A

  The present invention has been made in view of the above problems, and the problem to be solved is that even when the content of the coloring material in the coloring layer is increased, the transferability of the transfer layer can be maintained high, An object of the present invention is to provide a thermal transfer sheet having high blocking resistance.

  The thermal transfer sheet of the present invention includes a substrate and a transfer layer including a coloring layer and an adhesive layer, wherein the coloring layer includes an ethylene-vinyl acetate copolymer, a terpene resin, and a coloring material, and the adhesive layer includes ethylene. -It is characterized by containing a vinyl acetate copolymer, a terpene resin and a filler.

  In one embodiment, the melt flow rate of the ethylene-vinyl acetate copolymer contained in the coloring layer and the adhesive layer is 100 g / 10 min or more and 1000 g / 10 min or less.

  In one embodiment, the softening point of the terpene resin contained in the coloring layer and the adhesive layer is from 70 ° C to 140 ° C.

  In one embodiment, the content of the ethylene-vinyl acetate copolymer in the adhesive layer is from 20% by mass to 60% by mass.

  In one embodiment, the content of the terpene resin in the adhesive layer is from 20% by mass to 60% by mass.

  In one embodiment, the content of the filler in the adhesive layer is from 10% by mass to 40% by mass.

  In one embodiment, the ratio of the content of the ethylene-vinyl acetate copolymer to the content of the terpene resin in the colored layer (the content of the ethylene-vinyl acetate copolymer / the content of the terpene resin) is based on mass. And is not less than 1/3 and not more than 3/1.

  In one embodiment, the ratio of the content of the ethylene-vinyl acetate copolymer to the content of the terpene resin in the adhesive layer (the content of the ethylene-vinyl acetate copolymer / the content of the terpene resin) is based on mass. And is not less than 1/3 and not more than 3/1.

  In one embodiment, the thickness of the coloring layer is 1 μm or more and 3.5 μm or less.

  In one embodiment, the thickness of the adhesive layer is 0.5 μm or more and 1.5 μm or less.

  In one embodiment, the colorant is titanium oxide.

  In one embodiment, the content of the coloring material in the coloring layer is 55% by mass or more and 90% by mass or less.

  In one embodiment, the filler is titanium oxide.

  According to the present invention, it is possible to provide a thermal transfer sheet that can maintain high transferability of the transfer layer and has high blocking resistance even when the content of the coloring material in the colored layer is increased.

FIG. 1 is a schematic sectional view showing one embodiment of a thermal transfer sheet of the present invention. FIG. 1 is a schematic sectional view showing one embodiment of a thermal transfer sheet of the present invention.

(Thermal transfer sheet)
As shown in FIG. 1, the thermal transfer sheet 10 of the present invention includes a base material 11 and a transfer layer 14 having a coloring layer 12 and an adhesive layer 13 in this order.
In one embodiment, the transfer layer 14 further includes a release layer 15 below the colored layer 12, as shown in FIG.
In one embodiment, as shown in FIGS. 1 and 2, the thermal transfer sheet 10 of the present invention further includes a back layer 16 on a surface of the substrate 11 opposite to the surface on which the transfer layer 14 is provided.
Further, in one embodiment, the thermal transfer sheet 10 of the present invention may further include a release layer and a primer layer on the substrate (not shown).

  Hereinafter, each layer included in the thermal transfer sheet according to the present invention will be described.

(Base material)
The substrate has heat resistance enough to withstand thermal energy applied during thermal transfer (for example, heat from a thermal head), and has mechanical strength and solvent resistance capable of supporting a colored layer and the like provided on the substrate. If there is, it can be used without particular limitation.

As the base material, for example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), 1,4-polycyclohexylene dimethylene terephthalate, terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, etc. Polyester such as polyester, nylon 6 and nylon 6,6, etc., polyolefin such as polyethylene (PE), polypropylene (PP) and polymethylpentene, polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, polyvinyl chloride-vinyl acetate Copolymers, vinyl resins such as polyvinyl butyral and polyvinyl pyrrolidone (PVP), (meth) acrylic resins such as polyacrylate, polymethacrylate and polymethyl methacrylate, poly Imide resins such as amide and polyether imide, cellophane, cellulose acetate, nitrocellulose, cellulose resins such as cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB), styrene resins such as polystyrene (PS), polycarbonate, In addition, a film composed of an ionomer resin or the like (hereinafter, simply referred to as “resin film”) can be used.
Among the above-mentioned resins, polyesters such as PET and PEN are preferable from the viewpoint of heat resistance and mechanical strength, and PET is particularly preferable.
In the present invention, “(meth) acryl” means to include both “acryl” and “methacryl”. Further, “(meth) acrylate” is meant to include both “acrylate” and “methacrylate”.

  Further, a laminate of the above resin films can be used as a base material. The laminate of the resin film can be produced by using a dry lamination method, a wet lamination method, an extrusion method, or the like.

  When the substrate is a resin film, the resin film may be a stretched film or an unstretched film, but from the viewpoint of strength, a stretched film stretched in a uniaxial or biaxial direction. preferable.

  The thickness of the substrate is preferably 2 μm or more and 25 μm or less, more preferably 3.0 μm or more and 10 μm or less. This makes it possible to improve the mechanical strength of the substrate and the transmission of thermal energy during thermal transfer.

(Transfer layer)
The transfer layer included in the thermal transfer sheet of the present invention includes at least a coloring layer and an adhesive layer. In one embodiment, the transfer layer further includes a release layer below the colored layer.

(Colored layer)
The thermal transfer sheet of the present invention includes a coloring layer containing an ethylene-vinyl acetate copolymer, a terpene resin, and a coloring material.

  The ratio of the content of the ethylene-vinyl acetate copolymer to the content of the terpene resin in the colored layer (the content of the ethylene-vinyl acetate copolymer / the content of the terpene resin) is 1/3 by mass. It is preferably not less than 3/1 and more preferably not less than 3/5 and not more than 5/3. Thereby, the transferability of the transfer layer can be further improved.

  In the present invention, the ethylene-vinyl acetate copolymer is a copolymer obtained by copolymerizing an ethylene monomer and a vinyl acetate monomer, but as long as the properties of the present invention are not impaired, the ethylene monomer and vinyl acetate are used. Other monomers other than monomers can be included. The proportion of the constituent unit derived from the other monomer in the ethylene-vinyl acetate copolymer is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3% by mass or less. preferable.

The melt flow rate (MFR) of the ethylene-vinyl acetate copolymer is preferably from 100 g / 10 min to 1000 g / 10 min, and more preferably from 150 g / 10 min to 800 g / 10 min. Thereby, the transferability of the transfer layer can be further improved.
In the present invention, the MFR is measured at a temperature of 190 ° C. and a load of 2.16 kg in accordance with JIS K7210.

The proportion of the constituent units derived from the vinyl acetate monomer in the ethylene-vinyl acetate copolymer (hereinafter, sometimes referred to as a vinyl acetate constituent ratio) is preferably from 10% by mass to 35% by mass, and more preferably from 14% by mass or more. More preferably, the content is 30% by mass or less. Thereby, the transferability of the transfer layer can be further improved.
In the present invention, the vinyl acetate composition ratio is measured using a Fourier transform infrared spectrophotometer according to JIS K 7192.

  Further, the coloring layer can include two or more kinds of ethylene-vinyl acetate copolymers.

  The content of the ethylene-vinyl acetate copolymer in the coloring layer is preferably from 5% by mass to 30% by mass, and more preferably from 8% by mass to 23% by mass. Thereby, the transferability of the transfer layer can be further improved.

  In the present invention, a terpene resin is a polymer of a terpene monomer. , Γ-terpinene, terpinolene, 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol, sabinene and the like.

In the present invention, the terpene resin includes a modified terpene resin, for example, an aromatic modified terpene resin which is a copolymer of a terpene monomer and an aromatic monomer.
As the aromatic monomer, for example, styrene, α-methylstyrene, p-styrene, 3,4-dimethylstyrene, o-divinylbenzene, p-divinylbenzene, α-chlorostyrene, p-chlorostyrene, 2,4- Examples include dichlorostyrene, vinyltoluene and 1-vinylnaphthalene.

In the present invention, the terpene resin includes a terpene phenol resin which is a copolymer of a terpene monomer and a phenol monomer.
Examples of the phenol monomer include phenol, cresol, xylenol, catechol, resorcin, hydroquinone, and bisphenol A.

  In addition, the terpene resin may contain a monomer other than the above-mentioned monomers as long as the properties of the present invention are not impaired. The proportion of the structural unit derived from the other monomer in the terpene resin is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less.

  In addition, the coloring layer may include two or more terpene resins.

The softening point of the terpene resin is preferably from 70 ° C to 140 ° C, more preferably from 90 ° C to 120 ° C. As a result, the transferability of the transfer layer can be further improved, and the blocking resistance of the thermal transfer sheet can be further improved.
In the present invention, the softening point of the resin is measured according to JIS K 7234.

  The content of the terpene resin in the coloring layer is preferably 5% by mass or more and 30% by mass or less, more preferably 7% by mass or more and 25% by mass or less, and 8% by mass or more and 23% by mass or less. Is more preferred. Thereby, the transferability of the transfer layer can be further improved.

The coloring material contained in the coloring layer is not particularly limited, and is preferably appropriately selected according to the required color tone and the like, and inorganic pigments, organic pigments, dyes, and the like can be used.
The thermal transfer sheet of the present invention can exhibit high transferability even when the content of a coloring material such as a white inorganic pigment in the coloring layer is increased in order to improve the image density (whiteness). Examples of the white inorganic pigment include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, and calcium carbonate. Of these, titanium oxide is preferable from the viewpoint of image density (whiteness).

  Further, the coloring layer can include two or more coloring materials.

  The content of the coloring material in the coloring layer is preferably 55% by mass or more and 90% by mass or less, and more preferably 65% by mass or more and 87% by mass or less. Thereby, while maintaining the transferability of the transfer layer, the image density of a print (hereinafter simply referred to as a print) produced using the thermal transfer sheet of the present invention can be improved.

  As long as the properties of the present invention are not impaired, the colored layer may contain a resin material other than the ethylene-vinyl acetate copolymer and the terpene resin, and examples thereof include polyamide, polyolefin, vinyl resin, (meth) acrylic resin, and imide. Resins, cellulose resins and styrene resins.

  As long as the properties of the present invention are not impaired, the colored layer may contain additives such as fillers, plasticizers, antistatic materials, ultraviolet absorbers, inorganic particles, organic particles, release agents and dispersants.

  The thickness of the coloring layer is preferably from 1 μm to 3 μm, more preferably from 1.6 μm to 2.8 μm. Thereby, the transferability of the transfer layer can be improved. Further, the image density of the print can be improved.

  The colored layer is obtained by dispersing or dissolving the above material in water or a suitable solvent, and applying a known method such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method. It can be formed by applying a film on a base material or the like to form a coating film and drying the coating film.

(Adhesive layer)
The thermal transfer sheet of the present invention includes an adhesive layer containing an ethylene-vinyl acetate copolymer, a terpene resin, and a filler.

  The ratio of the content of the ethylene-vinyl acetate copolymer to the content of the terpene resin in the adhesive layer (the content of the ethylene-vinyl acetate copolymer / the content of the terpene resin) was 1/3 by mass. It is preferably not less than 3/1 and more preferably not less than 3/5 and not more than 5/3. Thereby, the transferability of the transfer layer can be further improved.

  The preferred MFR and vinyl acetate constituent ratio of the ethylene-vinyl acetate copolymer are as described above.

  In addition, the adhesive layer can include two or more ethylene-vinyl acetate copolymers.

  The content of the ethylene-vinyl acetate copolymer in the adhesive layer is preferably from 20% by mass to 60% by mass, and more preferably from 25% by mass to 55% by mass. Thereby, the transferability of the transfer layer can be further improved.

  The preferred softening point of the terpene resin is as described above.

  The adhesive layer can include two or more terpene resins.

  The content of the terpene resin in the adhesive layer is preferably 20% by mass or more and 60% by mass or less, and more preferably 25% by mass or more and 55% by mass or less. Thereby, the transferability of the transfer layer can be further improved.

  In the present invention, any of an organic filler, an inorganic filler and an organic-inorganic hybrid type filler can be used as the filler, and these may be used in combination.

Examples of the organic filler include particles containing a resin material such as (meth) acrylic resin, polyamide, fluororesin, polyolefin, and silicone resin.
Examples of the inorganic particles include particles containing metal oxides such as titanium oxide, calcium carbonate, and silica.

  By using titanium oxide or calcium carbonate as a filler, the image density of a print can be further improved when a white inorganic pigment such as titanium oxide is used as a coloring material contained in the coloring layer.

The average particle size of the filler is preferably 0.05 μm or more and 3.0 μm or less, more preferably 0.1 μm or more and 2.0 μm or less. Thereby, the blocking resistance of the thermal transfer sheet can be further improved while maintaining the transferability of the transfer layer.
In the present invention, the average particle diameter means a volume average particle diameter and is measured according to JIS Z 8819-2.

  The content of the filler in the adhesive layer is preferably 10% by mass or more and 40% by mass or less, more preferably 15% by mass or more and 35% by mass or less. Thereby, the blocking resistance of the thermal transfer sheet can be further improved while maintaining the transferability of the transfer layer. Further, the image density of a print can be further improved when titanium oxide or calcium carbonate is used as a filler and a white inorganic pigment such as titanium oxide is used as a coloring material contained in the coloring layer.

  As long as the characteristics of the present invention are not impaired, the coloring layer may contain a resin material other than the ethylene-vinyl acetate copolymer and the terpene resin, and the above-mentioned additives.

  The thickness of the adhesive layer is preferably 0.5 μm or more and 2 μm or less, and more preferably 0.6 μm or more and 1.4 μm or less. As a result, the transferability of the transfer layer can be further improved, and the blocking resistance of the thermal transfer sheet can be further improved.

  The adhesive layer is obtained by dispersing or dissolving the above material in water or a suitable solvent, and applying a known method such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method. It can be formed by applying a coating film on a colored layer or the like to form a coating film and drying the coating film.

(Release layer)
In one embodiment, the transfer layer provided in the thermal transfer sheet of the present invention includes a release layer below the colored layer. Thereby, the transferability of the transfer layer can be further improved.

In one embodiment, the release layer may include wax as a main component. Examples of the wax include natural waxes such as beeswax, spermaceti, wood wax, rice bran wax, carnauba wax, candelilla wax and montan wax, paraffin wax, microcrystalline wax, oxidized wax, ozokerite, ceresin, ester wax and polyethylene wax. Synthetic waxes, higher saturated fatty acids such as margaric acid, lauric acid, myristic acid, palmitic acid, stearic acid, freunic acid and behenic acid, higher saturated monohydric alcohols such as stearyl alcohol and behenyl alcohol, and higher esters such as fatty acid esters of sorbitan And higher fatty acid amides such as stearic acid amide and oleic acid amide. Among them, carnauba wax is preferred from the viewpoint of transferability of the transfer layer.
Note that the release layer can contain two or more waxes.

  The wax content in the release layer is preferably from 70% by mass to 99% by mass, and more preferably from 80% by mass to 98% by mass. Thereby, the transferability of the transfer layer can be further improved.

  In one embodiment, the release layer may include a resin material as a main component. When the release layer contains a resin material as a main component, the scratch resistance of the print can be further improved. Examples of the resin material include (meth) acrylic resin, cellulose resin, vinyl resin, polyurethane, silicone resin, and fluororesin.

  The content of the resin material in the release layer is preferably from 70% by mass to 99% by mass, more preferably from 80% by mass to 98% by mass. This makes it possible to further improve the scratch resistance of the print while maintaining the transferability of the transfer layer.

  The thickness of the release layer is preferably from 0.1 μm to 3.0 μm, more preferably from 0.2 μm to 2.0 μm. Thereby, the transferability of the transfer layer can be further improved.

  The release layer is formed by dispersing or dissolving the above material in water or a suitable solvent, and applying a known method such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method. It can be formed by applying a film on a substrate or the like by a means to form a coating film and drying the coating film.

(Back layer)
In one embodiment, the thermal transfer sheet of the present invention includes a back layer on the surface of the substrate on which the transfer layer is not provided. Thus, it is possible to prevent sticking and wrinkles due to heating during thermal transfer.

  In one embodiment, the back layer contains a resin material, and includes, for example, cellulose resin, styrene resin, vinyl resin, polyester, polyurethane, silicone-modified polyurethane, fluorine-modified polyurethane, and (meth) acrylic resin.

In one embodiment, the back layer comprises inorganic or organic particulates. Thereby, generation of sticking and wrinkles due to heating during thermal transfer can be further prevented.
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. , Graphite, saltpeter, and inorganic fine particles such as boron nitride. As the organic fine particles, organic resin fine particles composed of (meth) acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenol resin, acetal resin, styrene resin, polyamide, or the like, or reacting them with a crosslinking material And crosslinked resin fine particles.

  The thickness of the back layer is preferably 0.01 μm or more and 5.0 μm or less, more preferably 0.03 μm or more and 2 μm or less. This can prevent sticking and wrinkles from occurring while maintaining the transfer of thermal energy during thermal transfer.

  The back layer is obtained by dispersing or dissolving the above material in water or a suitable solvent, and applying a known method such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method. It can be formed by applying a film on a substrate to form a coating film and drying the coating film.

(Release layer)
In one embodiment, the thermal transfer sheet of the present invention includes a release layer between the substrate and the transfer layer. Thereby, the transferability of the thermal transfer layer can be improved.

  In one embodiment, the release layer contains a resin material, and includes, for example, (meth) acrylic resin, polyurethane, acetal resin, polyamide, polyester, melamine resin, polyol resin, cellulose resin, silicone resin, and the like.

  In one embodiment, the release layer includes a release material such as a silicone oil, a phosphate plasticizer, a fluorine compound, a wax, a metal soap, and a filler.

  The thickness of the release layer is not particularly limited, and may be, for example, 0.2 μm or more and 2.0 μm or less.

  The release layer is formed by dispersing or dissolving the above-mentioned material in water or a suitable solvent, and applying a known means such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method and a rod coating method. To form a coating film by coating on a substrate or the like, and drying the coating film.

(Primer layer)
In one embodiment, the thermal transfer sheet of the present invention includes a primer layer on one side or both sides of the substrate. Thereby, the adhesion between the base material and the adjacent layer can be improved.

  In one embodiment, the primer layer includes a resin material such as polyester, vinyl resin, polyurethane, (meth) acrylic resin, polyamide, polyether, polystyrene, and cellulose resin.

  The thickness of the primer layer is not particularly limited, and can be, for example, 0.2 μm or more and 2.0 μm or less.

  The primer layer is obtained by dispersing or dissolving the above material in water or a suitable solvent, and applying a known method such as a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method. It can be formed by applying a film on a substrate to form a coating film and drying the coating film.

  Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
A PET film having a thickness of 4.5 μm was prepared, and a coating liquid for forming a release layer having the following composition was applied to one surface of the PET film and dried to form a release layer having a thickness of 0.5 μm.
<Coating liquid for forming release layer>
・ 100 parts by mass of carnauba wax (WE-95, manufactured by Konishi Co., Ltd.)
・ 25 parts by mass of water ・ 75 parts by mass of isopropanol (IPA)

On the release layer formed as described above, a coating liquid for forming a colored layer having the following composition was applied and dried to form a colored layer having a thickness of 2.3 μm.
<Coating liquid for forming colored layer>
・ 70 parts by mass of titanium oxide (R-630, manufactured by Ishihara Sangyo Co., Ltd.)
-Ethylene-vinyl acetate copolymer 15 parts by mass (Evaflex (registered trademark) EV 220 ETR, manufactured by Du Pont-Mitsui Chemicals, Inc., MFR 150 g / 10 min, 28% by mass of vinyl acetate)
・ 15 parts by mass of terpene resin (Yasuhara Chemical Co., Ltd., YS Polystar (registered trademark) T100, terpene phenol resin, softening point 100 ± 5 ° C.)
・ 100 parts by weight of methyl ethyl ketone (MEK) ・ 100 parts by weight of toluene

On the colored layer formed as described above, a coating solution for forming an adhesive layer having the following composition was applied and dried to form an adhesive layer having a thickness of 1 μm.
<Coating liquid for forming adhesive layer>
・ Titanium oxide 30 parts by mass (R-630, manufactured by Ishihara Sangyo Co., Ltd.)
35 parts by mass of ethylene-vinyl acetate copolymer (manufactured by Mitsui Dupont Chemical Co., Ltd., Evaflex (registered trademark) EV 220 ETR, MFR 150 g / 10 min, vinyl acetate constituting ratio 28% by mass)
35 parts by mass of terpene resin (Yasuhara Chemical Co., Ltd., YS Polystar (registered trademark) T100, terpene phenol resin, softening point 100 ± 5 ° C)
-100 parts by weight of MEK-100 parts by weight of toluene

On the other surface of the PET film, a coating liquid for forming a back layer having the following composition was applied and dried to form a back layer having a thickness of 0.1 μm to obtain a thermal transfer sheet.
<Coating liquid for back layer formation>
・ Acrylic-modified silicone 10 parts by mass (NATCO Corporation, polyalloy NSA-X55)
・ MEK 20 parts by mass ・ Toluene 20 parts by mass

Examples 2 to 32 and Comparative Examples 1 to 8
Except that at least one of the composition of the coating solution for forming the colored layer, the thickness of the colored layer, the composition of the coating solution for forming the adhesive layer, and the thickness of the adhesive layer was changed as shown in Tables 1 and 2, A thermal transfer sheet was produced in the same manner as in Example 1.
The details of each component in Tables 1 and 2 are as follows, and the units of MFR are omitted in the tables.
(Filler)
・ Eposter (registered trademark) S6: manufactured by Nippon Shokubai Co., Ltd. (ethylene-vinyl acetate copolymer)
-Evaflex (registered trademark) EV 210 ETR: manufactured by Mitsui Dupont Chemical Co., Ltd., MFR 400 g / 10 minutes, vinyl acetate composition ratio 28% by mass
-Evaflex (registered trademark) EV 205WR: manufactured by Mitsui Dupont Chemical Co., Ltd., MFR 800 g / 10 minutes, vinyl acetate composition ratio 28% by mass
(Terpene resin)
・ YS Resin PX1000: manufactured by Yashara Chemical Co., Ltd., softening point 100 ± 5 ° C
・ YS resin TO105: manufactured by Yashara Chemical Co., Ltd., softening point 105 ± 5 ° C
・ YS resin TO115: manufactured by Yashara Chemical Co., Ltd., softening point 115 ± 5 ° C
-YS Polystar (registered trademark) T115: a terpene phenol resin, manufactured by Yashara Chemical Co., Ltd., softening point 115 ± 5 ° C
-YS Polystar (registered trademark) T80: a terpene phenol resin, manufactured by Yashara Chemical Co., Ltd., softening point 80 ± 5 ° C
(Polyolefin)
Ceramer 1608: Toyo Adress Co., Ltd., melting point 78 ° C
-AUROLENE (registered trademark) 100S: manufactured by Nippon Paper Industries, softening point 70 ± 5 ° C
((Meth) acrylic resin)
・ Dianal (registered trademark) BR-80: manufactured by Mitsubishi Chemical Corporation

<< Transferability Evaluation-1 >>
Using the thermal transfer sheet obtained in the above Examples and Comparative Examples and a printer (SD3C, manufactured by Markem Image, Inc., having a thermal head of 300 dpi), a laminate of a PET film and an LLDPE film (transferred object) was used. A two-dot character pattern image and a barcode image are formed on a PET film surface of Nippon Printing Co., Ltd. (hereinafter, sometimes referred to as a transfer-receiving body 1) at a print density of 130% and a print speed of 10 m / min. A print was obtained.
Also, when a laminated body of a stretched PP film and an unaxially stretched PP film (hereinafter, sometimes referred to as a transferred body 2) is used as a transfer target, an image is similarly formed on the surface of the stretched PP film. And a print was obtained.
The images formed on the two types of transfer-receiving members were visually checked, and the transferability of the thermal transfer sheet was evaluated based on the following evaluation criteria. The evaluation results are summarized in Tables 1 and 2.
(Evaluation criteria)
A: No omission or blurring was observed in the images formed on both the transfer-receiving bodies, and it was confirmed that a good image was formed.
B: There was no omission or blurring in the image formed on the transfer object 1, and it was confirmed that a good image was formed. However, the image formed on the transfer object 2 had practical problems. There was no omission or blurring.
NG: Missing and blurred images are formed on both the transfer-receiving members, and there is a practical problem.

<< Evaluation of transferability-2 >>
An image was formed in the same manner as described above, except that the printing speed was changed to 15 m / min, and its transferability was evaluated. The evaluation results are summarized in Tables 1 and 2.

<< Blocking resistance test >>
The thermal transfer sheets obtained in the above Examples and Comparative Examples were superposed two by two so that the adhesive layer and the back layer faced each other, and a pressure of 1.17 Mpa was applied, and the sheets were allowed to stand at 45 ° C. for 24 hours. After standing, the adhesive layer and the back layer were peeled off, and the blocking resistance of the thermal transfer sheet was evaluated based on the following evaluation criteria. The evaluation results are summarized in Tables 1 and 2.
(Evaluation criteria)
A: The adhesive layer and the back layer can be easily peeled off.
B: Adhesion between the adhesive layer and the back layer slightly occurs, but there is no practical problem.
NG: Sticking of the adhesive layer and the back layer occurs, and there is a practical problem.

<< Image density test >>
Using a thermal transfer sheet obtained in the above Examples and Comparative Examples, and a printer (SD3C, manufactured by Markem Image, Inc., provided with a thermal head of 300 dpi), a print density of 130% At a printing speed of 10 m / min, a solid pattern image was formed to obtain a print.
The printed matter was measured on black paper (whiteness 4.7), and the whiteness of the solid pattern image was measured according to JIS Z 8715 using OPTRON BRIGHTNESS manufactured by Toyo Seiki Seisaku-Sho, Ltd. based on the following evaluation criteria. Was evaluated. The evaluation results are summarized in Tables 1 and 2.
(Evaluation criteria)
A: Whiteness was 60 or more.
B: Whiteness was 55 or more and less than 60.
C: Whiteness was 50 or more and less than 55.
D: Whiteness was less than 50.

  10: thermal transfer sheet, 11: base material, 12: colored layer, 13: adhesive layer, 14: transfer layer, 15: release layer, 16: back layer

Claims (13)

A substrate, and a transfer layer including a coloring layer and an adhesive layer,
The coloring layer includes an ethylene-vinyl acetate copolymer, a terpene resin, and a coloring material,
The thermal transfer sheet, wherein the adhesive layer contains an ethylene-vinyl acetate copolymer terpene resin and a filler.   2. The thermal transfer sheet according to claim 1, wherein a melt flow rate of the ethylene-vinyl acetate copolymer contained in the coloring layer and the adhesive layer is from 100 g / 10 min to 1000 g / 10 min. 3.   The thermal transfer sheet according to claim 1, wherein a softening point of the terpene resin contained in the coloring layer and the adhesive layer is 70 ° C. or more and 140 ° C. or less.   The thermal transfer sheet according to any one of claims 1 to 3, wherein the content of the ethylene-vinyl acetate copolymer in the adhesive layer is from 20% by mass to 60% by mass.   The thermal transfer sheet according to any one of claims 1 to 4, wherein the content of the terpene resin in the adhesive layer is from 20% by mass to 60% by mass.   The thermal transfer sheet according to any one of claims 1 to 5, wherein the content of the filler in the adhesive layer is from 10% by mass to 40% by mass.   The ratio of the content of the ethylene-vinyl acetate copolymer to the content of the terpene resin (the content of the ethylene-vinyl acetate copolymer / the content of the terpene resin) in the coloring layer is 1 / mass. The thermal transfer sheet according to any one of claims 1 to 6, wherein the thermal transfer sheet has a ratio of 3 or more and 3/1 or less.   The ratio of the content of the ethylene-vinyl acetate copolymer in the adhesive layer to the content of the terpene resin (the content of the ethylene-vinyl acetate copolymer / the content of the terpene resin) is 1 / The thermal transfer sheet according to any one of claims 1 to 7, wherein the thermal transfer sheet has a ratio of 3 or more and 3/1 or less.   The thermal transfer sheet according to claim 1, wherein the thickness of the colored layer is 1 μm or more and 3 μm or less.   The thermal transfer sheet according to claim 1, wherein a thickness of the adhesive layer is 0.5 μm or more and 2 μm or less.   The thermal transfer sheet according to any one of claims 1 to 10, wherein the coloring material is titanium oxide.   The thermal transfer sheet according to any one of claims 1 to 11, wherein the content of the coloring material in the coloring layer is 55% by mass or more and 90% by mass or less.   The thermal transfer sheet according to any one of claims 1 to 12, wherein the filler is titanium oxide.

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