JP2015163466A - Thermal transfer double-sided image receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal transfer double-sided image-receiving sheet which has good folding properties while suppressing occurrence of paper powder and wrinkles in folded parts.SOLUTION: A thermal transfer double-sided image-receiving sheet 100 is provided with a receiving layer 5 on both sides of a substrate sheet, and the substrate sheet 1 has a laminate structure in which a first resin film layer 3 is provided on one side of a paper substrate 2 and a second film layer 4 is provided on the other side of the paper substrate 2. The total thickness of the paper substrate, the first resin film layer and the second resin film layer is 145-200 μm, and, with the total thickness taken as 100%, the thickness of the first resin film and that of the second resin film are both 18% or smaller.

Description

  The present invention relates to a thermal transfer double-sided image receiving sheet.

  Excellent thermal transparency, high reproducibility and gradation of intermediate colors, and easy formation of high-quality images equivalent to conventional full-color photographic images. It is widely done. Examples of the printed material on which a thermal transfer image is formed on a transfer object include digital photographs, ID cards used in many fields such as identification cards, driver's licenses, and membership cards.

  For the formation of a thermal transfer image by the sublimation transfer method, a thermal transfer sheet having a dye layer provided on one side of a substrate and a thermal transfer image receiving sheet having a receiving layer provided on one side of the other substrate are used. . Then, by superposing the receiving layer of the thermal transfer image-receiving sheet and the dye layer of the thermal transfer sheet, by applying heat from the back side of the thermal transfer sheet by the thermal head, the dye of the dye layer is transferred onto the receiving layer, A printed matter having a thermal transfer image formed on the receiving layer is obtained. According to such a sublimation transfer method, since the amount of dye transfer can be controlled by the amount of energy applied to the thermal transfer sheet, density gradation is possible, so that the image is very clear, transparent, and halftone. Therefore, it is possible to form a high-quality printed product comparable to a full-color photographic image.

  Recently, there has been proposed a thermal transfer image receiving sheet in which a receiving layer is provided on both sides of a base sheet (hereinafter, a thermal transfer image receiving sheet in which a receiving layer is provided on both sides of the base sheet is referred to as a thermal transfer double side image receiving sheet). This thermal transfer double-sided image-receiving sheet is often used for the production of photo books and the like, and from its usage form, it has good “foldability”, that is, the folded thermal-transfer double-sided image-receiving sheet does not restore to its original state. For example, one of the problems is that the folded thermal transfer double-sided image-receiving sheet does not spread. In addition to this, when the thermal transfer double-sided image-receiving sheet is folded, one of the problems is that wrinkles do not occur in the thermal transfer image formed on the receiving layer at the folded portion.

  In order to solve the above problem, Patent Document 1 discloses that a dye receiving layer is provided on both surfaces of a substrate sheet obtained by laminating two or more kinds of substrates, and the most preferable dye receiving layer is provided on both surfaces of the substrate sheet. The substrate located nearby is a film (porous film) having fine voids (microvoids) inside the substrate on both sides, and passes through the dye-receiving layer on both sides of the substrate sheet. There has been proposed a thermal transfer double-sided image-receiving sheet in which up to a part of the sheet is half-cut. Moreover, the said literature is disclosed the form which used the paper base material inside the base material sheet. According to the thermal transfer double-sided image-receiving sheet proposed in Patent Document 1, it is said that when folded at a half-cut portion, defects such as wrinkles do not occur in the thermal transfer image formed on the receiving layer at the folded portion. Yes.

  However, in order to prevent the folded double-sided thermal transfer image-receiving sheet from being restored to its original state and to prevent wrinkles from occurring at the folded portion, if the half cut that penetrates part of the substrate sheet is applied, the folded sheet When the paper base material is exposed, paper dust is generated and the appearance is deteriorated.

JP 2010-228410 A

  The present invention has been made in view of such a situation, and in a thermal transfer double-sided image-receiving sheet provided with a receiving layer on both sides, while suppressing the occurrence of paper dust and wrinkles in the folded portion, good `` foldability '' is achieved. The main object is to provide a thermal transfer double-sided image-receiving sheet.

  In order to solve the above problems, the present invention provides a thermal transfer double-sided image-receiving sheet in which a receiving layer is provided on both sides of a base sheet, wherein the base sheet is a first resin on one side of a paper base. A film layer is provided, and a second resin film layer is provided on the other surface of the paper substrate, and the paper substrate, the first resin film layer, the second resin layer are provided. The total thickness of the resin film layer is 145 μm or more and 200 μm or less, and the thickness of the first resin film layer and the thickness of the second resin film layer when the total thickness is 100% are both It is characterized by being 18% or less.

  Further, a ruled line may be provided on both surfaces of the thermal transfer double-sided image-receiving sheet or on either surface.

Further, the basis weight of the paper base material may be 120 g / m ² or more and 190 g / m ² or less.

  Further, the resin material constituting the first resin film layer and the resin material constituting the second resin film layer may be the same kind of resin material having a common basic monomer.

  According to the thermal transfer double-sided image-receiving sheet of the present invention, it is possible to suppress the generation of wrinkles in paper dust and folded portions while having good “foldability”.

It is a schematic sectional drawing of the thermal transfer double-sided image receiving sheet of one Embodiment of this invention. (A) is a top view of the thermal transfer double-sided image receiving sheet of one embodiment of the present invention, and (b) is a schematic sectional view.

<< Thermal transfer double-sided image-receiving sheet >>
Hereinafter, the thermal transfer double-sided image receiving sheet of the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the thermal transfer double-sided image receiving sheet of the present invention. As shown in FIG. 1, a thermal transfer double-sided image receiving sheet 100 according to an embodiment of the present invention is provided with a receiving layer 5 on both sides of a base sheet 1, and the base sheet 1 is on one side of a paper base 2. The first resin film layer 3 is provided, and the second resin film layer 4 is provided on the other surface of the paper base material 2. The paper base 2, the first resin film layer 3, the second resin film layer 4, and the receiving layer 5 provided on both sides of the base sheet 1 are the thermal transfer double-sided image receiving sheet of the present invention. 100 is an essential configuration. The thermal transfer double-sided image receiving sheet 100 of the present invention is not limited to the form shown in FIG. 1, and can take various modifications. For example, an intermediate layer may be provided between the base sheet 1 and the receiving layer. In the base sheet 1, an adhesive layer may be provided between the paper base 2 and the first resin film layer 3 and between the paper base 2 and the second resin film layer 4. An intermediate | middle layer and an adhesive layer are arbitrary structures in the thermal transfer double-sided image receiving sheet 100 of this invention.

<Base material sheet>
As shown in FIG. 1, a base sheet 1 constituting a thermal transfer double-sided image receiving sheet 100 has a first resin film layer 3 on one side of a paper base 2 (in the form shown, the top side of the paper base 2). It is provided and has a laminated structure in which the second resin film layer 4 is provided on the other surface of the paper substrate 2 (in the illustrated form, the lower surface of the paper substrate 2).

The thermal transfer double-sided image receiving sheet 100 of the present invention is characterized in that the base sheet 1 constituting the thermal transfer double-sided image receiving sheet 100 satisfies the following conditions.
(Condition 1): Total thickness of the paper base material 2, the first resin film layer 3, and the second resin film layer 4 constituting the base sheet 1 (hereinafter referred to as "total thickness"). Is 145 μm or more and 200 μm or less.
(Condition 2): The thickness of the first resin film layer 3 and the thickness of the second resin film layer 4 when the total thickness is 100% are both 18% or less.

  According to the base sheet 1 satisfying the above conditions 1 and 2, it is possible to impart good “foldability” to the thermal transfer double-sided image-receiving sheet including the base sheet 1. In addition to this, it is possible to suppress the occurrence of wrinkles in the thermal transfer image formed on the receiving layer at the folded portion when folded. As used herein, “foldability” means a degree of suppression that can prevent the folded thermal transfer double-sided image-receiving sheet from being restored to its original state, and the better the “foldability”, the more the folded thermal transfer. The degree to which the double-sided image receiving sheet is restored to the original state is small.

  In addition, good “foldability” in the thermal transfer double-sided image-receiving sheet of the present invention and suppression of the generation of wrinkles in the folded portion can be realized without applying a half-cut process that causes paper dust when folded. is there. That is, according to the thermal transfer double-sided image receiving sheet of the present invention, the above effects can be achieved without generating paper dust.

  The thermal transfer double-sided image-receiving sheet 100 of the present invention is made by paying attention to both the “total thickness” and the thicknesses of the respective layers constituting the base sheet 1. While suppressing the generation of paper dust, the thermal transfer double-sided image receiving sheet 100 can be provided with good “foldability”, and the generation of wrinkles when folded can be suppressed. Therefore, when either one of the above conditions 1 and 2 is not satisfied, it is not possible to impart a good “foldability” to the thermal transfer double-sided image-receiving sheet, and also suppress the generation of wrinkles at the folded portion. Can not do it. For example, even if the above condition 1 is satisfied, one of the thickness of the first resin film layer 3 and the thickness of the second resin film layer 4 when the “total thickness” is 100% If the thickness exceeds 18%, it is not possible to impart good “foldability” to the thermal transfer double-sided image-receiving sheet, and it is not possible to suppress the occurrence of wrinkles at the folded portion. This is the case where both the thickness of the first resin film layer 3 and the thickness of the second resin film layer 4 exceed 18%, or the base sheet satisfies the above condition 2. The same applies to the case where the “total thickness” exceeds 200 μm.

  In the above condition 1, the lower limit value of “total thickness” is defined as 145 μm, but this is inherently required for the base sheet when the “total thickness” is less than 145 μm. Functions, specifically, the heat resistance of the thermal transfer double-sided image-receiving sheet required during image formation and the elasticity of the thermal transfer double-sided image-receiving sheet required when transported by a printer cannot be sufficiently satisfied. .

  There is no particular limitation on the lower limit of the thickness of the first resin film layer 3 and the thickness of the second resin film layer 4 in condition 2, but the first resin film layer when the total thickness is 100%. As the thickness of 3 and the thickness of the second resin film layer 4 are less than 8%, the texture of the thermal transfer double-sided image-receiving sheet tends to deteriorate. Considering this point, it is preferable that the thickness of the first resin film layer 3 and the thickness of the second resin film layer 4 when the total thickness is 100% are both 8% or more.

  Moreover, when aiming at further improvement of the “foldability”, the thickness of the first resin film layer 3 and the thickness of the second resin film layer 4 when the total thickness is 100%, Both are preferably 17% or less.

  Further, as shown in FIGS. 2A and 2B, ruled lines may be provided on one or both surfaces of the thermal transfer double-sided image-receiving sheet (both surfaces in the illustrated form). 2A is a top view of a thermal transfer double-sided image receiving sheet according to an embodiment of the present invention, and FIG. 2B is a schematic cross-sectional view. By providing a ruled line on the surface of the thermal transfer double-sided image-receiving sheet, the thermal transfer double-sided image-receiving sheet can be easily folded using the ruled line as a fold, and the “foldability” and the effect of suppressing the generation of wrinkles at the fold are improved. Can be. Note that, unlike the half-cut process that causes the generation of paper dust, the ruled line formed by the pressing die does not cause the generation of paper dust.

  The method for forming the ruled line is not particularly limited, and for example, the ruled line can be formed by pressing a pressing die such as a ruled line forming blade on the planned ruled line formation position on the surface of the thermal transfer double-sided image receiving sheet.

  The thermal transfer double-sided image receiving sheet 100 according to an embodiment of the present invention is provided with a ruled line on the surface of the thermal transfer double-sided image receiving sheet, thereby improving the “foldability” and the effect of suppressing the occurrence of wrinkles at the folded portion. This is not due to the effect of the ruled line alone, but due to the synergistic effect of the ruled line and the base sheet 1 satisfying the above conditions 1 and 2. Therefore, even if a ruled line is provided on the surface of the thermal transfer double-sided image-receiving sheet, if the base sheet 1 does not satisfy one or both of the above conditions 1 and 2, the thermal transfer double-sided Sufficient “foldability” cannot be imparted to the image receiving sheet, and the occurrence of wrinkles in the folded portion cannot be sufficiently suppressed. This is also clear from the results of Examples described later.

  There is a particular limitation on the total thickness of the thermal transfer double-sided image-receiving sheet, that is, the overall thickness of the thermal-transfer double-sided image-receiving sheet 100 including the base material sheet 1, the receiving layer 5, and optional layers provided as necessary. Even if the base sheet 1 satisfies the above conditions 1 and 2, if the total thickness of the thermal transfer double-sided image-receiving sheet exceeds 280 μm, “foldability” and generation of wrinkles at the folded portion are suppressed. There is a tendency for the effect to be reduced. Therefore, considering this point, it is preferable that the entire thickness of the thermal transfer double-sided image-receiving sheet is 280 μm or less.

  Each configuration will be specifically described below.

(Paper substrate)
The paper substrate 2 constituting the substrate sheet 1 is not particularly limited, and a conventionally known paper substrate can be appropriately selected and used in the field of thermal transfer image receiving sheets. As such a paper substrate 2, synthetic paper (polyolefin, polystyrene, etc.), fine paper, art paper, coated paper, cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated Examples thereof include cellulose fiber paper such as paper, synthetic resin-containing paper, and paperboard.

Although the thickness of the paper base material 2 should just be in the range which satisfy | fills the said conditions 1 and ² , it is preferable that they are 120 g / m < ² > or more and 190 g / m < ² > or less by basic weight. As the basis weight of the paper substrate 2 exceeds 190 g / m ² , the “foldability” and the effect of suppressing wrinkles at the folded portion tend to decrease. Further, as the basis weight of the paper base material 2 is less than 120 g / m ² , the texture of the thermal transfer double-sided image-receiving sheet tends to deteriorate. Note that curling tends to occur more easily as the thickness of the paper substrate 2 becomes thinner.

(First resin film layer)
As shown in FIG. 1, on one surface of the paper substrate (in the illustrated form, the upper surface of the paper substrate), the first resin film layer 3 that constitutes the substrate sheet 1 and contains a resin material, in other words, For example, the 1st resin film layer 3 comprised from a resin material is provided. As long as the first resin film layer 3 satisfies the above-described conditions 1 and 2, any other conditions are not limited. That is, no limitation is imposed on the resin material and the like contained in the first resin film layer 3.

  Examples of the resin material of the first resin film layer 3 include polyester, polyethylene, polypropylene, polybutene, polyisobutene, polyisobutylene, polybutadiene, polyisoprene, and ethylene-vinyl acetate that have high heat resistance such as polyethylene terephthalate and polyethylene naphthalate. Mention may be made of polyolefin resins such as polymers. The first resin film layer 3 may be a single type of resin, or a combination of two or more types. Further, the first resin film layer 3 may be stretched or unstretched. Further, the first resin film layer 3 may contain a white pigment or a filler. Moreover, you may have a micro void inside. By satisfying the above conditions 1 and 2 and using a resin film having a microvoid inside as the first resin film layer 3, in other words, a porous resin film, the wrinkle suppression effect can be further enhanced. . Further, at the time of image formation using the thermal transfer double-sided image receiving sheet of one embodiment, the print density of the formed image can be improved. In other words, high density image formation is possible. This is the same also about the 2nd resin film layer 4 mentioned later.

  As a method of generating microvoids (fine vacancies) inside, a method of generating microvoids using inorganic fine particles as nuclei when kneading inorganic fine particles in a polymer and stretching the compound, A method for preparing a compound in which incompatible polymers (one kind or plural kinds) are blended can be mentioned. When the compound in the latter method is viewed microscopically, the polymers form a fine sea-island structure, and by stretching this compound, microvoids are generated due to separation of the sea-island interface or large deformation of the polymer that forms the island. To do. In addition, the 1st resin film layer 3 and the 2nd resin film layer 4 mentioned later are not limited to the resin film which has a micro void.

  Although there is no limitation in particular about the thickness of the 1st resin film layer 3, it is preferable that they are 18 micrometers or more and 28 micrometers or less. By satisfying the above conditions 1 and 2, and by setting the thickness of the first resin film layer 3 to 18 μm or more and 28 μm or less, the texture of the thermal transfer double-sided image-receiving sheet and the “foldability” and the effect of suppressing wrinkles at the folded portion are further improved. It can be maintained in good balance. The same applies to the preferred thickness of the second resin film layer 4 to be described later.

  There is no limitation in particular about the formation method of the 1st resin film layer 3, The resin film which satisfy | fills the said conditions 1 and 2 is affixed on one surface of the paper base material 2 through the adhesive layer etc. which are arbitrary layers. They may be formed together, or may be formed by EC sand lamination using polyethylene or the like. When EC sand lamination is performed, the lamination layer is also included in the first resin film layer 3. It can also be formed by extrusion lamination or the like. The same applies to the method of forming the second resin film layer 4.

  Further, the first resin film layer 3 may be subjected to easy adhesion treatment such as primer treatment, corona discharge treatment or plasma treatment on the surface facing the paper substrate 2. The same applies to the surface of the second resin film layer 4 to be described later that faces the paper substrate 2. Further, instead of the easy adhesion treatment, an adhesive layer can be provided between the first resin film layer 3 and the paper substrate 2 and between the second resin film layer 4 and the paper substrate 2. The adhesive layer will be described later.

(Second resin film layer)
As shown in FIG. 1, a second resin film layer 4 that constitutes a base sheet 1 and contains a resin material is provided on the other side of the paper base (in the illustrated form, the bottom of the paper base). It has been. Similarly to the 1st resin film layer 3, if the 2nd resin film layer 4 satisfy | fills the said conditions 1 and 2, it will not be limited at all about other conditions.

  The resin material constituting the second resin film layer 4 may be the same as or different from the resin material constituting the first resin film layer 3, but the first resin film layer It is preferable that the resin material which comprises and the resin material which comprises a 2nd resin film layer are the same kind of resin materials which have a common basic monomer. For example, when the first resin film layer is mainly composed of polypropylene resin, it is preferable that the second resin film layer is also composed mainly of polypropylene resin. By using the same kind of resin material as the resin material constituting the first resin film layer 3 and the resin material constituting the second resin film layer 4, the first resin film layer 3 and the second resin It is possible to balance the stress generated by the contraction of the film layer 4 and the like, and curling can be suppressed.

  Further, instead of the above configuration, or together with this, the difference between the thickness of the first resin film layer 3 and the thickness of the second resin film layer 4 can be reduced to suppress the occurrence of curling. The heat transfer double-sided image receiving sheet 100 in a preferred form has a ratio (%) of the thickness of the first resin film layer 3 and a ratio (%) of the thickness of the second resin film layer 4 when the “total thickness” is 100%. ) Is within 1.0%, more preferably within 0.5%.

(Adhesive layer)
An adhesive layer (not shown) may be provided between the paper substrate 2 and the first resin film layer 3 and between the paper substrate 2 and the second resin film layer 4. The adhesive layer is an arbitrary layer constituting the base sheet. Note that the thickness of the arbitrary adhesive layer is not included in the “total thickness” described above. The optional adhesive layer contains an adhesive and has an adhesive function. Examples of the adhesive component include urethane resins, polyolefin resins such as α-olefin-maleic anhydride resins, polyester resins, acrylic resins, epoxy resins, urea resins, melamine resins, phenol resins, Examples thereof include vinyl acetate resins and cyanoacrylate resins. Among them, a reactive type of acrylic resin, a modified type, etc. can be preferably used. Further, it is preferable to cure the adhesive using a curing agent because the adhesive force is improved and the heat resistance is also increased. As the curing agent, an isocyanate compound is generally used, but aliphatic amines, cycloaliphatic amines, aromatic amines, acid anhydrides and the like can be used.

  The thickness of the adhesive layer is not particularly limited, but is usually about 2 μm or more and 7 μm or less in a dry state. For the formation of the adhesive layer, generally used coating means can be used, for example, by means of gravure printing, screen printing, reverse roll coating using a gravure plate, etc., It can be obtained by drying. EC sand lamination using polyethylene or the like may also be performed.

(Receptive layer)
As shown in FIG. 1, the receiving layer 5 is provided on both surfaces of the base material sheet 1. The receiving layer 5 is an essential component in the thermal transfer double-sided image receiving sheet 100 of the present invention.

  As the resin material contained in the receiving layer 5, a conventionally known resin that can easily receive the dye of the dye layer of the thermal transfer sheet can be used. For example, polyolefin resin such as polypropylene, halogenated resin such as polyvinyl chloride or polyvinylidene chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer or polyacrylate Vinyl resins, polyester resins such as polyethylene terephthalate or polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene or propylene and other vinyl polymers, cellulose resins such as ionomers or cellulose diastases And solvent-based resins such as polycarbonate and acrylic resins.

  Further, in place of the solvent-based resin exemplified above, a water-based resin such as a water-soluble resin, a water-soluble polymer, or a water-based resin can be used as the binder resin. According to the receiving layer 5 containing a water-based resin, an image having a higher printing density can be formed as compared with a solvent-based receiving layer, and light resistance and glossiness after image formation are improved. Can do.

  Examples of the water-soluble resin and water-soluble polymer include polyvinyl pyrrolidone resin, polyvinyl alcohol resin, and gelatin. Examples of the water-based resin include emulsions such as a vinyl chloride resin, an acrylic resin, and a urethane resin, or a resin in which a part of a solvent such as a dispersion is composed of water. The aqueous resin can be formed, for example, by dispersing and preparing a solution containing a solvent-based resin by a method such as a homogenizer.

  Further, the receiving layer 5 may contain a release agent for improving the releasability from the thermal transfer sheet. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder, fluorine or phosphate surfactant, silicone oil, reactive silicone oil, and curable silicone oil. And various modified silicone oils, and various silicone resins.

  The various binder resins described above are preferably contained in an amount of 50% by mass or more based on the total solid content of the receiving layer 5. In particular, by setting the content of the water-soluble resin, water-soluble polymer, or water-based resin within the above range, high gloss can be imparted to the formed image. The same applies to the case of using other binder resins.

  There is no particular limitation on the method for forming the receiving layer 5, and the binder resin described above and various additives added as necessary are dissolved or dispersed in an appropriate solvent such as water or a solvent to form a receiving layer. A coating liquid is prepared, and this is applied to the first resin film layer and the second resin film layer by means of a gravure printing method, a screen printing method or a reverse coating method using a gravure plate, or the first It can be formed by coating and drying on an arbitrary layer provided on the resin film layer and the second resin film layer.

  The thickness of the receiving layer is not particularly limited, but is preferably 1 μm or more and 7 μm or less.

  Further, an intermediate layer (illustrated) for imparting various functions to the thermal transfer double-sided image-receiving sheet 100 between the first resin film layer 3 and the receiving layer 5 and between the second resin film layer 4 and the receiving layer 5. Not). Examples of the various functions include an antistatic function, a concealing function, a plasticizer resistance function, and the like, and a material constituting the intermediate layer may be appropriately selected depending on the function.

  The thermal transfer double-sided image-receiving sheet of the present invention has been described in detail above, but the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention. Good.

  Next, the present invention will be described more specifically with reference to examples and comparative examples. Hereinafter, unless otherwise specified, parts or% is based on mass.

Example 1
<Creation of base sheet (1)>
Polypropylene film (1) (thickness 23 μm, density 0.6 g) having voids (microvoids) inside the base material on one side of the coated paper (1) (basis weight 157 g / m ² , thickness 130 μm) and the other side / m ³ ) by using an adhesive layer coating solution (coating amount: 4 g / m ² (after drying)) having the following composition, to form a polypropylene film (1) [second resin film layer] ] / Adhesive layer / coated paper (1) [corresponding to paper substrate] / adhesive layer / polypropylene film (1) [corresponding to first resin film layer] 1) was created.

Next, the primer layer coating solution having the following composition was applied and dried on both surfaces of the base sheet (1) prepared above with a bar coater so that the coating amount on drying was 2.0 g / m ^2. Thus, a primer layer was formed. Next, on each primer layer, a receiving layer coating solution having the following composition is coated with a bar coater so that the coating amount upon drying is 3.0 g / m ² and dried to form a receiving layer. Thermal transfer of Example 1 in which the receiving layer / primer layer / polypropylene film (1) / adhesive layer / coated paper (1) / adhesive layer / polypropylene film (1) / primer layer / receptive layer are laminated in this order A double-sided image receiving sheet was obtained. The total thickness of the first resin film layer, the paper base material, and the second resin film layer, and the thicknesses of the first resin film layer and the second resin film layer when the total thickness is 100% are shown. It is shown in 1.

<Coating liquid for adhesive layer>
・ 30 parts of urethane resin (Takelac A-969V, manufactured by Mitsui Takeda Chemical Co., Ltd.)
・ Isocyanate 10 parts (Takenate A-5 manufactured by Mitsui Takeda Chemical Co., Ltd.)
・ 60 parts of ethyl acetate

<Primer layer coating solution>
・ Polyester resin 50 parts (Polyester WR-905 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
・ Titanium oxide 20 parts (TCA888 manufactured by Tochem Products Co., Ltd.)
・ Fluorescent whitening agent 1.2 parts (Ubitex BAC Ciba Specialty Chemicals Co., Ltd.)
Water / isopropyl alcohol = 1/1 28.8 parts

<Coating liquid for receiving layer>
・ Vinyl chloride-vinyl acetate copolymer 20 parts (Solvine CN Nissin Chemical Industry Co., Ltd.)
・ 0.4 parts of silicone oil (X-22-3000T Shin-Etsu Chemical Co., Ltd.)
・ Toluene 80 parts ・ Methyl ethyl ketone 80 parts

(Example 2)
The thermal transfer double-sided image-receiving sheet of Example 2 was obtained by pressing a blade for creating ruled lines against one side and the other side of the thermal-transfer double-sided image-receiving sheet of Example 1 to form folding lines as ruled lines.

(Example 3)
In place of the polypropylene film (1), a polyethylene terephthalate film (1) [2nd] was used in the same manner as in Example 1 except that a polyethylene terephthalate film (1) (T-60 Toray Co., Ltd., thickness 25 μm) was used. Corresponding to resin film layer] / adhesive layer / coated paper (1) [corresponding to paper substrate] / adhesive layer / polyethylene terephthalate film (1) [corresponding to first resin film layer] are laminated in this order. A base sheet (2) was prepared. Further, a thermal transfer double-sided image-receiving sheet of Example 3 was obtained in the same manner as Example 1 except that the base sheet (2) was used instead of the base sheet (1).

Example 4
A polypropylene film (1) (thickness 23 μm, density 0.6 g / m ³ ) having voids (microvoids) inside the base material on one side of the coated paper (1) (basis weight 157 g / m ² , thickness 130 μm) On the other surface of the coated paper (1), a polyethylene terephthalate film (1) (T-60 Toray Co., Ltd., thickness 25 μm) is applied to the adhesive layer coating solution having the above composition (coating amount: 4 g / m ² ( After drying)), the polypropylene film (1) [corresponding to the second resin film layer] / adhesive layer / coated paper (1) [corresponding to paper substrate] / adhesive layer / polyethylene terephthalate A base sheet (3) in which the film (1) [corresponding to the first resin film layer] was laminated in this order was prepared. Further, a thermal transfer double-sided image-receiving sheet of Example 4 was obtained in the same manner as Example 1 except that the base sheet (3) was used instead of the base sheet (1).

(Example 5)
The polypropylene film (1) [second resin] was used in the same manner as in Example 1 except that the coated paper (2) (basis weight 186 g / m ² , thickness 154 μm) was used instead of the coated paper (1). Corresponding to film layer] / adhesive layer / coated paper (2) [corresponding to paper substrate] / adhesive layer / polypropylene film (1) [corresponding to first resin film layer] laminated in this order Sheet (4) was prepared. Further, a thermal transfer double-sided image-receiving sheet of Example 5 was obtained in the same manner as Example 1 except that the base sheet (4) was used instead of the base sheet (1).

(Example 6)
The polypropylene film (1) [second resin] was used in the same manner as in Example 1 except that the coated paper (3) (basis weight 127 g / m ² , thickness 106 μm) was used instead of the coated paper (1). Corresponding to film layer] / adhesive layer / coated paper (3) [corresponding to paper substrate] / adhesive layer / polypropylene film (1) [corresponding to first resin film layer] laminated in this order Sheet (5) was prepared. Further, a thermal transfer double-sided image-receiving sheet of Example 6 was obtained in the same manner as Example 1 except that the base sheet (5) was used instead of the base sheet (1).

(Example 7)
The polypropylene film (1) [second resin] was used in the same manner as in Example 1 except that the coated paper (4) (basis weight 130 g / m ² , thickness 130 μm) was used instead of the coated paper (1). Corresponding to film layer] / adhesive layer / coated paper (4) [corresponding to paper substrate] / adhesive layer / polypropylene film (1) [corresponding to first resin film layer] laminated in this order A sheet (6) was prepared. Further, a thermal transfer double-sided image-receiving sheet of Example 7 was obtained in the same manner as Example 1 except that the base sheet (6) was used instead of the base sheet (1).

(Example 8)
A polyethylene terephthalate film (1) (T-60 Toray Co., Ltd., thickness 25 μm) is bonded to one side of the coated paper (5) (basis weight 128 g / m ² , thickness 102 μm) and the other side with the above composition. Polyethylene terephthalate film (1) [corresponding to second resin film layer] / adhesive layer / coated paper by laminating using layer coating liquid (coating amount: 4 g / m ² (after drying)) (5) A substrate sheet (7) was produced in which [corresponding to paper substrate] / adhesive layer / polyethylene terephthalate film (1) [corresponding to first resin film layer] was laminated in this order. Further, a thermal transfer double-sided image-receiving sheet of Example 8 was obtained in the same manner as Example 1 except that the base sheet (7) was used instead of the base sheet (1).

Example 9
Polypropylene film (2) (Toyopearl SS Toyobo Co., Ltd.) with voids (microvoids) inside the base material on one side and the other side of coated paper (1) (basis weight 157 g / m ² , thickness 130 μm) 35 [mu] m) by using an adhesive layer coating solution having the above composition (coating amount: 4 g / m < ² > (after drying)), so that the polypropylene film (2) [corresponding to the second resin film layer] ] / Adhesive layer / coated paper (1) [corresponding to paper substrate] / adhesive layer / polypropylene film (2) [corresponding to the first resin film layer] laminated in this order (8) It was created. Further, a thermal transfer double-sided image-receiving sheet of Example 9 was obtained in the same manner as Example 1 except that the base sheet (8) was used instead of the base sheet (1).

(Comparative Example 1)
The polypropylene film (2) / adhesive layer / coating was the same as in Example 1 except that the polypropylene film (2) (thickness 37 μm, density 0.7 g / m ³ ) was used instead of the polypropylene film (1). A base sheet (A) in which paper (1) / adhesive layer / polypropylene film (2) was laminated in this order was prepared. Further, a thermal transfer double-sided image-receiving sheet of Comparative Example 1 was obtained in the same manner as in Example 1 except that the base sheet (A) was used instead of the base sheet (1).

(Comparative Example 2)
A half cut that penetrates to a part of the polypropylene film (2) is formed on one side of the thermal transfer double-sided image-receiving sheet of Comparative Example 1 and the other side by a press method of an upper mold with a cutter blade and a pedestal. The thermal transfer double-sided image-receiving sheet of Comparative Example 2 was obtained.

(Comparative Example 3)
A thermal transfer double-sided image-receiving sheet of Comparative Example 3 was obtained by pressing a blade for creating ruled lines on one side and the other side of the thermal-transfer double-sided image-receiving sheet of Comparative Example 1 to form folding lines as ruled lines. .

(Comparative Example 4)
A polypropylene film (2) / adhesive layer / coat in the same manner as in Comparative Example 1 except that the coated paper (3) (basis weight 127 g / m ² , thickness 106 μm) was used instead of the coated paper (1). A base sheet (B) in which paper (3) / adhesive layer / polypropylene film (2) was laminated in this order was prepared. Further, a thermal transfer double-sided image-receiving sheet of Comparative Example 4 was obtained in the same manner as in Example 1 except that the base sheet (B) was used instead of the base sheet (1).

(Bendability evaluation)
The “foldability” of the thermal transfer double-sided image-receiving sheet of each example and comparative example was performed based on the following evaluation criteria. The evaluation results are shown in Table 1.

"Evaluation criteria"
(Double-circle): It can be folded neatly and the folded thermal transfer double-sided image-receiving sheet is not restored. ○: Although it can be folded neatly, the folded thermal transfer double-sided image-receiving sheet is slightly restored.
Δ: Although it can be beautifully folded, the folded thermal transfer double-sided image receiving sheet is restored.
X: It cannot be bent neatly.

(Evaluation of paper dust generation)
It was evaluated whether paper dust was generated when the thermal transfer double-sided image-receiving sheet of each Example and Comparative Example was folded. The evaluation results are also shown in Table 1. In the table, ○ means that paper dust is not generated, and x means that paper dust is generated.

(Wrinkle evaluation)
It was visually confirmed whether or not wrinkles were generated at the folded portion when the thermal transfer double-sided image-receiving sheets of each Example and Comparative Example were folded, and wrinkles were evaluated based on the following evaluation criteria. The evaluation results are also shown in Table 1.
"Evaluation criteria"
A: Wrinkles are not generated in the folded portion. B: Wrinkles are slightly generated in the folded portion, but the level is not problematic in use.
Δ: Wrinkles that cause problems in use at the folded portion.
X: Many wrinkles are generated in the folded portion.

(Curl evaluation)
A black solid was printed on the thermal transfer double-sided image-receiving sheet of each example using a DP-1045 printer (manufactured by Symphonia Technology Co., Ltd.) and a thermal transfer sheet for DP-1045. The curl amount was measured by storing the printed material in an environment of 90% at 40 ° C. for 6 hours, placing the printed material on a flat plate, and taking the average of the curled amounts at both ends of the printed material as the curled amount.
"Evaluation criteria"
○: 10 mm or less Δ: Greater than 10 mm and 15 mm or less X: Greater than 15 mm

DESCRIPTION OF SYMBOLS 1 Base material sheet 2 Paper base material 3 1st resin film layer 4 2nd resin film layer 5 Receiving layer 100 Thermal transfer double-sided image receiving sheet

Claims (4)

A thermal transfer double-sided image-receiving sheet provided with a receiving layer on both sides of a base sheet,
The base sheet has a laminated structure in which a first resin film layer is provided on one side of a paper base and a second resin film layer is provided on the other side of the paper base. ,
The total thickness of the paper base material, the first resin film layer, and the second resin film layer is 145 μm or more and 200 μm or less,
The thermal transfer double-sided image-receiving sheet, wherein the thickness of the first resin film layer and the thickness of the second resin film layer are both 18% or less when the total thickness is 100%.   2. The thermal transfer double-sided image receiving sheet according to claim 1, wherein a ruled line is provided on both surfaces of the thermal transfer double-sided image receiving sheet or any one of the surfaces. The thermal transfer double-sided image-receiving sheet according to claim 1 or 2, wherein the paper substrate has a basis weight of 120 g / m ² or more and 190 g / m ² or less.   4. The resin material constituting the first resin film layer and the resin material constituting the second resin film layer are the same kind of resin material having a common basic monomer. The thermal transfer double-sided image-receiving sheet according to any one of the above.

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