JP2019155769A - Protective layer transfer sheet - Google Patents

Abstract

To provide a protective layer transfer sheet including a transferable protective layer that, after transferred onto a printed matter, can significantly improve the glossiness of an image formed on the printed matter while maintaining the density of it.SOLUTION: A protective layer transfer sheet has a base material 11, and a transferable protective layer 12. The transferable protective layer 12 has at least a peeling layer 13 containing zirconium oxide and resin material, and the content of zirconium oxide in the peeling layer 13 is 15 mass% or more and 92 mass% or less.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a protective layer transfer sheet, and more specifically, to a protective layer transfer sheet provided with a transferable protective layer that can remarkably improve the glossiness of a printed matter after transfer onto the printed matter.

Because it is excellent in transparency, has high reproducibility and gradation of intermediate colors, and can easily form a high-quality image equivalent to a conventional full-color photographic image, a thermal transfer image is formed by a sublimation thermal transfer method. It is widely done. The sublimation thermal transfer method uses a thermal transfer sheet in which a dye layer is provided on one side of a base material and a transfer target in which a receiving layer is provided on one side of the other base, and from the back layer of the thermal transfer sheet. In this method, a heat transfer image is formed by applying heat to transfer the color material contained in the dye layer to the receiving layer to produce a printed material (for example, Patent Documents 1 and 2).
Here, the thermal transfer image formed on the receiving layer by the sublimation type thermal transfer method is excellent in gradation, but the receiving layer on which the thermal transfer image is formed is located on the outermost surface, so that the durability such as scratch resistance is inferior. And the problem that the formed image deteriorates with time.

  In order to solve these problems, a receiving layer on which a thermal transfer image is formed and a protective layer transfer sheet having a transferable protective layer are overlapped, and a transfer property is transferred onto the receiving layer using a thermal head or a heating roll. The durability of printed matter is improved by transferring a protective layer (see Patent Document 3, etc.).

  By the way, in recent years, printed materials having a wide variety of design properties, for example, printed materials having high glossiness and high-class feeling have been demanded.

JP 2013-75480 A JP 2013-82212 A Japanese Patent Application Laid-Open No. 2015-85554

  The problem to be solved by the present invention is to provide a protective layer transfer sheet comprising a transferable protective layer capable of improving the glossiness while maintaining the density of an image formed on a printed material.

  The protective layer transfer sheet of the present invention includes a substrate and a transferable protective layer, the transferable protective layer includes at least a release layer containing zirconium oxide and a resin material, and the content of zirconium oxide in the release layer Is 15 mass% or more and 92 mass% or less.

  In one embodiment, the release layer includes at least a (meth) acrylic resin as a resin material.

  In one embodiment, the zirconium oxide is particles having an average particle diameter of 5 nm or more and 50 nm or less.

  In one embodiment, the transferable protective layer further comprises an adhesive layer on the release layer.

  In one embodiment, the transferable protective layer further includes a primer layer between the release layer and the adhesive layer.

  According to the present invention, it is possible to provide a protective layer transfer sheet including a transferable protective layer capable of remarkably improving the glossiness while maintaining the image density of the image formed on the printed matter.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the protective layer transfer sheet of the present invention. FIG. 2 is a schematic cross-sectional view showing an embodiment of the protective layer transfer sheet of the present invention.

(Protective layer transfer sheet)
Hereinafter, the structure of the protective layer transfer sheet of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the protective layer transfer sheet 10 of the present invention includes a substrate 11 and a transferable protective layer 12. The transferable protective layer 12 includes at least a release layer 13.
In one embodiment, as shown in FIG. 2, the transferable protective layer 12 includes an adhesive layer 14 on the release layer 13.
In one embodiment, as shown in FIG. 2, the transferable protective layer 12 further includes a primer layer 15 between the release layer 13 and the adhesive layer 14.
In one embodiment, as shown in FIG. 2, the protective layer transfer sheet 10 of the present invention further includes a back layer 16 on the surface opposite to the surface on which the transferable protective layer 12 of the substrate 11 is provided. Prepare.
Furthermore, in one embodiment, the protective layer transfer sheet 10 of the present invention includes a release layer (not shown) between the substrate 11 and the transferable protective layer 12.
Hereinafter, each layer constituting the protective layer transfer sheet of the present invention will be described.

<Base material>
If the substrate has heat resistance that can withstand thermal energy applied during thermal transfer (for example, heat from a thermal head) and has mechanical strength and solvent resistance that can support the transferable protective layer, in particular, Can be used without limitation.
Examples of the base material include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), 1,4-polycyclohexylenedimethylene terephthalate, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer. Polyester such as nylon 6, polyamide 6 such as nylon 6 and nylon 6, polyolefin such as polyethylene (PE), polypropylene (PP) and polymethylpentene, polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, vinyl chloride-vinyl acetate Copolymers, vinyl resins such as polyvinyl butyral (PVB) and polyvinylpyrrolidone (PVP), (meth) acrylic resins such as poly (meth) acrylate and polymethyl (meth) acrylate, From polyimides such as imide and polyetherimide, cellophane, cellulose acetate, nitrocellulose, cellulose resin such as cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB), polystyrene (PS), polycarbonate, and ionomer resin A constructed film (hereinafter simply referred to as “resin film”) can be used.
The resin film may be a stretched film or an unstretched film, but from the viewpoint of mechanical strength, it is preferable to use a stretched film stretched in a uniaxial direction or a biaxial direction.
In the present invention, “(meth) acryl” includes both “acryl” and “methacryl”. In the present invention, “(meth) acrylate” includes both “acrylate” and “methacrylate”.

  Moreover, the laminated body of the above-mentioned resin film can also 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.

From the viewpoint of improving the adhesion to the transfer protective layer or the like, the substrate preferably has irregularities on the surface. Moreover, even if the protective layer transfer sheet of the present invention is not provided with a back layer, blocking resistance can be improved because the substrate has irregularities on its surface.
Examples of means for forming irregularities on the surface of the base material include a mat material kneading process, a sandblasting process, a hairline process, a mat coating process, and a chemical etching process. The mat material kneading process is a processing method of forming a base material with a resin kneaded with an inorganic substance or an organic substance. The mat coating process is a processing method in which a coating material containing an organic substance or an inorganic substance is coated on the surface of a substrate, and irregularities are imparted to the surface of the substrate.

  The thickness of the substrate is preferably 4 μm or more and 50 μm or less, and more preferably 12 μm or more and 30 μm or less. By making the thickness of the substrate within the above numerical range, it is possible to improve the transfer of thermal energy during thermal transfer while maintaining the mechanical strength of the substrate, and the transferability of the transferable protective layer Can be improved.

(Transferable protective layer)
As described above, the transferable protective layer includes at least a release layer. The transferable protective layer can include an adhesive layer on the release layer, and can further include a primer layer between the release layer and the adhesive layer.

(Peeling layer)
The peeling layer is a layer that is positioned on the outermost surface of the transferable protective layer transferred onto the printed material, and improves the durability of the printed material and prevents deterioration of the formed image over time. This layer is responsible for protecting things.

The release layer contains zirconium oxide, and the content thereof is 15% by mass or more and 92% by mass or less.
The content of zirconium oxide in the release layer is more preferably 25% by mass or more and 70% by mass or less, and further preferably 30% by mass or more and 60% by mass or less. Thereby, the glossiness of the printed matter can be further improved while maintaining the density of the image formed on the printed matter.

The zirconium oxide is more preferably a particle having an average particle diameter of 5 nm or more and 50 nm or less, and further preferably a particle of 10 nm or more and 30 nm or less. By making the zirconium oxide particles having an average particle diameter within the above numerical range, the glossiness of the printed material can be further improved while maintaining the density of the image formed on the printed material.
In the present invention, the “average particle diameter” can be determined by a method of directly measuring the size of primary particles from an electron micrograph of a vertical cross section of a thermal transfer sheet. Specifically, the minor axis diameter and major axis diameter of the primary particles were measured, and the average was taken as the particle diameter of the particles. Next, for 100 particles, the particle diameter was measured in the same manner, and the average of these was taken as the average particle diameter. Note that the same result can be obtained regardless of whether the electron microscope is a transmission type (TEM) or a scanning type (SEM).

  The release layer may contain metal oxide particles other than zirconium oxide within a range not impairing the characteristics of the present invention, for example, beryllium, magnesium, calcium, barium, scandium, yttrium, lanthanum, cerium, gadolinium, Examples thereof include oxide particles containing atoms such as terbium, titanium, niobium, zinc, boron, aluminum, silicon, germanium, tin, and lead.

The release layer contains a resin material such as (meth) acrylic resin, polystyrene, vinyl resin, polyolefin, polyester, polyamide, polyimide, cellulose resin, thermosetting resin, and actinic ray curable resin. Among these, (meth) acrylic resin and polystyrene are preferable from the viewpoint of the glossiness of the release layer. Furthermore, a (meth) acrylic resin is preferable from the viewpoint of durability such as scratch resistance. Note that the release layer can include two or more resin materials.
In the present invention, the “actinic ray curable resin” means a resin in a state where an actinic ray curable resin is irradiated with an actinic ray and cured.
In the present invention, “active light” means radiation that chemically acts on the active light curable resin to promote polymerization, and specifically includes visible light, ultraviolet light, X-rays, electrons. It means a line, α ray, β ray, γ ray and the like.

  In the present invention, the (meth) acrylic resin includes (1) a polymer of acrylic acid or methacrylic acid monomer or derivative thereof, (2) a polymer of acrylic acid ester or methacrylic acid ester monomer or derivative thereof, (3 And a copolymer of a monomer of acrylic acid or methacrylic acid and another monomer or a derivative thereof, and (4) a copolymer of a monomer of acrylic acid ester or a methacrylate ester and another monomer or a derivative thereof.

Examples of the acrylic ester or methacrylic ester monomer include alkyl acrylate, alkyl methacrylate, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, lauryl acrylate, and lauryl methacrylate.
Examples of other monomers include aromatic hydrocarbons, aryl group-containing compounds, amide group-containing compounds, and vinyl chloride, and more specifically, styrene, benzylstyrene, phenoxyethyl methacrylate, acrylamide, and methacrylamide. .

  More specifically, examples of the (meth) acrylic resin include poly (meth) acrylate, polymethyl (meth) acrylate, poly (meth) acrylamide, and styrene acrylic copolymer. Among these, polymethyl (meth) acrylate is particularly preferable from the viewpoint of scratch resistance and transparency.

  The content of the resin material in the release layer is preferably 10% by mass or more and 95% by mass or less, and more preferably 70% by mass or more and 90% by mass or less. By setting the content of the resin material within the above numerical range, the durability of the printed matter can be further improved.

  Further, the release layer is a plastic material, filler, UV stabilizer, anti-coloring material, fluorescent whitening material, matting material, deodorant material, flame retardant material, and weathering material as long as the properties of the present invention are not impaired. In addition, additives such as an antistatic material, a yarn friction reducing material, a slip material, an antioxidant material, an ion exchange material, a dispersion material, a polymerization initiator, an ultraviolet absorber, and a coloring material such as a pigment or a dye can be included.

The glossiness of the release layer surface is preferably 50 or more, and more preferably 55 or more.
In addition, in this invention, glossiness can be measured by reflection angle 20 degrees using Gloss Meter VG7000 (made by Nippon Denshoku Industries Co., Ltd.) based on JIS-Z-8741 (1997).

  The thickness of the release layer is preferably 0.5 μm or more and 10 μm or less, and more preferably 0.8 μm or more and 2 μm or less. By setting the thickness of the release layer within the above numerical range, the glossiness of the printed product can be further improved, the transparency of the release layer can be maintained, and the decrease in the density of the formed image can be prevented.

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

(Adhesive layer)
In one embodiment, the transferable protective layer comprises an adhesive layer on the release layer. The adhesive layer is a layer provided on the outermost surface of the protective layer transfer sheet, and is a layer provided for improving the adhesion of the transferable protective layer to the printed material.

  In one embodiment, the adhesive layer may include a resin material that melts or softens by heat and exhibits adhesive properties, such as polyvinyl acetate, PVB, ethylene-vinyl acetate copolymer, and vinyl chloride-vinyl acetate. Vinyl resins such as copolymers, polyolefins such as PE and PP, polyesters such as PET and PBT, polyamides, polyimides, polyacrylates, (meth) acrylic resins such as polymethacrylate and polymethyl methacrylate, and celluloses such as cellulose diastase Examples thereof include resins and polyurethane.

  The content of the resin material in the adhesive layer is preferably 50% by mass or more, and more preferably 70% by mass or more. By making content of the said resin material into the said numerical range, the adhesiveness of a transferable protective layer and a printed matter can be improved more.

  In addition, the adhesive layer is a plastic material, filler, UV stabilizer, anti-coloring material, fluorescent whitening material, matting material, deodorant material, flame retardant material, and weathering material as long as the characteristics of the present invention are not impaired. In addition, an antistatic material, a yarn friction reducing material, a slip material, an antioxidant material, an ion exchange material, a dispersion material, an ultraviolet absorber, and an additive such as a coloring material such as a pigment or a dye can be included.

  The thickness of the adhesive layer is preferably 0.3 μm or more and 5.0 μm or less, more preferably 0.3 μm or more and 1.0 μm or less, and 0.5 μm or more and 0.8 μm or less. Is particularly preferred. By adjusting the thickness of the adhesive layer to the above numerical range, the adhesiveness between the transferable protective layer and the printed material can be further improved while maintaining the transferability of the transferable protective layer.

  The adhesive layer is prepared by dispersing or dissolving the above material in water or a suitable solvent, and using a known means such as a roll coater, reverse roll coater, gravure coater, reverse gravure coater, bar coater and rod coater, a release layer or a primer layer It can be formed by coating on top to form a coating film and drying it.

(Primer layer)
In one embodiment, the transferable protective layer comprises a primer layer between the release layer and the adhesive layer. Thereby, the adhesiveness of a peeling layer and an contact bonding layer can be improved.

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

When the primer layer contains a resin having an active hydroxyl group, it preferably contains an isocyanate compound.
As an isocyanate compound, the polyisocyanate compound which has a 2 or more isocyanate group in a molecule | numerator is preferable. For example, xylene diisocyanate, paraphenylene diisocyanate, 1-chloro-2,4-phenyl diisocyanate, 2-chloro-1,4-phenyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,5-naphthalene Diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, trans-cyclohexane, 1,4-diisocyanate, hexamethylene diisocyanate, 4,4′-biphenylene diisocyanate, triphenylmethane triisocyanate and 4,4 ′, 4 ″ -trimethyl-3 , 3 ′, 2′-triisocyanate-2,4,6-triphenyl cyanurate and the like.

In one embodiment, the primer layer may include inorganic or organic fine particles.
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, aluminum oxide and silica. And inorganic fine particles such as graphite, nitrate and boron nitride.
Organic fine particles include (meth) acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenolic resin, acetal resin, polystyrene, polyamide, and other organic resin fine particles, and a crosslink obtained by reacting these with a crosslinking material. Examples include resin fine particles.

  The thickness of the primer layer is not particularly limited, but can be 0.1 μm or more and 5 μm or less.

  The primer layer is dispersed or dissolved in water or a suitable solvent, and is applied onto the release layer by a known means such as a roll coater, reverse roll coater, gravure coater, reverse gravure coater, bar coater and rod coater. It can be formed by forming a coating film and drying it.

(Back layer)
In one embodiment, the protective layer transfer sheet of the present invention comprises a back layer on the surface opposite to the surface on which the transferable protective layer of the substrate is provided. When the protective layer transfer sheet includes the back layer, it is possible to prevent the occurrence of sticking or wrinkles due to heating during transfer. Moreover, the blocking resistance of the protective layer transfer sheet of the present invention can be improved.

  In one embodiment, the back layer includes a binder resin. Examples of the binder resin include cellulose resin, polystyrene, vinyl resin, polyester, polyurethane, silicone-modified polyurethane, fluorine-modified polyurethane, and (meth) acrylic resin.

Moreover, in one Embodiment, a back surface layer contains 2-part curable resin which can be hardened by using an isocyanate compound etc. as binder resin. Examples of such a resin include polyvinyl acetal.
As the isocyanate compound, conventionally known isocyanate compounds can be used without any particular limitation. Among them, it is desirable to use an adduct of an aromatic isocyanate. As the aromatic polyisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, Examples include p-phenylene diisocyanate, trans-cyclohexane-1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, and tris (isocyanatophenyl) thiophosphate.

  In one embodiment, the back layer includes the fine particles. By including such fine particles in the back layer, it is possible to further prevent the occurrence of sticking or wrinkles due to heating during thermal transfer.

  The thickness of the back layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.3 μm or more and 2 μm or less. By making the thickness of the back layer in the above numerical range, it is possible to prevent sticking, wrinkles, etc. while maintaining the transferability of thermal energy during thermal transfer.

  The back layer is dispersed or dissolved in water or a suitable solvent and coated on the substrate by a known means such as a roll coater, reverse roll coater, gravure coater, reverse gravure coater, bar coater and rod coater. It can be formed by forming a coating film and drying it.

<Release layer>
In one embodiment, the protective layer transfer sheet of the present invention includes a release layer between the substrate and the transferable protective layer. When the protective layer transfer sheet includes a release layer, the transferability of the transferable protective layer can be improved. The release layer is a layer that remains on the substrate side during thermal transfer.

  In one embodiment, the release layer includes a binder resin of silicone resin such as (meth) acrylic resin, polyurethane, acetal resin, polyamide, polyester, melamine resin, polyol, and cellulose resin. Of the above materials, silicone resin is particularly preferable.

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

  The thickness of the release layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.3 μm or more and 2 μm or less.

  The release layer is obtained by dispersing or dissolving the above materials in water or a suitable solvent, and then applying the above-mentioned material onto the substrate by a known means such as a roll coater, reverse roll coater, gravure coater, reverse gravure coater, bar coater, rod coater, It can be formed by coating to form a coating film and drying it.

  In the present specification, the resin constituting each layer is exemplarily described. However, these resins may be homopolymers of monomers constituting each resin, and constitute each resin. It may be a copolymer of the main component monomer and one or a plurality of other monomers, or a derivative thereof. For example, an acrylic resin may contain an acrylic acid or methacrylic acid monomer or an acrylic ester or methacrylic ester monomer as a main component. Moreover, the modified material of these resin may be sufficient. Resins other than those described in the present specification may be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

Example 1
A back layer forming coating solution having the following composition was applied to one surface of a 4.5 μm thick PET film and dried to form a 0.5 μm thick back layer.
<Back layer forming coating solution>
Polyvinyl acetal (PVA) 51.2 parts by mass
(Sekisui Chemical Co., Ltd., ESREC (registered trademark) KS-1)
・ Isocyanate compound 17.8 parts by mass
(Bernock (registered trademark) D750, manufactured by DIC Corporation)
・ Silicone resin fine particles 1 part by mass
(Momentive Performance Materials Japan GK, Tospearl (registered trademark) 240)
・ Zinc stearyl phosphate 10 parts by mass
(Manufactured by Sakai Chemical Industry Co., Ltd., LBT1830 purification)
・ 10 parts by mass of zinc stearate
(SZ-PF, manufactured by Sakai Chemical Industry Co., Ltd.)
・ Polyethylene wax 10 parts by mass
(Toyo ADR Co., Ltd., Polywax 3000)
・ Methyl ethyl ketone (MEK) 200 mass parts ・ Toluene 100 mass parts

A release layer-forming coating solution having the following composition was applied to the other surface of the PET film and dried to form a release layer having a thickness of 1.0 μm.
<Peeling layer forming coating solution>
・ 12 parts by mass of (meth) acrylic resin (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Zirconium oxide particles 20 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ 68 parts by mass of MEK

On the release layer, a primer layer-forming coating solution having the following composition was applied and dried to form a primer layer having a thickness of 0.1 μm.
<Primer layer forming coating solution>
-Polyvinylpyrrolidone (PVP) 3 parts by mass (manufactured by IS Japan Co., Ltd., K-90)
・ Alumina sol 30 parts by mass (manufactured by Nissan Chemical Industries, Ltd., alumina sol 200, solid content 10%)
・ Water 50 parts by mass ・ Isopropanol (IPA) 17 parts by mass

On the primer layer, a coating liquid for forming an adhesive layer having the following composition is applied and dried to form an adhesive layer having a thickness of 1.0 μm, and a release layer, a primer layer, and an adhesive layer are provided as a transferable protective layer. A protective layer transfer sheet was obtained.
<Adhesive layer forming coating solution>
・ 20 parts by mass of polyester (Toyobo Co., Ltd., Byron (registered trademark) 200)
-10 parts by mass of a copolymer obtained by reactive bonding of an ultraviolet absorber (manufactured by BASF Japan, UVA-635L)
・ MEK 40 parts by mass ・ Toluene 40 parts by mass

Example 2
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ (Meth) acrylic resin 11.3 parts by mass (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
・ Zirconium oxide particles 25 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ MEK 63.8 parts by mass

Example 3
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ (Meth) acrylic resin 10.5 parts by mass (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Zirconium oxide particles 30 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ MEK 59.5 parts by mass

Example 4
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ 7.5 parts by mass of (meth) acrylic resin (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Zirconium oxide particles 50 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ MEK 42.5 parts by mass

Example 5
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ 4.5 parts by mass of (meth) acrylic resin (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Zirconium oxide particles 70 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ 25.5 parts by mass of MEK

Example 6
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ (Meth) acrylic resin 1.5 parts by mass (Mitsubishi Chemical Corporation, Dianal (registered trademark) BR-87)
Zirconium oxide particles 90 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ 8.5 parts by mass of MEK

Example 7
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
-10.5 parts by mass of polystyrene (manufactured by DIC Corporation, Dick Styrene (registered trademark) CR-3500)
Zirconium oxide particles 30 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ MEK 59.5 parts by mass

Comparative Example 1
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ 15 parts by mass of (meth) acrylic resin (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
・ 85 parts by mass of MEK

Comparative Example 2
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
-Polystyrene 15 parts by mass (manufactured by DIC Corporation, Dick Styrene (registered trademark) CR-3500)
・ 85 parts by mass of MEK

Comparative Example 3
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ 0.8 parts by mass of (meth) acrylic resin (manufactured by Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Zirconium oxide particles 95 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ MEK 4.2 parts by mass

Comparative Example 4
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ 13.5 parts by mass of (meth) acrylic resin (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Zirconium oxide particles 10 parts by mass (CIK Nanotech Co., Ltd., ZRMIBK15WT% -E41, average particle size: 20 nm, solid content 15%)
・ MEK 76.5 parts by mass

Comparative Example 5
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ (Meth) acrylic resin 10.5 parts by mass (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Silicon oxide particles 15 parts by mass (manufactured by Nissan Chemical Industries, Ltd., MEK-ST-ZL, average particle size: 70 to 100 nm, solid content 30%)
・ MEK 74.5 parts by mass

Comparative Example 6
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ (Meth) acrylic resin 10.5 parts by mass (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Silicon oxide particles 11.3 parts by mass (manufactured by Nissan Chemical Industries, Ltd., MEK-AC-2140Z, average particle size: 10 to 15 nm, solid content 40%)
・ MEK 78.3 parts by mass

Comparative Example 7
A protective layer transfer sheet was produced in the same manner as in Example 1 except that the composition of the release layer forming coating solution was changed as follows.
<Peeling layer forming coating solution>
・ (Meth) acrylic resin 10.5 parts by mass (Mitsubishi Chemical Corporation, Dianar (registered trademark) BR-87)
Silicon oxide particles 11.3 parts by mass (manufactured by Nissan Chemical Industries, MEK-AC-5140Z, average particle size: 70 to 100 nm, solid content 40%)
・ MEK 78.3 parts by mass

<< Transparency evaluation >>
A sublimation type thermal transfer printer (Dai Nippon Printing Co., Ltd., DS620) and a genuine thermal transfer sheet of the printer (Dai Nippon Printing Co., Ltd.) are provided on the receiving layer of the thermal transfer image receiving sheet manufactured by Dai Nippon Printing Co., Ltd. A black solid image (0/255 image gradation) was printed.

  By transferring the transferable protective layer provided in the protective layer transfer sheet prepared in the examples and comparative examples onto the receiving layer on which the image has been printed, the printed matter of each of the examples and comparative examples is transferred. Obtained.

The image density of the printed matter of each example and comparative example was measured with an optical densitometer (manufactured by X-Rite, RD918). Image density of the printed materials of Examples 1 to 7 and Comparative Examples 2 to 5 relative to the image density of the printed material of Comparative Example 1 (Image density of the printed materials of Examples 1 to 7 and Comparative Examples 2 to 5 / Comparative Example 1 The image density of the printed product x 100) was calculated (hereinafter referred to as image density maintenance rate), and the transparency of the transferable protective layers of Examples 1 to 7 and Comparative Examples 2 to 7 was evaluated based on the following evaluation criteria. .
(Evaluation criteria)
A: The image density maintenance ratio was over 98%, and high transparency of the transferable protective layer could be confirmed.
B: The image density maintenance ratio was more than 95% and less than 98%, and the transparency of the transferable protective layer was confirmed to have no practical problem.
NG: The image density maintenance ratio was less than 95%, the transparency of the transferable protective layer was low, and there was a problem in practical use.

<< Glossiness measurement >>
According to JIS-Z-8741 (1997), the gloss level of the printed matter surface (release layer surface) of each example and comparative example is based on Gloss Meter VG7000 (manufactured by Nippon Denshoku Industries Co., Ltd.). Measurements were made at a reflection angle of 20 ° and are summarized in Table 1.

<< Scratch resistance evaluation >>
The surface of the printed matter (peeling layer surface) of each example and comparative example was set on a Gakushin Tester (manufactured by Suga Test Instruments Co., Ltd.), and was rubbed 10 times with a friction material (Kanakin No. 3) at a load of 200 g. did. After rubbing, the surface condition was visually confirmed, and the scratch resistance of the surface of the printed material was evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: It was confirmed that the surface was free of scratches and had good scratch resistance.
B: Although there were some scratches on the surface, it was possible to confirm the scratch resistance to the extent that there was no practical problem.
C: There were many scratches on the surface.

10: protective layer transfer sheet 11: substrate 12: transferable protective layer 13: release layer 14: adhesive layer 15: primer layer 16: back layer

Claims (5)

A protective layer transfer sheet comprising a substrate and a transferable protective layer,
The transferable protective layer includes a release layer containing zirconium oxide and a resin material,
The protective layer transfer sheet, wherein the content of the zirconium oxide in the release layer is 15% by mass or more and 92% by mass or less.   The protective layer transfer sheet according to claim 1, wherein the release layer contains at least a (meth) acrylic resin as a resin material.   The protective layer transfer sheet according to claim 1, wherein the zirconium oxide is particles having an average particle diameter of 5 nm or more and 50 nm or less.   The protective layer transfer sheet according to any one of claims 1 to 3, wherein the transferable protective layer further comprises an adhesive layer on the release layer.   The protective layer transfer sheet according to claim 4, wherein the transferable protective layer further comprises a primer layer between the release layer and the adhesive layer.

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