JP2017061072A - Transfer sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer sheet that is improved in the collapse or blur of a transfer layer when making printed matter.SOLUTION: A transfer sheet has a base material, and a release layer and a transfer layer on the base material in order, the release layer having binder resin, and the binder resin having a crosslinked product of silanol group-containing polyurethane resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermal transfer sheet, and more particularly to a transfer sheet comprising a base material and a release layer and a transfer layer in that order on the base material.

  Currently, a thermal transfer recording method is widely used as a simple printing method. Since the thermal transfer recording method can easily form various images, printed materials that require a relatively small number of copies, such as creation of ID cards such as identification cards, business photographs, personal computer printers, video printers, etc. Is used.

  The thermal transfer sheet used in the thermal transfer recording system can be roughly classified into a so-called melt transfer type thermal transfer sheet in which the heat-fusible colored layer is melted and softened by heating, and the heat-fusible colored layer is transferred to a transfer target, that is, an image receiving sheet. And a so-called sublimation type thermal transfer sheet in which the dye in the color material layer sublimes due to heat and the dye moves to the image receiving sheet. Here, when an ID such as an identification card is produced, particularly when a monotonous image such as letters and numbers is formed, a heat melting type thermal transfer sheet is used. As such a heat-melting type heat transfer sheet, for example, a heat transfer sheet in which a base material, a release layer made of an acrylic-styrene resin, and a heat-melting colored layer are laminated in this order is known. However, when an acrylic-styrene resin is used as the release layer of the thermal transfer sheet, the release layer is softened by the heat applied from the thermal head, and the peeling force between the release layer and the transfer layer is increased. Problems such as transfer failure where the layer is not transferred, whitening of the image due to roughening of the peeling interface, and abnormal noise during peeling may occur.

  In addition, when an ID such as an identification card is produced using the thermal transfer sheet as described above, for the purpose of protecting the image, on the image obtained by thermal transfer of the heat-fusible colored layer, A release layer composed of polyvinyl alcohol (PVA) and water-dispersed urethane and a protective layer thermal transfer sheet in which a protective layer is laminated in this order are superposed, and the protective layer is transferred using a thermal head, a heating roll, etc. A method for forming a protective layer thereon is known. Furthermore, in order to improve the durability of the image, a method of forming a laminate material using a heating roll after forming a protective layer on the image is also known. However, the water-based release layer (release layer made of polyvinyl alcohol and water-dispersed urethane) is unstable with respect to humidity, and in a high humidity environment, the whitening of the image due to the roughened peeling interface of the transfer layer, Problems such as abnormal noise during peeling may occur.

  In order to solve the above problems, a thermal transfer sheet provided with a release layer containing a polyamide-based resin is provided to reduce the effects of heat applied to the thermal head and the humidity environment and to improve releasability. It has been proposed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-73383

  However, the thermal transfer sheet described in Patent Document 1 has found a new technical problem that a transfer layer slippage and a transfer layer blurring occur in order to form an image such as fine characters and numbers.

  The present invention has been made in view of the above-described background art, and an object of the present invention is to provide a transfer sheet having improved transfer layer slippage and transfer layer blurring when a printed product is produced.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a transfer sheet having a release layer having a specific composition containing a binder resin. The present invention has been completed based on such findings.

That is, according to one aspect of the present invention,
A transfer sheet comprising a base material, and a release layer and a transfer layer on the base material in order,
There is provided a transfer sheet in which the release layer comprises a binder resin, and the binder resin comprises a crosslinked product of a silanol group-containing polyurethane resin.

  In the said aspect of this invention, it is preferable that content of the said silanol group containing polyurethane resin is 50 mass% or more with respect to the binder resin in the said mold release layer.

  In the above aspect of the present invention, it is preferable that a release layer is further provided between the release layer and the transfer layer.

  In the said aspect of this invention, it is preferable that the said peeling layer comprises a vinyl acetate resin.

  In the above aspect of the present invention, it is preferable that the release layer further comprises a release agent.

  In the said aspect of this invention, it is preferable that the said transfer layer contains a coloring agent.

  ADVANTAGE OF THE INVENTION According to this invention, the transfer sheet which improved the blur of the transfer layer at the time of producing a printed matter and the blur of a transfer layer can be provided.

It is the schematic cross section which showed one Embodiment of the transfer sheet by this invention. It is a figure which shows the printing pattern (white line and black line) of the transfer conditions in evaluation of thin line reproducibility.

<Transfer sheet>
The transfer sheet according to the present invention includes a release layer and a transfer layer in this order, and may further include a release layer between the release layer and the transfer layer, or a surface of the substrate opposite to the release layer. A heat-resistant layer may be further provided. Hereinafter, the layer structure of the transfer sheet according to the present invention will be described with reference to the drawings.

  A schematic cross-sectional view of an embodiment of a transfer sheet according to the present invention is shown in FIG. A transfer sheet 10 shown in FIG. 1 includes a base material 11, a release layer 12, a release layer 13, and a transfer layer 14 in this order on the base material 11. A heat-resistant layer 15 is further provided on the surface opposite to the layer 12. Hereinafter, each layer constituting the transfer sheet according to the present invention will be described in detail.

<Base material>
The base material in the present invention has a role of holding the transfer layer and heat is applied during thermal transfer. Therefore, the base material is preferably a material having a mechanical strength that does not hinder handling even in a heated state. Such base materials include polyethylene terephthalate film, 1,4-polycyclohexylenedimethylene terephthalate film, polyethylene naphthalate film, polyphenylene sulfide film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film. , Polyvinyl alcohol film, cellophane, cellulose derivatives such as cellulose acetate, polyethylene film, polyvinyl chloride film, nylon film, polyimide film, ionomer film and the like. The thickness of the substrate is preferably 0.5 μm or more and 50 μm or less, more preferably 1 μm or more and 10 μm or less.

  As the base material, a surface subjected to an easy adhesion treatment may be used. The easy adhesion treatment is a treatment for forming an easy adhesion layer between the base material and a later-described release layer. As such an easy-adhesion layer, for example, those composed of aqueous acrylic, aqueous polyester and aqueous epoxy compound are preferable. The water-based acrylic is a water-soluble or water-dispersible acrylic resin, preferably having an alkyl acrylate or alkyl methacrylate as a main component, and the component is 30 mol% or more and 90 mol% or less and is copolymerized. The ones made are preferred. The water-based polyester is a water-soluble or water-dispersible polyester resin, and examples of components constituting the polyester resin include polyvalent carboxylic acids and polyvalent hydroxy compounds. An aqueous epoxy compound is a compound containing an epoxy group that is water-soluble or water-dispersible, preferably water-soluble, and contains at least one, preferably two or more epoxy groups in the molecule. is there. Examples of such aqueous epoxy compounds include glycols, polyethers, glycidyl ethers of polyols, glycidyl esters of carboxylic acids, glycidyl-substituted amines, and the like, but glycidyl ethers are preferred. For the easy adhesion treatment, a method of forming an easily adhesive coating film on the surface of the substrate is preferably used.

<Release layer>
The release layer in the present invention is a layer provided so that the transfer layer can be easily peeled from the substrate (at the interface between the release layer and the transfer layer) during thermal transfer. It is preferable that the release layer is formed of a material having releasability, includes a binder resin, and further includes an additive such as a release agent.

  As the binder resin used for the release layer, a cross-linked product of a silanol group-containing polyurethane resin is used. In the present invention, the silanol group-containing polyurethane resin refers to a polyurethane resin containing at least one silanol group in the molecule. The presence (bonding) site of the silanol group contained in the silanol group-containing polyurethane resin is not particularly limited, and may be present (bonded) at both ends, any one end, or any intermediate portion of the polyurethane resin. . In addition, a silanol group-containing polyurethane resin into which a hydrophilic group is introduced is preferable, and examples of the hydrophilic group include a carboxyl group, a sulfonic acid group, a sulfonate group, an epoxy group, and a polyoxyethylene group. It is done. The silanol group-containing polyurethane resin is not particularly limited. For example, as a raw material component, a compound containing at least two isocyanate groups in one molecule and a compound containing at least two active hydrogen groups in one molecule Are obtained by reacting and introducing a compound containing at least one active hydrogen group and hydrolyzable silicon group in one molecule with respect to the polyurethane compound obtained from (1).

  The form of use of the silanol group-containing polyurethane resin is not particularly limited, but those in which the silanol group-containing polyurethane resin is dissolved in an aqueous medium or those in a colloidal dispersion system (dispersion) dispersed in fine particles are preferably used. It is done. In the present invention, a commercially available silanol group-containing polyurethane-based resin can also be used. For example, Takelac WS-4022, Takelac WS-5000, Takelac WS-5100, etc., manufactured by Mitsui Chemicals, Inc. can be preferably used.

  The cross-linked structure of the cross-linked product of the silanol group-containing polyurethane resin is not particularly limited, but is preferably a cross-linked structure in which silanol group-containing polyurethane resins are cross-linked (self-cross-linked). Regarding the self-crosslinking formation mechanism, for example, a crosslinked structure can be formed by evaporation of moisture.

  The content of the crosslinked product of the silanol group-containing polyurethane resin in the release layer is preferably 50% by mass or more and 100% by mass or less, more preferably 55% by mass or more with respect to the total solid content of the binder resin. It is 100 mass% or less, More preferably, it is 60 mass% or more and 100 mass% or less, More preferably, it is 70 mass% or more and 100 mass% or less. If the content of the cross-linked product of the silanol group-containing polyurethane resin in the release layer is within the above range, it is possible to obtain a transfer sheet having improved transfer layer slippage and transfer layer blurring when a printed product is produced. it can.

  As the binder resin (added resin) used together with the silanol group-containing polyurethane resin in the release layer, a polyvinyl alcohol resin is preferable. The content of the additive resin in the release layer is preferably 1% by mass to 45% by mass, more preferably 5% by mass to 40% by mass, and even more preferably 10% by mass to 30% by mass. is there. When the content of the additive resin is within the above range, a transfer sheet having improved transfer layer slippage and transfer layer blurring when a printed product is produced can be obtained.

  Examples of the mold release agent used in the mold release layer include silicone oil, phosphate ester plasticizer, fluorine compound, wax, metal soap, and filler. Silicone oil is preferably used.

  The method for forming the release layer is not particularly limited, but can be formed by a conventionally known coating method. For example, after adding the binder resin and an additive such as a mold release agent in an appropriate solvent and dissolving or dispersing each component to prepare a coating solution, the coating solution is applied to the base material. Furthermore, it can be formed by applying and drying using a known means such as a gravure coating method, a roll coating method, a comma coating method, a gravure printing method, a screen printing method, and a gravure reverse roll coating method. The thickness of the release layer is not particularly limited, but is preferably 0.05 μm or more and 5.0 μm or less, more preferably 0.1 μm or more and 3 μm or less.

<Peeling layer>
The release layer in the present invention is a layer provided so that the transfer layer can be easily released from the substrate (at the interface between the release layer and the release layer) during thermal transfer. The release layer can be formed using a binder resin. Examples of the binder resin used for the release layer include acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyvinyl alcohol resin, polyvinyl acetate resin, vinyl acetate resin, polyvinyl butyral resin, polyvinyl acetal resin, Vinyl resins such as polyvinylpyrrolidone, polyester resins such as polyethylene terephthalate resin, polyethylene naphthalate tree, urethane resins such as polyurethane acrylate, ethyl cellulose resin, hydroxyethyl cellulose resin, ethyl hydroxy cellulose resin, methyl cellulose resin, cellulose acetate resin, etc. Cellulosic resins, polyamide resins, aromatic polyamide resins, polyamideimide resins such as polyamideimide resins, acetal resins, polycarbonate resins, etc. Among them, acrylic resins, vinyl resins, polyester resins, urethane resins, the use of acetal resin, and cellulosic resin.

  In the present invention, the acrylic resin means a polymer of a (meth) acrylic acid monomer or a derivative thereof, a polymer of a monomer of a (meth) acrylic acid ester or a derivative thereof, a (meth) acrylic monomer and other derivatives. Copolymers with monomers or derivatives thereof, and copolymers of (meth) acrylic acid ester monomers with other monomers or derivatives thereof. Other “system resins” may also contain copolymers with other monomers other than the main component or derivatives thereof.

  As the binder resin used in the release layer, it is particularly preferable to use a vinyl acetate resin (vinyl chloride-vinyl acetate copolymer). Here, the vinyl chloride-based resin includes not only a copolymer of vinyl chloride and vinyl acetate, but also a copolymer of vinyl chloride, vinyl acetate, and other monomers. The content of the vinyl chloride resin in the release layer is preferably 50% by mass or more and 100% by mass or less, and more preferably 55% by mass or more and 99% by mass or less with respect to the total solid content of the binder resin. Yes, more preferably 60 mass% or more and 95 mass% or less, still more preferably 70 mass% or more and 90 mass% or less. When the content of the vinyl chloride-based resin is within the above range, a transfer sheet with improved transfer layer slippage and transfer layer blurring when a printed product is produced can be obtained.

  As the binder resin (addition resin) used together with the vinyl chloride resin for the release layer, an acrylic resin or a polyester resin is preferable. The content of the additive resin in the release layer is preferably more than 0% by mass and 45% by mass or less, more preferably 5% by mass to 40% by mass, and further preferably 10% by mass to 30% by mass. is there. When the content of the additive resin is within the above range, a transfer sheet having improved transfer layer slippage and transfer layer blurring when a printed product is produced can be obtained.

  The release layer may further contain an additive such as a release agent. As the release agent, silicone oil and / or a wax component are used. By adding a release agent such as silicone oil and a wax component to the release layer, even after the transfer sheet is stored in a high-temperature environment, the transfer layer slips and the transfer layer is distorted when a printed product is produced. Can be obtained (excellent storage stability). Examples of the silicone oil include amino-modified silicone, epoxy-modified silicone, aralkyl-modified silicone, epoxy-aralkyl-modified silicone, alcohol-modified silicone, vinyl-modified silicone, urethane-modified silicone, and it is preferable to use epoxy-modified silicone oil. Examples of the wax component include microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low molecular weight polyethylene, wood wax, beeswax, whale wax, ibota wax, wool wax, shellac wax, candelilla wax, petrolactam, one Various waxes such as partially modified waxes, fatty acid esters, and fatty acid amides can be used, and polyethylene wax is preferably used.

  The content of the release agent in the release layer (total content of silicone oil and wax component) is preferably 0.1% by mass or more and 15% by mass or less, more preferably, based on the solid content mass of the binder resin. It is 0.5 mass% or more and 12 mass% or less, More preferably, it is 1 mass% or more and 10 mass% or less. If the content of the release agent is within the above range, even after the transfer sheet is stored in a high temperature environment, the transfer layer slippage and transfer layer blurring when the printed matter is produced are improved (storage stability). Transfer sheet can be obtained.

  Although the formation method of a peeling layer is not specifically limited, It can form by a conventionally well-known coating method. For example, after adding the above-mentioned binder resin and an additive such as a release agent in an appropriate solvent to dissolve or disperse each component to prepare a coating solution, the coating solution is then removed from the substrate or the release agent. On the mold layer, it can be formed by applying and drying using a known means such as a gravure coating method, a roll coating method, a comma coating method, a gravure printing method, a screen printing method, and a gravure reverse roll coating method. The thickness of the release layer is not particularly limited, but is preferably 0.05 μm or more and 5.0 μm or less, more preferably 0.1 μm or more and 3 μm or less.

<Transfer layer>
The transfer layer in the present invention is conventionally known, such as a printer having a transfer sheet and an object to be transferred, and a back side of the base material (side on which the transfer layer of the base material is not provided) provided with a thermal head for thermal transfer. It is a layer which is peeled off from the release layer and / or release layer by being heated by the heating means and transferred onto the transfer target.

  The transfer layer preferably contains a binder resin used for the transfer layer and a colorant in order to form an image such as letters and numbers by being transferred onto the transfer target. Binder resins include acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyvinyl alcohol resins, polyvinyl acetate resins, vinyl acetate resins, polyvinyl butyral resins, polyvinyl acetal resins, vinyl pyrrolidone and other vinyls. Resin, polyethylene terephthalate resin, polyester resin such as polyethylene naphthalate tree, urethane resin such as polyurethane acrylate, ethyl cellulose resin, hydroxyethyl cellulose resin, ethyl hydroxy cellulose resin, methyl cellulose resin, cellulose acetate resin such as cellulose acetate resin, polyamide Resin, aromatic polyamide resin, polyamide-imide resin such as polyamide-imide resin, acetal resin, polycarbonate resin, etc. It is preferable to use a resin.

As the colorant, conventionally known colorants can be used, but those having good characteristics as a printing material, for example, those having a sufficient color density and not discolored by light, heat, temperature, etc. preferable. Further, it may be a substance that develops color when heated or a substance that develops color when it comes into contact with a component applied to the surface of the transfer target. The colorant preferably exhibits at least one color selected from the group consisting of black, white, silver, cyan, magenta, yellow, red, green, and blue. For example, as a colorant, carbon black for black, titanium oxide for white, and inorganic materials such as aluminum for silver, C.I. for cyan, magenta, yellow, red, green, and blue. I. It is preferable to use each pigment described in Pigment.

  The method for forming the transfer layer is not particularly limited, but can be formed by a conventionally known coating method. For example, after adding the above binder resin and a colorant in an appropriate solvent and dissolving or dispersing each component to prepare a coating solution, the coating solution is applied to the release layer on the gravure coating method, roll coating. It can be formed by applying and drying using known means such as a method, a comma coating method, a gravure printing method, a screen printing method, and a gravure reverse roll coating method. The thickness of the transfer layer is not particularly limited, but is preferably 0.5 μm or more and 30 μm or less, more preferably 1 μm or more and 20 μm or less.

<Heat resistant layer>
The heat-resistant layer in the present invention is a layer provided to prevent adverse effects such as sticking and wrinkles due to heating from the back side of the base material (the side where the base material transfer layer is not provided) during thermal transfer. . By providing a heat-resistant layer, thermal printing can be performed without causing sticking even in a thermal transfer sheet based on a plastic film that is inferior in heat resistance. Benefit from the benefits.

  The heat-resistant layer preferably contains a binder resin and additives such as a slip agent. Examples of the binder resin used for the heat-resistant layer include acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyvinyl alcohol resins, polyvinyl acetate resins, vinyl acetate resins, polyvinyl butyral resins, polyvinyl acetal resins, Vinyl resins such as polyvinyl pyrrolidone, polyester resins such as polyethylene terephthalate resin, polyethylene naphthalate tree, urethane resins such as polyurethane acrylate, ethyl cellulose resin, hydroxyethyl cellulose resin, ethyl hydroxy cellulose resin, methyl cellulose resin, cellulose acetate resin, etc. Cellulosic resins, polyamide resins, aromatic polyamide resins, polyamideimide resins such as polyamideimide resins, acetal resins, polycarbonate resins, etc. And the like. Examples of the slip agent include metal soap, wax, silicone oil, fatty acid ester, filler, talc and the like.

  Although the formation method of a heat-resistant layer is not specifically limited, It can form with a conventionally well-known coating method. For example, after adding the above-mentioned binder resin and an additive such as a slipping agent in an appropriate solvent and dissolving or dispersing each component to prepare a coating solution, the coating solution is applied to the substrate. Furthermore, it can be formed by applying and drying using a known means such as a gravure coating method, a roll coating method, a comma coating method, a gravure printing method, a screen printing method, and a gravure reverse roll coating method. Further, the thickness of the heat-resistant layer is not particularly limited, but is preferably 0.05 μm or more and 5.0 μm or less, and more preferably 0.1 μm or more and 3 μm or less.

<Transfer material>
The transfer medium that can be used for transfer of the thermal transfer sheet according to the present invention is not particularly limited, and examples thereof include a conventionally known base material provided with a receiving layer having dye receptivity. Examples of the substrate in the transfer target include plain paper, high-quality paper, tracing paper, plastic film, and the like, and the substrate is not particularly limited. The receiving layer in the transfer target can be formed by a coating method, a forming method using a thermal head, a hot roll, or the like. In addition, if the base material itself has dye receptivity, it is not necessary to provide a receiving layer for the transfer target.

<Transfer method>
Transfer to the transfer medium using the transfer sheet according to the present invention can be performed directly on the transfer medium using a conventionally known thermal transfer printer. In addition, when it is difficult to directly transfer the transfer object, the transfer layer is transferred onto the receiving layer of the intermediate transfer recording medium (primary transfer), and then the receiving layer of the intermediate transfer recording medium is transferred to the transfer object. (Retransfer) can also be performed. For thermal transfer printers, for example, transfer conditions may be set separately such as for sublimation transfer, thermal melt transfer, and protective layer transfer. May be. The heating means is not particularly limited, and transfer may be performed using a hot plate, a hot stamper, a hot roll, a line heater, an iron, or the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples. In addition, the mass parts of the binder resin, the silicone oil, and the wax component are described as solid contents.

[Example 1]
A polyester film with an easy adhesion treatment having a thickness of 6 μm was prepared as a substrate. A heat-resistant layer is formed by applying the heat-resistant layer coating solution 1 having the following composition to the surface of the polyester film that has not been subjected to the easy-adhesion treatment so that the heat-resistant layer is 1.0 g / m ² when dried. A release layer was formed by applying a release layer coating solution 1 having the following composition to the surface on which the coating layer was dried at 0.3 g / m ² . Next, a release layer was formed by applying a release layer coating solution 1 having the following composition on the release layer so as to be 1.0 g / m ² when dried. Next, a transfer layer coating liquid having the following composition was applied onto the release layer so as to be 1.0 g / m ² upon drying to form a transfer layer, whereby a transfer sheet 1 was produced.

<Coating solution 1 for heat-resistant layer>
・ Polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., trade name: ESREC BX-1)
2.0 parts by mass / isocyanate (manufactured by DIC Corporation, trade name: Bernock D750) 4.4 parts by mass / phosphate ester surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Prisurf A208N) 1.3 parts by mass / talc (trade name: Microace P-3, manufactured by Nippon Talc Co., Ltd.) 0.3 parts by mass / viscosity adjusting solvent (toluene / methyl ethyl ketone = 1/1) 92 parts by mass <for release layer Coating liquid 1>
-Urethane resin (silanol group-containing, manufactured by Mitsui Chemicals, Inc., trade name: WS-4022)
100 parts by mass / viscosity adjusting solvent (toluene / isopropyl alcohol = 1/1) 1900 parts by mass <exfoliation layer coating solution 1>
・ Vinyl chloride-based resin (manufactured by Nissin Chemical Industry Co., Ltd., trade name: Solvain CNL) 100 parts by mass ・ Epoxy-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KP-1800U)
1 part by mass / viscosity adjusting solvent (toluene / methyl ethyl ketone = 1/1) 300 parts by mass <coating liquid 1 for transfer layer>
-60 parts by weight of vinyl chloride-based resin-40 parts by weight of carbon black-Viscosity adjusting solvent (toluene / methyl ethyl ketone = 1/1)

[Example 2]
A transfer sheet 2 was produced in the same manner as in Example 1 except that the composition of the release layer coating solution was as follows.
<Peeling layer coating solution 2>
・ Vinyl vinyl chloride resin (Nissin Chemical Industry Co., Ltd., trade name: Solvain CNL) 95 parts by mass ・ Polyester resin (Made by Unitika Ltd., trade name: Elitel UE-9985)
5 parts by mass / epoxy-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KP-1800U)
1 part by mass / viscosity adjusting solvent (toluene / methyl ethyl ketone = 1/1) 300 parts by mass

[Comparative Example 1]
A transfer sheet 12 was produced in the same manner as in Example 1 except that the composition of the release layer coating solution was as follows.
<Release layer coating solution 6>
-Urethane resin (silanol group-free, manufactured by DIC Corporation, trade name: AP-40)
100 parts by mass / viscosity adjusting solvent (toluene / isopropyl alcohol = 1/1) 1900 parts by mass

[Performance evaluation of transfer sheet]
(1) Evaluation of fine line reproducibility First, an intermediate transfer medium was produced as follows.
(Preparation of intermediate transfer medium)
Using a polyethylene terephthalate (PET) film having a thickness of 12 μm as a base material, a release layer coating liquid having the following composition is 1.0 μm after drying by gravure coating on one surface of the base material. It was applied and dried to form a release layer. Next, the following primer layer coating solution was applied onto the release layer by gravure coating so as to have a thickness of 1.0 μm after drying, and dried to form a primer layer. Next, the following protective layer coating solution was applied onto the primer layer by a gravure coating method so as to be 2.0 μm after drying, and dried to form a protective layer. Next, on the protective layer, the following receiving layer coating solution 1 was applied by gravure coating so as to be 2.5 μm after drying and dried to form a receiving layer, whereby an intermediate transfer medium 1 was prepared. . The release layer / primer layer / protective layer / receiving layer constitutes a transfer layer of the intermediate transfer medium, and the transfer layer is a layer that is retransferred onto the transfer target.

<Coating liquid for release layer>
・ 95 mass parts of acrylic resin (Mitsubishi Rayon Co., Ltd., trade name: BR-87) ・ Polyester resin (manufactured by Toyobo Co., Ltd., trade name: Byron 200) 5 mass parts ・ 200 mass parts of toluene ・ MEK 200 Mass part <Coating liquid for forming protective layer>
・ Polyester resin (manufactured by Unitika Ltd., trade name: UE-9885, number average molecular weight 6000, Tg = 82 ° C.) 20 parts by mass / toluene 40 parts by mass / MEK 40 parts by mass <Receptive layer coating solution>
・ Vinyl chloride-based resin (Nissin Chemical Industry Co., Ltd., trade names: CNL, Mn: 12000)
95 parts by mass, epoxy-modified silicone (Shin-Etsu Chemical Co., Ltd., trade name: KP-1800U)
5 parts by mass, 200 parts by mass of toluene, 200 parts by mass of methyl ethyl ketone

Next, the printing pattern was transferred onto the receiving layer of the intermediate transfer medium prepared above using the transfer sheets manufactured in Examples 1-2 and Comparative Example 1 described above and the test printer described below.
(Test printer)
-Thermal head; KEE-57-12GAN2-STA (manufactured by Kyocera Corporation)
-Heating element average resistance value: 3303 (Ω)
・ Print density in the main scanning direction; 300 dpi
・ Print density in the sub-scanning direction; 300 dpi
・ Printing voltage: 18 (V)
-1 line cycle; 3.0 (msec.)
・ Printing start temperature: 35 (℃)
・ Pulse duty ratio: 85%

Subsequently, under the following retransfer conditions, the transfer layer of each image formed product was retransferred onto a white PVC card, and the ratio of the area of the white and black thin line portions of the produced printed material was calculated. The fine line reproducibility was evaluated according to the evaluation criteria.
(Re-transfer conditions)
・ Laminator: Lami Packer LPD3212 (manufactured by Fuji Plastics)
・ Temperature: 145 ℃, 140 ℃, 135 ℃
・ Speed: 0.8 (set value)
<Evaluation criteria>
A: The area of the printed material with respect to the input image was 95% or more and 100% or less.
X: The area of the printed matter with respect to the input image was less than 95%.

(2) Evaluation of Storage Stability The transfer sheets produced in Examples 1-2 and Comparative Example 1 were stored for 96 hours in a 50 ° C. dry environment. (1) In the same manner as in the evaluation of fine line reproducibility, a print was prepared using each of the transfer sheet before storage and the transfer sheet after storage. Calculate the ratio of the area of the white and black thin line portions of the printed material prepared using the transfer sheet after storage to the area of the white and black thin line portions of the printed material prepared using the transfer sheet before the storage. The fine line reproducibility was evaluated in the same manner as the above evaluation criteria.

  The results of the above evaluations are shown in Table 1. The better the reproducibility of the white thin line portion, the less the printed product is blurred, and the better the reproducibility of the black thin line portion, the less the print product is blurred. It was found that by using the transfer sheet according to the present invention, the printed matter produced was excellent in the reproducibility of white fine lines and black fine lines, that is, the printed matter had less blur and blur. Furthermore, by adding a release agent to the release layer, even after the transfer sheet is stored in a high-temperature environment, the white and black fine lines of the produced printed matter are excellent in reproducibility. Was found to be small (excellent storage stability).

DESCRIPTION OF SYMBOLS 10 Transfer sheet 11 Base material 12 Release layer 13 Release layer 14 Transfer layer 15 Heat resistant layer

Claims (6)

A transfer sheet comprising a base material, and a release layer and a transfer layer on the base material in order,
The transfer sheet, wherein the release layer comprises a binder resin, and the binder resin comprises a crosslinked product of a silanol group-containing polyurethane resin.   The transfer sheet according to claim 1, wherein the content of the silanol group-containing polyurethane resin is 50% by mass or more based on the binder resin in the release layer.   The transfer sheet according to claim 1, further comprising a release layer between the release layer and the transfer layer.   The transfer sheet according to claim 3, wherein the release layer comprises a vinyl acetate resin.   The transfer sheet according to claim 3 or 4, wherein the release layer further comprises a release agent.   The transfer sheet according to claim 1, wherein the transfer layer contains a colorant.

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