JP2019199000A - Transfer foil, transfer image forming member, and transfer image forming method - Google Patents

Abstract

To provide an image which can form an arbitrary image on demand by a structure based on optical technology, and which is excellent in gradation representation, brightness and stability of dot representation.SOLUTION: The transfer foil 10 is formed by laminating, on a transfer foil base material 11, at least a release layer 15, a relief structure forming layer 16 having an uneven structure on its surface, a light reflection layer 17 formed so as to cover at least a part of the surface of the relief structure forming layer 16, and an adhesive layer 18. The relief structure forming layer 16 has a plurality of panels each having a substantially uniform uneven structure in its plane. The plurality of panels comprise a plurality of panels 12 and clear panels 13, arranged in a plane sequential manner. The plurality of panels 12 are different from each other in at least one of a pitch of a concave portion or a convex portion of an uneven structure, or a depth or a height of the concave portion or the convex portion, or an alignment direction of the concave portion or the convex portion, and the clear panels 13 do not have an uneven structure and are typically flat.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a structure based on an optical technique that provides an anti-counterfeit effect, a decorative effect, or an aesthetic effect, and more particularly, a transfer foil for forming an image comprising the structure on demand, and transfer image formation About the body.

  In the fields of securities, certificates, branded products, dedicated consumables and dedicated replacement parts for electronic devices and various machines, and personal authentication media, it is desired that forgery or alteration is difficult. Therefore, in such a field, an optical structure excellent in the forgery prevention effect may be provided.

  Many of such optical structures include fine structures such as diffraction gratings, holograms, scattering structures, or lens arrays. These fine structures have an effect of causing a change in color or visual image in accordance with, for example, a change in observation angle.

  In addition, these fine structures are difficult to analyze, and forgery is difficult because they require expensive equipment such as an electron beam drawing apparatus to manufacture. Therefore, these optical structures can exhibit an excellent anti-counterfeit effect.

  As a technique related to such a structure, for example, Patent Document 1 proposes a technique in which a pixel is divided into three as an RGB channel and a photographic image quality color image is expressed by a diffractive structure by area gradation inside the channel. .

  Further, Patent Document 2 proposes a computer generated hologram that can display a full color pattern by providing each pixel of RGB in a long slit shape.

JP-A-8-211821 JP 2001-331085 A

  However, all of these structures need to form the desired image at the time of producing the original, and it is difficult to form a relief structure having the same effect on demand.

  Therefore, the main object of the present invention is to form an arbitrary image by a structure based on optical technology on demand, and to provide an image excellent in gradation expression, brightness, and stability of dot expression. .

The present invention has been made to solve these problems.
That is, the invention according to claim 1 is formed on the transfer foil base so as to cover at least a part of the release layer, the relief structure forming layer having a concavo-convex structure on the surface, and the surface of the relief structure forming layer. A transfer foil comprising at least a laminated light reflecting layer and an adhesive layer, wherein the relief structure forming layer has a plurality of panels having a substantially uniform concavo-convex structure in the plane thereof, and the plurality of panels A plurality of panels in which at least one of at least one of the pitch of the concave or convex portions of the concave-convex structure, the depth or height of the concave or convex portions, or the orientation direction of the concave or convex portions is different, and the concave and convex portions A transfer foil characterized in that a flat clear panel, which is typically flat without having a structure, is provided in a surface sequence.

  The invention according to claim 2 is a diffraction grating in which the concavo-convex structure provided in the plurality of panels emits red, green, or blue diffracted light when the panel is observed from a specific angle. It is a structure, It is a transfer foil of Claim 1 characterized by the above-mentioned.

  According to a third aspect of the present invention, the transfer foil according to the first or second aspect has a back coat layer on the surface opposite to the surface in contact with the release layer of the transfer foil base material. It is.

  According to a fourth aspect of the present invention, the light formed on the substrate to be transferred so as to cover at least a part of the release layer, the relief structure forming layer having a concavo-convex structure on the surface, and the surface of the relief structure forming layer. A transfer image forming body comprising a plurality of dots having at least a reflective layer and an adhesive layer, wherein a peeling layer and the concavo-convex structure are provided between the plurality of dots and the substrate to be transferred. A clear panel layer having at least a relief structure forming layer having a typically flat surface, a light reflecting layer formed so as to cover at least a part of the surface of the relief structure forming layer, and an adhesive layer; A transfer image forming body is provided at least.

  In the invention according to claim 5, the concavo-convex structure provided on the relief structure forming layer surface of each dot in the plurality of dots has a substantially uniform concavo-convex structure within a single dot, and the plurality of dots are A plurality of groups differing in at least one or more of the pitch of the concave or convex portion of the concave-convex structure, the depth or height of the concave or convex portion, or the orientation direction of the concave or convex portion, 5. The transfer image forming body according to claim 4, wherein in the dot arrangement of the group, at least part of the dots belonging to different groups has an overlapping portion.

  The invention according to claim 6 is characterized in that the concavo-convex structure is a diffraction grating structure that emits red, green, or blue diffracted light when observed from a specific angle. Alternatively, the transfer image forming body according to claim 5.

  According to the seventh aspect of the present invention, a plurality of panels that emit red, green, and blue diffracted light and a clear panel are sequentially arranged on the transfer foil base material when observed from a specific angle. Preparation 1 for preparing the provided transfer foil, transfer 1 in which the transfer foil and the substrate to be transferred are opposed to each other, and the clear panel is transferred to at least a part of the substrate to be transferred using a thermal head Step 2 and transfer 2 that sequentially transfers the plurality of panels as a plurality of dots arranged in an arbitrary pattern using the thermal head to the region of the substrate to which the clear panel is transferred. A transfer image forming method, wherein, in the transfer step 2, dots formed by different panels are transferred so as to have at least a part of an overlapping portion.

  According to the aspect of the present invention, it is possible to form an arbitrary color image having a relief structure having a high anti-counterfeit effect on demand and as an image excellent in gradation expression, brightness, and stability of dot reproduction. Become.

It is a perspective view which shows an example of the transfer foil which concerns on embodiment of this invention. It is sectional drawing which shows an example of the transfer foil structure which concerns on embodiment of this invention. It is sectional drawing which shows an example of the transfer image forming body which concerns on embodiment of this invention. It is a top view which shows an example of the printing method. It is a perspective view which shows an example of the information recording body using the transfer foil of this invention. It is a perspective view which shows an example of the conventional transfer foil. It is sectional drawing which shows the example of the transfer image forming body using the conventional transfer foil. (I) Dot juxtaposition method (II) Dot overlap method (III) Half dot overlap method

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same reference numerals are given to components that exhibit the same or similar functions, and duplicate descriptions are omitted.

  Each drawing shows one example of an embodiment of the present invention, and is not limited to these.

(Transfer foil)
FIG. 1 is a perspective view showing an example of a transfer foil according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a configuration example of the transfer foil.

  In FIG. 1, the transfer foil (10) has a diffraction grating region (12) and a clear panel (13) region having no diffraction grating structure, and the diffraction grating region (12) is further separated from a specific angle. Are provided with a red panel (R), a green panel (G), and a blue panel (B) provided with a diffraction grating structure for emitting red, green, and blue light.

  These red panel (R), green panel (G), blue panel (B), and clear panel (13) are provided in the surface order.

  In the configuration example of the transfer foil (10) shown in FIG. 2, the back coat layer (14) is provided on one side of the transfer foil base (11), and the side opposite to the side on which the back coat layer (14) is provided. A release layer (15), a relief structure forming layer (16), a light reflecting layer (17), and an adhesive layer (18) are provided in this order on the surface.

  The relief structure forming layer (16) is provided with a diffractive structure region (12) and a clear panel (13) region.

  In the clear panel (13) region, the surface of the relief structure forming layer typically has a flat structure, and the diffractive structure region (12) includes a red panel (R), a green panel (G), a blue panel ( B), and each panel has a concavo-convex structure that becomes a diffractive structure that emits red, green, and blue light when observed from a specific angle.

  Here, the diffractive structure can be a hologram or a diffraction grating, and can be formed by heating and pressing a nickel press plate or the like having a desired uneven shape on the surface of the relief structure forming layer. it can.

  The transfer foil base material (11) desirably has heat resistance and strength that does not cause softening deformation due to heat pressure in a thermal transfer process or the like. Examples of the material include polyvinyl chloride, polyester, polycarbonate, and poly (meth) acrylic acid. Use a synthetic resin such as methyl, polystyrene, polyethylene, polyethylene terephthalate, polyethylene naphthalate, polypropylene, triacetyl cellulose, polyvinyl alcohol, polyimide, etc., natural resin, paper, synthetic paper, etc. alone or in combination of two or more. However, in consideration of cost and ease of handling, polyethylene terephthalate can be preferably used.

  The transfer foil base material (11) having a thickness of 2 to 100 μm can be used in consideration of operability and workability. However, when the transfer foil base material (11) is thick, the thermal head For example, when the transfer is performed, the heat generation energy of the thermal head is increased. As a result, the life of the thermal head may be shortened, so that a thickness of about 2 μm to 25 μm is suitable. Can be used.

  The back coat layer (14) is a layer for preventing the occurrence of problems such as sticking when the panel portions are thermally transferred from the transfer foil (10) to the transfer target using a thermal head. Any conventionally known one can be used as long as it has a function.

  Specific examples of the material for the back coat layer (14) include thermoplastic resins, thermosetting resins, and radiation curable resins. When a thermoplastic resin is used, for example, an acrylic resin is used. Examples of such resins include epoxy resins, epoxy resins, cellulose resins, vinyl resins, polycarbonate resins, norbornene resins, but are not necessarily limited thereto.

  Examples of the thermosetting resin include a urethane resin, a melamine resin, a phenol resin, an epoxy resin, etc. that are crosslinked by adding polyisocyanate or the like as a crosslinking agent to a polyol resin having a reactive hydroxyl group. However, it is not necessarily limited to these.

  Examples of the radiation curable resin include, for example, a mixture of various resins having a radical polymerizable vinyl group and a radical initiator, a mixture of various resins having a cationic polymerizable epoxy group and a cationic initiator, and the like. However, the present invention is not necessarily limited thereto.

  The various resins as described above may be used alone or in combination of two or more materials without any problem.

  Such a backcoat layer (14) includes slipping agents such as various surfactants, lubricants such as polyethylene wax, carnauba wax, silicon wax, metal soaps, talc, silica, organic filler, and the like as necessary. Various additives such as a filler may be added.

  Although the thickness of a backcoat layer (14) can be set suitably, it can be set as about 0.1 micrometer-20 micrometers.

  The release layer (15) is for improving transferability of the transfer foil (10) to the transfer target, and any release layer (15) can be used as long as it can be easily peeled off from the transfer foil substrate (11). Examples thereof include thermoplastic resins, thermosetting resins, and radiation curable resins.

  Among these, a thermoplastic resin can be suitably used because it is excellent in flexibility, foil breakage, and the like.

Examples of thermoplastic resins used for the release layer (15) include acrylic resins, chlorinated rubber resins, vinyl chloride-vinyl acetate copolymers, cellulose resins, chlorinated polypropylene resins, epoxy resins, polyester resins, Examples include styrene acrylate resins, polyether resins, polycarbonate resins, norbornene resins, but are not necessarily limited thereto.

  In addition, the release layer (15) has various waxes such as vegetable wax, petroleum wax, mineral wax and synthetic wax, metal salts of higher fatty acids such as stearic acid, etc. for the purpose of improving the foil cutting property. Metallic soaps made of, a lubricant such as silicone oil, an organic filler such as fluorine resin powder or silicon resin powder, acrylonitrile fine particles, or an inorganic filler such as silica fine particles may be added. The thickness of such a release layer (15) can be about 0.1 μm to 20 μm.

  Any material can be used for the relief structure forming layer (16) as long as it can be hot-pressed by a press plate. For example, various resins such as a thermoplastic resin, a thermosetting resin, and a radiation curable resin are used. Can do.

  When a thermoplastic resin is used, for example, an acrylic resin, an epoxy resin, a cellulose resin, a vinyl resin, a mixture thereof, a copolymer thereof, or the like can be used.

  In the case of using a thermosetting resin, for example, a urethane resin, a melamine resin, or an epoxy resin formed by a crosslinking reaction between a polyol resin such as an acrylic polyol resin or a polyester polyol resin and an isocyanate compound. Phenolic resins, mixtures thereof, and copolymers thereof can be used.

  When using a radiation curable resin, the radiation curable resin typically includes a polymerizable compound and an initiator.

  As the polymerizable compound, for example, a compound capable of photo radical polymerization is used. Specifically, a monomer, oligomer or polymer having an ethylenically unsaturated bond or an ethylenically unsaturated group can be used. Alternatively, as a compound capable of photo radical polymerization, 1,6-hexanediol, neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol acrylate, pentaerythritol tetraacrylate, pentaacethritol pentaacrylate and dipentaerythritol hexaacrylate Monomers such as epoxy acrylate, urethane acrylate and polyester acrylate, or polymers such as urethane-modified acrylic resin and epoxy-modified acrylic resin may be used.

  When a compound capable of photoradical polymerization is used as the polymerizable compound, a photoradical polymerization initiator can be used as the initiator.

  Examples of the photo radical polymerization initiator include benzoin compounds such as benzoin, benzoin methyl ether and benzoin ethyl ether, anthraquinone compounds such as anthraquinone and methylanthraquinone, acetophenone, diethoxyacetophenone, benzophenone, hydroxyacetophenone, 1-hydroxy Phenyl ketone compounds such as cyclohexyl phenyl ketone, α-aminoacetophenone and 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, benzyldimethyl ketal, thioxanthone, acylphosphine oxide, or Michler's ketone, etc. can be used.

  Alternatively, a compound capable of photocationic polymerization may be used as the polymerizable compound. As the compound capable of photocationic polymerization, for example, a monomer, oligomer or polymer having an epoxy group, a xetane skeleton-containing compound, or vinyl ethers are used.

  When a compound capable of photocationic polymerization is used as the polymerizable compound, a photocationic polymerization initiator is used as the initiator. As this photocationic polymerization initiator, for example, an aromatic diazonium salt, an aromatic iodonium salt, an aromatic sulfonium salt, an aromatic phosphonium salt, or a mixed ligand metal salt is used.

  Alternatively, a mixture of a compound capable of photoradical polymerization and a compound capable of photocationic polymerization may be used as the polymerizable compound.

  In this case, as the initiator, for example, a mixture of a radical photopolymerization initiator and a cationic photopolymerization initiator is used. Alternatively, in this case, a polymerization initiator that can function as an initiator for both photoradical polymerization and photocationic polymerization may be used.

  As such an initiator, for example, an aromatic iodonium salt or an aromatic sulfonium salt is used.

  As an example in which a polymerization initiator is not used, a method of causing a polymerization reaction of a polymerizable compound by electron beam irradiation may be used.

  The radiation curable resin is a sensitizing dye, dye, pigment, polymerization inhibitor, leveling agent, antifoaming agent, sagging inhibitor, adhesion improver, coating surface modifier, plasticizer, nitrogen-containing compound, epoxy resin, etc. An additive, a release agent, or a combination thereof may further be included.

  The radiation curable resin may further contain a non-reactive resin in order to improve its moldability. As the non-reactive resin, for example, the thermoplastic resin, the thermosetting resin, or the like can be used alone or as a mixture.

  On the surface of the relief structure forming layer, a concavo-convex structure region (12) in which a concavo-convex structure is formed using a press plate and a clear panel (13) region having no concavo-convex structure are provided.

  The concavo-convex structure region (12) includes a plurality of panels having a concavo-convex structure, and generates a red panel (R) that generates red diffracted light, a green panel (G) that generates green diffracted light, and blue diffracted light. It consists of a blue panel (B).

  Specifically, the transfer foil base material (11) is continuously provided along the conveyance direction which is also the longitudinal direction, and heat is applied by a thermal head from the back coat layer (14) side of the transfer foil base material (11). It is possible to form an image made of diffracted light by being transferred to a transfer medium via an adhesive layer (18) described later.

  As described above, a margin portion may be provided on at least one width direction side of each panel (R, G, B) arranged in the transport direction, and is detected at a specific position with respect to any panel. A mark may be provided.

  The light reflecting layer (17) is formed so as to cover at least a part of the relief structure forming layer (16). For example, metals such as Al, Sn, Cr, Ni, Cu, Au, Ag, and these It consists of a metal material selected from the group consisting of alloys, a dielectric having a refractive index different from that of the relief structure forming layer (16).

Examples of the dielectric include Sb ₂ S ₃ , Fe ₂ O ₃ , TiO ₂ , CdS, CeO ₂ , ZnS, PbCl ₂ , CdO, Sb ₂ O ₃ , WO ₃ , SiO, Si ₂ O ₃ , In ₂ O ₃ , dielectrics composed of metal compounds such as PbO, Ta ₂ O ₃ , ZnO, ZrO ₂ , Cd ₂ O ₃ , Al ₂ O ₃ can be exemplified.

  The material constituting these light reflecting layers (17) may be used singly or may be provided by laminating a plurality of materials, but there are no problems as the light reflecting layer (17). When is used, it is desirable that the pattern is formed in a fine pattern, and it is desirable that the pattern be so fine that the pattern cannot be visually recognized.

  As a method of forming the light reflecting layer (17) as described above, a known coating method or vapor deposition method capable of depositing the material so as to correspond to the surface shape of the relief structure forming layer (16). Can be used.

  Examples of the coating method include a spray coating method. Examples of the vapor deposition method include a vacuum deposition method, a sputtering method, and a chemical vapor deposition method (CVD method). Among these, a vacuum vapor deposition method or a sputtering method is preferably used.

  The film thickness of the light reflecting layer (17) can be in the range of 10 nm to 150 nm.

  Examples of the material used for the adhesive layer (18) include acrylic resins, polyester resins, vinyl chloride-vinyl acetate copolymer resins, ethylene- (meth) acrylate ester copolymer resins, polyamide resins, and polyolefin resins. Resin, chlorinated polyolefin resin, epoxy resin, urethane resin and the like can be used alone or as a composite of two or more kinds of mixtures and copolymers, but are not necessarily limited to these materials. It is not a thing.

  In addition, in consideration of blocking prevention and foil breakage, the adhesive layer is made of waxes such as plant waxes, mineral waxes, petroleum waxes and synthetic waxes, metal salts of higher fatty acids such as stearic acid, silicone oils, etc. An organic filler such as a lubricant, fluororesin powder, silicon powder, acrylonitrile fine particles, and an inorganic filler such as silica can be added.

(Transfer image forming body and transfer image forming method)
FIG. 3 is a cross-sectional view showing an example of a transfer image forming body in which an image is formed using the transfer foil (10) obtained as described above.

  In FIG. 3, in the transfer image forming body (20), a clear panel layer (13 ′) is first provided on a transfer substrate (21) by a transfer process, and then a red panel (13) is formed thereon by a transfer process. A pixel (Px) composed of dots (Dr, Dg, Db) formed by transferring the R, green panel (G), and blue panel (B) is provided.

  Further, in the pixel (Px), the dots (Dr, Dg, Db) are arranged so that at least part of the dots (Dr, Dg, Db) have overlapping portions (22) among the dots of different panels.

  Here, in FIG. 3, the red dot (Dr) is in a state where the entire surface is in contact with the clear panel layer (13 ′) which is the printing surface, but the green dot (Dg) and the blue dot (Db). Is drawn such that one end is in contact with the underlying dot surface, while the other end is floating in the air.

  This is an expression for the sake of convenience. Actually, the end portion is not necessarily held in a suspended state, and can be considered to be in contact with at least the printing surface. The same applies to other similar drawings.

  The substrate to be transferred (21) is made of various materials such as paper, vinyl chloride, polycarbonate, acrylonitrile-butadiene-styrene, polyolefin, acrylic resin, polyethylene terephthalate, polyethylene naphthalate, and triacetyl cellulose. It can be used as a composite material combining the above.

  These materials may be added with various fillers such as titanium oxide, calcium carbonate, talc, silica, white lead white, and even if voids such as bubbles are provided, there is no problem.

  In addition, the substrate to be transferred (21) may be subjected to various kinds of processing and processing such as arbitrary printing processing, antistatic processing, easy adhesion processing, adhesion layer application, and adhesion processing, or magnetic recording. There is no problem even if a layer, an IC chip, an antenna, or the like is provided.

  Further, the substrate to be transferred (21) may be an intermediate transfer film in which an image receiving layer or the like is provided on a support so that the image receiving layer can be peeled off. In this case, the final printed material is a transfer foil (10). It is formed by retransferring the formed image and the layer including the image receiving layer and the like to a transfer target.

  When the intermediate transfer film is used as the substrate to be transferred (21), for example, a peelable protective layer and an intermediate layer are formed on a support made of polyethylene terephthalate, polyethylene naphthalate, vinyl chloride, polyimide, polyvinyl alcohol, triacetyl cellulose or the like. Examples thereof include a layer, an image receiving layer and the like.

  The peelable protective layer has peelability from the support and is intended to impart durability to the final printed product. For example, acrylic resins, polyester resins, vinyl resins such as vinyl chloride, triacetyl Various resins such as cellulose resins such as cellulose and nitrocellulose, urethane resins, polyimide resins, norbornene resins, epoxy resins, melamine resins, and phenol resins can be exemplified, but the present invention is not necessarily limited thereto. There is no problem even if, for example, a radiation curable resin is used.

  For the peelable protective layer, waxes such as plant waxes, mineral waxes, petroleum waxes, synthetic waxes, metal salts of higher fatty acids such as stearic acid, lubricants such as silicone oil, organic fillers, silica, etc. An inorganic filler or the like may be added.

  The intermediate layer is not necessarily provided, but the durability of the final printed product is improved, the adhesiveness between the peelable protective layer and the image receiving layer is improved, and further, decorative properties and security as various printing layers and OVD (Optical Variable Device) layers are provided. It can be arbitrarily provided for the purpose of improving the property.

  Examples of the OVD layer include a layer having a special material such as a high brightness pigment, a pearl pigment, various liquid crystal materials, a hologram, a diffraction grating, and the like.

  The image receiving layer only needs to have an image receiving ability with respect to the transfer foil (10) and an adhesive property to a transfer target body as a final printed material, and any conventionally known material can be used.

Specific examples include acrylic resins, polyester resins, urethane resins, vinyl resins such as vinyl chloride and vinyl acetate, epoxy resins, rosin resins, polyamide resins, polyolefin resins, and rubber materials. These materials can be used alone or as a composite such as a mixture or copolymer, but are not necessarily limited thereto.

  In addition, for the purpose of preventing blocking and improving the foil cutting property, for example, extender pigments such as titanium oxide, calcium carbonate, silica, talc, diatomaceous earth, organic fillers, and various waxes are added to the image receiving layer. May be.

  Hereinafter, in the transfer image forming body (20) of the present invention, in a region where dots (Dr, Dg, Db) composed of a red panel (R), a green panel (G), a blue panel (B) and the like are formed. The reason for providing the clear panel layer (13 ′) will be described.

  When the transfer image forming body (20) is observed from a specific angle, a specific color is obtained by combining the dots (Dr, Dg, Db) having the respective light intensities of the diffracted lights of red, green, and blue. The expressed pixel (Px) is recognized as an image by arbitrarily arranging it.

  At this time, the light intensity of each of red, green, and blue is expressed by the area of each dot (Dr, Dg, Db), and the area of each dot (Dr, Dg, Db) is transferred using a thermal head. It is adjusted by the difference in applied energy at the time.

  Here, FIG. 6 shows a conventional transfer foil (50) that does not have a clear panel (13). Using this conventional transfer foil (50), dot forming means for image formation is shown. An example is shown in FIG.

  In FIG. 7, as an example of the dot forming means, the dot juxtaposition (I) method in which the dots (Dr, Dg, Db) are arranged side by side without overlapping, or the dot overlap for overlapping the formation positions of the dots (Dr, Dg, Db) 3 shows a (II) method and a half-dot overlapping (III) method in which a part of each dot (Dr, Dg, Db) is overlapped.

  Each of these methods has advantages and disadvantages as means for forming an image using a transfer foil (10) such as a hologram or a diffraction grating. Table 1 shows the general trends.

  As shown in Table 1, in the dot juxtaposition (I) method, the red panel (R), green panel (G), and blue panel (B) are thermally transferred to form each dot (Dr, Dg, Db). Since the substrate to be transferred (21) is symmetric regardless of the dots on the target surface, there is no unevenness in the printing sensitivity, and a stable dot diameter can be obtained with respect to the applied thermal energy. Since the relative area of the dots (Dr, Dg, Db, etc.) constituting the pixel Px is stable, the gradation and color reproducibility are good, but each dot is juxtaposed so that one pixel (Px) is used. Since a large area is required, the number of formed pixels is reduced, and the brightness of an image made of diffracted light becomes insufficient.

  In the case of the dot overlap (II) method in which the formation positions of the dots are overlapped, the dots (for example, Dr) transferred to the transfer substrate (21) first are the dots (for example, Dg, Db) transferred from the next. ) Is printed on the surface of dots already formed.

  Since the substrate to be transferred (21) and the release layer (15) which is the surface of each dot (Dr, Dg, Db) are not necessarily the same material, the printing sensitivity at the time of dot formation will be different.

  Accordingly, even when the same applied energy is applied, the dot size is inferior because the size of dots formed differs depending on the print target surface.

  Further, since each dot (Dr, Dg, Db) is a pixel (PxII) formed by overlapping at the same arrangement position, the dot (for example, Dr or Dg) provided in the lower layer is covered by the upper dot. As a result, the diffraction efficiency of the dots decreases, and the color reproducibility decreases.

  On the other hand, in the half-dot overlap (III) method in which a part of dots is overlapped for printing, the print target surface is printed on both the surface of the dots provided in the lower layer and the surface of the transfer substrate (21). Therefore, compared to the dot juxtaposition (I) method, although the dot diameter stability is inferior, the dots provided in the lower layer are not completely covered. Sufficient color reproduction is possible.

  However, the half-dot overlap (III) method is not necessarily sufficient in terms of dot diameter reproducibility, and improvement has been demanded.

  On the other hand, the effect at the time of forming a dot using the transfer foil (10) of this invention was shown in FIG.

  FIG. 4 shows an example in which the upper half of the transfer image forming body (30) is printed using the conventional transfer foil (50), and the lower half is printed using the transfer foil (10) of the present invention. An example is shown.

  That is, in the lower half, a clear panel layer (13 ′) is provided in advance in one transfer step for each dot formation region of the substrate (21) to be transferred, and then each dot is formed in two transfer steps. Yes.

  Here, it is assumed that red dots (Dr) in the figure are formed with the same dot area regardless of the print target surface.

  It is assumed that green dots (Dg) are formed with the same applied energy in the first and third rows and the second and fourth rows in FIG.

  As shown in FIG. 4, when the clear panel layer (13 ′) is not provided, the dot diameters are different between Dg11 and Dg12 or Dg21 and Dg22 even when the same applied energy is applied. It has become.

  This is because in the first and second rows, red dots (Dr) are provided, but green dots (Dg) are formed so as to partially overlap, whereas the third and fourth rows. Then, green dots (Dg) are formed directly on the substrate to be transferred (21).

  Accordingly, the printing target surfaces of the green dots (Dg) are different. As a result, the dot diameter is not stable, and the dot diameters are formed with different sizes.

  On the other hand, when the clear panel layer (13 ') is provided, Dg13 and Dg14 and Dg23 and Dg24 are formed with the same dot diameter. That is, a stable dot diameter is obtained according to the applied energy.

This is because the clear panel layer (13 ′) is provided in advance in the area where each dot is to be formed, so that both the case where the dot is formed first and the case where it is formed later are both This is because the release layer (15) in the transfer foil (10) serves as a printing target surface, so that a stable dot diameter can be obtained without changing the printing sensitivity.

  As can be seen from FIG. 4, it can be seen that Dg22 and Dg24 have different dot diameters even when the applied energy is the same.

  However, by providing the clear panel layer (13 ′) so as to cover at least the entire region where each dot (Dr, Dg, Db) is formed, dot formation without the clear panel layer (13 ′) is eliminated. Thus, the change in the dot diameter can be suppressed, and a stable image can be obtained by controlling the applied energy so that the desired dot diameter is obtained.

  The above results are shown in Table 2.

  As shown in Table 2, by forming an image by the transfer image forming method of the present invention using the transfer foil of the present invention, a full color image made of diffracted light having extremely stable and good image quality is formed. Is possible.

  FIG. 5 shows an example of an information recording body (40) produced by an intermediate transfer method using the transfer foil, transfer image forming body and transfer image forming method of the present invention.

  That is, after using the intermediate transfer foil as a transfer material for the transfer foil, and forming the YMC print image portion (41) with the transfer ink containing the dye and the RGB print image portion (42) using the transfer foil of the present invention, It is re-transferred on a booklet to form an information recording medium.

  In this way, color image information (personal authentication information) such as a face photograph can be printed on demand as a color image using a diffraction grating as a high-quality and stable image, which can be tampered with. It is possible to provide a difficult and extremely high anti-counterfeit printed matter.

DESCRIPTION OF SYMBOLS 10 ... Transfer foil 11 ... Transfer foil base material 12 ... Diffraction structure area | region 13 ... Clear panel 13 '... Clear panel layer 14 ... Backcoat 15 ... Release layer 16 ... Relief structure formation layer 17 ... Light reflection layer 18 ... Adhesive layer 20, DESCRIPTION OF SYMBOLS 30 ... Transfer image forming body 21 ... Transfer material 22 ... Overlapping part 40 ... Information recording body 41 ... YMC print image part 42 ... RGB print image part 50 ... Conventional transfer foil R ... Red panel G ... Green panel B ... Blue Panel Dr, Dg, Db ... Print dots Dg11, Dg12, Dg13, Dg14, Dg21, Dg22, Dg23, Dg24 ... Print dots Px, PxI, PxII, PxIII ... Pixel

Claims (7)

On the transfer foil substrate, a release layer, a relief structure forming layer having an uneven structure on the surface, a light reflecting layer formed so as to cover at least a part of the surface of the relief structure forming layer, and an adhesive layer, A transfer foil that is at least laminated,
The relief structure forming layer has a plurality of panels having a substantially uniform concavo-convex structure in the plane thereof,
The plurality of panels are different from each other in at least one of the pitches of the concave or convex portions of the concavo-convex structure, the depth or height of the concave or convex portions, or the orientation direction of the concave or convex portions. And a typically flat clear panel that does not have the concavo-convex structure in a surface sequential manner.   The concavo-convex structure provided on the plurality of panels is a diffractive structure that emits one of red, green, and blue diffracted light when the panel is observed from a specific angle. Item 2. The transfer foil according to Item 1.   The transfer foil according to claim 1, further comprising a backcoat layer on a surface opposite to the surface in contact with the release layer of the transfer foil base material. On the substrate to be transferred, a release layer, a relief structure forming layer having an uneven structure on the surface, a light reflecting layer formed so as to cover at least a part of the surface of the relief structure forming layer, and an adhesive layer A transfer image forming body in which a plurality of dots at least are arranged,
Between the plurality of dots and the substrate to be transferred,
A release layer, a relief structure forming layer having a typically flat surface not having the uneven structure, a light reflecting layer formed to cover at least a part of the surface of the relief structure forming layer, an adhesive layer, A transfer image forming body comprising at least a clear panel layer having at least The concavo-convex structure provided on the relief structure forming layer surface of each dot in the plurality of dots has a substantially uniform concavo-convex structure in a single dot,
The plurality of dots are a plurality of groups in which at least one or more of the pitch of the concave or convex portions of the concavo-convex structure, the depth or height of the concave or convex portions, or the orientation direction of the concave or convex portions is different. Configure
5. The transfer image forming body according to claim 4, wherein in the dot arrangement of the group, at least a part of the overlapping portion is present between dots belonging to different groups.   The transferred image according to claim 4 or 5, wherein the concavo-convex structure is a diffractive structure that emits any one of red, green, and blue diffracted light when observed from a specific angle. Formed body. Preparatory process for preparing a transfer foil with a plurality of panels and clear panels that emit red, green, or blue diffracted light when viewed from a specific angle on the transfer foil base material. When,
Transfer 1 step of transferring the clear panel to at least a part of the transfer substrate using a thermal head, the transfer foil and the transfer substrate are arranged opposite to each other, and
Transfer 2 step of sequentially transferring the plurality of panels as a plurality of dots arranged in an arbitrary pattern using the thermal head to the area of the substrate to which the clear panel is transferred, Have
A transfer image forming method, wherein in the two transfer steps, dots formed by different panels are transferred so that at least a part thereof has an overlapping portion.