JP5907672B2 - Protective layer transfer sheet - Google Patents

Description

  The present invention relates to a protective layer transfer sheet, and in particular, has a protective layer transfer body excellent in releasability from a substrate and adhesion to a transfer body, and has high gloss and light resistance on the transfer body. It is related with the protective layer transfer sheet which can provide.

  Conventionally, monotonous images such as gradation images, letters, symbols, etc. have been formed on a substrate using a thermal transfer method, and as a thermal transfer method, a thermal sublimation transfer method and a thermal fusion transfer method are widely used. ing. Among these, the heat-sensitive sublimation transfer method uses a thermal transfer sheet in which a base layer sheet carries a dye layer in which a sublimable dye used as a coloring material is melted or dispersed in a binder resin, and this thermal transfer sheet is used as a dye-receiving layer. The sublimation dye contained in the dye layer on the thermal transfer sheet is transferred to the image receiving sheet by applying energy corresponding to the image information to a heating device such as a thermal printer head. It is a method of forming.

  The image formed in this manner is very clear and excellent in transparency because the color material used is a dye, and thus the resulting image is excellent in reproducibility and gradation of intermediate colors, It is possible to form a high-quality image similar to a conventional image by offset printing or gravure printing and comparable to a full-color photographic image.

  The above heat-sensitive sublimation transfer method can control the amount of dye transferred in dot units according to the amount of energy applied to the thermal transfer sheet, so it is excellent in forming a gradation image, but the formed image is a normal printing ink. Unlike the above, the coloring material is not a pigment, is a dye having a relatively low molecular weight, and has no vehicle, so that it has a disadvantage of poor durability such as light resistance. On the other hand, as a means for improving the durability of the formed image and as a means for improving the glossiness of the formed image, the image obtained by the sublimation type thermal transfer method or the hot melt type recording method is used. A method of forming a protective layer on an image by overlaying a protective layer transfer sheet having a protective layer thereon and transferring the protective layer using a thermal head, a heating roll or the like is known.

  Various studies have been made on a protective layer for imparting “light resistance” and “glossiness” to an image. For example, Patent Document 1 discloses a coexistence of a reactive ultraviolet absorber and a monomer of a thermoplastic resin. A protective layer transfer film containing a polymer has been proposed, and Patent Document 2 proposes a sublimation ribbon with a protective layer having a protective layer mainly composed of a styrene / acrylic copolymer resin.

Japanese Patent No. 3830985 JP 2003-39836 A

  However, the protective layer transfer film proposed in Patent Document 1 is said to be able to improve “light resistance” and “glossiness”, but has a high peeling force of the heat transfer resin layer, There was a problem in terms of "sex". Moreover, although the sublimation ribbon with a protective layer proposed in Patent Document 2 is said to be improved in “release properties” and “glossiness”, it cannot be said that “light resistance” is sufficient.

  The present invention has been made in view of such a situation, and has a protective layer transfer body excellent in releasability from a substrate and adhesiveness to a transfer body, and has a high gloss on the transfer body. The main object is to provide a protective layer transfer sheet capable of simultaneously imparting properties and light resistance.

The present invention for solving the above-described problems has a base material and a protective layer transfer body provided on one surface of the base material and composed of one or more layers, and the above-described transfer material is provided on the transfer target body. A protective layer transfer sheet for transferring a protective layer transfer body, and of the layers constituting the protective layer transfer body, the surface layer located on the outermost surface after being transferred onto the transfer body has at least A copolymer containing styrene and an ultraviolet absorbing monomer is contained, and the copolymerization ratio of the styrene in the copolymer is 45% to 95%; The polymerization ratio is 5% to 25%.

  According to the present invention, it has a protective layer transfer body excellent in releasability from the substrate and adhesiveness to the transferred body, and has high gloss on the transferred body after transferring the protective layer transfer body, Light resistance can be imparted simultaneously.

It is a schematic sectional drawing which shows the protective layer transfer sheet which concerns on embodiment of this invention. It is a state figure which shows the state before and behind transcription | transfer. It is a state figure which shows the state before and behind transcription | transfer. It is a schematic sectional drawing which shows the protective layer transfer sheet which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing a protective layer transfer sheet according to an embodiment of the present invention.

  As shown in FIG. 1, the protective layer transfer sheet 10 of the present invention is provided on one surface of the substrate 1 (on the upper surface of the substrate 1 in the case shown in FIG. 1) so as to be peelable 1 or 2 A protective layer transfer body 2 composed of the above layers (in the case shown in FIG. 1, a protective layer transfer body 2 composed of one layer) is provided. In particular, the protective layer transfer sheet of the present invention is composed of styrene and ultraviolet rays as main components in the surface layer 20 located on the outermost surface after being transferred onto the transfer target among the layers constituting the protective layer transfer body 2. The present invention is not limited to this embodiment as long as a copolymer obtained by copolymerizing at least an absorptive monomer is contained, and the copolymer has this requirement.

  The protective layer transfer sheet 10 of the present invention is a copolymer obtained by copolymerizing at least styrene and an ultraviolet-absorbing monomer as main components on the surface layer 20 located on the outermost surface after being transferred onto a transfer target. Since a polymer is contained, high “glossiness” and “light resistance” can be simultaneously imparted to a transfer target, for example, a printed material on which an image is formed. Further, even when the protective layer transfer body 2 is a single layer of the surface layer 20, it is excellent in releasability from the substrate 1 during thermal transfer and adhesiveness with the transfer target.

(Base material)
The substrate 1 used for the protective layer transfer sheet 10 of the present invention is not particularly limited as long as it has a certain degree of heat resistance and strength, and is used for a conventionally known protective layer transfer sheet. The same base material can be used as it is. Examples of such a substrate 1 include polyester films such as polyethylene terephthalate (PET), polycarbonate, polyamide, polyimide, cellulose acetate, polyvinylidene chloride, polyvinyl chloride, polystyrene, fluororesin, polypropylene, polyethylene, ionomer, and other plastic films; glassine Papers such as paper, condenser paper, paraffin paper; cellophane and the like. Further, the base material may be composed of only one kind of the above-mentioned resin, or may be composed of two or more kinds of resins. The base material may be a composite film in which two or more of the plastic film, paper, and cellophane are laminated.

  The thickness of the base material can be appropriately set depending on the material so that the strength and heat resistance thereof are appropriate, and for example, it is preferably about 2 to 100 μm.

(Protective layer transfer body)
As shown in FIG. 1, a protective layer transfer body 2 that can be peeled off from the base material 1 is provided on the base material 1. The protective layer transfer body 2 is an essential component in the protective layer transfer sheet of the present invention, and includes at least one or more layers including the surface layer 20.

  First, using FIG. 2 and FIG. 3, the surface layer 20 located on the outermost surface after being transferred onto the transfer target will be described among the layers constituting the protective layer transfer body 2. 2 shows a state before and after transfer when the protective layer transfer body 2A is transferred onto the transfer target 100 using a protective layer transfer sheet provided with the protective layer transfer body 2A made of only the layer A on the substrate 1. FIG. 3 is a diagram illustrating the state of the transfer target 100 using a protection layer transfer sheet including a protection layer transfer body 2B composed of a plurality of layers (layer B, layer C, layer D) on the transfer target. It is a state figure which shows the state before and behind at the time of transferring the protective layer transfer body 2B to.

  As shown in FIG. 2, when the protective layer transfer body 2 is a protective layer transfer body 2A composed of only one layer A, among the layers constituting the protective layer transfer body, the uppermost layer after transfer onto the transfer body. The layer located on the surface is the first layer A. That is, the layer A of the protective layer transfer body 2 </ b> A becomes the surface layer 20. Further, as shown in FIG. 3, when the protective layer transfer body 2 is a protective layer transfer body 2B in which layers B, C, and D are laminated in this order from the base material 1 side, Of the layers constituting the layer transfer body, the layer located on the outermost surface after transfer onto the transfer body is the layer B. That is, the layer B becomes the surface layer 20 in the protective layer transfer body 2B.

(Surface layer)
Of the layers constituting the protective layer transfer body 2, the surface layer 20 positioned on the outermost surface after being transferred onto the transfer target is coated with a copolymer of styrene and an ultraviolet absorbing monomer (hereinafter referred to as the present invention). May be referred to as an inventive copolymer).

  Examples of the ultraviolet-absorbing monomer constituting the copolymer of the present invention include salicylate-based, benzophenone-based, benzotriazole-based, triazine-based, substituted acrylonitrile-based, nickel chelate-based, hinhine, which are conventionally known organic ultraviolet absorbers. Examples of non-reactive ultraviolet absorbers such as dartamines include addition polymerizable double bonds such as vinyl groups, acryloyl groups, and methacryloyl groups, or alcoholic hydroxyl groups, amino groups, carboxyl groups, epoxy groups, and isocyanate groups. Etc. can be used. Among reactive ultraviolet absorbers, benzophenone series represented by the following general formula 1 and benzotriazole series represented by the general formula 2 are particularly preferable.

  Further, in the copolymer of the present invention, when the copolymerization ratio of the UV-absorbing monomer is less than 5% by mass ratio, “light resistance” is deteriorated, and when it is more than 25%, “ "Releasability" will deteriorate. On the other hand, when the copolymerization ratio of styrene is less than 10% by mass, the “release property” will be deteriorated. Therefore, in the present invention, the copolymerization ratio of the ultraviolet absorbing monomer is 5% to 25% by mass ratio, and the copolymerization ratio of styrene is specified within the range of 10% to 95% by mass ratio. Yes. By containing a copolymer obtained by copolymerizing an ultraviolet absorbing monomer and styrene within this range in the surface layer 20, "light resistance", "glossiness", "release property" and "transfer object" The surface layer 20 can satisfy all the requirements for “adhesiveness”. In addition, by using a copolymer obtained by copolymerizing an ultraviolet absorbing monomer and styrene within the above range, the advantageous effects of the present invention can be obtained as described above. When improvement in property is required, the copolymerization ratio of styrene is preferably 45% to 95% by mass ratio.

  In addition, the copolymer of the present invention can be copolymerized with the UV absorbing monomer and styrene as long as the UV absorbing monomer and styrene are copolymerized at the above copolymerization ratio. May be. Examples of the other substance include an acrylic monomer that can provide the surface layer 20 with physical properties necessary for the surface layer such as plasticizer resistance and scratch resistance. As the acrylic monomer, a conventionally known acrylic monomer can be appropriately selected and used. Such acrylic monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tertiary butyl acrylate, tertiary Libutyl methacrylate, isodecyl acrylate, isodecyl methacrylate, lauryl acrylate, lauryl methacrylate, lauryl tridecyl acrylate, lauryl tridecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, cetyl stearyl acrylate, cetyl stearyl methacrylate, Stearyl acrylate, stearyl methacrylate , 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, octyl acrylate, octyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, isobornyl acrylate, iso Bornyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyl methacrylate, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl acrylate, dimethyl Aminoethyl methacrylate, diethylamino Tyl acrylate, diethylaminoethyl methacrylate, tertiary butylaminoethyl acrylate, tertiary butylaminoethyl methacrylate, glycidyl acrylate, glycidyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, ethylene diacrylate, ethylene dimethacrylate, Diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, decaethylene glycol diacrylate, decaethylene glycol dimethacrylate, pentadeca ethylene Glycol diacrylate, pentadecaethylene glycol dimethacrylate, pentacontahector ethylene glycol diacrylate, pentacontahector ethylene glycol dimethacrylate, butylene diacrylate, butylene dimethacrylate, allyl acrylate, allyl methacrylate, trimethylolpropane triacrylate , Trimethylolpropane trimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, tripyropyrene glycol dimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate Acrylate, dipentaerythritol hexaacrylate, dipentae Sri tall hexametaphosphate acrylate, neopentyl glycol pentaacrylate, neopentyl glycol pentaerythritol methacrylate, phosphazene hexaacrylate, phosphazene hexa meta acrylate.

  Among the acrylic monomers exemplified above, methyl methacrylate can be particularly preferably used. By using methyl methacrylate as the acrylic monomer constituting the copolymer of the present invention, the surface layer 20 is further effectively imparted with other performances necessary for the surface layer such as plasticizer resistance and scratch resistance. Can do.

  The copolymer of the present invention may be any of random copolymerization, block copolymerization, graft copolymerization, and alternating copolymerization.

  Moreover, when the content of the copolymer of the present invention is less than 50% by mass with respect to the total mass of the surface layer 20, various effects of the present invention may not be able to be improved to a necessary level. Can occur. Considering this point, the copolymer of the present invention is preferably in the range of 50% by mass to 100% by mass with respect to the total mass of the surface layer 20.

  The surface layer 20 of the present invention is excellent in “releasability” from the base material and “adhesiveness” with the transfer target, and has a high “gloss” on the transfer target, for example, a printed matter on which an image is formed. Property "and" light resistance "are simultaneously provided. That is, only the surface layer 20 can exhibit a function as a release layer or an adhesive layer generally called in the field of the conventional protective layer transfer sheet.

  The name of the surface layer 20 is not limited as long as the surface layer 20 is a layer located on the outermost surface when the protective layer transfer body 2 is transferred onto the transfer body as described above. Any name such as a layer, a release layer, an adhesive layer, or a conductive layer may be used.

  The surface layer 20 is mainly composed of a copolymer of styrene and an ultraviolet absorbing monomer, and other components may be added as necessary. There is no limitation in particular about another component, For example, additives, such as the material which comprises the contact layer illustrated below, a filler, a light stabilizer, antioxidant, an antistatic agent, etc. can be added.

  As a method for forming the surface layer 20, a reverse coating using a gravure printing method, a screen printing method, or a gravure plate in which one or two or more of the above copolymers are formed into a form that can be applied such as a solution or an emulsion. It can be formed by applying and drying by a conventionally known means such as a method. In addition, the thickness of the surface layer 20 is preferably about 0.1 μm to 5 μm.

  Further, the protective layer transfer body 2 may have a laminated structure including two or more layers including the surface layer 20. For example, as shown in FIG. 4, the protective layer transfer body 2 may have a laminated structure in which the surface layer 20 and the adhesive layer 21 are laminated directly or indirectly in this order from the substrate side. Below, the adhesive layer 21 provided arbitrarily as a structure of the protective layer transfer body 2 is demonstrated.

(Adhesive layer)
In order to satisfactorily adhere the protective layer transfer body 2 of the present invention onto the transfer target, the protective layer transfer body 2 is formed by laminating the essential surface layer 20 and the adhesive layer 21 in the present invention as shown in FIG. It may be a structure. Here, since the surface layer 20 of the present invention has adhesiveness to the transferred body, it is not always necessary to provide the adhesive layer 21 for bonding to the transferred body, and the adhesive layer has an arbitrary configuration. is there.

  As shown in FIG. 4, the adhesive layer 21 for satisfactorily adhering the protective layer transfer body 2 on the transfer target is the farthest from the substrate 1 side among the layers constituting the protective layer transfer body 2. It is preferable to be provided at a position at a distance. Note that the material constituting the adhesive layer exemplified below may be added to the surface layer 20 without providing the adhesive layer 21.

  The material of the adhesive layer 21 is not particularly limited, and a conventionally known adhesive resin or the like can be appropriately selected and used. Examples of such adhesive resins include acrylic resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, styrene-acrylic copolymer resins, polyester resins, polyamide resins, and the like. Is mentioned. As a method for forming the adhesive layer 21, a gravure printing method, a screen printing method, a reverse coating method using a gravure plate, or the like obtained by applying one or more of the above resins into a form that can be applied as a solution or emulsion. It can form by apply | coating and drying by the conventionally well-known means. In addition, the thickness of the adhesive layer 21 is preferably about 0.1 μm to 5 μm.

  In addition, the adhesive layer 21 is composed of the above resin, an organic ultraviolet absorber such as a benzophenone compound, a benzotriazole compound, an oxalic acid anilide compound, a cyanoacrylate compound, or a salicylate compound, or zinc, titanium, cerium. Additives of fine particles having an inorganic ultraviolet absorbing ability such as oxides of tin, iron and the like can be added. Further, as an additive, a coloring pigment, a white pigment, an extender pigment, a filler, an antistatic agent, an antioxidant, a fluorescent whitening agent, and the like can be used as necessary.

  Although not shown, a conductive layer formed by containing a known conductive agent in the binder resin as the layer constituting the protective layer transfer body 2 may be separately provided together with the surface layer 20. Moreover, it is good also as the surface layer 20 provided with the electroconductive function by adding the material of this conductive layer to the surface layer 20. FIG.

(Release layer)
Moreover, as shown in FIG. 4, it is good also as providing the release layer 24 for making the release property of the protective layer transfer body 2 suitable between the base material 1 and the protective layer transfer body 2. As shown in FIG. As described above, the surface layer 20 is excellent in “release property” at the time of thermal transfer, and the protective layer transfer body 2 can be peeled from the substrate without providing a release layer. 24 is not necessary, and the release layer 24 is an arbitrary configuration in the protective layer transfer sheet 10 of the present invention.

  As the release layer 24, a conventionally known resin can be appropriately selected and used as long as it is a resin having excellent release properties. Examples of such resins include waxes, silicone waxes, silicone resins, silicone-modified resins, fluorine resins, fluorine-modified resins, polyvinyl alcohol, acrylic resins, heat-crosslinkable epoxy-amino resins, and heat-crosslinkable alkyd-amino resins. Is mentioned. Moreover, the said resin may be used independently and may mix and use 2 or more types of resin. Further, in addition to the above resin, a cross-linking agent such as an isocyanate compound and a catalyst such as a tin-based catalyst may be used.

The release layer is, for example, a coating solution obtained by dissolving the resin in a solvent, in a region of the surface of the base material where the protective layer transfer body 2 is formed, a gravure coating method, a roll coating method, a screen printing method, It can form by apply | coating and drying so that the application amount after drying may be set to about 0.5-5 g / m < ² > by conventionally well-known formation means, such as the reverse roll coating method using a gravure plate. Moreover, a coating liquid can be prepared by dissolving the said resin and the crosslinking agent or catalyst mix | blended as needed in suitable solvents, such as methyl ethyl ketone, toluene, and isopropyl alcohol. Such a coating liquid preferably has a solid content concentration of about 5 to 50% by mass.

  When the protective layer transfer sheet 10 and the transfer target are opposed to each other and the protective layer transfer member 2 is transferred onto the transfer target from the heat resistant slipping layer side by a heating means such as a thermal head or a laser, the mold release is performed. The layer 24 remains on the substrate 1 side.

(Heat resistant slipping layer)
Further, as shown in FIG. 4, the heat resistance and the running performance of the thermal head during printing are improved on the other surface of the substrate 1 (the lower surface of the substrate 1 in the case shown in FIG. 1). A heat resistant slipping layer 25 may be provided. The heat-resistant slip layer 25 is an arbitrary configuration in the protective layer transfer sheet 10 of the present invention.

  The heat-resistant slip layer 25 can be formed by appropriately selecting a conventionally known thermoplastic resin or the like. Examples of such thermoplastic resins include polyester resins; polyacrylate resins; polyvinyl acetate resins; styrene acrylate resins; polyurethane resins; polyolefin resins such as polyethylene resins and polypropylene resins; Polystyrene resin; Polyvinyl chloride resin; Polyether resin; Polyamide resin; Polyimide resin; Polyamideimide resin; Polycarbonate resin; Polyacrylamide resin; Polyvinyl chloride resin; Polyvinyl butyral resin, Polyvinyl acetoacetal resin, etc. Polyvinyl acetal resin; thermoplastic resins such as these, and silicone-modified products thereof. Among these, from the viewpoint of heat resistance, a polyamideimide resin or a modified silicone product thereof can be preferably used.

  In addition to the thermoplastic resin, the heat-resistant slip layer 25 is a mold release agent such as wax, higher fatty acid amide, ester, metal soap, silicone oil, surfactant, etc. for the purpose of improving slip properties; Various additives such as organic powders such as silica; clay, talc, calcium carbonate, etc .;

The method for forming the heat-resistant slip layer 25 is not particularly limited, and a coating liquid obtained by dispersing or dissolving the thermoplastic resin (added with an additive that is optionally blended if necessary) in a solvent is used. It is applied to the other surface of the material 1 (that is, on the surface opposite to the protective layer transfer body 2) by a known means such as a gravure printing method, a screen printing method, a reverse roll coating printing method using a gravure plate, It can be formed by drying. Further, the thickness of the heat-resistant slip layer 25 is preferably ² g / m ² or less in terms of the coating amount after drying in that a protective layer transfer sheet having excellent heat resistance and the like is obtained. More preferably, m ² is used.

(Heat resistant primer layer)
In addition, a primer layer (not shown) may be provided between the heat resistant slipping layer 25 and the substrate 1 for improving the adhesion between the heat resistant slipping layer 25 and the substrate 1. The primer layer is generally made of a thermoplastic resin, and the thermoplastic resin is not particularly limited as long as it exhibits adhesive properties such as a polyester resin and an acrylic resin.

  Although not shown, the protective layer transfer sheet of the present invention comprises a dye layer and / or a heat-meltable ink layer having a hue such as yellow, magenta, cyan, and black on the same substrate 1 and a protective layer. The thermal transfer image and the protective layer transfer body 2 can be used efficiently by continuously transferring the thermal transfer image and the protective layer transfer body 2 with the same thermal head using those provided in a surface sequential manner.

(Transfer method)
The protective layer transfer sheet of the present invention heats a predetermined portion from the heat-resistant slipping layer side of the substrate 1 (a surface different from the surface on which the protective layer transfer body 2 is provided) by heating means such as a thermal head. -By applying pressure, the protective layer transfer body 2 can be transferred onto the transfer target. There is no particular limitation on the heating means, and transfer may be performed using a heating plate such as a thermal head, a hot plate, a hot stamper, a heat roll, a line heater, or an iron.

  Next, an Example is given and this invention is demonstrated further more concretely. Hereinafter, unless otherwise specified, parts or% is based on mass.

(Example 1)
As a base sheet, a polyethylene terephthalate film having a thickness of 6 μm (manufactured by Lumirror Toray Co., Ltd.) was used. On one surface of the base sheet, the following heat-resistant slipping layer coating solution was applied to a gravure coater. The heat-resistant slipping layer was formed by applying and drying after drying so that the coating amount after drying was 1.0 g / m ² . Next, on the surface opposite to the surface on which the heat-resistant slip layer of the base material sheet is formed, the following protective layer coating solution is applied using a gravure coater to a coating amount after drying of 1.0 g / The protective layer transfer sheet of Example 1 was produced by forming a protective layer by applying and drying to m ² .

<Coating fluid for heat resistant slipping layer>
13.6 parts of polyvinyl butyral resin (SREC BX-1 manufactured by Sekisui Chemical Co., Ltd.)
0.6 parts of polyisocyanate curing agent (Takenate D218, manufactured by Mitsui Chemicals Polyurethanes)
Phosphate 0.8 parts (Plysurf A208N, Daiichi Kogyo Seiyaku Co., Ltd.)
Toluene 42.5 parts Methyl ethyl ketone 42.5 parts

<Protective layer coating solution 1>
-Copolymer 20 parts methyl methacrylate (copolymerization ratio (15%))
Styrene (copolymerization ratio (75%))
3- (2H-1,2,3-benzotriazol-2-yl) -4-hydroxyphenethyl methacrylate (copolymerization ratio (10%))
・ Toluene 40 parts ・ Methyl ethyl ketone 40 parts

(Examples 2 to 5, Reference Examples 1 and 2 )
Except for using the protective layer coating solution in which the copolymerization ratio of the copolymer in the protective layer coating solution 1 was changed to the ratio shown in Table 1 below, the same procedure as in Example 1 was repeated. 5. The protective layer transfer sheet of Reference Examples 1 and 2 was produced. The “ultraviolet absorbing monomer” in Table 1 means “3- (2H-1,2,3-benzotriazol-2-yl) -4-hydroxyphenethyl methacrylate”.

(Comparative Example 1)
A protective layer transfer sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that the protective layer coating solution 1 was changed to the protective layer coating solution 2 described below.
<Protective layer coating solution 2>
・ Methyl methacrylate (100%) 20 parts ・ Toluene 40 parts ・ Methyl ethyl ketone 40 parts

(Comparative Example 2)
A protective layer transfer sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that the protective layer coating solution 1 was changed to the following protective layer coating solution 3.
<Coating liquid 3 for protective layer>
-Copolymer 20 parts methyl methacrylate (copolymerization ratio (25%))
Styrene (copolymerization ratio (75%))
・ Toluene 40 parts ・ Methyl ethyl ketone 40 parts

<< Adhesion evaluation >>
Using the protective layer transfer sheets of Examples 1 to 5, Reference Examples 1 and 2, and Comparative Examples 1 and 2, combined with a thermal transfer image receiving sheet of Canon Inc. color ink / paper set KP-36IP (trade name) A sample was prepared by transferring the protective layer transfer body under the following conditions. At least 30 minutes after the transfer, a mending tape (manufactured by Nichiban Co., Ltd.) is rubbed twice with the thumb on the protective layer transfer area, and then 90 ° vertical peeling is performed immediately to protect each gradation. The presence or absence of a layer transfer member was examined and evaluated based on the following criteria. The evaluation results are shown in Table 2.

(Printing conditions)
Thermal head: KGT-217-12MPL20 (manufactured by Kyocera Corporation)
Heating element average resistance value: 2994 (Ω)
Main scanning direction printing density; 300 dpi
Sub-scanning direction print density; 300 dpi
Applied power: 0.10 (w / dot)
1 line cycle: 5 (msec.)
Printing start temperature; 40 (° C)
Applied pulse (gradation control method): Using a multi-pulse test printer that can vary the number of divided pulses from 0 to 255 in one line period and having a pulse length obtained by equally dividing one line period into 256 The duty ratio of the divided pulses was fixed at 70%, and the number of pulses per line period was fixed at 180.

(Evaluation criteria)
◯: A protective layer transfer body remained on the printed matter.
X: The protective layer transfer body was peeled off by tape peeling.

<< Peeling force evaluation >>
Example, in assessing the releasability of the protective layer transfer member of Example and Comparative Example (protective layer), Example 1-5, Reference Examples 1 and 2, and a protective layer transfer sheet of Comparative Examples 1 and 2 In combination with a thermal transfer image-receiving sheet of a color ink / paper set KP-36IP (trade name) manufactured by Canon Inc. A sample with a layer transfer sheet adhered thereto was prepared. Within 3 minutes after the transfer, the peeling force when the protective layer transfer sheet was peeled 180 ° from the transferred material was measured by the following apparatus and evaluated based on the following criteria. The evaluation results are shown in Table 2.
(Peeling force measuring device)
Peeling device: Instron's universal material testing machine 5565
Peeling speed: 300 mm / min (evaluation criteria)
A: Less than 5 g peeling force: A peeling force of 5 g or more and less than 50 g Δ: A peeling force of 50 g or more but at a level that does not cause a problem in use.

<< Light resistance evaluation >>
Printing similar to the above adhesive evaluation test, except that the color transfer ink / paper set KP-36IP (trade name) manufactured by Canon Inc. was combined with the thermal transfer image receiving sheet and the number of applied pulses per line cycle was changed to the following. Thermal transfer was performed under the conditions to form a gray 16 gradation gradation image.
(Number of applied pulses)
By increasing the number of pulses per line cycle from 0 to 255, from 0 to 255, and from 0 to 255, the number of pulses per line period is 0 in steps, 0 in steps, 17 in steps, and 2 in steps. Up to 16 gradations were controlled. Next, the number of pulses per line period is fixed to 180 on the gradation image formed by the above method using the protective layer transfer sheets of Examples 1 to 5, Reference Examples 1 and 2, and Comparative Examples 1 and 2. Except for the above, the protective layer transfer body was transferred under the same printing conditions as in the above-mentioned adhesion evaluation test to prepare a sample.

The printed materials of Examples 1 to 5, Reference Examples 1 and 2, and Comparative Examples 1 and 2 to which the protective layer transfer body obtained above was transferred were subjected to a light resistance test using a xenon fade meter under the following conditions.
(Light resistance test conditions)
Irradiation tester: Atlas Ci35
Light source: Xenon lamp Filter: Inside = IR filter, Outside = soda lime glass black Panel temperature: 45 ° C

Next, using the following optical densitometer, the optical reflection density of the gray image is measured with a visual filter, and ΔE ^* is calculated by the following formula for the step where the optical reflection density before irradiation is around 1.0, The light resistance of the prints of each Example and Comparative Example was evaluated. The evaluation results are shown in Table 2.
ΔE ^* = ((difference between L ^* values before and after storage) ² + (difference between a ^* values before and after storage) ² + (difference between b ^* values before and after storage) ² ) ^1/2
(Colorimetric conditions)
Colorimeter: Spectrometer SpectroLino (manufactured by GretagMacbeth)
Light source: D65
Viewing angle: 2 °
Density measurement filter: ANSI Status A

<< Glossiness evaluation >>
Using the protective layer transfer sheets of Examples 1 to 5, Reference Examples 1 and 2, and Comparative Examples 1 and 2, combined with a thermal transfer image receiving sheet of Canon Inc. color ink / paper set KP-36IP (trade name) Then, a sample to which the protective layer transfer body was transferred under the same printing conditions as in the above adhesive evaluation was prepared. With respect to the prints of Examples 1 to 5, Reference Examples 1 and 2, and Comparative Examples 1 and 2 to which the protective layer transfer body obtained above was transferred , the 20-degree reflection glossiness was measured with the following apparatus. The results are shown in Table 2.
(Glossiness measuring device)
BYK Gardner Micro-Haze Plus

  As is clear from Table 2, according to the protective layer transfer sheet of the example having the configuration of the present invention, good results were obtained in both glossiness and light resistance. On the other hand, the protective layer transfer sheet of the comparative example was inferior to either or both of glossiness and light resistance as compared to the examples.

DESCRIPTION OF SYMBOLS 1 Base material 2 Protective layer transfer body 10 Protective layer transfer sheet 20 Surface layer 21 Adhesive layer 24 Release layer 25 Heat-resistant slip layer 100 Transfer object

Claims (1)

A protective layer having a base material and a protective layer transfer body provided on one surface of the base material and composed of one or more layers, and for transferring the protective layer transfer body onto a transfer target body A transfer sheet,
Of the layers constituting the protective layer transfer body, the surface layer located on the outermost surface after being transferred onto the transfer body contains a copolymer containing at least styrene and an ultraviolet absorbing monomer. And
The protective layer transfer sheet, wherein the copolymer has a copolymerization ratio of 45% to 95% of the styrene and a copolymerization ratio of the ultraviolet absorbing monomer of 5% to 25%.

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