JP2011002749A - Security film and transfer foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a security film and a transfer foil, having specific design properties and security properties, including at least a surface-relief type hologram forming layer, and to provide a transparent reflection layer and a pattern layer in a part of the film or the foil.SOLUTION: The security film includes at least a surface-relief type hologram forming layer and a transparent reflecting layer successively layered on one surface of a support, and further includes a pattern layer disposed entirely or partially on the transparent reflecting layer, in which the pitch of a concavo-convex pattern of the surface relief type hologram recorded in the hologram-forming layer is set at a range of 200 to 500 nm.

Description

  The present invention relates to a security film and a transfer foil that have at least a surface relief type hologram forming layer, a transparent reflection layer, and a pattern layer, and have a special design and security.

  Holograms are widely used for various security applications, and examples of usage forms include hologram seals, hologram transfer foils, and thread holograms that are used by mixing with various paper media.

Conventional holograms used in various applications generally appear to shine in silver by using a metal thin film made of aluminum or the like as a reflective layer. In addition, a transparent hologram transfer foil that uses a transparent thin film layer as a reflection layer and can display a hologram image on a pattern of a transfer object is also known.
Furthermore, a hologram provided with a printed pattern that synchronizes with the hologram image is also known. However, the hologram with such a configuration can simultaneously see the hologram image and the image of the printed pattern, thereby further enhancing the forgery prevention effect. And used in various fields (for example, see Patent Document 1).

Japanese Patent No. 2774440

  However, recent color copiers have further improved copy reproduction accuracy, and if they are used, general holograms such as those described above should be used with caution, except for the reproducibility of metallic glossy parts. If you don't see it, it can be reproduced so precisely that you will miss the duplicate. In addition, the hologram itself, which has a simple structure and layer structure, is becoming more easily counterfeited, and the effect of preventing forgery is fading.

  The present invention has been made in order to solve the above-described problems. The reflective layer is a transparent layer, and the hologram image cannot be recognized from the front, but can be visually recognized only when it is largely inclined. First, because holograms are not reproduced by color copying, it is possible to prevent the copied counterfeit product from being mistakenly recognized as a genuine product, and second, security is achieved by combining it with a picture layer. An object of the present invention is to provide a security film and a transfer foil which have the effect of clearly confirming a picture layer without being obstructed by a hologram when viewed from the front while improving the properties.

  In view of the above situation, the invention according to claim 1 is provided such that at least a surface relief type hologram forming layer and a transparent reflective layer are sequentially laminated on one side of a support, and further an upper portion of the transparent reflective layer. A pattern layer is provided on all or a part of the surface, and the pitch of the concavo-convex pattern of the surface relief hologram recorded on the hologram forming layer is set between 200 and 500 nm. It is a film.

According to a second aspect of the present invention, in the security film according to the first aspect, a black solid print layer is provided on the entire surface of the transparent reflective layer.

  Furthermore, the invention according to claim 3 is the security film according to claim 1, wherein a metal reflective layer is further laminated on the pattern layer on the transparent reflective layer and on the portion where the pattern layer is not provided. It is provided.

  Furthermore, the invention according to claim 4 is provided such that at least a surface relief type hologram forming layer, a transparent reflective layer, and an adhesive layer are laminated in this relative order on one side of the support, and the upper portion of the transparent reflective layer is further provided. A pattern layer is provided on all or a part of the pattern, and the pitch of the concavo-convex pattern of the surface relief hologram recorded on the hologram forming layer is set between 200 and 500 nm. Transfer foil.

  Furthermore, the invention described in claim 5 is the transfer foil according to claim 4, wherein a black solid print layer is provided on the entire surface of the transparent reflective layer.

  Furthermore, the invention according to claim 6 is the transfer foil according to claim 4, wherein a metal reflective layer is further laminated on the pattern layer on the transparent reflective layer and on the portion where the pattern layer is not provided. It is provided.

  According to invention of Claim 1 and 4, the hologram image of the upper area | region of a pattern layer has transparent reflectivity by a transparent reflection layer. Then, the concavo-convex structure of the relief-type hologram forming layer having a fine pitch of 200 to 500 nm makes the diffraction angle very large, and the hologram image is visible only within a limited angle range. The hologram forming layer is simply a transparent layer, and only the image of the lower pattern layer is visible. That is, the hologram image on the pattern layer exhibits a watermark effect. For this reason, when viewed from the front, a security film and a transfer foil are provided in which the picture layer can be confirmed without being disturbed by the hologram image, and when the angle is greatly inclined, the hologram image can be confirmed. When this security film or transfer foil is color-copied, the hologram image is not reproduced at all, and tampering and manufacturing are difficult, so that a high anti-counterfeiting effect can be expected.

  Further, according to the inventions of claims 2 and 5, the black solid print layer is provided on the transparent reflection layer, so that when viewed from the front, black is seen when tilted. A security film and a transfer foil capable of observing a hologram image are provided. And the effect which the visibility of a hologram image improves can be anticipated by making a base pattern layer into black solid.

  Further, according to the third and sixth aspects of the invention, since the metal reflective layer is provided on the transparent reflective layer not provided with the pattern layer, only the metallic luster is confirmed when viewed from the front. A security film and a transfer foil that can observe a hologram image when tilted are provided. And the effect which the visibility of a hologram image improves more by providing a metal reflective layer can be anticipated.

  In addition, the security film of this invention can be used as a structural member of media, such as a banknote, securities, a ticket, a boarding ticket, a gift certificate, a certificate, a label, a card | curd, and a thread | sled, for example. Further, the transfer foil of the present invention can be used as a transfer body for transferring a part of the transfer foil to another medium such as paper or a card and imparting excellent design properties and security.

It is explanatory drawing which shows the schematic planar state of the security film which concerns on one Example of this invention. It is explanatory drawing which shows the general | schematic cross-section structure of the security film which concerns on one Example of this invention. It is explanatory drawing which shows the general | schematic cross-section structure of the security film which concerns on the other Example of this invention. It is explanatory drawing which shows the general | schematic cross-section structure of the transfer foil which concerns on one Example of this invention.

  FIG. 1 and FIG. 2 show a schematic configuration of a planar portion and a cross-sectional portion related to a sticker type security film. As is clear from the drawing, this security film is provided with at least a surface relief type hologram forming layer 2 and a transparent reflective layer 3 sequentially laminated on one side of the support 1, and further on the upper side of the transparent reflective layer 3. A pattern layer 4 is provided in part, and the pitch of the concavo-convex pattern of the surface relief hologram recorded on the hologram forming layer 2 is set between 200 and 500 nm. In the figure, 7 is a pattern portion showing a formation area of the pattern layer 4 provided on a part of the upper part of the transparent reflective layer 3, and 8 is a non-display area showing no formation area of the upper part of the transparent reflective layer 3. It is a design part. Reference numeral 6 denotes an anchor layer, and 5 denotes an adhesive layer.

  On the other hand, the security film shown in FIG. 3 is also a sticker type security film, and the basic structure is the same as that of the security film shown in FIG. 2, but on the transparent reflective layer 23 in which the pattern layer 24 is provided in part. 1 in that a metal reflective layer 29 is further laminated.

  On the other hand, in the transfer foil of the present invention shown in FIG. 4, the release layer 10, the surface relief hologram forming layer 32, the transparent reflective layer 33, and the adhesive layer 11 are arranged in this relative order on one surface of the support 31. A surface relief type in which the adhesive layer 11 is provided so as to be positioned on the surface, and a picture layer 34 is further provided on a part of the upper part of the transparent reflective layer 33, and is recorded in the hologram forming layer 32. The pitch of the concavo-convex pattern of the hologram is set between 200 and 500 nm.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The supports 1, 21, and 31 constituting the security film and the transfer foil of the present invention have a function of supporting the hologram forming layers 2, 22, and 32 and the transparent reflecting layers 3, 23, and 33, which are sequentially laminated thereon. In addition, when used as a security film, it has a protective function to prevent the optical image obtained by the hologram forming layers 2 and 22 from being disturbed by external factors. Further, the support 31 of the transfer foil needs to be peelable from the transfer material having the hologram forming layer after being attached to the transfer material by a method such as hot stamping.

  As such a support, a film made of polyethylene terephthalate (polyester), polyvinyl chloride, polyolefin, cellulose acetate or the like can be given as a specific example.

  When making a security film or transfer foil by laminating colored layers, hologram forming layers, anchor layers, etc. on a support using constituent materials containing solvents, erosion of the solvents in the constituent materials of those layers It should be noted that a solvent having a degree of solvent resistance not used is used.

Among the resin materials described above, polyester resins are preferable, and among the polyester resins, polyethylene terephthalate is more preferable.

  The support may not be transparent, it may be transparent as long as the hologram forming layers 2, 22, and 32 can be visually recognized, and may be colored.

  The thicknesses of the supports 1, 21, and 31 are not particularly limited, but may be in the range of about 12 μm to 200 μm.

  On the other hand, the surface relief hologram forming layers 2, 22, and 32 can record surface relief holograms by hot embossing, and have a heat resistance that does not cause an optical image to disappear in the manufacturing process and use environment. It is a layer made of a constituent material having properties.

  As a constituent material of the hologram forming layers 2, 22, and 32, it is preferable to use a material that easily adheres to the supports 1, 21, 31 or the later-described release layer 10. Prior to laminating hologram forming layers 2, 22, and 32, surface activation treatment such as anchor coating treatment and corona discharge treatment is performed on the above-described supports 1, 21, 31 or the surface of the release layer 10 described later. It may be.

  The hologram forming layers 2, 22, and 32 are formed by forming a thin film of a constituent material by a general printing method or various coating methods such as gravure coating, micro gravure coating, roll coating, kiss coating, die coating, and comma coating. After that, the concavo-convex pattern relating to the surface relief hologram may be recorded and provided on the thin film by hot embossing. At this time, a dye or pigment may be blended in the hologram forming layer so that the same coloring effect as that of the colored layer can be obtained.

  The thickness of the hologram forming layers 2, 22, and 32 is not particularly limited as long as the uneven pattern of the surface relief type hologram can be shaped, but about 0.3 μm to about 3 μm is appropriate.

  The relief shape formed on the hologram forming layer is a fine concavo-convex pattern, the pitch is between 200 and 500 nm, and the height difference of the concavo-convex is in the range of about 0.01 to 1 μm. The concavo-convex pattern includes a diffraction grating and a pattern in which a plurality of fine convex portions or concave portions are regularly arranged. Further, the uneven pattern on the surface may be provided by hot pressing using a press plate having an uneven pattern having a shape opposite to the uneven shape of the hologram original plate prepared in advance.

  On the other hand, the transparent reflection layers 3, 23, and 33 are for imparting reflectivity to the hologram images of the hologram forming layers 2, 22, and 32 to increase the hologram effect. The transparent reflective layers 3, 23, 33 are reflective layers having reflective transparency, and are a continuous thin film made of a material having a refractive index different from that of the hologram forming layers 2, 22, 32, and a thickness of less than 200 mm. It is a layer made of a metal thin film or the like.

  The transparent reflective layers 3, 23, and 33 are provided on the hologram forming layers 2, 22, and 32 before or after forming the concavo-convex pattern of the surface relief hologram. Examples of the constituent material of the transparent reflective layers 3, 23, and 33 include zinc sulfide and titanium dioxide, but are not necessarily limited to these. Examples of the method for forming the transparent reflective layers 3, 23, and 33 include vapor deposition and sputtering.

The pattern layers 4, 24, and 34 are provided on at least a part of the transparent reflective layers 3, 23, and 33, by combining characters, figures, symbols, patterns, patterns, or combinations thereof with colors. This is a layer for displaying predetermined information. The pattern layers 4, 24, and 34 may be formed with an appropriate ink thickness by using ink in consideration of concealability with respect to the metal reflection layers 29 and 39 described later.

  Examples of the method for forming the pattern layers 4, 24, and 34 include a printing method such as silk printing, gravure printing, offset printing, and flexographic printing, or a thermal transfer method using a pattern transfer sheet.

  The metal reflection layers 29 and 39 are opaque reflection layers, and are layers formed on the pattern layers 24 and 34 and on the transparent reflection layers 23 and 33 where there is no pattern layer. When the security film or the transfer foil is viewed from the support side, the metallic reflective layers 29 and 39 are hidden by the pattern layers 24 and 34 in a part of the pattern layer, and thus do not show metallic luster, but the pattern layers 24 and 34 With respect to the portion where there is not, the hologram image obtained by the transparent reflection layers 23 and 33 is further increased by the metal reflection layers 29 and 39, and a high-luminance hologram image can be expressed.

  As a metal material which comprises the metal reflection layers 29 and 39, the simple substance selected from chromium, nickel, aluminum, iron, titanium, silver, gold | metal | money, copper, or those mixtures, an alloy can be mentioned, for example. The metal reflective layers 29 and 39 made of such a metal material may be used for gravure printing, flexographic printing, screen printing, offset printing, etc. by using a metal material by vapor deposition or sputtering, or using ink containing metal fine particles. What is necessary is just to form by printing with a general printing system.

  In the case of a sticker type security film, as shown in FIGS. 2 and 3, adhesive layers 5 and 25 are provided on the surface opposite to the support. The constituent material of the pressure-sensitive adhesive layers 5 and 25 is not particularly limited as long as it is a general pressure-sensitive adhesive material exhibiting desired adhesiveness to the transfer object.

  On the other hand, in the transfer foil of the present invention, the release layer 10 is provided between the support 31 and the hologram forming layer 32. The release layer 10 is peeled off from the support 31 after the transfer and comes to be positioned on the outermost surface of the transfer product, and functions as a protective layer. In order to improve the peeling performance, a release layer may be provided between the support and the peeling layer.

  When the security film of the present invention is used as a brittle sticker, a release layer may be provided as a brittle layer between the support and the hologram forming layer. In this way, the sticker is used with the support attached to the object to be pasted through the adhesive layer. However, when the sticker is intentionally peeled off from the object to be pasted, it is supported. Exfoliation occurs between the body and the exfoliation layer, and the sticker is destroyed, so that illegal reuse and the like can be prevented.

  On the other hand, in the transfer foil, the adhesive layer 11 is provided on the surface opposite to the support 31. The constituent material of the adhesive layer 11 is not particularly limited as long as it exhibits desired adhesiveness to the transfer object. Further, in order to further improve the adhesion of the adhesive layer, it may be provided via an adhesive anchor layer.

  The thickness of the adhesive layer 11 is not particularly limited as long as the desired adhesiveness can be expressed with respect to the transfer object, but is preferably within a range of about 1 μm to 10 μm, and various coatings are applied like the hologram forming layer. It can be provided using a method.

In the present invention, an anchor layer may be provided as necessary in order to improve the adhesion between the layers in addition to the above-described minimum required thin film layers. Moreover, you may make it improve the adhesiveness between layers by surface treatment. Examples of the surface treatment include corona discharge treatment, plasma treatment, ozone gas treatment, and alkali treatment.

  When the anchor layer is provided, for example, between the support and the hologram forming layer, it is possible to improve the adhesion, and it is possible to suppress the plate taking during molding.

  Hereinafter, the present invention will be specifically described with reference to examples.

[Example 1]
FIG. 1 shows a configuration example of a sticker type security film according to Embodiment 1 of the present invention. This sticker type security film includes a support 1, an anchor layer 6, a hologram forming layer 2, a transparent reflective layer 3, a pattern layer 4 partially formed on the transparent reflective layer 3, and a transparent reflective layer. 3 and an adhesive layer 5 formed on the entire surface of the pattern layer 4. In this embodiment, the anchor layer 6 is provided for improving the adhesion between the support 1 and the hologram forming layer 2.

  As shown in FIG. 2, the sticker type security film has a picture portion 7 represented by the hologram forming layer 2, the transparent reflection layer 3, and the picture layer 4, as shown in FIG. It is divided into a non-picture portion 8 expressed by the transparent reflective layer 3.

  Hereinafter, a specific example of a method for producing a sticker type security film according to Example 1 will be described.

  A polyethylene terephthalate film (trade name E5100, manufactured by Toyobo Co., Ltd.) having a thickness of 50 μm was used as a support, and an anchor layer and a hologram forming layer were sequentially laminated on the surface subjected to the corona treatment using a gravure coater. After drying in the oven, the film thickness of the hologram forming layer was 2 μm.

  Next, the obtained film was hot-pressed with a roll embossing device, and a surface relief hologram having a concavo-convex pattern pitch of 200 to 500 nm was formed on the hologram forming layer.

  Then, ZnS vapor deposition was performed on the hologram formation layer provided in the previous process, and the transparent reflection layer was provided. The film thickness of the transparent reflective layer was 40 nm.

  And the pattern layer was provided in a part on the transparent reflective layer of ZnS by the gravure printing method. The thickness of the pattern layer after drying in the oven was 5 μm.

  Finally, an adhesive layer was applied to the entire surface of the transparent reflective layer provided with the pattern layer and dried in an oven. The thickness of the adhesive layer after drying was 10 μm.

  Through the steps as described above, a security film according to Example 1 of the present invention having a layer structure of support / anchor layer / hologram forming layer / transparent reflective layer / picture layer / adhesive layer was obtained.

In the security film prepared as described above, the pitch of the concavo-convex pattern is between 200 and 500 nm, and the transparent reflection layer is provided thereon, so that the hologram image can be obtained only when tilted greatly. Became visible. In addition, when the pattern layer was present under the transparent reflective layer, only the printed pattern was recognized when viewed from the front and when color copying was performed. As for the portion having no pattern layer under the transparent reflective layer, the pattern was not recognized when viewed from the front and when color copying was performed.

[Example 2]
FIG. 3 shows a cross-sectional configuration of a sticker-type security film according to Example 2 of the present invention. The security film includes a support 21, a hologram forming layer 22, a transparent reflection layer 23, a pattern layer 24 partially formed on the transparent reflection layer 23, the transparent reflection layer 23, and the pattern layer 24. The metal reflection layer 29 formed on the entire surface and the adhesive layer 25 are included.

  In the security film of Example 2, the hologram forming layer 22 was directly applied on the support 21 and the metal reflective layer 29 was provided after the pattern layer 24 was applied and before the adhesive layer 25 was applied. Except for this, the same method as in Example 1 was used.

  In the security film according to the second embodiment created as described above, the effect of the portion with the pattern layer 24 is exactly the same as that of the first embodiment, but the portion without the pattern layer is a hologram when tilted greatly. The image was recognizable, and it was recognized as a simple metallic luster when viewed from the front, and was copied as a black solid when color copying was performed.

[Example 3]
FIG. 4 shows a cross-sectional configuration of a transfer foil according to Example 3 of the present invention. The transfer foil includes a support 31, a release layer 10, a hologram forming layer 32, a transparent reflection layer 33, a pattern layer 34 formed on the transparent reflection layer 33, and the transparent reflection layer 33 and the pattern layer 34. The metal reflection layer 39 is formed on the entire surface, the anchor layer 36 is formed on the metal reflection layer 39, and the adhesive layer 11 is formed on the anchor layer 36. In this embodiment, the anchor layer 36 is provided to improve the adhesion between the metal reflective layer 39 and the adhesive layer 11.

  Hereinafter, a specific example of a method for producing a transfer foil according to Example 3 will be described.

  A polyethylene terephthalate film having a thickness of 16 μm was used as a support, and a release layer and a hologram forming layer were sequentially provided by a gravure coater. After drying in the oven, the film thickness of the hologram forming layer was 1 μm.

  Next, the film was hot-pressed with a roll embossing device to form a surface relief hologram having a concavo-convex pattern pitch of 200 to 500 nm on the hologram forming layer.

  Subsequently, after depositing ZnS on the hologram forming layer to provide a transparent reflective layer, a pattern layer was printed on a part thereof by a gravure printing method.

  And aluminum vapor deposition was performed on the transparent reflection layer without a pattern layer and a pattern layer, and the metal reflection layer was provided. The film thickness of the metal reflective layer was 50 nm. At this point, when viewed from the support side, only the pattern printed on the portion with metallic gloss was confirmed when viewed from the front, and when it was tilted greatly, a hologram image could be confirmed on both the metallic gloss portion and the pattern portion.

Finally, an anchor layer and an adhesive layer were sequentially laminated on the metal reflective layer with a gravure coater. After oven drying, the film thickness of the adhesive layer was 3 μm.
The transfer foil which concerns on Example 3 of this invention which has a layer structure of a support body / peeling layer / hologram formation layer / transparent reflection layer / pattern layer / metal reflection layer / anchor layer / adhesion layer was obtained by the above process.

By using the transfer foil configured as described above, and transferring and pasting a part of printed matter such as banknotes, gift certificates, certificates and cards, it has the same appearance as the security films of Examples 1 and 2. The transferred product can be applied to a part of the printed material.

  In this embodiment, the case where the transparent reflective layer is formed by ZnS vapor deposition and the metal reflective layer is formed by aluminum vapor deposition has been described, but the security film and transfer foil of the present invention are not limited thereto. However, the constituent material of the transparent reflective layer is limited to a material having a high transmittance.

1, 2, 31 ... Supports 2, 22, 32 ... Hologram forming layers 3, 32, 33 ... Transparent reflection layers 4, 24, 34 ... Pattern layers 5, 25 ... Adhesive layers 6, 36 ... Anchor layers 7, 27 ... Pattern part 8, 28 ... Non-pattern part 9, 29, 39 ... Metal reflective layer 10 ... Release layer 11 ... Adhesive layer

Claims (6)

  At least a surface relief hologram forming layer and a transparent reflective layer are sequentially laminated on one side of the support, and a pattern layer is further provided on all or part of the upper part of the transparent reflective layer. A security film, wherein the pitch of the concavo-convex pattern of the surface relief hologram recorded in the hologram forming layer is set between 200 and 500 nm.   The security film according to claim 1, wherein a black solid print layer is provided on the entire surface of the transparent reflective layer.   2. The security film according to claim 1, wherein a metal reflective layer is further laminated and provided on the pattern layer on the transparent reflective layer and on a portion where the pattern layer is not provided. 3.   At least a surface relief hologram forming layer, a transparent reflective layer, and an adhesive layer are provided on one side of the support so as to be laminated in this relative order, and the adhesive layer is positioned on the surface, and further on the upper side of the transparent reflective layer. A transfer foil characterized in that a pattern layer is provided in whole or in part and the pitch of the concavo-convex pattern of the surface relief hologram recorded in the hologram forming layer is set between 200 and 500 nm .   The transfer foil according to claim 4, wherein a black solid print layer is provided on the entire surface of the transparent reflective layer.   5. The transfer foil according to claim 4, wherein a metal reflective layer is further laminated and provided on the pattern layer on the transparent reflective layer and on a portion where the pattern layer is not provided.