WO2017159636A1

WO2017159636A1 - Diffraction structure forming body, article provided with diffraction structure forming body, and production method for diffraction structure forming body

Info

Publication number: WO2017159636A1
Application number: PCT/JP2017/010035
Authority: WO
Inventors: 井出　英誉
Original assignee: 凸版印刷株式会社
Priority date: 2016-03-14
Filing date: 2017-03-13
Publication date: 2017-09-21
Also published as: JPWO2017159636A1; TW201740140A; JP6939772B2

Abstract

This diffraction structure forming body is provided with: a diffraction structure forming layer that includes a diffraction structure portion in which optical image information is recorded; a reflection layer that is disposed at a part on the diffraction structure portion and that includes at least one reflection element; and a printing layer that includes at least one printing element, the printing element being disposed on the reflection element. The printing layer is at least a part of a mask which is used for forming the reflection layer.

Description

Diffraction structure forming body, article with diffraction structure forming body, and method for manufacturing diffraction structure forming body

The present invention relates to a diffractive structure formed body, an article with a diffractive structure formed body, and a diffractive structure formed body that can be used in a forgery prevention medium that is required to prevent counterfeiting and falsification of securities and to easily detect fraud. It relates to the manufacturing method.

In recent years, it is possible to easily determine the authenticity of an article at a glance by attaching it to an article that is a target for preventing counterfeiting, and since the handling is easy, there is a diffraction structure portion on which a diffraction grating pattern is recorded. It is widely used as a means to prevent counterfeiting. Examples of the diffractive structure forming body in which the diffractive structure portion employed as such a forgery preventing means is formed include a peelable layer having peelability, a diffractive structure forming layer having a diffraction grating, and a reflective layer having a metallic luster. And an adhesive layer are sequentially laminated on a base material to form a diffractive structure formed body as a transfer foil (see, for example, Patent Document 1).

In addition, by forming a transparent metal-deposited thin film or an inorganic compound thin film as a reflective layer on a transparent diffraction grating, it is possible to visually observe what is located below the reflective layer through the diffraction grating. There are some (see, for example, Patent Document 2).

Furthermore, Patent Document 3 proposes a molded article in which a metal reflective layer is partially provided for a hologram and a method for manufacturing the same.

In these conventionally used diffractive structure forming bodies, a reflective layer composed of a vapor-deposited thin film or a transparent thin film having a metallic luster is laminated on the diffractive structure part with a predetermined pattern shape, The entire diffractive structure is laminated.

JP 61-190369 A Japanese Utility Model Publication No. 1-59671 JP 62-79489 A

To further increase the anti-counterfeiting effect, when a patterned printed layer is formed on the opposite side of the diffractive structure from the reflective layer, the reflective layer and the printed layer are formed separately. It is difficult to align the layers with high accuracy. Therefore, the print layer and the reflective layer have to be arranged in consideration of the positional deviation in advance.

The present invention has been made in order to solve the above-described problems, and can provide a diffraction structure-forming body, an article with a diffraction structure-forming body, and a diffraction structure-forming body capable of suppressing the displacement of the position of the printed layer with respect to the pattern-like reflective layer, and An object of the present invention is to provide a method for producing a diffractive structure forming body.

A diffractive structure forming body for solving the above problems includes a diffractive structure forming layer including a diffractive structure part on which optical image information is recorded, and at least one reflecting element located on a part of the diffractive structure part. A reflective layer comprising: at least one printing element, and wherein the printing element is located on the reflective element, wherein the printing layer is a mask used to form the reflective layer At least some.

In the diffractive structure forming body, it is preferable that the printing element is located inside an edge of the reflecting element where the printing element is located in a plan view facing a plane in which the diffractive structure forming layer extends.

In the diffractive structure forming body, the printing layer includes a plurality of the printing elements, and the printing elements are positioned in a plurality of the printing elements in a plan view facing a plane in which the diffractive structure forming layer extends. The printing element having a shape similar to the reflective element may be included.

In the diffractive structure forming body, it is preferable that the printing layer is a photoresist layer including at least one of a color material, a fluorescent material, and fillers.

The diffractive structure forming body further includes a support that contacts the diffractive structure forming layer on a side opposite to the reflective layer with respect to the diffractive structure forming layer, and the diffractive structure forming layer and the support include a laminate. The printed layer, the reflective layer, and the laminate, the printed layer has the highest transmission density, the laminated body has the lowest transmission density, and the reflective layer has a transmission density, It is preferably a value between the transmission density of the printed layer and the transmission density of the laminate.

In the diffractive structure forming body, the transmission density of the printing layer is 0.5 or more and less than 2.0, the transmission density of the reflection layer is 1.0 or more, and the transmission density of the support is 0.00. It may be 8 or more and 2.0 or less.

An article with a diffractive structure forming body for solving the above-mentioned problem is an article with a diffractive structure forming body including a diffractive structure forming body and an article that supports the diffractive structure forming body, The diffraction structure forming body.

A method for manufacturing a diffractive structure forming body for solving the above problem is a method for manufacturing a diffractive structure forming body including a diffractive structure forming layer including a diffractive structure portion, a reflective layer including a reflective element, and a printed layer including a printing element. is there. Forming a thin film for forming the reflective layer on the diffractive structure, forming a mask for etching the thin film into a predetermined shape on the thin film, and using the mask to Forming the reflective element from the thin film by etching a thin film and forming the printing element located on the reflective element from the mask.

According to the present invention, it is possible to suppress the displacement of the position of the printed layer with respect to the patterned reflective layer.

It is a top view which shows the planar structure in an example of a diffraction structure formation body. It is a top view which shows the planar structure which observed the diffraction structure formation body shown in FIG. 1 from the printing layer side. FIG. 3 is a cross-sectional view taken along line AA shown in FIG. It is a top view which shows a planar structure when the diffraction structure formation body of FIG. 1 is observed with transmitted light. It is sectional drawing which shows the cross-section of a sticker when the diffraction structure formation body is embodied as a sticker. It is sectional drawing which shows the cross-section of transfer foil when a diffraction structure formation body is embodied as transfer foil. It is process drawing which shows the exposure process using a mask plate. It is process drawing which shows a image development process. It is process drawing which shows an etching process. It is process drawing which shows a image development process. It is a top view which shows the planar structure in another example of a diffraction structure formation body. It is a top view which shows the planar structure which observed the diffraction structure formation body of FIG. 8 from the printing layer side. It is a top view which shows a planar structure when the diffraction structure formation body of FIG. 8 is observed with transmitted light. It is a top view which shows the planar structure in an example of the articles | goods which stuck the diffraction structure formation body. It is an enlarged plan view which expands and shows a planar structure when the broken-line part of FIG. 11 is observed with transmitted light.

Hereinafter, preferred embodiments in which a diffractive structure formed body, an article with a diffractive structure formed body, and a method for producing the diffractive structure formed body are embodied will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing a planar structure of the diffractive structure forming body 10 and shows an example of the state of the optical image information section 101 observed from the diffractive structure forming layer 12 side with forward light, that is, reflected light.

On the other hand, FIG. 2 shows an example of a planar structure in the diffractive structure forming body 10 when observed by forward light from the side on which the printing layer 15 is formed. A printed layer 15 having a pattern different from the pattern of the reflective layer 14 provided in the optical image information unit 101 is provided.

From this, the diffractive structure forming body 10 can express different patterns in the observation with forward light from the diffractive structure forming body 10 side and the observation with forward light from the printed layer 15 side.

FIG. 3 is a cross-sectional view showing a cross-sectional structure taken along line AA of the diffractive structure forming body 10 in FIG. On the surface of the diffractive structure forming layer 12 opposite to the support 11, a diffractive structure portion 13 composed of fine irregularities is formed.

A reflective layer 14 is laminated on the diffractive structure forming layer 12. The printed layer 15 is at least a part of a mask used for forming the reflective layer 14. More specifically, a part of the photoresist applied for selective removal in the thin film for forming the reflective layer 14 is exposed to light, that is, irradiated with light and developed, and then etched to form a part of the thin film. Even after the portion is removed, the diffraction structure forming body 10 functions as the print layer 15 by being positioned in a pattern on the reflective layer 14. These manufacturing methods will be described in detail later.

As shown in FIG. 3, the diffractive structure forming body 10 includes a support 11 and a diffractive structure forming layer 12 positioned on one surface of the support 11. The diffractive structure 13 is located on the surface opposite to the surface in contact with 11. Of the diffractive structure forming layer 12, the surface on which the diffractive structure portion 13 is located is an uneven surface. A reflective layer 14 having a predetermined shape is located on the concavo-convex surface of the diffractive structure forming layer 12, and the reflective layer 14 includes a plurality of reflective elements positioned apart from each other on the concavo-convex surface. A printed layer 15 having a predetermined shape is located on the surface of the reflective layer 14 opposite to the surface in contact with the uneven surface. The printing layer 15 includes a plurality of printing elements that are located apart from each other in a plan view facing the uneven surface, and at least one printing element is located on one reflective element.

One direction is the X direction, and the direction orthogonal to the X direction is the Y direction. The direction orthogonal to both the X direction and the Y direction is the Z direction. The diffractive structure forming body 10 has a plate shape extending along the X direction and the Y direction, and the thickness direction of the diffractive structure forming body 10 is a direction parallel to the Z direction.

The first observation direction and the second observation direction can be set for the diffraction structure forming body 10. The first observation direction is a direction in which the diffractive structure forming body 10 is observed from the side opposite to the diffractive structure forming layer 12 with respect to the support 11, and the second observation direction is a support with respect to the diffractive structure forming layer 12. 11 is a direction in which the diffractive structure forming body 10 is observed from the opposite side.

When observing the diffractive structure forming body 10 from the first observation direction, it is possible to observe the light incident on the diffractive structure forming body 10 from the support 11 and reflected by the reflective layer 14. is there. Further, when observing the diffractive structure forming body 10 from the first observation direction, the light that has entered the diffractive structure forming body 10 from the diffractive structure forming layer 12 and has passed through at least the diffractive structure forming layer 12 and the support 11. Can be observed.

On the other hand, when observing the diffractive structure forming body 10 from the second observation direction, in the diffractive structure forming body 10, the light is incident on the reflective layer 14, the printed layer 15, and the diffractive structure forming layer 12, It is possible to observe the light reflected at each part. Further, when observing the diffractive structure forming body 10 from the second observation direction, light that has entered the diffractive structure forming body 10 from the support 11 and that has transmitted through at least the support 11 and the diffractive structure forming layer 12 is observed. Is possible.

As described above, the planar structure shown in FIG. 1 is a planar structure when the diffractive structure forming body 10 is observed from the diffractive structure forming layer 12 side with forward light. In other words, in FIG. 1, light that is observed from the first observation direction of the diffractive structure forming body 10 and is incident on the diffractive structure forming body 10 from the support 11 and reflected by the reflective layer 14. The image which the diffraction structure formation body 10 displays when observing is shown.

On the other hand, the planar structure shown in FIG. 2 is a planar structure in the diffractive structure forming body 10 when the diffractive structure forming body 10 is observed by forward light from the side on which the printing layer 15 is formed. In other words, in FIG. 2, the light incident on the reflection layer 14, the printing layer 15, and the diffraction structure forming layer 12 in the diffraction structure forming body 10 is observed from the second observation direction. And the image which the diffraction structure formation body 10 displays when the light reflected in each site | part is observed is shown.

Hereafter, each element with which the diffraction structure formation body 10 is provided is demonstrated in detail.
(Support)
The support 11 plays a role as a base material when the diffraction structure forming body 10 is manufactured. In addition, when the diffractive structure forming body 10 is embodied as a sticker, the diffractive structure forming body 10 may be attached to an article in a state including a support. On the other hand, when the diffractive structure forming body 10 is embodied as a transfer foil, the support serves as a support base material when a part of the diffractive structure forming body 10 is transferred to the article. After a part of 10 is transferred to the article, the diffractive structure forming body 10 is peeled from a portion other than the support.

Note that the support is not necessarily required, and the support 11 and the diffraction structure forming layer 12 may be made of the same material. That is, if the diffractive structure forming layer 12 has mechanical strength capable of supporting the reflective layer 14 and the printed layer 15 formed on the diffractive structure forming layer 12, the support 11 is omitted. May be.

The support 11 may be a film or a sheet. Examples of film or sheet materials include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate, triacetyl cellulose (TAC), polyvinyl chloride, polyethylene (PE), polyimide (PI), polyvinyl alcohol (PVA), etc. However, the present invention is not limited to these.

Generally speaking, polyethylene terephthalate (PET) can be said to be most suitable as a material for forming a support from the viewpoints of availability and ease of handling during processing.

(Diffraction structure)
Optical image information is recorded in the diffractive structure section 13. When light enters the diffractive structure 13 in the presence of the reflective layer 14, the diffractive structure 13 generates diffracted light. Display images that can be

Generally, when the diffractive structure forming body 10 is attached to an article, an adhesive layer is provided on the diffractive structure portion 13 according to the use of the diffractive structure forming body 10. In this case, if the reflective layer 14 is not formed on the diffractive structure portion 13, the difference in refractive index between the diffractive structure forming layer 12 and the adhesive layer is small, so that diffracted light having sufficient luminance is obtained. Cannot be obtained. Therefore, the reflective layer 14 is located on the diffractive structure portion 13.

The optical image information is 2D or 3D visible image information displayed by diffracted light generated when light enters the diffractive structure 13. Specifically, the pattern includes a pattern, a character, and a color change, and is configured by a pattern that can be recognized visually.

Also, an image is information that can be recognized visually, and includes characters, patterns, colors, and predetermined shapes in addition to pictorial images such as illustrations. Further, the image is not limited to the image displayed by the diffracted light, and includes the image formed by the printing layer 15 and the color of each component.

As a material of the diffraction structure forming layer 12 on which the diffraction structure portion 13 is formed, a thermoplastic resin, a thermosetting resin, an ultraviolet ray, an electron beam curable resin, or the like can be used. For example, examples of the thermoplastic resin include acrylic resin, epoxy resin, cellulose resin, and vinyl resin. Further, as the thermosetting resin, urethane resin, melamine resin, phenol resin, and the like obtained by adding polyisocyanate as a crosslinking agent to acrylic polyol having a reactive hydroxyl group, polyester polyol, or the like can be used. In addition, as the ultraviolet or electron beam curable resin, epoxy (meth) acryl, urethane (meth) acrylate, or the like can be used. Using these materials as main materials, the diffractive structure forming layer 12 can be formed by a known coating method such as a gravure printing method or a micro gravure method.

Also, a method well known in the art can be used as a method for recording optical image information on the diffractive structure 13.

When optical image information is recorded using a diffractive structure consisting of fine irregularities, a relief plate is used to form this fine irregular structure. When forming the relief plate, first, the surface of the electron beam curable resin is irradiated with an electron beam, the electron beam curable resin is exposed in a desired pattern, and then developed to produce a master plate. Subsequently, a relief plate is formed by forming a metal film on the surface of the master plate by electroplating and replicating the concave / convex pattern of the master plate.

Then, the diffractive structure 13 composed of a fine concavo-convex structure is formed by thermocompression bonding the relief plate to the diffractive structure forming layer 12 or by curing the relief plate in close contact with an uncured curable resin. The

Further, a diffracted light of an image obtained with light having good coherence may be incorporated in the diffractive structure 13 by recording on a photosensitive material.

(Reflective layer)
Examples of the material that can be used for the reflective layer 14 include various metals such as aluminum, silver, gold, tin, copper, and chromium, and alloys containing these metals. In addition, a metal compound such as titanium oxide, zinc sulfide, magnesium fluoride, antimony sulfide, or silicon oxide can be used as the material of the reflective layer 14. The thickness of the reflective layer 14 is, for example, 10 nm or more and 100 nm or less, and preferably 30 nm or more and 80 nm or less.

As a method of forming a thin film for forming the reflective layer 14 using the materials as described above, a known method such as a vacuum deposition method, a sputtering method, or an ion plating method can be used.

As the material of the reflective layer 14, aluminum is most suitable in view of availability and ease of removal when removing a part of the reflective layer.

(Print layer)
The printed layer 15 is a layer that can visually recognize the shape of characters, illustrations, patterns, and the like. The print layer 15 is formed as follows. That is, a photoresist is uniformly applied to the entire surface of the thin film for forming the reflective layer 14 by a known printing method such as a gravure printing method, a screen printing method, a relief printing method, or a coating method. After that, a portion positioned on the reflective layer 14 through exposure and development becomes a printed layer 15 having characters, illustrations, and a predetermined pattern shape.

As the photoresist, either positive or negative photoresist may be used. A typical example of a positive type photoresist is a so-called DNQ novolak resist in which a novolak resin is a main component and naphthoquinone diazide (DNQ) is added as a photosensitive material. However, a positive type photoresist is limited to this. It is not a thing.

In addition, examples of the negative photoresist include epoxy resin type and carboxyl group-containing resin type, but the negative photoresist is not limited to these. The thickness of the printing layer 15 is, for example, 1 μm or more and 30 μm or less.

It is desirable that the development process of the photoresist and the process of forming the reflective layer 14 by partial removal by etching of a vacuum deposited film such as aluminum can be performed in a single process. Therefore, it is desirable that the photoresist can be developed with acid or alkali.

The material for forming the printing layer 15 may be any material that can function as a mask when the thin film for forming the reflective layer 14 is etched, and may be various metals or metal compounds, for example. . That is, the mask used when the thin film is etched to form the reflective layer 14 may be a hard mask.

The printing layer ink may contain a light-absorbing agent that changes the light transmittance according to the exposure amount with respect to the above-mentioned photoresist, and the printing layer ink may have a color. One or more kinds of additives composed of a material, a fluorescent material, and fillers may be added. That is, the printing layer 15 may be a photoresist layer including at least one of a color material, a fluorescent material, and fillers.

As pigments, pigments and dyes can be used. The diffractive structure forming body 10 has a configuration in which a diffractive structure forming layer 12, a reflective layer 14, and a printing layer 15 are laminated in order from the support 11 side. Further, in the observation from the support 11 side, the diffractive structure forming body 10 has an anti-counterfeiting property due to a change in the pattern visually recognized by observation with forward light, that is, reflected light, and observation with reverse light, that is, transmitted light. Is given.

Here, the use of a pigment as a coloring material has a higher concealability with respect to transmitted light, and the visibility is improved with respect to observation under backlight. Therefore, it can be said that a pigment is more suitable as a coloring material than a dye.

As the pigment to be used, various known pigments such as carbon black can be used, and examples thereof include azo, phthalocyanine, quinacridone, thioindigo, anthraquinone, and isoindolinone pigments.

Fluorescent materials can also use dye types and pigment types, but it can be said that the pigment type is more preferable.

As the fillers, various inorganic fillers such as titanium oxide, precipitated barium sulfate, silica, talc, calcium carbonate, and aluminum oxide can be used. As the fillers, various organic fine particles such as acrylic fine particles, styrene fine particles, acrylic-styrene fine particles, silicon fine particles, and fluorine fine particles can be used. Furthermore, as the fillers, organic or inorganic hollow fine particles can be used, but the fillers are not limited to these.

(Other components)
The diffractive structure forming body 10 may include any other component as long as the configuration and function described above are not hindered. For example, in addition to the antistatic layer, the antifouling layer, the release layer, the easy adhesion treatment layer, and the like, constituent elements as described later may be provided, but the other constituent elements are not limited thereto.

(Adhesive layer)
The adhesive layer 16 is used for attaching the diffractive structure forming body 10 to an adherend substrate. FIG. 5 shows an example in which the diffractive structure forming body 10 is embodied as a sticker. As shown in FIG. 5, the sticker includes a support 11 and a diffractive structure forming layer 12 formed on the support 11, and the diffractive structure forming layer 12 is on the side opposite to the surface in contact with the support 11. The surface includes a diffractive structure 13. In the sticker, the reflective layer 14 is located on a part of the diffractive structure 13, and the printed layer 15 is located on the reflective layer 14. A portion of the diffractive structure 13 where the reflective layer 14 is not located is covered with an adhesive layer 16, and the reflective layer 14 and the print layer 15 are covered with the adhesive layer 16.

FIG. 6 shows an example in which the diffractive structure forming body 10 is embodied as a transfer foil. In the transfer foil, a release layer 17 is provided between the support 11 and the diffractive structure forming layer 12. Note that the release layer 17 is also referred to as a release layer. The thickness of the release layer 17 is, for example, from 0.1 μm to 5 μm, and preferably from 0.5 μm to 2 μm. As shown in FIG. 6, the transfer foil has the same structure as the sticker except that the release layer 17 is positioned between the support 11 and the diffraction structure forming layer 12.

A material known in the art can be used for the adhesive layer, and a pressure-sensitive type or heat-sensitive type adhesive can also be used depending on the object to be pasted. The thickness of the adhesive layer is, for example, 1 μm or more and 20 μm or less.

(Sticker support)
The support for the sticker is a release paper for protecting the adhesive surface of the adhesive layer 16 when the diffractive structure formed body 10 is embodied as a sticker, that is, when the diffractive structure formed body 10 has the adhesive layer 16. Or it is used as a release film. The sticker support is peeled off from the adhesive layer 16 when the sticker is attached to an object to be stuck.

As the support for the sticker, release paper coated with a release material on high-quality paper, coated paper, and nonwoven fabric, vinyl chloride resin, polyester terephthalate resin (PET), polyethylene resin, etc. are made into a film. It is possible to use a release film provided with a release layer.

(Diffraction structure forming body manufacturing method)
As described above, the fine concavo-convex shape of the diffractive structure portion 13 can be formed by thermocompression bonding a relief plate to the diffractive structure forming layer 12.

Thereafter, a thin film made of aluminum or the like is uniformly provided on the entire diffractive structure 13 by vacuum deposition or the like. Next, a diffractive structure forming body before the printing layer 15 is formed is obtained by uniformly applying a photoresist layer to be the printing layer 15 on the surface of the thin film.

7A to 7D are diagrams schematically showing a manufacturing process after pattern exposure using a mask plate. As shown in FIG. 7A, the photoresist layer 19 side of the diffractive structure forming body 10a is irradiated with an irradiation beam, that is, irradiation light 40 through a mask plate 30, and thereby the photoresist layer 19 is exposed. That is, the irradiation light 40 is irradiated to the photoresist layer 19 through the mask plate 30 from the side opposite to the reflective layer 14 before patterning with respect to the photoresist layer 19. Here, the radiation with which the photoresist layer 19 is irradiated, that is, the irradiation beam with which the photoresist layer 19 is exposed means light such as ultraviolet rays, electron beams, and the like.

In the diffractive structure forming body 10a, the support 11, the diffractive structure forming layer 12, the reflective layer 14 before patterning, and the photoresist layer 19 are stacked in the order described.

The mask plate 30 includes a first region 30a having a radiation transmittance A, a second region 30b having a radiation transmittance B, and a third region 30c having a radiation transmittance C, and having three different transmittances. A pattern consisting of regions is formed. That is, the mask plate 30 includes a first region 30a having a radiation transmittance of A%, a second region 30b having a radiation transmittance of B%, and a third region 30c having a radiation transmittance of C%. Has a predetermined pattern.

The radiation transmittance in each region of the mask plate 30 is set as follows. That is, in the photoresist layer 19, the resistance to the developer in the region irradiated with radiation through the first region 30a is the lowest, and the developer in the region irradiated with radiation through the third region 30c. The transmittance of the first region 30a and the transmittance of the third region 30c in the mask plate 30 are set so that the resistance to the highest is obtained. In addition, the second region 30b of the mask plate 30 has a resistance to the developer in the region irradiated with radiation through the second region 30b so that it is between the first region 30a and the third region 30c. The transmittance is set.

For example, the transmittance of the first region 30a is such that the region irradiated with radiation through the first region 30a is uncured in the photoresist layer 19, so that the photoresist layer 19 becomes a developer. When the exposure time reaches the first time, this region is set to a value to be etched. In addition, the transmittance of the second region 30b is such that a part of the region irradiated with radiation through the second region 30b is cured in the photoresist layer 19, thereby exposing the photoresist layer 19 to the developer. When this time is a second time longer than the first time, this region is set to a value to be etched. The transmittance of the third region 30c is such that the region irradiated with radiation through the third region 30c in the photoresist layer 19 is completely cured and is in close contact with the reflective layer 14 as a lower layer. Set to a value.

More specifically, when the photoresist layer 19 is formed from a positive resist, the transmittance A is the highest, the transmittance C is the lowest, and the transmittance B is the transmittance A and the transmittance C. Is set to the transmittance between. On the other hand, when the photoresist layer 19 is formed from a negative resist, the transmittance A is the lowest, the transmittance C is the highest, and the transmittance B is the difference between the transmittance A and the transmittance C. The transmittance is set between.

The radiation applied to the photoresist layer 19 through the mask plate 30 can be an ultra-high pressure mercury lamp, a metal halide lamp, an ultraviolet ray using an LED lamp or the like, and the radiation is applied to the photoresist layer 19. In this case, it is desirable that the radiation is parallel light.

In this way, pattern exposure is performed on the photoresist layer 19 through the mask plate 30, so that the photoresist layer 19 has a first region 19a with an exposure amount A, a second region 19b with an exposure amount B, Then, a third region 19c having an exposure amount C is formed.

When the photoresist layer 19 is formed from a positive resist, the exposure amount A is the largest, the exposure amount C is the smallest, and the exposure amount B is an exposure between the exposure amount A and the exposure amount C. Amount. In contrast, when the photoresist layer 19 is formed from a negative resist, the exposure amount A is the smallest, the exposure amount C is the largest, and the exposure amount B is between the exposure amounts A and C. Exposure amount.

As shown in FIG. 7B, when the exposed diffractive structure forming body is put into a developer, the photoresist layer 19 is developed according to the exposure amount. For example, in the photoresist layer 19, the first region 19 a whose exposure amount is the exposure amount A is the reflective layer 14 that is first removed by development and formed of aluminum or the like, and the reflective layer 14 before patterning. Of these, the portion covered by the first region 19a is exposed.

Thus, as shown in FIG. 7C, only the portion exposed from the photoresist layer 19 in the reflective layer 14 before patterning is etched, thereby forming the reflective layer 14 having a predetermined pattern.

Thereafter, as shown in FIG. 7D, by further developing the photoresist layer 19, the second region 19b having the exposure amount B of the exposure amount B is removed from the photoresist layer 19, and the development is stopped. The third region 19c having the exposure amount C remains, and thereby the printing layer 15 is formed. The printing layer 15 includes a plurality of printing elements, and each printing element is located on the inner side of the edge of the reflective element on which the printing element is located.

In addition, the edge of each printing element and the edge of the reflective element in which the printing element is located may substantially coincide. In other words, in a plan view opposite to the plane in which the diffractive structure forming layer 12 extends, each printing element may have a shape that is homologous to the reflective element in which the printing element is located. In this case, in the manufacturing method of the diffractive structure forming body 10, the steps described above with reference to FIG. 7D can be omitted.

As described above, the method for manufacturing the diffractive structure forming body 10 includes forming a thin film for forming the reflective layer 14 on the diffractive structure portion 13 included in the diffractive structure forming layer 12 and etching the thin film into a predetermined shape. Forming a mask on the thin film. Further, in the method of manufacturing the diffractive structure forming body 10, the reflective element included in the reflective layer 14 is formed from the thin film by etching the thin film using a mask, and the printed layer 15 is positioned on the reflective element. Forming a printing element comprising a mask.

Note that the print layer 15 or the reflective layer 14 may have the following shape depending on the conditions under which the second region 19b of the photoresist layer 19 is etched. That is, the direction in which the second region 19b and the third region 19c are arranged in the photoresist layer 19 is the arrangement direction, and the end portion in contact with the reflective layer 14 in the printed layer 15 is the base end. The opposite end is the tip. Each printing element constituting the printing layer 15 may include a portion where the thickness of the printing element gradually decreases toward each edge in the arrangement direction.

Further, in a plan view facing the diffractive structure portion 13, a portion of each reflective element located outside the printing element is an outer element. In the reflective element, the thickness of the outer element may be smaller than the thickness of the portion other than the outer element in the reflective element.

Further, depending on the conditions under which the photoresist layer 19 is exposed, the photoresist layer 19 may have the following shape. Each printing element constituting the printing layer 15 formed from the photoresist layer 19 may include a portion in which the thickness of the printing element gradually decreases toward each edge in the arrangement direction. The portion where the thickness of the printing element gradually decreases is formed so as to border each printing element. In each printing element constituting the printing layer 15 formed from the photoresist layer 19, there are the following two cases where the thickness of the printing element gradually decreases toward each edge in the arrangement direction. That is, when the printing elements constituting the printing layer 15 formed from the photoresist layer 19 are gradually reduced in thickness toward the respective edges in the arrangement direction and from the leading end to the base end. In some cases, the thickness of each printing element constituting the printing layer 15 gradually decreases toward each edge in the arrangement direction and from the base end to the tip end. Which case is determined depends on whether the photoresist is a positive type or a negative type, the characteristics of the photoresist, development conditions, etching conditions, and the like.

When the photoresist layer 19 is formed of a positive type photoresist, in each printing element constituting the printing layer 15, the printing element 15 is directed toward each edge in the arrangement direction and from the leading end to the base end. The thickness tends to become smaller gradually. When the photoresist layer 19 is formed of a negative photoresist, the thickness of the printing element in each printing element constituting the printing layer 15 is directed to each edge in the arrangement direction and from the base end to the tip end. Tends to become smaller gradually.

Therefore, depending on whether or not the reflective layer 14 and the printed layer 15 include the above-described shape, the printed layer 15 included in the diffraction structure forming body 10 is used for the etching of the photoresist layer 19 used for etching to form the reflective layer 14. It may be possible to determine whether it is a part.

Here, if the photoresist layer 19 is a material that can be developed by acid or alkali, the developing process of the photoresist layer 19 and the etching process of the reflective layer 14 can be performed as one process, and the diffractive structure forming body. The productivity of 10 can be improved.

(Diffraction structure formed body verification method)
The diffractive structure forming body 10 has the configuration illustrated in FIGS. 1 to 3, and the optical image information unit 101 includes a patterned reflection layer 14 and a diffractive structure forming layer 12 including the diffractive structure portion 13. It is configured.

Here, the transmission density of the printing layer 15 is 0.5 or more and less than 2.0, the transmission density of the reflection layer 14 is 1.0 or more, and the transmission density of the support 11 that supports them is By being 0.8 or more and 2.0 or less, the following effects can be acquired. The transmission density of the printing layer 15, the transmission density of the reflection layer 14, and the transmission density of the laminated body of the diffraction structure forming layer 12 and the support 11 have the following relationship. That is, the transmission density of the printed layer 15 is the highest among the printed layer 15, the reflective layer 14, and the laminate of the diffractive structure forming layer 12 and the support 11. The transmission density of the laminate is the lowest, and the transmission density of the reflective layer 14 is a value between these transmission densities.

As shown in FIG. 1, only the optical image information displayed by the optical image information unit 101 is observed in the observation with the forward light, that is, the reflected light from the diffraction structure forming layer 12 side. FIG. 1 shows an image formed by light reflected by the diffractive structure forming body 10 when observed from the first observation direction. At this time, since the image formed by the light reflected by the reflective layer 14 is visually recognized, the image formed by the print layer 15 located on the opposite side to the observation side with respect to the reflective layer 14 is not visually recognized.

On the other hand, as shown in FIG. 2, by observing from the printed layer 15 side, the pattern of the printed layer 15 formed with high alignment accuracy with the pattern of the reflective layer 14 is observed. FIG. 2 shows an image formed by light reflected by the diffractive structure forming body 10 when observed from the second observation direction. Therefore, an image formed by the light reflected by the printing layer 15 and the light reflected by the reflective layer 14 is visually recognized. Therefore, an image formed by the reflective layer 14 and an image formed by the print layer 15 located inside the reflective layer 14 are visually recognized.

Further, when the diffractive structure forming body 10 is observed by back light, that is, transmitted light, as shown in FIG. 4, the pattern of the reflective layer 14 and the pattern of the printed layer 15 formed with high alignment accuracy, as shown in FIG. The watermark image 20 composed of contrast can be observed. In other words, in FIG. 4, the diffractive structure forming body 10 is observed from the first observation direction, and the light is incident on the diffractive structure forming body 10 and passes through at least the diffractive structure forming layer 12 and the support 11. An image displayed by the diffraction structure forming body 10 when light is observed is shown.

As described above, in the diffractive structure forming body 10, the transmission density of the printed layer 15 is the highest, the transmission density of the laminate of the diffractive structure forming layer 12 and the support 11 is the lowest, and the transmission density of the reflective layer 14. Is a value between the transmission density of the printing layer 15 and the transmission density of the laminate of the diffraction structure forming layer 12 and the support 11. Therefore, when the light transmitted through the diffractive structure forming body 10 is observed from the first observation direction, the amount of light transmitted through the printing layer 15 is the smallest among the observed lights, and the diffractive structure forming layer 12 and the support 11 The amount of light transmitted through is the largest. When the light transmitted through the diffractive structure forming body 10 is observed from the first observation direction, the amount of light transmitted through the reflective layer 14 is equal to the amount of light transmitted through the printing layer 15, the diffractive structure forming layer 12 and the support. It is a size between the amount of light transmitted through the body 11.

Therefore, when the light transmitted through the diffractive structure forming body 10 is observed from the first observation direction, it is visually recognized so that the image formed by the printing layer 15 overlaps the image formed by the reflection layer 14.

8 to 10 are plan views showing an example of another diffractive structure forming body 10. The optical image information portion 101 observed from the diffraction structure forming layer 12 side shown in FIG. 8 is the same shape as the reflective layer 14 as shown in FIG. A printed layer 15 is formed. In other words, the printing layer 15 includes a plurality of printing elements, and each printing element is smaller than the reflecting element in which the printing element is located in a plan view opposite to the plane in which the diffraction structure forming layer 12 extends, and It has a shape similar to the printing element. Note that only some of the printing elements may have a shape similar to the reflective element in which the printing element is located.

Conventionally, when a printed layer is formed in accordance with a pattern of a reflective layer that has already been formed, while aligning with the pattern of a reflective layer that has already been formed in a printing process for forming the printed layer, I had to print. Therefore, in reality, a slight positional deviation occurs between the position of the reflective layer and the position of the printed layer.

Therefore, as shown in FIG. 9, it is difficult to form the print layer 15 while accurately aligning with the pattern of the reflective layer 14 while leaving a slight outline. In other words, in the conventional method, the printed layer 15 positioned slightly inside the edge of the reflective layer 14 is formed on the reflective layer 14 while accurately aligning the position of the printed layer 15 with respect to the position of the reflective layer 14. Was difficult. On the other hand, by using the manufacturing method of the diffractive structure forming body 10 described above, the alignment accuracy between the reflective layer 14 and the print layer 15 can be increased, and the position of the reflective layer 14 and the position of the print layer 15 It is possible to suppress the deviation between the two.

Thus, as shown in FIG. 10, when the diffractive structure forming body 10 is observed with backlight, that is, transmitted light, it becomes possible to recognize a pattern as a double grayscale image leaving a uniform outline. More specifically, the light incident on the diffractive structure forming body 10 from the opposite side of the support 11 with respect to the diffractive structure forming layer 12 and transmitted through at least the diffractive structure forming layer 12 and the support 11. Observation is performed from the second observation direction described above. Thereby, an image in which the watermark image 20 that is an image formed by the light transmitted through the printing element is positioned inside the image formed by the light transmitted through the reflective element is visually recognized.

It should be noted that the print element is positioned on the reflective element so that the center of each print element substantially coincides with the center of the reflective element on which the print element is located in a plan view opposite to the plane on which the diffractive structure forming layer 12 extends. ing. Therefore, when the light transmitted through the diffractive structure forming body 10 is visually recognized from the first observation direction, the image formed by the reflective element is outside the image formed by the printing element positioned on the reflective element. The portion located at has a substantially equal width.

Further, the mask plate at the time of exposure includes three types of portions having different transmittances, but may be configured to include four or more regions having different transmittances. In this way, when the photoresist layer 19 is exposed using a pattern composed of four or more regions having different transmittances, the printed layer 15 is observed when the diffractive structure forming body 10 is observed with transmitted light. It is also possible to express shading in the inside. This makes it possible to make the watermark image that can be confirmed by the observer at the time of observation with backlight, that is, transmitted light more expressive, in other words, to improve the design of the watermark image.

Hereinafter, examples and effects thereof will be described, but the examples do not limit the scope of application of the present invention.

Example 1
As a support for the sticker, a polyethylene terephthalate (PET) film having a thickness of 50 μm was used. The following ink composition was applied to one side of the support by the gravure printing method, and then the coating film was dried to form the diffraction structure forming layer 12 having a thickness of 1.5 μm.

(Diffraction structure forming layer ink composition)
Urethane resin 15.0 parts by weight Toluene 42.5 parts by weight Methyl ethyl ketone 42.5 parts by weight

Next, while applying pressure to the relief plate for expressing the diffracted light pattern, it was pressed against the diffractive structure forming layer 12 to form the desired diffractive structure 13 on the diffractive structure forming layer 12.

Next, on the diffractive structure forming layer 12 having the diffractive structure 13, aluminum is laminated by a vacuum deposition method, and a thin film for forming the reflective layer 14 having a film thickness of 40 nm, that is, the reflective layer 14 before patterning. Formed.

Next, after applying the following ink composition on the reflection layer 14 before patterning by a gravure printing method, the coating film was dried to form a photoresist layer 19 having a film thickness of 10 μm. Note that a negative photoresist was used as the photoresist.

(Photoresist layer ink composition)
UV curable photoresist 20.0 parts by weight Hydrophobic inorganic filler 5.0 parts by weight Methyl ethyl ketone 75.0 parts by weight

Next, a third region having a light transmittance of 98% or more, a second region having a light transmittance of 20%, and a first region having a light transmittance of 0%, each having three different transmittances. A mask plate for exposure was prepared in which characters and pattern patterns were formed by these areas. The first area was opaque, the second area was translucent, and the third area was transparent. This mask plate is overlaid on the photoresist layer 19, and the photoresist layer 19 is exposed by irradiating the photoresist layer 19 with collimated ultraviolet rays through the mask plate using an ultrahigh pressure mercury lamp as a light source. It was.

Next, a film including the exposed photoresist layer 19, that is, a laminate composed of the support 11, the diffractive structure forming layer 12, the reflective layer 14, and the photoresist layer 19 is converted into a 1% sodium hydroxide aqueous solution. It was immersed in the developing solution.

When the laminate was immersed in the developer, when the photoresist layer 19 was exposed in the photoresist layer 19, the mask plate had an area where the light transmittance was 0%, that is, the first area facing the first area. The first region 19a, which is the exposed portion, was first dissolved, thereby exposing the reflective layer 14 located immediately below the first region 19a. Furthermore, when the laminate was kept immersed in the developer, the portion of the reflective layer 14 exposed from the photoresist layer 19 was etched and dissolved. Furthermore, if the laminate is kept immersed in the developer, the region of the mask plate where the light transmittance is 20% when the photoresist layer 19 is exposed in the photoresist layer 19, that is, the second layer. The second region 19b facing the region is dissolved, and finally, in the photoresist layer 19, when the photoresist layer 19 is exposed, a region having a light transmittance of 98% or more in the mask plate, that is, the first layer A third region 19c facing the three regions remained on the reflective layer 14 as the print layer 15. Thereby, the reflective layer 14 and the printing layer 15 patterned into a predetermined shape were formed.

Next, the following ink composition is applied by gravure printing so as to cover the entire surface of the diffraction structure forming layer 12, the reflective layer 14, and the printing layer 15, and then the coating film is dried, whereby the film thickness is 5 μm. In other words, an adhesive layer 16 was laminated. Next, a polyethylene layer was laminated on one side of kraft paper having a thickness of about 100 μm, and silicon treatment was performed on the polyethylene layer to form a separator. By sticking this separator to the adhesive layer 16, a sticker was obtained.

(Ink composition for adhesive layer)
Acrylic adhesive 30.0 parts by weight Ethyl acetate 50.0 parts by weight Toluene 20.0 parts by weight

In the sticker as the diffractive structure forming body 10 obtained in this way, diffracted light is generated when light is incident on the portion where the reflective layer 14 is located in a normal light environment, and the diffractive structure corresponding to the pattern shape of the reflective layer 14 is used. Letters and images were observed. Furthermore, in a backlit environment, it was recognized that the printed layer 15 located under the reflective layer 14 was formed in a character or pattern pattern, so that it was observed as a black watermark image.

Further, in a backlit environment, it was recognized that the reflective layer 14 having the same shape as the printed layer 15 of the character pattern was observed as a contour because the alignment accuracy of the reflective layer 14 and the printed layer 15 was high. . In other words, it was recognized that micro characters and patterns finer than the micro characters displayed by the reflective layer 14 can be observed inside the micro characters by the reflective layer 14.

Note that the normal light environment refers to a state in which the light reflected by the diffractive structure forming body 10 is observed from the first observation direction, while the reverse light environment refers to a diffraction structure from the first observation direction. In this state, the light transmitted through the formed body 10 is observed.

(Example 2)
As the support 11, a polyethylene terephthalate (PET) film having a thickness of 25 μm was used. The following ink composition was applied to one side of the support 11 by a gravure printing method, and then the coating film was dried to form a release layer 17 having a film thickness of 0.5 μm.

(Peeling layer ink composition)
Polyamideimide resin 19.0 parts by weight Polyethylene powder 1.0 part by weight Dimethylacetamide 30.0 parts by weight Toluene 50.0 parts by weight

Next, after applying the following ink composition on the release layer 17 by a gravure printing method, the coating film was dried to laminate the diffraction structure forming layer 12 having a film thickness of 1.5 μm. Then, the desired diffraction structure part 13 was formed on the diffraction structure formation layer 12 by performing the embossing which presses against the diffraction structure formation layer 12, applying a hot pressure to the relief plate for expressing a diffraction light pattern.

Next, on the diffractive structure forming layer 12 having the diffractive structure part 13, aluminum was laminated by a vacuum vapor deposition method to form a reflective layer 14 having a film thickness of 40 nm.

Next, after applying the following ink composition on the reflective layer 14 by a gravure printing method, the coating layer was dried to form a photoresist layer 19 having a thickness of 10 μm.

Next, a third region having a light transmittance of 98% or more, a second region having a light transmittance of 20%, and a first region having a light transmittance of 0%, each having three different transmittances. We prepared a mask version in which characters and patterns of patterns were composed of the above areas. The first area was opaque, the second area was translucent, and the third area was transparent. This mask plate is overlaid on the photoresist layer 19, and the photoresist layer 19 is exposed by irradiating the photoresist layer 19 with collimated ultraviolet rays through the mask plate using an ultrahigh pressure mercury lamp as a light source. It was.

Next, a film including the exposed photoresist layer 19, that is, a laminate composed of the support 11, the release layer 17, the diffraction structure forming layer 12, the reflective layer 14, and the photoresist layer 19, is 1%. It was immersed in the developing solution which is sodium hydroxide aqueous solution.

When the laminate is immersed, in the photoresist layer 19, when the photoresist layer 19 is exposed, the mask plate is a region where the light transmittance is 0%, that is, an unexposed portion facing the first region. A certain first region 19a was first dissolved, thereby exposing a reflective layer located immediately below the first region 19a. Furthermore, when the laminate was kept immersed in the developer, the portion of the reflective layer 14 exposed from the photoresist layer 19 was etched and dissolved. Further, when the laminated body is kept immersed, when the photoresist layer 19 is exposed in the photoresist layer 19, the mask plate is opposed to the region having a light transmittance of 20%, that is, the second region. When the second region 19b is dissolved and finally the photoresist layer 19 is exposed in the photoresist layer 19, the mask plate has a light transmittance of 98% or more, that is, the third region. The opposing third region 19c remained on the reflective layer 14 as the printed layer 15. Thereby, the reflective layer 14 and the printing layer 15 patterned into a predetermined shape were formed.

Next, after coating the following ink composition by the gravure printing method so as to cover the entire surface of the diffractive structure forming layer 12, the reflective layer 14, and the printing layer 15, the film thickness is reduced by drying the coating film. An adhesive layer 16 having a thickness of 3 μm was laminated. Thereby, the transfer foil as the diffractive structure forming body 10 was obtained.

(Ink composition for adhesive layer)
Vinyl chloride vinyl acetate copolymer resin 15.0 parts by weight Acrylic resin 10.0 parts by weight Silica 1.0 part by weight Methyl ethyl ketone 44.0 parts by weight Toluene 30.0 parts by weight

Next, a transparent PET film having a thickness of 50 μm was prepared as a substrate for transfer foil. Then, the transfer foil is placed on the substrate to be transferred, and a part of the transfer foil is transferred with a hot roll transfer machine, and then the support 11 is peeled off, whereby the adhesive layer 16, the printing layer 15, and the reflective layer 14. The support 11 was removed from the laminate composed of the diffraction structure forming layer 12 and the release layer 17.

Thereby, as shown in FIG. 11, an article 50 which is a forgery prevention medium having the diffractive structure forming body 10 was obtained. In Example 2, the article 50 is embodied as a gift card.

In the article 50 with a diffractive structure formed body thus obtained, diffracted light is generated when light is incident on the portion where the reflective layer 14 is located from the release layer 17 side in a normal light environment, whereby the observation is performed from the release layer 17 side. Then, it was recognized that the character and image by the diffraction structure corresponding to the pattern shape which the reflection layer 14 has are observed.

As shown in FIG. 12, in a backlit environment, it was recognized that the printed layer 15 positioned below the reflective layer 14 was formed in a pattern of characters or a pattern, so that it was observed as a black watermark image. In addition, in a backlit environment, it is recognized that the reflective layer 14 having the same shape as the printed layer 15 of the character pattern is observed as a contour because the alignment accuracy of the reflective layer 14 and the printed layer 15 is high. It was. In other words, it was recognized that micro characters and patterns finer than the micro characters represented by the reflective layer 14 can be observed inside the micro characters formed by the reflective layer 14.

On the other hand, when the article 50 is observed from the adhesive layer 16 side through the transparent substrate to be transferred, the reflective layer 14 and the printed layer 15 are observed in an aligned state, and the printed layer 15 is colored. It was recognized that the color of the printing layer 15 that cannot be confirmed from the peeling layer 17 side is also visually recognized.

As described above, the diffractive structure forming body 10 is embodied as a forgery prevention medium such as a sticker or a transfer foil, and thus the diffractive structure forming body 10 is attached to various articles, so that it is difficult to forge or tamper. Article 50 can be provided.

DESCRIPTION OF SYMBOLS 10 ... Diffraction structure formation body 10a ... Pre-pattern formation diffraction structure formation body 11 ... Support body 12 ... Diffraction structure formation layer 13 ... Diffraction structure formation part 14 ... Reflection layer 15 ... Print layer 16 ... Adhesion layer 17 ... Release layer DESCRIPTION OF SYMBOLS 19 ... Photoresist layer 19a ... 1st area | region 19b ... 2nd area | region 19c ... 3rd area | region 101 ... Optical image information part 20 ... Watermark image 30 ... Mask plate 30a ... 1st area | region 30b ... 2nd area | region 30c ... 3rd area | region 40 ... Irradiation light 50 ... Article

Claims

A diffractive structure forming layer including a diffractive structure portion on which optical image information is recorded;
A reflective layer located on a portion of the diffractive structure and including at least one reflective element;
A printing layer comprising at least one printing element, wherein the printing element is located on the reflective element,
The printed layer is at least a part of a mask used for forming the reflective layer.
In a plan view facing the plane in which the diffractive structure forming layer spreads,
The diffractive structure forming body according to claim 1, wherein the printing element is located inside an edge of the reflective element where the printing element is located.
The printing layer includes a plurality of the printing elements,
The plurality of printing elements include the printing element having a shape similar to the reflective element in which the printing element is located in a plan view facing a plane in which the diffraction structure forming layer extends. Diffraction structure formed body.
The diffractive structure forming body according to any one of claims 1 to 3, wherein the print layer is a photoresist layer including at least one of a color material, a fluorescent material, and fillers.
A support body in contact with the diffractive structure forming layer on the side opposite to the reflective layer with respect to the diffractive structure forming layer;
The diffraction structure forming layer and the support constitute a laminate,
Among the printed layer, the reflective layer, and the laminated body, the transmission density of the printed layer is the highest, the transmission density of the laminated body is the lowest, and the transmission density of the reflective layer is the printed layer. The diffractive structure forming body according to any one of claims 1 to 4, wherein the diffractive structure forming body is a value between the transmission density of the laminated body and the transmission density of the laminated body.
The transmission density of the printed layer is 0.5 or more and less than 2.0, the transmission density of the reflective layer is 1.0 or more, and the transmission density of the support is 0.8 or more and 2.0 or less. The diffractive structure formed body according to claim 5.
A diffractive structure forming body;
An article with a diffractive structure forming body, the article supporting the diffractive structure forming body,
The article with a diffractive structure forming body is the diffractive structure forming body according to any one of claims 1 to 6.
A method for producing a diffractive structure forming body comprising a diffractive structure forming layer including a diffractive structure part, a reflective layer including a reflective element, and a printed layer including a printing element,
Forming a thin film for forming the reflective layer on the diffractive structure;
Forming a mask on the thin film for etching the thin film into a predetermined shape;
Forming the reflective element from the thin film by etching the thin film using the mask, and forming the printing element positioned on the reflective element from the mask. Production method.