JP2013037029A - Hologram sheet - Google Patents

Abstract

【Task】
In order to increase the authenticity of hologram sheets using holograms, a new hologram sheet that can reproduce relief holograms by applying a predetermined electric field in addition to reproducing volume holograms that can be observed under normal illumination light is provided. To do.
[Solution]
By alternately providing relief hologram forming layers behind the volume hologram forming layer, following the hologram relief, providing an electroluminescence element layer, applying a predetermined electric field, the electroluminescence element layer emits light and is visible A relief hologram reconstructed image in the light region by the color tone of the emitted light was reconstructed so that it could be visually judged and a hologram sheet with improved anti-counterfeiting properties was obtained.
[Selection] Figure 1

Description

The present invention relates to a novel hologram sheet, and more particularly to a composite hologram sheet in which a relief hologram forming layer that expresses a relief hologram reproduction image by light emission of an electroluminescence element layer is provided behind a volume hologram.
Furthermore, the recording area of the volume hologram recorded on the volume hologram forming layer and the formation area of the hologram relief are alternately provided. When observing, the recording area and the forming area do not overlap and are generated from each area. The present invention relates to a hologram sheet in which a light beam of a volume hologram reproduction image and a light speed of a relief hologram reproduction image do not interfere with each other and can be clearly visually recognized.
However, when each region is alternately provided as a band having a width of 300 μm or less, when a predetermined electric field is applied, the light flux of each reproduced image interferes, and any hologram reproduced image does not appear, The present invention relates to a hologram sheet that is observed as if a hologram reproduction image has disappeared and has excellent anti-counterfeiting properties.
In the present specification, “part” indicating the formulation is based on mass. The “hologram” includes a hologram and a hologram having a light diffractive function such as a diffraction grating.

(Main applications)
The main use of the hologram sheet of the present invention is in the art / craft field and commercial field using the hologram itself for decoration, but is not limited to this, and is a hologram sheet used in the counterfeit prevention field. In particular, credit cards and other counterfeited products that can damage cardholders and card companies, driver's licenses, employee ID cards, ID cards such as membership cards, and entrance examinations Votes, passports, banknotes, gift certificates, point cards, stock certificates, securities, lottery tickets, horse betting tickets, bank passbooks, boarding tickets, passports, air tickets, admission tickets for various events, amusement tickets, transportation facilities and public telephones There are prepaid cards.
Each of these is an information recording body that holds information having economic or social value, and it is desirable to have a function that can identify the authenticity of the recording body for the purpose of preventing damage caused by forgery. .

In addition to these information recording media, expensive products such as luxury watches, luxury leather products, precious metal products, jewelry, etc., often referred to as luxury brand products, or storage of such expensive products. Boxes and cases can also be forged. In addition, mass-produced products of famous brands, such as audio products, electrical appliances, etc., or tags that are hung on them are also subject to forgery.
Furthermore, a storage body in which music software, video software, computer software, game software, or the like, which is a copyrighted work, or cases thereof can also be forged. In addition, it is desirable that products such as printer toner, paper, and the like in which supplies to be replaced are limited to genuine materials have a function of identifying their authenticity for the purpose of preventing damage caused by forgery.

(Background technology)
Conventionally, for the purpose of preventing counterfeiting of information recording bodies and various articles described above (collectively referred to as authenticity identification objects), it is said that they have manufacturing difficulties due to the precision of their structures. In many cases, holograms are applied as authenticity distinguishable. However, since the hologram manufacturing method itself is known and can be precisely processed by that method, when the hologram is merely for visual judgment, there is no difference between a genuine hologram and a forged hologram. It is difficult to distinguish.
These authentic identification objects, in particular, articles that have been subjected to hologram images in a label form or transfer form, are not only used for authentic identification of visual confirmation of hologram images, but also by using a new authenticity identification method. There is a need to identify the authenticity of.

(Prior art)
In order to meet these requirements, there has been proposed a hologram sheet having a light selective reflection layer that is laminated on a hologram and reflects only one of the left-handed polarized light and the right-handed polarized light among the incident light. (For example, refer to Patent Document 1.)
As this light selective reflection layer, cholesteric liquid crystal is used, and the anti-counterfeiting property is enhanced by a method of confirming using a polarizing plate or the like.
However, as described in Patent Document 1, since the reflectance of the reflective thin film layer on the hologram forming layer is high, the light that is transmitted without being reflected by the cholesteric liquid crystal layer (complementary light of selective reflected light) Reflecting on the reflective thin film layer and returning to the cholesteric liquid crystal layer again (hereinafter referred to as return light), this return light becomes a noise component when observing the cholesteric liquid crystal and is added to and mixed with the selectively reflected light. However, the color tone was not the original color of the liquid crystal, and it was even difficult to see and identify.

Further, as described in Patent Document 2, a reflection volume hologram that requires a high level of technology for its production is used as the hologram, and the hologram reproduction image having a three-dimensional effect is visually recognized even under white light. Anti-counterfeiting technology that performs forgery determination has also been proposed.
Such a reflection type volume hologram itself has transparency, and reflects only light of a predetermined wavelength (close to a single wavelength) when illuminated by a white light source having a wide wavelength range, and the reflected light. The hologram reproduction image by is made to appear.
However, this reflective volume hologram also interferes only with light in a very narrow wavelength region from illumination light having a light intensity over a wide wavelength region such as white light due to its wavelength selectivity. Since the hologram reproduction image appears only with the intensity of light, the “brightness” of the hologram reproduction image becomes 1/10 or less of the “brightness” of the illumination light. However, it has the disadvantage that it is not sufficient for the purpose of authenticity determination.

JP 2007-90538 A JP-A-10-97171

Accordingly, the present invention has been made to solve such problems. The object relates to a composite hologram sheet in which a relief hologram forming layer that expresses a relief hologram reproduction image by light emission of an electroluminescence element layer is provided behind the volume hologram forming layer.
Furthermore, the volume hologram recording area and the hologram relief forming area are alternately provided, and the hologram sheet is capable of clearly observing any hologram reproduction image. Further, each area is formed as a strip having a width of 300 μm or less. By providing them alternately, it is to provide a hologram sheet with excellent anti-counterfeit properties that is observed as if a hologram reproduction image has disappeared when a predetermined electric field is applied.
In addition, since such a hologram sheet has not existed so far, it is to provide a novel decorative property and an anti-counterfeit property to which this is applied.

To solve the above problem,
The first aspect of the hologram sheet of the present invention is:
A volume hologram forming layer, a relief hologram forming layer provided with a hologram relief, and an electroluminescence element layer provided following the hologram relief of the relief hologram forming layer in this order on one surface of the transparent substrate. The hologram sheet provided in
The volume hologram recording area recorded on the volume hologram forming layer and the hologram relief forming area are alternately provided.
According to the hologram sheet of the first aspect,
A volume hologram forming layer, a relief hologram forming layer provided with a hologram relief, and an electroluminescence element layer provided following the hologram relief of the relief hologram forming layer in this order on one surface of the transparent substrate. The hologram sheet provided in
It is possible to provide a hologram sheet in which a volume hologram recording area recorded on the volume hologram forming layer and a hologram relief forming area are alternately provided, and a hologram reproduction image can be clearly determined. A possible hologram sheet is provided.
The second aspect of the hologram sheet of the present invention is:
The volume hologram recording area and the hologram relief forming area are band-like areas having a width of 100 μm to 300 μm.
According to the hologram sheet of the second aspect,
The recording area of the volume hologram and the formation area of the hologram relief can be provided as a band-like area having a width of 100 μm to 300 μm, and as a result of application of a predetermined electric field, the entire hologram reproduction image has disappeared. It is possible to provide a hologram sheet that is excellent in unexpectedness and anti-counterfeiting properties.

The third aspect of the hologram sheet of the present invention is:
The electroluminescence element layer has a thickness of 0.01 μm to 2.0 μm.
According to the hologram sheet of the third aspect,
The hologram sheet according to the first or second aspect, wherein the electroluminescence element layer has a thickness of 0.01 μm to 2.0 μm, and by applying a predetermined electric field, Furthermore, it is possible to provide a hologram sheet that can improve the anti-counterfeit property by making it possible to visually recognize a clear relief hologram reproduction image or ensuring the disappearance of the hologram.

In the hologram sheet of the present invention, a volume hologram forming layer, a relief hologram forming layer provided with a hologram relief, and an electroluminescence element layer provided following the hologram relief are arranged in this order on a transparent substrate. The hologram sheet is provided with a volume hologram recording area recorded on the volume hologram forming layer and a hologram relief forming area alternately.
That is, from the viewpoint of the observer, the volume hologram recording area and the volume hologram recording area are observed to be alternately arranged in a predetermined shape and a predetermined size. For example, assuming a region in which a square with a side of 3 mm is spread vertically and horizontally, each region is formed in the individual square, and only under the illumination of natural light or a fluorescent lamp, only the volume hologram, Reproduced from the flying region and observed as one volume hologram reproduction image, but by applying a predetermined voltage, the relief holograms in the remaining squares are also reproduced and visually recognized as two independent hologram reproduction images. Will be able to.
If the size of each of these areas is 0.5 mm to 5.0 mm, the observer cannot determine that the holograms are separated individually, as if two holograms were recorded in multiple recording. Observed as is.
However, if the size of each region exceeds 5.0 mm, the presence of each region can be easily visually recognized by an observer. Therefore, considering the decorative properties of the hologram sheet of the present invention, the size of each region Is preferably 5.0 mm or less.
In addition, when the size of each region is smaller than 0.5 mm, the two hologram reproduction images start to interfere with each other, and when the size is 0.3 mm or less, that is, 300 μm or less, the mutual interference becomes stronger. The image cannot be formed as an independent hologram reproduction image, and it is observed as if the hologram reproduction image has disappeared.
However, in order to make one hologram reproduction image visible as an aggregate of fine regions, the size occupied by one fine region needs to be 100 μm or more. The minimum size of the recording area or formation area is set to 100 μm.

In this volume hologram forming layer, “reflection type volume hologram (Lippmann hologram)” and “transmission type volume hologram” which are visible under normal illumination light are recorded. It is observed as a hologram sheet on which “volume hologram (Lippmann hologram)” or “transmission volume hologram” is recorded. When a predetermined electric field is applied to this hologram sheet, the electroluminescence element layer emits light, and the light emission As a result, a relief hologram reproduction image is developed, and in addition to the volume hologram, a relief hologram can be observed.
This “volume hologram” can be recorded directly using a predetermined optical imaging method. However, an unrecorded volume hologram can be recorded by a contact exposure method using the directly recorded volume hologram as a copy master. It is also possible to record by copying to the formation layer.
In general, when recording a “volume hologram”, a diffraction condition called “Bragg condition” is important. In order to obtain diffracted light (ie, a volume hologram reproduction image) from this “volume hologram” The read light to be irradiated (meaning illumination light for reproducing a hologram reproduction image) must satisfy the “volume hologram” and the “Bragg condition”.
When light having exactly the same wavelength, incident angle, and beam divergence angle as the light used for recording is used as the readout light, the “Bragg condition” is automatically satisfied. Therefore, for reproduction of the volume hologram, it is necessary to use the “reference light” used for recording (the volume hologram is recorded by causing the “object light” and “reference light” to interfere with each other in the recording material). .
The “volume hologram forming layer on which the volume hologram is formed” used for the hologram sheet of the present invention is recorded on a transparent film itself such as a photopolymer film, and then laminated on a transparent substrate. Method, or a method in which a transparent resin is coated on a transparent substrate and a “volume hologram forming layer” is provided, and then directly photographed on the volume hologram forming layer, or an optical plate in which an original is adhered It is provided by a method of recording a volume hologram by a replication method.
At this time, by performing masking with an appropriate pattern, the volume hologram can be formed in a jumping manner.

On this volume hologram forming layer, a diffraction grating group for reproducing a hologram image is formed as a hologram relief on a relief hologram forming layer surface made of a transparent resin material substantially on a flat surface and at a predetermined interval. (The area where the hologram relief is not formed is a simple plane.) The electroluminescence element layer is provided on the hologram relief and on the simple plane with a uniform thickness. ing.
In other words, the hologram relief formed in a jumping manner shows the phase difference as a phase hologram in a “flying relief shape”, but the electroluminescence follows (along) the “hologram relief shape” having this phase difference. By providing the element layer, the light emitted from the electroluminescence element layer is emitted with (including) the phase difference.
Hereinafter, the principle that a relief hologram reproduction image appears by the electroluminescence element layer will be described below.
When reproducing a relief hologram, when the relief hologram is illuminated with a predetermined illumination light, Huygens secondary waves generated at every point (location) on the relief hologram surface are generated. In the case of the hologram sheet of the invention, what corresponds to this secondary wave is the light emission (emitted light) of the electroluminescence element layer arranged on the hologram relief surface, and this light plays its role, in the hologram image. The light (light emission) emitted including the phase difference of the corresponding hologram relief is delivered to the observer side.
That is, the emitted light (light emission) causes an interference phenomenon in the space on the hologram relief surface, and as a result, a predetermined relief hologram reproduction image is developed in a predetermined direction.
In the first place, electroluminescence is a phenomenon in which a fluorescent substance or the like emits light by the energy of an electric field, and a surface light source can be obtained. Broadly speaking, there are organic electroluminescence and inorganic electroluminescence.
Organic electroluminescence is a light emission phenomenon using an organic substance having a property of emitting light when an electric current is passed, and has a structure in which an organic substance is sandwiched between layers serving as a base.
By passing a current between the layers, molecules of the organic substance are excited to emit light.
A typical layer structure is composed of / anode (transparent conductive layer) / hole transport layer / organic material layer / electron transport layer / cathode (transparent conductive layer), and emits light (light emission) emitted from the anode side.
In other words, an organic electroluminescence device formed of a thin film has an electron that has reached the organic material layer from the cathode (cathode layer) through the electron transport layer and a hole that has reached the organic material layer from the anode through the hole transport layer. HYPERLINK "http://www.weblio.jp/content/%E5%8A%B1%E8%B5%B7%E5%AD%90" \ o "exciton" exciton (exciton) ).

That is, when an organic substance molecule or the like is excited by the energy generated at the time of recombination and returns from the excited state to the ground state again, fluorescence (including phosphorescence) emission or the like occurs.
As shown in the Jablonski diagram shown in FIG. 1, the principle of fluorescence emission is first absorbed by energy absorption from the ground state (S0: singlet state) of the organic substance (including a complex system of a plurality of substances). The molecules of the organic substance excited in one of the vibration states of one (S1), the second (S2), the third excited state (S3),... Or the triplet state (T1, T2) by intersystem crossing.
The phosphor in the lowest vibration state of S1 returns to the ground state by a non-radiation process or emits fluorescence, and the molecule in the triplet state returns to the ground state by phosphorescence or by phosphorescence.
Energy that cannot be used well for light even when excited is non-radiatively deactivated (thermally deactivated).
Since the transition between singlets occurs instantaneously, the half-life of fluorescence is as short as 10 ⁻⁴ sec or less. The time required for the transition is said to be excited at 10 ⁻¹⁵ sec and then to emit fluorescence at 10 ⁻⁹ to 10 ⁻⁷ sec.
On the other hand, the transition from triplet to singlet is a forbidden transition due to the prohibition of spin change, and spontaneous emission is less likely to occur. Therefore, the half-life of phosphorescence is large, and there are some in seconds.
Whether or not light is emitted when returning to the ground state, whether the light intensity is strong or weak, and whether the fluorescence lifetime is long or short depends greatly on the molecular structure of the organic substance molecule and the environment in which the molecule is placed. To do.
The wavelength distribution of emitted light such as molecules of an organic substance is called an emission spectrum, and the emission spectrum is created by plotting the emission intensity relative to the emission wavelength. The wavelength (energy) shown in the emission spectrum is equal to the energy difference from the lowest vibration energy level in the primary excited state to the preferential vibration energy level in the ground state.

Inorganic electroluminescence is a physical phenomenon that emits light when an electric field is applied to a substance. The mechanism is HYPERLINK "http://en.wikipedia.org/wiki/%E7%84%A1%E6" % A9% 9F% E5% 8C% 96% E5% 90% 88% E7% 89% A9 "\ o" Inorganic compounds "Pre-existing in the solid when a voltage is applied to an inorganic compound phosphor (emission layer) The electrons or the electrons injected from the electrodes are accelerated by a high electric field, collide with the light emission center and excite it, and the generated electrons and holes recombine to emit light. Organic electroluminescence, which emits light by recombination of electrons and holes injected by current from the outside, is different in terms of excitation.
That is, an inorganic electroluminescent element formed of a thin film has a double insulation structure, and light emission occurs when an electric field is applied to this structure.
The configuration of the light emitting layer is divided into “dispersion type” and “thin film type”. In the dispersion type, an insulating layer in which a ferroelectric powder is dispersed in an organic binder and a phosphor powder are dispersed in the organic binder. The light emitting layer is laminated and sandwiched between the transparent electrode and the back electrode. The typical structure is / transparent electrode / insulating layer / light emitting layer / back electrode / or / transparent electrode / insulating layer / Light emitting layer / insulating layer / back electrode /.
In this layer structure,
The thin film type is a structure in which a light emitting layer made of a thin film phosphor and an insulating layer are laminated on a substrate with a thin film electrode, and an electrode is attached. The layer is formed using a thin film forming method such as sputtering or vacuum evaporation. To do. Its typical configuration is the same as that of the distributed type.
In either case, emitted light (emission) is emitted from the transparent electrode side.
The relief hologram of the hologram sheet of the present invention is a conventional relief hologram reproduction method, that is, the illumination light from the illumination light source is applied to the relief hologram, and the wavelength of the illumination light is reflected by the interference phenomenon of the reflected light on the hologram relief surface. Unlike the one that reproduces a relief hologram, by applying a voltage, the electroluminescence element emits light, and the emitted light (emission) itself causes the above interference phenomenon, and the relief at the wavelength of the emitted light (emission). A hologram is reproduced. Therefore, the diffraction angle also depends on the wavelength of the light (emission) emitted.

For example, a transparent space where almost nothing can be seen (such as a laser reproduction hologram that requires single-wavelength light for reproduction cannot be viewed with a white light source, and is a rainbow hologram suitable for white light reproduction. However, even when the interface reflection intensity of the holographic relief surface is small, it is also difficult to visually recognize.) For example, a “green” relief hologram can be visually recognized for the first time by applying a voltage. As if there is no “green illumination light source” normally used for reproduction, only the relief hologram shines and appears to float in the air, and the design is excellent.
Further, which part of the electrode terminal for applying an electric field (an anode terminal and a cathode terminal. A plurality of these terminals may be provided, or by providing a dummy terminal, the anti-counterfeiting property can be improved) capable of reproducing a relief hologram. It can be made difficult to determine whether it is formed, and only those who can know the structure can reproduce the hologram, making it useful for authenticity determination.
In addition, only those who can know the wavelength of the emitted light (light emission) can predict the color tone of the relief hologram reproduction image, and can look through the bandpass filter adjusted to the reproduction wavelength and pass through the bandpass filter. Only can be determined to be authentic.
Further, the angle (diffraction angle) passing through the band-pass filter also depends on the emission wavelength, and only those who can know the value can make the determination at the predetermined angle.
Furthermore, by including a plurality of electroluminescent elements formed of a thin film, this reproduced image appears in different colors at a plurality of angles, which is superior in terms of both design and authenticity. be able to.
Of course, since the electroluminescence element has a light emission spectrum that varies greatly depending on the voltage applied, and has a light emission characteristic unique to each element, the applied voltage (voltage intensity, frequency, etc.) used for authenticity determination is known. It can be said that it is physically impossible for a counterfeiter who is unable to make a hologram sheet identical to the genuine product.

Specifically, the structure of the organic electroluminescence element has a single layer structure in which an organic thin film serving as a light emitting layer is sandwiched between a cathode and an anode, or a structure having a hole transport layer between the anode and the light emitting layer. , Having an electron transport layer between the cathode and the light-emitting layer, having a light-emitting layer portion having a three-layer structure of an electron transport layer, a light-emitting layer, and a hole transport layer, and having a multilayered structure as necessary A thing etc. can be used.
The layers sandwiched between these anodes and cathodes are all composed of an organic thin film (solid), and the thickness of each layer is 10 to 100 nm.
If the thickness is less than 10 nm, the function of each layer cannot be sufficiently exerted, and if the thickness is 100 nm, it is sufficient to achieve the function of each layer. And
The light-emitting layer is a two-component system of a main material (host material) and an impurity material (dopant material: added for improving functions such as emission intensity improvement). 30% addition is uniformly dispersed in the main material.
If it is less than 0.1%, the luminescent property is insufficient, and if it exceeds 30%, the impurity property (existence as a singular point) is weakened and the luminescent property starts to decrease.
For the anode, a transparent conductive thin film called ITO thin film (indium / tin oxide thin film), tin-doped tin oxide, antimony-doped tin oxide, zinc-doped tin oxide, fluorine-doped oxidation, which is both transparent and conductive Examples thereof include metal oxides such as tin and zinc oxide, multilayer structures in which a thin film of silver is sandwiched between high refractive index layers, and conjugated polymers such as polyaniline and polypyrrole.
As a forming method, a thin film forming method, that is, a sputtering method, a vacuum evaporation method, or the like is used to form a film with a thickness of 50 to 500 nm. From the above consideration, the surface resistance value of the transparent conductive thin film is set to 0.001Ω / □ to 0.1Ω / □.
Although a printing method or the like can be used as a forming method, it is necessary to contact and follow the hologram relief, and this layer maintains the relief shape, and the relief shape is also applied to the next thin film layer. In order to provide the above, the thickness of this layer needs to be thin and highly uniform, and the above-described thin film forming method is desirable.

The relief shape irregularities of the hologram relief are as fine as 0.01 μm to 1 μm, and the period is also 0.01 μm to 1 μm, which is very fine and has a gentle change, but faithfully this gentle change If it cannot be reproduced, the reproduced hologram image cannot be accurately and brightly reproduced.
Therefore, the above-mentioned “following capability to hologram relief” means that the thickness and uniformity of the light-emitting layer of the electroluminescence element and the transparent conductive thin-film layer from which light is emitted from the light-emitting layer have a multilayer structure. , Meaning thinner and more uniform.
That is, even if a multilayer is interposed between the hologram relief surface and the light emitting layer, it is important that the relief shape of the light emitting surface of the light emitting layer is the same or almost the same as the relief shape of the hologram relief. . “Substantially the same” means that the reproducibility of relief-shaped irregularities is preferably 90% or more, and more preferably 95% or more.
This is an index indicating the reproducibility of the entire region where the hologram is reproduced as well as the reproducibility of one unevenness.
For example, in the comparison of two three-dimensional curves, the reproducibility is such that the volume of the difference area from another three-dimensional curve is within 10% of the volume of the uneven area of the original three-dimensional curve, Means within 5%. This is an index indicating the reproducibility of the entire region where the hologram is reproduced as well as the reproducibility of one unevenness. As a simple evaluation, it is also preferable to use a method of comparing relief sections with a quadratic curve.
Considering the above, if the film thickness is less than 50 nm, the conductivity is insufficient, and if it exceeds 500 nm, the followability to the hologram relief is deteriorated. Further, when it is provided in contact with the hologram relief, the heating load causes deterioration of the transparent resin holding the hologram relief shape, that is, deformation (deterioration) of the hologram relief shape.
For the cathode, the same material as that of the anode is formed in a thickness of 50 to 500 nm using the same method.
If the thickness is less than 50 nm, the conductivity is insufficient, and if it exceeds 500 nm, the followability to the hologram relief is deteriorated. Furthermore, even if it is not provided in contact with the hologram relief, the transparent resin holding the hologram relief shape is deteriorated due to the heating load during the thin film formation, that is, the deformation of the hologram relief shape ( Deterioration).

For the organic thin film which is a light emitting layer, a low molecular weight type and a high molecular weight type can be used.
For low molecular weight systems, TPAC (1,1-bis [4- [N, N-di (p-tolyl) amino] phenyl] cyclohexane), TPD (N, N′-diphenyl-N) are used as hole transport materials. N′-di (m-tolyl) benzidine), CuPc (phthalocyanine copper), α-NPD (4,4′-bis [phenyl (1-naphthyl) amino] -1,1 ′ biphenyl, etc.
As an electron transport material, BND (2,5-bis (1-naphthyl) -1,3,4-oxadiazole), PBD (2- (tertiary-butylphenyl) -5- (4-biphenyl) -1 , 3,4-oxadiazole), Butyl-PBD (2-biphenyl-5- (para-tert-butylphenyl) -1,3,4-oxadiazole), TAZ (1-phenyl-2-biphenyl- 5-para-tert-butylphenyl-1,3,4-triazole), Alq ₃ (tris (8-hydroxyquinolinato) aluminum), Beq ₂ (bis (8-hydroxy-quinolino) beryllium), Zn (BOZ) 2 (zinc-bis-benzoxazole), Zn (BTZ) 2 (zinc-bis-benzothiazole), Eu (DBM) 3 (Phen) (tris (1,3-di Eniru-1,3 Jiono) (monophenanthroline) europium (III)) or the like,
As the light emitting layer material, ZnPBO (bis [2- (2-benzoxazolyl) phenolato] zinc), etc.
As a doping dye material, Coumarin 6 (3- (2-benzothiazolyl) -7- (diethylamino) coumarin, QN- (N, N′-dimethylquinacridone), Nile red, beryllenlabrene, TBP (1,1,4,4-tetra Phenyl-1,3-butadiene) quinacridone and the like, 4- (dicyanomethylene) -2-methyl-6- (4-dimethylaminostyryl) -4H-pyran, 3- (4-biphenylyl) -4-phenyl- 5- (4-tert-butylphenyl) -1,2,4-triazole, 4,4′-bis (9-carbazolyl) biphenyl, and the like can be used.
These low molecular weight materials can be provided by a thin film forming method such as a vacuum deposition method or a CVD method (chemical vapor deposition method).

For polymer systems,
As the light emitting layer material, PPV (polyparaphenylene vinylene), PAT (polythiophene), PF (polyfluorene), PPP (polyparaphenylene), etc.
PEDOT (poly-3,4-ethylenedioxythiophene) + PSS (polystyrene sulfonic acid: dopant) copolymer, PEDOT + PVS (polyvinyl sulfonic acid) copolymer, polyaniline + PSS copolymer, polypyrrole as hole layer materials + PSS copolymer or the like can be used.
These polymer materials can be provided by various coating methods and printing methods. The applied DC voltage is 1 to 10V.
The structure of the inorganic electroluminescence element is a basic structure in which a transparent electrode, an insulating layer, a light emitting layer, and a back electrode are laminated, and light emission comes out of a phosphor film that is a light emitting layer. In the case of a thin film type, a phosphor is a mixture of a dielectric base material with a small amount of an additive impurity that becomes a luminescent center, and when it receives energy, it moves to the outer shell orbit of the luminescent center substance or higher order. When excited (excited) electrons of the emission center substance return to the original order (transition), light emission occurs.
A structure in which a phosphor film as a light emitting layer is sandwiched between dielectrics as insulating layers and electrodes are arranged at both ends thereof can be considered as a circuit in which three capacitors are connected in series. When applied, polarization occurs in the dielectric and the phosphor, the applied voltage is increased, and when the electric field applied to the phosphor film becomes 100 MV / m or more, the energy of collision of electrons etc. whose emission center is accelerated by the electric field. To become excited.
As the light-emitting layer, ZnS, SrS, or other group II sulfide is used as the base material, Mn or rare earth is added to the light emission center, and BaAL ₂ S ₄ (barium / aluminum composite sulfide) is used as the base material. A material in which Eu is added to the material is used.
The light emitting layer is selected from the group consisting of at least one element selected from the group consisting of Group 2 elements and Group 16 elements of the Periodic Table and / or Group 13 elements and Group 15 elements of the Periodic Table. A semiconductor containing at least one kind of element can be preferably used.
The carrier density is preferably 10 ¹⁷ / cm ³ or less.
Specific examples of the material forming the light emitting layer include CdS, CdSe, CdTe, ZnSe, ZnTe, CaS, MgS, GaP, GaAs, GaN, InP, InAs, and mixed crystals thereof. CaS or the like can be preferably used.

_{Furthermore, BaAl 2 S 4, CaGa 2} S 4, Ga 2 O 3, Zn 2 SiO 4, Zn 2 GaO 4, ZnGa 2 O 4, ZnGeO 3, ZnGeO 4, ZnAl 2 O 4, CaGa 2 O 4, CaGeO 3 , Ca ₂ Ge ₂ O ₇ , CaO, Ga ₂ O ₃ , GeO ₂ , SrAl ₂ O ₄ , SrGa ₂ O ₄ , SrP ₂ O ₇ , MgGa ₂ O ₄ , Mg ₂ GeO ₄ , MgGeO ₃ , BaAl ₂ O ₄ , Ga ₂ Ge ₂ O ₇ , BeGa ₂ O ₄ , Y ₂ SiO ₅ , Y ₂ GeO ₅ , Y ₂ Ge ₂ O ₇ , Y ₄ GeO ₈ , Y ₂ O ₃ , Y ₂ O ₂ S, SnO ₂ and the like A mixed crystal of the above can be preferably used.
The carrier density and the like can be obtained by a generally used Hall effect measurement method or the like.
As the dielectric film that is an insulating layer, a metal oxide or a nitride is used. Perovskite-based oxides such as BaTiO3 are preferred because of their high dielectric constant.
As elements that can be included in the oxide, Group 2, Group 9, Group 9, Group 12 (former 2B (former IIb group)), Group 13 (former 3B (former III)) of the periodic table, Group 14 (former group 4B (former group IV)), group 15 and group 16 elements are preferred, and at least one element selected from the group consisting of group 12, group 13 and group 14 elements is used. More preferably. Specifically, Ga, In, Sn, Zn, Al, Sc, Y, La, Si, Ge, Mg, Ca, Sr, Rh, Ir and the like can be mentioned, and more preferably Ga, In, Sn, Zn, Si, Ge, etc. In addition to these elements, the transparent semiconductor can preferably contain chalcogenides such as S, Se, and Te, Cu, Ag, and the like.
The layer thickness of the insulating layer and the light emitting layer is 0.1 μm to 2 μm. Of course, when the thickness exceeds 2 μm and is about 10 μm, the luminous performance can be further improved, but 2 μm is the limit in the followability of the hologram relief.
As for the transparent electrode and the back electrode, ITO or a metal thin film is preferably used as in the organic electroluminescence element.
The phosphor films of different emission colors can be arranged in parallel to make a multicolor, but a color conversion material (coumarin system: coumarin 6, rhodamine system: rhodamine) is formed on a single color phosphor film with high luminance. 6G, a mixture of fluorescent dyes such as rhodamine B, and a mixture of two or more kinds of fluorescent dyes having a benzo-α-bilon skeleton absorb light with a wavelength of 350 nm to 600 nm and emit light in the visible region with a wavelength of 600 nm or more. It is also preferable to make multiple colors by superimposing light having a light emission.
As the applied voltage, an AC power source of 100 V · 50 to 1000 Hz or the like can be used.
When the electroluminescence element layer is multicolored, it is preferable to provide volume holograms corresponding to the emission wavelengths and simultaneously reproduce these volume holograms. It is further preferable to stack and reproduce individual volume holograms by individual light emission.

At this time, the difference between the emission wavelengths is 50 nm or more, and preferably 100 nm or more. Making the reproduction wavelength different means that the period of the fringe described above is made different, and unnecessary interference between the fringes in the volume hologram forming layer can be reduced.
The reproduction angle difference is 10 degrees to 40 degrees. If this difference exceeds 40 degrees, one observation angle becomes close to the hologram sheet surface, which is inconvenient to observe.
Next, the principle of holography will be described.
If an object is illuminated with coherent light and light diffracted from the object illuminates a recording medium (photoresist, etc.), the object wave is diffracted from the object and reaches the recording surface.
F (x, y) = A (x, y) EXP [φ (x, y)]
It is expressed. here,
A (x, y) is the amplitude distribution of the object wave,
φ (x, y) is a phase distribution.
At this time, the intensity distribution of the light wave reaching the recording medium is recorded on the recording medium. Its intensity distribution is
I (x, y) = | F (x, y) | ² = A ² (x, y) (1)
Thus, the phase distribution is not recorded.
Here, when an object wave and a coherent light wave (referred to as a reference wave) are superimposed, the intensity distribution of the recorded light wave is
I (x, y) = | F (x, y) + R (x, y) | ²
= | F (x, y) | ² + | R (x, y) | ²
+ F (x, y) R ^* (x, y) + F ^* (x, y) R (x, y) (2)
It becomes. (* Represents a complex conjugate term.)

However, if the reference light is a plane wave incident on the recording surface at an angle θ,
R (x, y) = r (x, y) EXP (2πiαx) (3)
Write,
α = SIN (θ) / λ (4)
It is. In the first and second terms of (2), the phase information is missing for both the intensity of the object wave and the intensity of the reference wave. The third term and the fourth term are interference terms. F (x, y) R * (x, y) =
A (x, y) r (x, y) EXP [i [φ (x, y) -2παx]] (5)
F * (x, y) R (x, y) =
A (x, y) r (x, y) EXP [-i [[phi] (x, y) -2 [pi] [alpha] x]] (6)
The phase term φ (x, y) of the object remains. (5) and (6) are complex conjugates of each other, and the third term in (4.2) includes the complex amplitude distribution of the object. Substituting (5) and (6) into (2),
I (x, y) = | F (x, y) | ² + | R (x, y) | ²
+ 2A (x, y) r (x, y) COS [2παx−φ (x, y)] (7)
It becomes. It can be seen that the object wave and the reference wave interfere to form an interference fringe.
In this way, holography is a method in which a reference wave is superimposed on an object wave and interference recording is performed, and the phase information of the object is recorded without being lost. A recording of (7) is called a “hologram”. The intensity transmission or amplitude reflectance of the hologram is the recorded intensity distribution I (x, y)
Proportional,
T (x, y) = τI (x, y) (8)
Let's call it. When the reference wave used when recording on this hologram is at a predetermined angle, the wavefront transmitted or reflected by the hologram is
T (x, y) R (x, y) = τ (| F (x, y) | ² + | R (x, y) | ² )
+ ΤF (x, y) | R (x, y) | ²
+ ΤF ^* (x, y) R ² (x, y) (9)
Can be expressed. This second term is τF (x, y) | R (x, y) | ² =
τA (x, y) r ² (x, y) EXP [iφ (x, y)]] (10)
The third term is
τF * (x, y) R ² (x, y) =
τA (x, y) r ² (x, y) EXP [−iφ (x, y) + 2πiα] (11)
Call it.

Therefore, the first term of (9) is a light beam penetrating the hologram in the same direction as the illumination light or a specularly reflected light beam, and the second term is a light wave having an amplitude proportional to the object light from (10). From (11), it can be seen that the third term is a light wave having a phase distribution conjugate with the object wave and propagating in the direction of 2θ.
In this way, the complex amplitude distribution can be recorded and reproduced using the holographic technique.
In the case of the present invention, the amplitude transmittance or reflectance of the hologram is proportional to the recorded intensity distribution and is expressed by the equation (8), but the reference wave used when recording on this hologram. Is not a predetermined angle, but a light-emitting wave having a spatial distribution similar to the amplitude transmittance or amplitude reflectance of (8) is emitted from this hologram.
Therefore, the emission wave is emitted while maintaining the phase term already recorded in the hologram, regardless of the conventional principle of hologram reproduction in which the phase term recorded in the hologram is given to the reference light. Therefore, theoretically, it has a three-dimensional continuous curved light emitting surface having a spatial function including the phase difference of an object, and light is emitted from the one curved surface.

To simplify the conventional hologram reproduction principle for the transmission type, when parallel light as reference light is applied to the hologram, the parallel light is shielded in the shielding part, and the parallel light is transmitted only from the transmission part. Diffraction occurs at the boundary between the transmission part and the shielding part, receives the phase term of the object, and the entire component transmitted through the hologram is superimposed, which becomes the hologram reproduction light and reaches the observer's eyes.
In the case of the present invention, there is no parallel light as the reference light described above, and the emitted light retains the phase term of the object when emitting light on the light emitting surface provided in contact with the hologram relief. Hologram reproduction is performed by an interference phenomenon between radiated lights.
The interference effect between synchrotron radiation without temporal and spatial coherence does not cause sufficient interference like laser light, but hologram reproduction is performed at the same level as when a hologram is illuminated with low coherent light. . Since the reproduction is based on the principle as described above, the reference light at the time of hologram photographing is preferably parallel light (because complicated reference light cannot be reproduced), or “hologram represented by a diffraction grating” (diffraction The grating is preferably both object light and reference light.) The diffraction grating formed by electron beam drawing, such as a computer generated hologram, is precise and suitable.
Further, for the above reason, in order to make the relief hologram reproduced image clearer, it is necessary to impart a characteristic relating to temporal or spatial coherence to the emitted light. The thickness of the light emitting part (distance in the radial direction) is made thin, the variation in the thickness direction of the light emitting point is made small, the light emitting layer and other layers are uniform (the layer thickness is uniform, the uniform dispersion, It is desirable to reduce the variation in emission spectrum and the width of the emission spectrum by eliminating the unevenness in the layer such as uniform composition.

In addition, the dominant wavelength of light used when optically recording a relief hologram, the dominant wavelength of diffracted light assumed when forming a diffraction grating, etc., and the emission wavelength from the electroluminescence element are the same or almost the same. By making them the same, a clearer relief hologram reproduction image can be obtained.
Furthermore, considering the multiple reflection of light in transparent layers such as transparent conductive thin films, insulating layers, and hole transport layers through which the emitted light passes, the intensity of light that passes through the emitted light emission wavelength is maximized. Furthermore, it is preferable to set the refractive index and thickness of each layer.
In particular, the thickness of the transparent conductive thin film used for the anode or the cathode is precisely controlled, and the light passing through the transparent conductive thin film is reflected multiple times within the transparent conductive layer to form a predetermined direction (usually formed) It is also preferable to increase the intensity of light traveling in a direction perpendicular to the surface.) And to suppress the intensity of light traveling in other directions.
However, the original purpose of the hologram sheet of the present invention is to emit light from the element while maintaining the phase difference distribution on the light emitting surface of the light emitting layer, and to prevent light interference based on the phase difference distribution in the space immediately after emission. Since it is sufficient, the multiple reflection that disturbs the phase difference distribution may increase the intensity of the light, but in turn causes a reduction in the sharpness of the reproduced hologram image.
Therefore, the refractive index distribution and thickness of the transparent conductive thin film layer and the like described above must be set in consideration of this. For example, when the hologram relief is almost as small as about 0.01 μm and a hologram having many regions parallel to the surface of the transparent substrate is used, this multiple reflection is used, and the thickness of the transparent conductive thin film layer is By setting the intensity of light that passes perpendicularly to the plane to be the maximum for the emission wavelength, the direction of the light “emitted” from the hologram relief surface can be set to only approximately the vertical direction. .
Of course, in order to improve the anti-counterfeiting property, it is also preferable that the wavelength of light emission is different from the wavelength at the time of recording formation. In that case, it is essential to anticipate and confirm beforehand the deformation of the hologram reproduction image and the change of the diffraction angle due to the different wavelengths.

Furthermore, partial variations in the electroluminescent element formation region, that is, variations in emission wavelength and emission intensity depending on the formation location deteriorate the quality of the hologram reproduction image, so the uniformity of the light emitting layer is important.
At least the partial variation of the peak value of the emission wavelength (difference between a certain 1 mm diameter spot region and the adjacent spot region of 1 mm diameter) and the half value width variation are within 30 nm, and the emission intensity variation is 10 % Is preferable. When the peak value of the emission wavelength and the variation of the half-value width exceed 30 nm, the reproduction position of the hologram reproduction image varies, and the hologram reproduction image is blurred and unclear. Further, if the variation in emission intensity exceeds 10%, variation in light interference also occurs, resulting in unclear reproduction.
In addition, when the electroluminescent element is provided as a large number of fine spots (for example, halftone dots) discretely (such as only the light emitting layer is halftone dots, the entire element may be provided discretely. In this case, only a single layer or a plurality of layers may be provided discretely.) Although the amount of light emission decreases and the overall brightness decreases, no light is emitted from the area adjacent to each spot. Therefore, unnecessary interference can be reduced, and the sharpness of the hologram reproduction image is increased, which is preferable.
However, when the size of the spot and the thickness of the light emitting layer, etc. are discretely formed on the hologram surface regardless of the hologram relief, the size distribution and the thickness distribution result. In some cases, the emission intensity distribution may cause unnecessary interference with the light for reproducing the hologram, or may disturb the desired interference and blur the hologram reproduction image.
In order to eliminate this factor, even when the light emitting layer is formed continuously or discretely, it has a uniform thickness and a uniform distribution following the unevenness forming the hologram relief. By forming the light-emitting element, light having the same intensity can be emitted from any region of the hologram relief surface, so that the hologram reproduction image can be sharpened.

Although the hologram reproduction image of the hologram sheet of the present invention includes a spatial hologram phase, the temporal and spatial coherence between the emitted lights is small, and this hologram reproduction image is an ordinary laser reproduction image. It is weaker than the reproduced image of the relief hologram and is unclear.
Of course, if only observing the beam-shaped diffracted light, it is easy to confirm the color tone and the diffraction direction, and this can be used to determine authenticity, but this weak and unclear hologram reproduction image. In order to make it possible for the observer to recognize and accurately determine the presence of the illuminant, and to improve the light emission performance of the illuminant and to increase the wavelength-diffraction angle dependency by increasing the diffraction angle, It is necessary to increase the difference in the diffraction angle of light emission, further reduce the thickness of the light emitting layer, suppress variation in the thickness direction of the light emitting layer, and make it uniform. (Since the light emitting surface contains phase information, its spatial shape is accurately reproduced.)
Furthermore, in order to express temporal coherence more strongly, it is also preferable that the voltage is applied in a pulsed manner and the time interval between the pulses is set at 10 ⁻⁷ sec or more, which is the emission time of fluorescence or the like. It is. As a result, one light emitting surface generated by one applied pulse does not cause a disturbance phenomenon with the light emitting surface generated by the next applied pulse, and is generated by one light emitting surface expressed by one pulse. Due to the interference phenomenon, a clear hologram reproduction image can be observed. Of course, even when a voltage application method (sheet that can be manually operated) that is simply turned on and off in seconds is used, the observer seems to emit light continuously. Even if it is a simple means, when it confirms visually, the above-mentioned effect can fully be acquired.

In the hologram sheet of the present invention, in the light emitting side of the electroluminescence element layer, that is, in the lamination of the light emitting layer, the hole transport layer, and the transparent conductive thin film, in the lamination of the light emitting layer, the insulating layer, and the transparent conductive thin film, etc. Since the outermost surface of the transparent conductive thin film is in contact with and follows the hologram relief of the relief hologram forming layer, the light emitted through the outermost surface of the transparent conductive thin film passes through the relief hologram forming layer and the transparent substrate. Pass through and reproduce the hologram reproduction image at the emission wavelength on the viewer side.
In this case, the refractive index difference of the relief hologram forming layer, the transparent conductive thin film, the light emitting layer, or the like is reduced (they have the same refractive index, or the refractive index difference is 0.1 or less. By controlling the distribution, unnecessary reflection at the interface of each layer can be suppressed, and visibility before applying a voltage to the electroluminescence element can be suppressed. , The design can be made higher. (It means the appearance of the electroluminescence element layer, and it is desirable that its presence is not conspicuous.)
Furthermore, by making the distance from the surface of the light emitting layer to the hologram relief surface of the relief hologram forming layer (the thickness of each layer between them) as small as possible, it is possible to follow the relief-shaped hologram relief on the surface of the light emitting layer. Can be expensive. Thereby, a clearer relief hologram reproduction image can be obtained.
Furthermore, when the electroluminescence element layer is provided so as to contact and follow the hologram relief shape, in order to make the relief hologram reproduction image clearer, the thickness of the electroluminescence element layer is: The total thickness of the element is preferably thin, and is preferably the same as the depth of the unevenness of the hologram relief and the size of the pitch, and is 0.01 μm to 2.0 μm. Is preferred.
If the thickness is 0.01 μm, that is, less than 10 nm, the performance as an element is insufficient, and if it exceeds 2.0 μm, the followability of the hologram relief is reduced, and in any case a clear hologram A reconstructed image cannot be obtained.

Further, when the thickness of the electroluminescence element layer is distributed (meaning fluctuation) on the relief hologram surface regardless of the hologram relief, the emission intensity distribution resulting from the thickness distribution is In some cases, unnecessary interference with the light for reproducing the relief hologram may occur, which may cause the relief hologram reproduction image to become unclear.
In addition, the “relief shape” of the “non-contact side of the relief hologram forming layer having the hologram relief” of the electroluminescence element layer and the “relief” of the “hologram relief” provided on the relief hologram forming layer having the hologram relief A “deviation” occurs between the “shape” and the shape.
This “displacement” is likely to occur in the depth direction of the “relief shape”, and the “displacement size” increases as the thickness of the electroluminescence element layer increases.
“Deviation in the depth direction” in the hologram relief strongly affects the “brightness” of the hologram reproduction image, and the depth of the hologram relief is “the optimum depth (the depth at which the brightest hologram reproduction image can be reproduced). ")", Even if it becomes evenly shallower or even deeper, the "brightness" will decrease.
In order to minimize this “deviation”, first, a “transparent layer having a uniform thickness” is formed on the transparent base material / volume hologram forming layer laminate, An “electroluminescent element layer having a uniform thickness” is formed.
At this time, a transparent substrate / volume hologram forming layer laminate having a high surface smoothness (for example, its surface roughness: Ra is 0.01 μm or less) is used. Using a material, it is formed with a thickness of 1 μm to 10 μm, and a “transparent layer with a uniform thickness” with a thickness accuracy within ± 1% is provided. Furthermore, an electroluminescent element layer is formed thereon with a thickness of 0.01 μm. An “electroluminescence element layer having a uniform thickness” is provided with a thickness accuracy of within ± 5%.
The plane in contact with the electroluminescence element layer of this “transparent layer of uniform thickness” is changed to the “relief shape” of “hologram relief” by the following deformation, and the “transparent layer of uniform thickness” Becomes a “relief hologram forming layer having a hologram relief”. Usually, the relief hologram forming layer is formed to a thickness of 1 μm to 30 μm, and it is formed thinner to achieve a more uniform thickness.

Such “uniformity” can be obtained by a precision coating method such as a spin coating method. In the ink composition to be used, the solid content in the ink is set as low as 0.5% to 5.0%. A method of making the thickness unevenness of the coating film before drying to be 1/20 to 1/200 by performing gentle drying after applying the ink can also be used.
For example, a transparent layer having a thickness of 3 μm is provided with a thickness accuracy of ± 1%, that is, a thickness variation of ± 0.03 μm or less, and an electroluminescent element layer having a thickness of 1.0 μm is formed thereon. The thickness accuracy is ± 5%, that is, with a thickness variation of ± 0.05 μm or less, “transparent layer with uniform thickness” and “electroluminescence with uniform thickness” on “transparent substrate” The “element layer” is formed to overlap.
An original plate (press mold) provided with a hologram relief in advance on the outermost surface of the electroluminescence element layer is pressed against the two uniform layers, and appropriate heating and pressurization are applied. Two layers are deformed, and in the “transparent layer of uniform thickness”, only the surface side in contact with the “electroluminescent element layer of uniform thickness” and “the electroluminescence element of uniform thickness” In the “layer”, the “electroluminescence element layer having a uniform thickness” itself is a “relief shape”.
As a result, “a transparent layer having a uniform thickness” and “an electroluminescence element layer having a uniform thickness” and an “outermost surface of the electroluminescence element layer having a uniform thickness” are formed. The surface shape of the totally reflective reflective layer formed on the outermost surface of this "uniform thickness electroluminescent element layer" is the same as the "hologram relief" provided in the mold with high accuracy. The “hologram relief” itself can be made with high accuracy.

As a transparent base material used for the hologram sheet of the present invention, it is possible to reduce the thickness, and it is possible to reduce the mechanical strength and the guide roll for conveying various processing machines in processing and processing when manufacturing the hologram sheet. It has high wear resistance against contact with the material, and has solvent resistance, heat resistance, wear resistance, etc. suitable for processing and processing thereof, and has appropriate adhesiveness with the material used for the envelope and It is preferable to use a transparent substrate having removability.
Since it depends on the processing method, it is not limited, but a film-like or sheet-like plastic is preferable.
For example, various plastic films such as polyethylene terephthalate (PET), polycarbonate, and triacetyl cellulose (TAC) can be exemplified.
The volume hologram used in the present invention forms hologram images as patterns of various refractive indexes in the layer of the volume hologram forming layer (also referred to as hologram recording. The volume hologram forming layer is formed on a hologram recording medium. This means a recording layer when a hologram image is formed.) A so-called phase hologram, in which light is applied to the transmission-type volume-volume hologram forming layer and transmitted therethrough, the phase of the light is “refractive index The volume hologram reproduction image can be observed with the transmitted light.
“Object” imaged as a hologram image (generally, a three-dimensional object or a two-dimensional object is used, or “object created” if it can provide “object light”) Or “electronically created” or “hologram reproduction image” from a separately created hologram.) According to the simplest method, coherent oscillation of a laser or the like is possible. Illuminated by light and a photosensitive recording medium is arranged to receive light reflected (diverged) from this “object”. Each point on the “object” reflects light to the entire recording medium, and each point on the recording medium accepts light from the entire “object”. This reflected (diverged) light beam is called “object light”.
At the same time, a part of the coherent light bypasses the “object” (means to pass through the “object”) and is directed to the recording medium by a reflecting mirror or the like. This light beam is called “reference light”.
What is recorded on the recording medium is an “interference pattern” generated by the interaction between the “reference light” and the “object light” impinging on the medium, and this recording becomes a hologram.
When this recording medium, i.e., the recorded hologram is illuminated and properly observed, the light from the illumination light source reproduces the wavefront that originally reached the recording medium from the "object". The hologram then recognizes the virtual image of the “object” to the viewer as if it saw a three-dimensional “object” with complete perspective through the “window” of the recording medium. Let

The principle of volume hologram recording and reproduction is the same as the principle of recording and reproduction of the relief hologram described above, but in the case of volume hologram, the refractive index distribution also exists in the thickness direction of the volume hologram forming layer, As a result, the wavelength of light that can reproduce the volume hologram and the illumination angle thereof are limited.
In other words, the volume hologram recorded in the volume hologram forming layer has a function of selecting “wavelength” and “direction” of illumination light.
The volume hologram used in the present invention allows the “reference light” and the “object light” to enter the recording medium from the same side except for the area masked with an appropriate pattern, and the two travel in the same direction while crossing. The hologram formed as described above is such that only the “phase distribution” remains as a record by making the formation layer itself transparent.

In this case, the interaction between the “object light” and the “reference light” in the recording medium forms a “fringe (interference fringe)” that is a change in the refractive index of the material whose refractive index changes. The surface is perpendicular or slightly inclined with respect to the surface of the recording medium.
When this volume hologram is a reflection volume hologram, when reproducing this reflection volume hologram, each of these fringes acts as a “mirror” that reflects incident light towards the viewer, so this reflection Type volume holograms are observed in “reflection” rather than “transmission”.
In addition, when this volume hologram is a transmission volume hologram, when reproducing this transmission volume hologram, each of these fringes reflects and transmits incident light at a shallow angle toward the observer. So that this transmission volume hologram is observed in “transmission” rather than “reflection”.
Since the “volume hologram” formed in this way has a very high “wavelength sensitivity” (wavelength selectivity, meaning that it only acts on a specific wavelength), the reproduction uses “white light”. It is something that can be done.
That is, light having a wide wavelength region (for example, a wavelength range of visible light wavelength [400 nm) can be easily obtained without preparing light of the wavelength used for the light source when the hologram is recorded and reproducing it with the light. Even if sunlight that covers up to 800 nm] or halogen lamp light is used as the reproduction light, light having a wavelength other than the “wavelength used for hologram recording” (“used for hologram recording”) Wavelength component other than “wavelength”) is transmitted as it is without undergoing almost any phase change, and only light of “wavelength used for hologram recording” (meaning the corresponding wavelength component) is diffracted to a predetermined angle, An image of the light (a reflection type or transmission type volume hologram reproduction image made by the corresponding wavelength component) can be visually recognized.

As an example, FIG. 2 shows a reflective volume hologram recording method and a reproducing method thereof. (However, the masking process is not shown.)
In FIG. 2, (1) shows a method (part 1) for creating a master hologram, and (2) shows a method (part 2) for creating a reflective volume hologram. And in (3), the reproduction | regeneration method of a reflection type volume hologram is shown.
Various transparent materials or transparent films are used for the volume hologram forming layer for forming the volume hologram.
That is, there are silver salt photographic emulsions, dichromated gelatin, photoresists, photopolymer materials, photorefractive materials made of inorganic materials, photochromic materials, etc., and films made of these materials.
A silver salt photographic emulsion is required to have high sensitivity and high resolution.
As the photoresist, either a positive photoresist or a negative photoresist can be used.
As the photopolymer material, a cross-linked photopolymer, a radical polymerization photopolymer, a cationic polymerization photopolymer, a chemically amplified photopolymer, a nanoparticle-dispersed photopolymer, or the like can be used.
Since the color tone of the photochromic material changes under a specific environment such as light or heat, the design property is further improved.
Bichromated gelatin is a material selected for the production of “reflection holograms” because of its high refractive index modulation (ie, high diffraction efficiency and bandwidth compatibility). However, dichromated gelatin has a problem in storability and requires wet treatment after the formation of the “reflection hologram”. For this reason, this material must be newly prepared immediately before hologram recording, or pre-hardened gelatin must be used, reducing the image reproduction efficiency.
Wet processing involves an additional step in forming the hologram and is subject to dimensional changes as the material swells and then contracts during processing. These dimensional changes affect the fringe spacing. Therefore, it is time consuming and difficult to produce a high quality “reflection hologram” with dichromated gelatin.

For silver salt photographic emulsions or several dichromated gelatins that require several processing steps, solid photopolymerizable materials that require only a single processing step, i.e. photopolymer materials, are preferred. .
Examples of photopolymer materials are solid photopolymerizable compositions that activate the polymerization of thermoplastic polymer binders, addition-polymerizable ethylenically unsaturated monomers, and unsaturated monomers. And a photopolymerizable composition having a refractive index modulation.
Thermoplastic polymer binders are solvent-soluble thermoplastic polymers, but can be used alone or in combination with each other, such as acrylate and alpha-alkyl acrylate esters, polyvinyl esters, saturated and unsaturated. Polyurethane, butadiene and isoprene polymers and copolymers, epoxidized products, polyamides, and the like, and mixtures thereof can be used.
Ethylenically unsaturated monomers include styrene, 2-chlorostyrene, 2-bromostyrene, methoxystyrene, phenyl acrylate, etc. as a single monomer or as a monomer that can be used in combination. Can be used.
As the photoinitiator, a free radical generating addition polymerization initiator or the like can be used.
As the photopolymer material, a photopolymerizable composition further having a fluorine-containing polymer, an addition-polymerizable ethylenically unsaturated monomer, and a photoinitiator can be used.
Fluorine-containing polymers include polymers made from perfluorinated monomers and vinyl acetate, such as tetrafluoroethylene or hexafluoropropylene.
Upon exposure with coherent light, this monomer (photo) polymerizes to form a high molecular weight photopolymer having a different refractive index and rheological properties than the unexposed areas. Although this high molecular weight photopolymer is substantially solid, each component is coherent until it is “fixed” by uniform irradiation with ionizing radiation and exposure over the entire surface or heat treatment at a high temperature. Internal diffusion occurs during and after exposure.

This photopolymer reflects light having a predetermined center wavelength and wavelength region (dispersion band) determined by its thickness and refractive index modulation. The thickness is then matched to the application and the optical requirements of the optical system, ie the bandwidth of the light used to illuminate (reproduce) the hologram during use. In general, a relatively thick photopolymer is selected for narrow bandwidth applications, and a relatively thin photopolymer is selected for wide bandwidth applications.
The fluorine-containing polymer used is a fluorine-containing polymer that is compatible with the other components of the photopolymer and produces a substantially solid transparent film when applied.
“Substantially solid” means that the applied film has the properties (eg, dimensional stability) that solid materials generally have after removal of the solvent.
The presence of fluorine in the fluorine-containing polymer generally lowers the refractive index of the photopolymer, thereby achieving increased (meaning “greater”) refractive index modulation in the photopolymer after holographic imaging. . Refractive index modulation increases with increasing fluorine content, but the amount of fluorine present is limited so as not to cause opacification of the photopolymer.
Therefore, the content of fluorine is typically in the range of 10 to 20% although the effect is achieved even at a low level such as 1%. The fluorine content can be adjusted to achieve refractive index modulation depending on the application.
Fluorine is introduced by copolymerizing another monomer constituting the fluorine-containing polymer with the fluorine-containing monomer or by reaction with the fluorine-containing polymer. For example, when the fluorine-containing polymer contains a functional group such as an alcohol or an acid substituent, a condensation, acetalization, ketalization, or esterification reaction can be used to introduce fluorine.
As the fluorine-containing polymer, vinyl ester, vinyl alcohol, vinyl ether, vinyl acetal / butyral, or a polymer of a prepolymer or a mixture thereof and a fluorinated monomer can be used.
A photopolymerizable composition comprising the above fluorine-containing polymer, an addition-polymerizable ethylenically unsaturated monomer, and a photoinitiator has high refractive index modulation while maintaining its transparency, and thus has high transparency. Therefore, it is suitable for the hologram sheet of the present invention that requires the reproduction of a clear hologram.

Further, as a transparent resin, that is, a photopolymerizable composition, a cationic polymerizable compound, a radical polymerizable compound, a photo radical polymerization initiator system that polymerizes a radical polymerizable compound by being exposed to light of a specific wavelength, and the above A photosensitive material composed of a photo-cationic polymerization initiator system that is low-sensitivity to light of a specific wavelength and is sensitive to light of another wavelength to polymerize a cationically polymerizable compound is used.
This photopolymerizable composition is irradiated with light such as laser light that is photosensitized by the radical photopolymerization initiator system, and then is irradiated with light having a wavelength different from that of the laser light or the like that is photosensitized by the photocationic polymerization initiator system. By irradiation, a volume hologram is recorded. After the radical polymerizable compound is polymerized by irradiation with light such as laser light (hereinafter referred to as first exposure), the cationic polymerizable compound is converted into a photocation in the composition by the subsequent overall exposure (hereinafter referred to as post exposure). Cationic polymerization is performed by Bronsted acid or Lewis acid generated by decomposing the polymerization initiator system.
As the cationically polymerizable compound, those which are liquid at room temperature are used so that the polymerization of the radically polymerizable compound is carried out in a composition having a relatively low viscosity. Examples of such a cationically polymerizable compound include diglycerol polyglycidyl ether.
The radically polymerizable compound preferably has at least one ethylenically unsaturated double bond in the molecule. Further, the average refractive index of the radical polymerizable compound is larger than that of the cationic polymerizable compound, preferably 0.02 or more, and if it is smaller, the refractive index modulation becomes insufficient, which is not preferable. Examples of the radical polymerizable compound include acrylamide and methacrylamide.

The radical photopolymerization initiator system may be an initiator system that generates active radicals by the first exposure for producing volume holograms, and the active radicals polymerize radical polymerizable compounds, and generally absorbs light. A sensitizer, which is a component, and an active radical generating compound or an acid generating compound may be used in combination. As the sensitizer in the radical photopolymerization initiator system, a colored compound such as a dye is often used to absorb visible laser light. However, in the case of a colorless transparent volume hologram, a cyanine dye is preferable.
Since cyanine dyes are generally easily decomposed by light, the dyes in the volume hologram are decomposed and absorbed in the visible region by being left exposed for several hours to several days under room light or sunlight. A colorless and transparent volume hologram is obtained.
Such colorless transparency can be achieved by adding an adhesive layer to the hologram sheet of the present invention to form a hologram label, or by inserting a release layer between the transparent substrate and the volume hologram forming layer. When sticking or transferring to an adherend or transferee as a transfer foil, when checking the design or face photo on the adherend or transferee through the hologram label or hologram transfer layer It is suitable for.
The cationic photopolymerization initiator system has low photosensitivity for the first exposure, irradiates light having a wavelength different from that of the first exposure, and then generates Bronsted acid or Lewis acid upon exposure to light. An initiator system for polymerizing the polymerizable compound may be used, and those that do not polymerize the cationic polymerizable compound during the first exposure are particularly preferable.
The volume hologram forming layer has a thickness of 10 μm to 100 μm. Preferably, it is 20 μm to 50 μm. Of course, a smaller thickness is advantageous in terms of cost and transparency, but if it is less than 10 μm, sufficient light selectivity cannot be obtained, and a clear hologram reproduction image can be obtained. Is difficult.
However, if it exceeds 100 μm, not only is it disadvantageous in terms of cost, but also distortion of the hologram reproduction image due to its thermal deformation becomes significant, and its processability also deteriorates.

Since the above method can be formed directly from the resin without going through the transparent base material for supporting the resin, it is possible to eliminate the step of coating the resin on the transparent base material in advance. In this case, the cost and management are excellent.
In the method of the present invention, that is, a method of forming a laminate in which a transparent resin is coated on a transparent substrate and a “volume hologram forming layer” having a volume hologram is provided, the volume hologram forming layer is photopolymerized. If the transparent substrate is in the form of a sheet for each sheet, a coating solution of the composition (for example, a solid content of 15 to 25%) is formed by bar coating, spin coating, dipping, or the like. If the material is applied in a roll-like long state, it is applied by gravure coating, roll coating, die coating, comma coating, or the like. The volume hologram forming layer is solidified by means of drying or curing according to the coating solution.
As an example of the photopolymerizable composition, 10 to 50% of the cationic polymerizable compound, 40 to 70% of the radical polymerizable compound, 1 to 5% of the radical photopolymerization initiator system, And it is good to make a photocationic polymerization initiator system into 1 to 5%, and it mix | blends so that the whole quantity may be 100%.
In the photopolymerizable composition, essential components and optional components are used as they are or, if necessary, a ketone solvent such as methyl ethyl ketone, an ester solvent such as ethyl acetate, an aromatic solvent such as toluene and xylene, and a cellosolve such as methyl cellosolve. It is prepared by blending with a system solvent, an alcohol solvent such as methanol, an ether solvent such as tetrahydrofuran or dioxane, or a halogen solvent such as dichloromethane or chloroform, and mixing in a cool dark place using a high-speed stirrer.

This photopolymerizable composition can reproduce a clear volume hologram while maintaining its transparency, and has a high breaking strength, a low breaking elongation, and a high pencil hardness. It is suitable for anti-counterfeiting applications that require high reliability such as tough physical properties such as tensile resistance and wear resistance.
A sheet or film made of the photopolymerizable composition itself, or a photopolymerizable composition coated on a transparent substrate, that is, a volume hologram forming layer can be used to form a volume hologram using the method described above. it can.
The volume hologram is a hologram recorded on the basis of the so-called volume hologram principle, as described above, with the interference fringes caused by the interference between the object light and the reference light. And a white light reproduction hologram, a color hologram utilizing these principles, a computer generated hologram (CGH), a holographic diffraction grating, and the like. Further, like a machine readable hologram, the reproduction light may be converted into data by a light receiving unit and transmitted as predetermined information, or authenticity may be determined.
Here, in order to make those who observe the hologram sheet of the present invention think that this hologram sheet is a normal “mere volume hologram”, the reflection type that those observers can visually appreciate under natural light. It is essential that at least one type of volume hologram, that is, a Lippmann hologram or a transmission volume hologram, is recorded in a multiplexed manner.
The volume hologram forming layer uses light such as laser light in a predetermined wavelength range by a so-called “holographic exposure apparatus” to polymerize the radical polymerizable compound and record interference fringes therein. At this stage, diffracted light by the recorded interference fringes is obtained and a volume hologram is formed. As the volume hologram forming layer, a cation polymerizable compound, a radical polymerizable compound, a photo radical polymerization initiator system, and a photo cation are used. In the case of using a photosensitive material comprising a polymerization initiator system, in order to further polymerize the unreacted cation polymerizable compound, the photocationic polymerization initiator system is exposed to light (for example, wavelength) as post-exposure. 200 to 800 nm) may be irradiated on the entire surface to fix the volume hologram. Note that the diffraction efficiency, the peak wavelength of diffracted light, the half-value width, and the like can be changed by treating the volume hologram forming layer with heat or infrared rays before post-exposure.

The volume hologram forming layer on which the volume hologram is formed has its “layer” depending on the wavelength of the light source such as a laser used when the hologram is formed (this is the above-mentioned “reference light” or “object light”). Among them, fringes (interference fringes) are recorded "three-dimensionally" in the form of "partial change in refractive index (refractive index modulation)" (meaning that the entire fringe has a three-dimensional structure). It is.
This fringe causes an “interference phenomenon” only when illuminated with the light source wavelength used at the time of the hologram formation described above, and causes a transmission reproduction image (volume hologram reproduction image) that can be visually recognized by the observer.
That is, when this fringe is illuminated with light having a wavelength other than that described above, the above-mentioned “interference phenomenon” does not occur, only a slight scattering phenomenon occurs, and the light is transmitted as it is.
Furthermore, in the light emission of the electroluminescence element layer, it is not necessary to use a light source that may adversely affect the eyes of the observer, such as an ultraviolet light source for emitting a fluorescent material. By making the light dark, it is possible to observe the hologram reproduced by the light emission more clearly.
Any light source can be used as the light source used when forming these volume holograms as long as it oscillates (emits) coherent light in the visible light wavelength region. For example, as a gas laser, HeNe can be used. Laser LG series (oscillation (emission) wavelengths are 594 nm, 633 nm, 0.5 mW to 30 mW), HeNe laser LH series (same as 594 nm, 604 nm, 612 nm, 633 nm, 0.3 mW to 4.0 mW), argon laser (same as above) 488 nm, 40 mW), HeCd laser IK series (442 nm, 20 mW to 200 mW), nitrogen / dye laser GL-301, nitrogen / dye laser GL-302 (selectable from 360 nm to 990 nm), etc.
Ruby laser (same as 694 nm, pulsed laser), small CW laser (Nd: YAG, Nd: YLF, Nd: YVO ₄ laser) Direct (same as 405 nm, 445 nm, 447 nm, 488 nm, 638 nm, 643 nm, 655 nm) 690 nm), small CW laser (same) Crystal (same as 473 nm, 523 nm, 532 nm, 555 nm, 561 nm, 593 nm, 657 nm, 660 nm, 671 nm), wavelength conversion laser Opti series (same as 488 nm, 589 nm), TOL90 dye laser ( The same can be selected from 420 nm to 900 nm.)
As semiconductor lasers, SWL-7513H (same as 633 nm, 660 nm, 8 mW to 20 mW), FK LA-100 (same as 457 nm, 1 W), LDM (same as 405 nm, 440 nm, 473 nm, 532 nm, 635 nm, 658 nm, 665 nm, 690 nm) 10 mW to 200 mW) can be used.

Furthermore, in order to make the relief hologram reproduced image reproduced by the light emission of the electroluminescence element layer clearer, it is preferable to impart a characteristic similar to temporal or spatial coherence to the emitted light, for example, , The thickness of the electroluminescence element layer is made relatively thin (meaning that the positions of the phosphors included in the electroluminescence element layer as the light emitting point are aligned in the light traveling direction), or the emission wavelength width is narrowed (Because light having a wavelength that does not cause an interference phenomenon becomes noise or stray light as it is for the hologram reproduction image, except for the “broadband light source” effect).
The electroluminescence element layer has strong reflectivity when a metal thin film layer is provided on one of the electrodes, but has transparency when both of the electrodes are transparent. Alternatively, it may be visually recognized as “white” due to the light scattering property of the phosphor surface, so that it is visually recognized as a simple mirror sheet, a transparent sheet, or a white sheet under normal illumination light. .
In the hologram sheet of the present invention, it is necessary to make the electroluminescence element layer highly transparent in order to conceal the presence of the relief hologram forming layer, that is, the relief hologram, and to enhance its forgery prevention property. .
That is, the anode and the cathode, which are constituent layers of the electroluminescence element layer, are made of a transparent conductive thin film, and the light emitting layer is made of a highly transparent material. The presence of the relief hologram can be concealed by covering the outermost surface of the electroluminescence element layer with a transparent resin material.
Further, the outermost surface of the transparent resin material is a flat surface and the difference in refractive index of these constituent layers is within 0.3, preferably within 0.1, so that it is only under ordinary illumination light. In addition, it is possible to make it difficult to recognize or discriminate the presence of the relief hologram even under illumination such as a simple semiconductor laser.

Here, the light emitted from the electroluminescence element layer also has light that travels almost omnidirectionally at an angle different from the light that travels from the electroluminescence element layer in the direction of forming the relief hologram reproduction image. Since these lights are simply divergent light and are not affected by the interference phenomenon, they diverge quickly, attenuate in inverse proportion to the square of the distance, and become weak light when reaching the observer's eyes. ing.
Conversely, the light emission intensity of the electroluminescence element layer is such that these lights are sufficiently attenuated at a distance at which the hologram sheet of the present invention is observed, that is, at a point about 30 cm to 50 cm away from the surface of the hologram sheet. It is preferable to set.
In this case, it is preferably 1 to 500 cd (candela) / m ^2, and more preferably 10 to ²⁰⁰ cd / m ² .
In particular, the volume hologram recording area and the hologram relief forming area are designed as strip-shaped areas having a width of 100 μm to 300 μm so that the electroluminescence element layer emits light and any hologram reproduction image disappears. Therefore, it is necessary to make the brightness of the volume hologram reproduction image and the brightness of the relief hologram reproduction image approximately the same, and this brightness ratio depends on the design of each hologram reproduction image itself. /0.5 to 1 / 1.5 is preferable.
And since the length of a strip | belt-shaped area | region is enough if it is 300 micrometers or more, it shall normally be 300 micrometers-5.0 mm.
The hologram sheet thus formed can be used by providing an appropriate adhesive layer or adhesive layer on the electroluminescence element layer to form a “label” and affixing to an appropriate adherend.
In addition, an appropriate release layer is provided between the transparent substrate and the reflective volume hologram forming layer, and an adhesive layer is provided on the electroluminescence element layer to form a “transfer foil”, which is transferred to an appropriate transfer target. It is also suitable to use.
Furthermore, it is also preferable to appropriately print each desired layer of the hologram sheet of the present invention to enhance its designability and anti-counterfeiting properties.

According to the hologram sheet of the present invention,
A hologram in which a volume hologram forming layer, a relief hologram forming layer provided with a hologram relief, and an electroluminescence element layer provided following the hologram relief are provided in this order on one surface of a transparent substrate It is possible to provide a hologram sheet characterized in that a volume hologram recording area and a hologram relief forming area are alternately provided, and any hologram reproduction image can be clearly observed A hologram sheet can be provided.
Furthermore, by providing each region in a band shape with a width of 300 μm or less alternately, a hologram sheet with excellent anti-counterfeit properties that can be observed as if the hologram reproduction image has disappeared by applying a predetermined electric field is provided. can do.
In addition, since such a hologram sheet has not existed so far, it is to provide a novel decorative property and an anti-counterfeit property to which this is applied.

These are the figures which show the recording method and reproducing method of a reflection type volume hologram. Is a Jablonsky diagram. These are sectional drawings of hologram sheet A showing one example of the present invention. Is a process for determining an embodiment of the present invention. Is a process for determining another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Transparent substrate) The transparent substrate 1 used in the present invention can be reduced in thickness, and can withstand mechanical strength and solvent resistance and heat resistance that can withstand processing when manufacturing the hologram sheet A. Those having the following are preferred. Since it depends on the purpose of use, it is not limited, but a film-like or sheet-like plastic is preferable. (See Figure 3.)
For example, various plastic films such as polyethylene terephthalate (PET), polycarbonate, polyvinyl alcohol, polysulfone, polyethylene, polypropylene, polystyrene, polyarylate, triacetyl cellulose (TAC), diacetyl cellulose, and polyethylene / vinyl alcohol can be exemplified. .
Among these, those having resistance to heat treatment at the time of forming the electroluminescence element layer 4 and resistance to heat generation or electric field at the time of light emission of the electroluminescence element layer 4 are desirable. Furthermore, the thing containing the ultraviolet absorber which prevents the ultraviolet-ray deterioration of the fluorescent substance (light-emitting body) contained in a light emitting layer is also suitable.
The thickness of the transparent substrate 1 is usually 5 to 100 μm. However, when considering the visibility of the volume hologram reproduction image and the relief hologram reproduction image, it is preferably 5 to 50 μm, particularly 5 to 25 μm. .

(Volume Hologram Formation Layer) Volume hologram formation layers 2 and 3 are provided on the transparent substrate 1 described above. (See Figure 3.)
Here, the volume hologram forming layer 2 is a region where a volume hologram is not formed.
The volume hologram forming layer 3 is an area where volume holograms are formed, and these areas are alternately provided.
For the volume hologram forming layers 2 and 3, various transparent materials or transparent films are used.
That is, a silver salt photographic emulsion, gelatin dichromate, a photoresist, a photopolymer material, a photorefractive material made of an inorganic material, a photochromic material, and a film made of these materials can be used.
Silver salt photographic emulsions are required to have high sensitivity and high resolution, and ultrafine silver salts, gold-chalcogen sensitization, reduction sensitized materials, and the like can be used.
As the photoresist, a novolak-DNQ-based or chemically amplified photoresist can be used as a positive photoresist, and a photocrosslinked photoresist or a photopolymerizable photoresist can be used as a negative photoresist.
Silver salt photographic emulsion or dichromated gelatin has many processing steps and is complicated, but a solid photopolymerizable material, that is, a photopolymer material, is preferable because the processing step is only once.
This makes it possible to create a stable, high-resolution hologram from a solid photopolymerizable film in one step, and “one-time exposure to a coherent light source with holographic information” It means that an “image” is obtained. The hologram formed in this way is fixed or enhanced rather than destroyed by subsequent uniform exposure to light.

The photopolymer material comprises a thermoplastic polymer binder, an addition-polymerizable ethylenically unsaturated monomer, and a photopolymerization with refractive index modulation comprising a photoinitiator that activates the polymerization of the unsaturated monomer. Sex composition is used.
The thermoplastic polymer binder is a solvent-soluble thermoplastic polymer and is used alone or in combination. In particular,
Acrylates and alpha-alkyl acrylate esters, such as polymethyl methacrylate and polyethyl methacrylate,
Polyvinyl esters, such as polyvinyl acetate, polyacetic acid / vinyl acrylate, polyacetic acid / vinyl methacrylate and hydrolyzable polyvinyl acetate; ethylene / vinyl acetate copolymers;
Saturated and unsaturated polyurethanes;
Butadiene and isoprene polymers and copolymers;
An epoxidized product, for example an epoxidized product having an acrylate or methacrylate group,
Polyamides such as N-methoxymethyl polyhexamethylene acylamide,
Cellulose esters such as cellulose acetate, cellulose acetate succinate and cellulose acetate butyrate;
Cellulose ethers such as methyl cellulose, as well as ethyl cellulose; polycarbonate and the like;
And
Polyvinyl acetals such as polyvinyl butyral and polyvinyl formal.
Particularly preferred are cellulose acetate lactate polymers, polymethyl methacrylate, acrylic polymers and prepolymers including methyl methacrylate / methacrylic acid and methyl methacrylate / acrylic acid copolymers, methyl methacrylate / acrylic acid or methacrylic. Acid (C2-C4) alkyl / acrylic acid or methacrylic acid terpolymers, polyvinyl acetate, polyvinyl acetal, polyvinyl butyral, polyvinyl formal, and the like, and mixtures thereof.

In addition, polystyrene, poly (styrene / acrylonitrile), poly (styrene / methyl methacrylate), and polyvinyl pendels, and mixtures thereof can also be included.
The ethylenically unsaturated monomer may be styrene, 2-chlorostyrene, 2-bromostyrene, methoxystyrene, phenyl acrylate, as a single monomer or as a monomer that can be used in combination. P-chlorophenyl acrylate, 2-phenylethyl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, phenol ethoxylate acrylate, 2- (p-chlorophenoxy) ethyl acrylate, benzyl acrylate, acrylic acid 2- (1-naphthyloxy) ethyl or dimethacrylate, 2,2-di (p-hydroxyphenyl) propane dimethacrylate, polyoxyethyl-2,2-di (p-hydroxyphenyl) propane dimethacrylate, bisphenol-A Di (2-methacryloxyethyl) Ether, ethoxylated hisphenol-A diacrylate, bisphenol-A-di (3-acryloxy-2-hydroxypropyl) ether, bisphenol-A-di (2-acryloxyethyl) ether, tetrachloro-bisphenol-A-di (3-acryloxy-2-hydroxypropyl) ether, tetrachloro-bisphenol-A-di (2-methacryloxyethyl) ether, tetrabromo-bisphenol-A-di (3-methacryloxy-2-hydroxypropyl) ether, tetrabromo- Bisphenol-A-di (2-methacryloxyethyl) ether, diphenolic acid-di (3-methacryloxy-2-hydroxypropyl) ether, 1,4-benzene fold dimethacrylate, 1,4-diisopropenylben Emissions, benzoquinone monomethacrylate, and acrylic acid 2- [beta-(N-Karubajiru) propionyloxy] ethyl and the like, can be used.

One or more moieties wherein the monomer is selected from the group consisting of substituted or unsubstituted phenyl, phenoxy, naphthyl, naphthoxy, heteroaromatic having up to three aromatic rings, chlorine, bromine When it contains, the photopolymerizable composition containing these can be called a “monomer orientation type system”.
Suitable monomers for this monomer-oriented system include 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, phenol ethoxylate acrylate, 2- (p-chlorophenoxy) ethyl acrylate, and acrylic acid. p-chlorophenyl, phenyl acrylate, 2-phenylethyl acrylate, bisphenol-A-di (2-acryloxyethyl) ether, ethoxylated hisphenol-A diacrylate, and 2- (1-naphthyloxy) ethyl acrylate, It is.
And ethylenically unsaturated carbazole monomer; 2-naphthyl acrylate; interchlorophenol acrylate; bisphenol-A diacrylate; 2- (2-butyoxy) ethyl acrylate; and N-phenylmaleimide It may be used by mixing with a second solid monomer.
Also, a preformed polymer material (meaning a prepolymer) consists of substituted or unsubstituted phenyl, phenoxy, naphthyl, naphthoxy, heteroaromatic having up to 3 aromatic rings, chlorine, bromine If it contains one or more moieties selected from the group, the photopolymerizable composition comprising these can be referred to as a “binder-oriented system”.

Monomers used in this system are those that do not contain phenyl, phenoxy, naphthyl, naphthyloxy, heteroaromatics with up to 3 aromatic rings, no moieties taken from the group consisting of chlorine and bromine .
Suitable monomers for the “binder oriented system” are liquid, ethylenically unsaturated compounds that can undergo addition polymerization and have a boiling point higher than 100 ° C. Suitable monomers of this type that can be used as a single monomer or in combination with other monomers include:
That is, butyl acrylate, cyclohexyl acrylate, isoformyl acrylate, 1,5-bentanediol diacrylate, N, N'-ethylaminoethyl acrylate, ethylene glycol diacrylate, 1,4-butanediol diacrylate, diethylene glycol Acrylate, hexamethylene glycol diacrylate, 1,3-pronodioldiol acrylate, decamethylene glycol diacrylate), 1,4-cyclohexanediol diacrylate, glycerol diacrylate, trimethylolpropane diacrylate, pentaerythritol triacrylate , Trimethacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, triethylene glycol diacrylate Tacrylate, polyoxypropyltrimethylolpropane diacrylate, butylene glycol dimethacrylate, 1,3-propanediol dimethacrylate, 1,2,4-butanetriol trimethacrylate, 2,2,4-trimethyl-1,3-propanediol Dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, trimethylol-JR trimethacrylate, 1,5-bentanediol dimethacrylate, diallyl fumarate, perfluorooctyl acrylate, fluorooctyl methacrylate, and 1-vinyl- 2-pyrrolidinone and the like.

In addition to the above ethylenically unsaturated monomer, it may also contain one or more free radical initiated, chain-grown, addition-polymerizable, ethylenically unsaturated compounds having a molecular weight of at least 300.
Also, the monomer is alkylene or polyalkylene glycol diacrylate prepared from alkylene glycol of 2 to 15 carbon atoms or polyalkylene ether glycol of 1 to 10 ether bonds, and when present as a terminal bond, It may have an addition-polymerizable ethylene bond.
Further, decanediol diacrylate, iso-bornyl acrylate, triethylene glyfur diacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, ethoxyethoxyethyl acrylate, triacrylate ester of ethoxylated trimethylolpronone, etc. . Further, it may be used by mixing with a second solid monomer of the same type, for example, N-vinylcaprolactam.
Suitable free radical generating addition polymerization initiators as photoinitiators are substituted or unsubstituted polynuclear quinones, such as 9,10-anthraquinones, which are compounds having two endocyclic carbon atoms in a conjugated carbocyclic ring system. -Chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthrene Quinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dichloronaphthoquinone, 1,4-dimethylanthraquinone, 2,3-dimethylanthraquinone 2-phenylanthraquinone, 2,3-dimethylanthraquinone, anthraquinone alpha-sulfur Include sodium salts of phosphate, 3-chloro-2-methyl-anthraquinone, 7,8,9,10-tetrahydronaphthalene naphthacene quinone, a.

It may also contain an α-hydrocarbon substituted aromatic acyloin, including benzoin, piperoin, acyloin ethers such as benzoin methyl and ethyl ether; α-methylbenzoin, α-allylbenzoin, and α-phenylbenzoin.
Further suitable photoinitiators include 2- (0-chlorophenyl) -4,5-bis (m-methoxyphenyl) imidazole dimer; 1,1'-biimidazole, 2,2'-hist (0- Chlorophenyl) -4,4 ′, 5,5′-tetraphenyl: as well as 1H-imidazole, 2,5-bis (0-chlorophenyl) -4-3,4-dimethoxyphenyl dimer (each of which Typically used with hydrogen donors, such as 2-mercaptobenzoxazole).
The photopolymer material further comprises a fluorine-containing polymer, an addition-polymerizable ethylenically unsaturated monomer, and a photoinitiator. When imaged (optical recording), the photopolymer material has a refractive index modulation greater than 0.001. The photopolymerizable composition can be used. This may further include a plasticizer.
The fluorine-containing polymer can be a polymer made from a perfluorinated monomer and vinyl acetate, such as tetrafluoroethylene or hexafluoropropylene, and can also contain other monomers. For example, a material containing 10 to 20% fluorine is used.
The fluorine-containing polymer used is a fluorine-containing polymer that is compatible with the other components of the photopolymer and produces a substantially solid transparent film when applied.
Fluorine is introduced by copolymerizing other monomers constituting the fluorine-containing polymer with the fluorine-containing monomer, or by reaction with the fluorine-containing polymer, and the fluorine-containing polymer is an alcohol or an acid substituent. When a functional group is contained, a condensation, acetalization, ketalization, or esterification reaction is used to introduce fluorine.

Fluorine-containing polymers include polymers of fluorinated monomers with vinyl esters, vinyl alcohol, vinyl ether, vinyl acetal / butyral, or prepolymers or mixtures thereof. For example, the fluorine-containing polymer can be a polymer of vinyl acetate and a fluorinated monomer, and if necessary, the acetate substituents of the polymer can be removed by hydrolysis to remove the fluorinated poly (vinyl alcohol) derivative. It can also be obtained. This fluorinated poly (vinyl alcohol) can be made into, for example, a fluorinated poly (vinyl butyral) derivative by condensation with butyraldehyde.
Fluorinated poly (vinyl formal), poly (vinyl acetal), etc., or mixtures thereof can be made in the same manner. The fluorinated monomer is preferably a perfluorinated monomer, such as tetrafluoroethylene and / or hexafluoropropylene, but other monomers such as vinyl fluoride or vinylidene fluoride may also be used for specific applications. Can be selected for.
Other monomers can also be present if desired. For example, ethyl vinyl ether can be mixed in the monomer mixture in order to adjust chemical or physical properties such as photopolymer solubility, adhesion, flexibility, or hardness. Such photopolymers are produced using conventional free radical polymerization methods.
Fluorinated fluorine-containing polymers can also be made by reacting appropriately substituted polymers with fluorinated compounds. Polymers with potential reactive sites, such as hydroxyl or carboxyl groups, can be converted to fluorinated fluorine-containing polymers by reaction with fluorinated compounds. For example, fluorinated poly (vinyl butyral) can be prepared by condensation of 2,2,3,3,4,4,4-heptafluorobutyraldehyde and poly (vinyl alcohol). Polymers containing carboxylic acids can be esterified with fluorinated alcohols; poly (vinyl alcohol), partially saponified poly (vinyl acetate), or polymers of fluorinated monomers and vinyl acetate Hydroxyl group-containing polymers, such as partially saponified or saponified, can be esterified with fluorinated carboxylic acids.

Fluoroolefins can be grafted onto appropriately substituted polymers using standard grafting techniques. Polymers with vinyl esters, at least one fluorinated monomer, and any other monomer to adjust the physical properties of the resulting polymer are preferred.
In general, as the fluorine content decreases, the effect also decreases, so that the fluorine-containing polymer contains at least 10% fluorine. However, if the fluorine content is too high, the resulting photopolymer tends to be opaque and is not useful for the preparation of a volume hologram forming layer. Furthermore, when used as a window film, the adhesiveness with the adhesive for re-adhesion is significantly reduced. Accordingly, preferred fluorine-containing polymers have a fluorine content of 10-20%.
Vinyl acetate is particularly preferred as the vinyl ester component of the fluorine-containing polymer, but other vinyl esters and structurally related compounds that give similar results may be selected in addition to or instead of vinyl acetate. it can. For example, vinyl pivalate, vinyl propionate, vinyl stearate, vinyl alcohol, or n-butyl vinyl ether can be selected. Perfluorinated monomers such as tetrafluoroethylene or hexafluoropropylene have been found to be particularly useful as fluorinated monomer components, but include vinyl fluoride, vinylidene fluoride, fluoroolefins, fluoroalkyls. Other compounds such as acrylates and methacrylates can also be selected for specific applications.

Choosing a fluorine-containing polymer that is fluorinated over its non-fluorinated counterpart dramatically increases the refractive index modulation, thus increasing the diffraction efficiency of the hologram.
For example, with all other ingredients the same, what is achieved with polyvinyl acetate is a value in the range of about 0.025-0, 031, whereas the vinyl acetate / perfluoride monomer photopolymer In use, high index modulation values of over 0.040 and 0.076 are achieved.
The fluorinated fluorine-containing polymer can be selected for only a portion of the total fluorine-containing polymer. In this case, the non-fluorinated counterpart of the fluorine-containing polymer is such that the two fluorine-containing polymers are compatible with each other and with the coating solvent and other photopolymer components, and the transparency, mechanical properties of the photopolymer. Other properties can be selected if they are not unduly sacrificed in nature.
The photopolymer contains at least one ethylenically unsaturated monomer that is free-radical initiated, has a boiling point of 100 ° C. or higher, and is compatible with the coating solvent and the selected fluorine-containing polymer. To get. This monomer usually contains an unsaturated group at the terminal position. Generally, liquid monomers are selected, but solid monomers can also be used in combination with one or several liquid monomers if the solid monomers can be internally diffused in the substantially solid photopolymer composition. it can.

Monomers are liquid, ethylenically unsaturated compounds that are capable of addition polymerization and have a boiling point of 100 ° C. or higher, which are substituted or unsubstituted, including up to three aromatic rings; chlorine; and bromine. It contains one or several moieties selected from the group consisting of phenyl, biphenyl, phenoxy, naphthyl, naphthyloxy, and heteroaromatic groups. The monomer contains at least one such moiety, and can contain two or more such moieties that are the same or different if the monomer remains liquid. Substituents such as lower alkyl, alkyloxy, hydroxy, phenyl, phenoxy, carboxy, carbonylimide, cyano, chloro, bromo or combinations thereof, if the monomer remains a liquid monomer and can diffuse in the photopolymerizable layer. Can exist.
Typical liquid monomers include 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, phenol ethoxylate monoacrylate, 2- (p-chlorophenoxy) ethyl acrylate, p-chlorophenyl acrylate, phenyl acrylate, 2-phenylethyl Acryl-1-, 2- (1-butyloxy) ethyl acrylate, 0-biphenyl methacrylate, 0-phenyl acrylate, and mixtures thereof are included.
The monomers are usually liquid, but can also be used in admixture with one or several ethylenically unsaturated solid monomers, such as ethylenically unsaturated carbazole monomers.

Ethylenically unsaturated carbazole monomers containing vinyl groups attached to the nitrogen atom of the carbazole moiety are typically solid. Suitable monomers of this type include N-vinyl carbazole and 3,6-dipromo 9-vinyl carbazole. Particularly preferred mixtures of ethylenically unsaturated monomers are one or several of N-vinylcarbazole and liquid monomers, in particular 2-phenoxyethyl acrylate, phenol ethoxylate monoacrylate, ethoxylate bisphenol-A diacrylate, or mixtures thereof. It consists of a combination with.
When the photopolymer is cross-linked (photopolymerized), up to 5% of at least one multifunctional monomer containing two or several terminal ethylenically unsaturated groups in the composition can be added. The polyfunctional monomer must be compatible with the other components of the composition and is preferably a liquid. Polyfunctional monomers include bisphenol-A di (2-acryloxyethyl) ether, ethoxylate bisphenol-A diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, and others. Ethoxylate bisphenol-A diacrylate is particularly preferred.
The photoinitiator system consists of one or several compounds that directly give free radicals when activated by ionizing radiation. “Ionizing radiation” means active radiation that generates free radicals necessary to initiate the polymerization of the monomer material.

The system can also be composed of a plurality of compounds, one of which produces free radicals after another compound or sensitizer is activated by radiation.
Useful initiator systems may contain various sensitizers and can utilize a number of free radical generating compounds. In particular, a redox system containing a pigment such as rose bengal / 2-dibutylaminoethanol can also be used. Photoreducing dyes and reducing agents, ogisazine, and quinone dyes, dye-oxalate complexes, dye-sensitized azinium salts, and trichloromethyltriazines can be used to initiate photopolymerization. it can.
A preferred photoinitiator system is 2,4,5-triphenylimidazolyl dimer, sensitized with a visible light sensitizer, with a chain transfer agent or a hydrogen donor, and mixtures thereof. This includes 2- (0-chlorophenyl) -4,5-bis (m-methoxyphenyl) -imidazole dimer; 1,1′-biimidazole, 2,2′-bis (0-chlorophenyl ′)-4, 4'5,5'-tetraphenyl; and IH-imidazole, 2,5-bis (0-chlorophenyl) -4- (3,4-dimethoxyphenyl] -timer, etc., each of which is typically a hydrogen donor Used with.
Sensitizers include bis (p-dialkylaminobenzilidine) ketones and arylitin aryl ketones.
Suitable hydrogen donors include 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 4-methyl-4H-1,2,4-1-riazol-3-thiol, and others.
Other hydrogen donors preferred for compositions containing N-vinylcarbazole monomers are 5-chloro-2-mercaptobenzothiazole; 2-mercaptobenzothiazole, IH-1,2,4-methyl-4H— 1,2,4-triazole-3-thiol, 1-dodecanethiol, and mixtures thereof.

As other components, each of the other components commonly added to photopolymer compositions is intended to alter the physical properties of the photopolymer. Such components include plasticizers, heat stabilizers, optical brighteners, UV stabilizers, adhesion modifiers, coating aids, release agents and the like.
Plasticizers are present to alter the photopolymer's adhesion, flexibility, hardness, and other physical properties. Plasticizers include triethylene glycol, triethylene glycol diacetate, triethylene glycol dipropionate, triethylene glycol dicaprylate, triethylene glycol dimethyl ether, poly (ethylene glycol), poly (ethylene glycol) methyl ether, triethylene Glycol bis (2-ethylhexanoate), tetraethylene glycol diheptanoate, diethyl sebacate, dibutyl suberate, tris (2-ethylhexyl) phosphate, isozolovir naphthalene, diisopropyl naphthalene, poly (propylene glycol), tri Includes glyceryl butyrate, diethyl adipate, diethyl sebacate, nopyl perphosphate, tributyl phosphate, tris (2-ethylhexyl) phosphate, etc.
Useful heat stabilizers include hydroquinone, phenidone, p-methoxyphenol, alkyl and aryl substituted hydroquinones and quinones, t-butylcatechol, pyrogallol, beta naphthol, cuprous chloride, 2,6-di-t-butyl. -P-cresol, phenothiazine, copper resinate, naphthylamine, pyridine, nitrobenzene, dinitrobenzene, floranil, chloranneal and the like. Dinitroso dimers are also useful.
As a coating aid, a nonionic surfactant can be added to the photopolymerizable composition. Preferred coating aids are fluorinated nonionic active agents.
A useful optical brightener is 7- (4′-chloro-6′-diethylamino-1 ′, 3 ′, 5′-triazine-4′yl) amino 3-phenylcoumarin. Furthermore, an ultraviolet absorbing material can be used as appropriate.

Further, the transparent resin, that is, the photopolymerizable composition comprises a cationic polymerizable compound, a radical polymerizable compound, a photo radical polymerization initiator system, and a photo cationic polymerization initiator system for polymerizing the cationic polymerizable compound. A photosensitive material is used.
As the cationically polymerizable compound, those which are liquid at room temperature are used so that the polymerization of the radically polymerizable compound is carried out in a composition having a relatively low viscosity throughout. Examples of such cationic polymerizable compounds include diglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, 1,4-bis (2,3-epoxypropoxyperfluoroisopropyl) cyclohexane, sorbitol polyglycidyl ether, trimethylolpropane polyglycidyl ether. Resorcin diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyethylene glycol diglycidyl ether, phenyl glycidyl ether and the like are used.
The radically polymerizable compound preferably has at least one ethylenically unsaturated double bond in the molecule. Further, the average refractive index of the radical polymerizable compound is larger than that of the cationic polymerizable compound, preferably 0.02 or more, and if it is smaller, the refractive index modulation becomes insufficient, which is not preferable. Examples of the radical polymerizable compound include acrylamide, methacrylamide, styrene, 2-bromostyrene, phenyl acrylate, 2-phenoxyethyl acrylate, 2,3-naphthalenedicarboxylic acid (acryloxyethyl) monoester, methylphenoxyethyl acrylate, and nonyl. Phenoxyethyl acrylate, β-acryloxyethyl hydrogen phthalate, or the like is used.
The radical photopolymerization initiator system may be an initiator system that generates active radicals by the first exposure for producing volume holograms, and the active radicals polymerize radical polymerizable compounds, and generally absorbs light. A sensitizer, which is a component, and an active radical generating compound or acid generating compound are used in combination.

As the sensitizer in the radical photopolymerization initiator system, a colored compound such as a dye is often used to absorb visible laser light, but a cyanine dye is preferable in the case of a colorless and transparent volume hologram. Since cyanine dyes are generally easily decomposed by light, the dyes in the volume hologram are decomposed by leaving them for several hours to several days under post-exposure or indoor light or sunlight. A colorless and transparent volume hologram is obtained.
Specific examples of the cyanine dye include anhydro-3,3′-dicarboxymethyl-9-ethyl-2,2′thiacarbocyanine betaine, anhydro-3-carboxymethyl-3 ′, 9-diethyl-2,2 'Thiacarbocyanine betaine, 3,3', 9-triethyl-2,2'-thiacarbocyanine iodine salt, 3,9-diethyl-3'-carboxymethyl-2,2'-thiacarbocyanine iodine salt Etc. are exemplified.
Examples of the active radical generating compound that may be used in combination with a cyanine dye include diaryliodonium compounds and 2,4,6-substituted-1,3,5-triazines. When high photosensitivity is required, the use of diaryliodonium compounds is particularly preferred. Examples of the diaryliodonium include diphenyliodonium, 4,4′-dichlorodiphenyliodonium, 4,4′-dimethoxydiphenyliodonium, and the like. Examples of 2,4,6-substituted-1,3,5-triazines include 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4,6-tris. (Trichloromethyl) -1,3,5-triazine and the like are exemplified.
The cationic photopolymerization initiator system has low photosensitivity for the first exposure, irradiates light having a wavelength different from that of the first exposure, and then generates Bronsted acid or Lewis acid upon exposure to light. An initiator system for polymerizing the polymerizable compound may be used, and those that do not polymerize the cationic polymerizable compound during the first exposure are particularly preferable. Examples of the cationic photopolymerization initiator system include diaryliodonium salts, triarylsulfonium salts, iron allene complexes, and the like. Preferred examples of the diaryl iodonium salts include tetrafluoroborate salts, hexafluorophosphate salts, hexafluoroarsenate salts and hexafluoroantimonate salts of iodonium compounds shown in the photoradical polymerization initiator system. Preferable triarylsulfonium salts include triphenylsulfonium, 4-tertiarybutyltriphenylsulfonium, and the like.

In the photopolymerizable composition, a binder resin, a thermal polymerization inhibitor, a silane coupling agent, a plasticizer, a colorant and the like may be used in combination as necessary. The binder resin is stable for improving the film formability and film thickness uniformity of the composition prior to volume hologram formation, and for interference fringes formed by polymerization by irradiation with light such as laser light until post-exposure. Used to be present. The binder resin only needs to be compatible with the cationic polymerizable compound or the radical polymerizable composition, and specific examples thereof include chlorinated polyethylene, polymethyl methacrylate, methyl methacrylate, and other (meth) acrylic acid alkyl esters. And a copolymer of vinyl chloride and acrylonitrile, polyvinyl acetate, and the like. The binder resin may have reactivity such as a cation polymerizable group in its side chain or main chain.
The thickness of the volume hologram forming layers 2 and 3 is 10 μm to 100 μm. Preferably, the thickness is 20 μm to 50 μm.
When the volume hologram forming layers 2 and 3 are provided on the transparent substrate 1 by coating a transparent resin, the volume hologram forming layers 2 and 3 are formed by applying a coating solution of the photopolymerizable composition to the bar coat. , Spin coating, dipping, or the like, or gravure coating, roll coating, die coating, or comma coating. The volume hologram forming layers 2 and 3 are solidified using drying or curing means.
The photopolymerizable composition includes 10 to 50% of the cationic polymerizable compound, 40 to 70% of the radical polymerizable compound, 1 to 5% of the photo radical polymerization initiator system, and light. The cationic polymerization initiator system is 1 to 5%, and the total amount is 100%.
The photopolymerizable composition is blended with a ketone solvent, an ester solvent, an aromatic solvent, a cellosolve solvent, an alcohol solvent, an ether solvent, a halogen solvent, etc., if necessary, at high speed in a cool and dark place. Prepare by mixing with a stirrer.

The volume hologram forming layers 2 and 3 can also be provided on the transparent substrate 1 by using the above-described resin material and using a casting method, a die coating method, or the like.
A volume hologram is recorded on these volume hologram forming layers 2 and 3 using an appropriate optical system. (See FIG. 2) Or, multiplex recording is performed. (Not shown)
Hereinafter, as an example, a recording method of a reflection type volume hologram will be described. (The masking process is not shown.)
First, an “object” to be imaged as a hologram image is prepared.
The “object” can be a real three-dimensional object such as a sculpture or a model (if it is a famous author, its design is very high), or a painting or brand design 2 A dimensional object is used. Alternatively, “light” that can provide “object light” and is projected onto the surface of the recording medium by an optical system using an optical element capable of electronic cell conversion, such as a spatial modulator. Image ".
Of course, a “hologram reproduction image” (a three-dimensional light image) from a “hologram” created in advance can also be used.
Illuminate this “object” with coherent light such as a gas laser, solid state laser, semiconductor laser, and various dye lasers with a predetermined wavelength selected, and prepare an optical system such as (1) in FIG. Record a master hologram.
Alternatively, a similar optical system is prepared on an appropriate hologram recording photoresist, and a master hologram is recorded and developed.
Further, this master hologram is applied to the reflection type volume hologram forming layers 2 and 3 by using the optical system as shown in (2) of FIG. It can also be recorded as a reflective volume hologram.
When natural light 5 (or 7) is applied as illumination light to this reflection type volume hologram, the reflection type volume hologram reproduction image 6 (or 8) can be observed on the near side. (See Figure 4.)

When the reflective volume hologram is illuminated in the same manner as the reference light used in (1) or (2) in FIG. 1, the reflective volume hologram forming layers 2 and 3 are observed by observation from the direction in which the reference light is transmitted. Through this, an image of an “object”, that is, a reflection type volume hologram reproduction image can be visually recognized on the other side.
When using the above method, two “objects” are prepared, and two light sources (a first wavelength and two laser light sources having a second wavelength) are used to form angles respectively for the volume hologram formation. It is possible to multiplex-record two reflection type volume holograms by changing the recording.
The reflection type volume hologram forming layers 2 and 3 used at this time include, for example, two kinds of sensitizers so as to have sensitivity to two light sources.
In addition, the reflective volume hologram forming layers 2 and 3 are formed as a single layer, and multiple recording is performed on one layer, and the reflective volume hologram forming layers 2 and 3 are formed in multiple layers, and each photopolymer is provided in each layer. It is also preferable to record each reflection type volume hologram using the method in order to increase the clarity of each reflection type hologram reproduction image.
When two reflection type volume holograms are multiplexed and recorded, each “object” image can be seen in two observation directions. (Not shown)
Holograms include laser reproduction holograms, white light reproduction holograms, color holograms using these principles, computer generated holograms (CGH), holographic diffraction gratings, holograms composed of composite diffraction gratings, and machine-readable holograms. Etc. can be recorded as appropriate.
The volume hologram is formed of the same laminate in which the volume hologram is not yet recorded on the volume hologram formation layers 2 and 3 of the laminate of the transparent base material 1 / volume hologram formation layers 2 and 3 recorded as described above. A volume hologram forming layer surface can be replicated in large quantities by a method of irradiating an appropriate laser beam on a layer that is adhered and overlapped (an index matching liquid or the like may be inserted therebetween). (Not shown)

(Relief hologram forming layer provided with hologram relief)
A relief hologram forming layer 4 is provided on the volume hologram forming layers 2 and 3 described above.
On the relief hologram forming layer 4, there are a region 5 having a hologram relief and a planar region having no hologram relief.
When forming a planar area without a hologram relief or a hologram relief by a photographing / developing method, masking is performed with a predetermined pattern, or once a hologram relief is formed on the entire surface, the predetermined area is formed by a flat plate press or the like. Obtained by flattening.
As the transparent resin material for constituting the relief hologram forming layer 4, various thermoplastic resins, thermosetting resins, or ionizing radiation curable resins can be used. (See Figure 3.)
Thermoplastic resins include acrylic ester resins, acrylamide resins, nitrocellulose resins, or polystyrene resins. Thermosetting resins include unsaturated polyester resins, acrylic urethane resins, epoxy-modified acrylic resins, and epoxy-modified unsaturated resins. A polyester resin, an alkyd resin, a phenol resin, etc. are mentioned.
These thermoplastic resins and thermosetting resins can be used alone or in combination of two or more. One or more of these resins may be cross-linked using various isocyanate resins, or various curing catalysts, for example, metal soap such as cobalt naphthenate or zinc naphthenate may be blended. Or peroxide such as benzoyl peroxide and methyl ethyl ketone peroxide for initiating polymerization with heat or ultraviolet light, benzophenone, acetophenone, anthraquinone, naphthoquinone, azobisisobutyronitrile, or diphenyl sulfide good.
Examples of the ionizing radiation curable resin include epoxy acrylate, urethane acrylate, acrylic-modified polyester, etc., for the purpose of introducing a crosslinked structure into such an ionizing radiation curable resin or adjusting the viscosity, A monofunctional monomer, a polyfunctional monomer, or an oligomer may be blended and used.
In order to form the relief hologram forming layer 4 using the above resin material, the relief hologram forming layer 4 can be directly formed by performing interference exposure of the hologram on the photosensitive resin material and developing it. It is preferable to perform molding by using the replica or a plating mold thereof as a replica mold and pressing the mold surface against the layer of the resin material.

When thermosetting resin or ionizing radiation curable resin is used, curing is performed by heating or ionizing radiation irradiation while keeping the uncured resin in close contact with the mold surface, and then cured by peeling after curing. The fine irregularities of the relief hologram can be formed on one side of the layer made of a transparent resin material. A diffraction grating forming layer having a diffraction grating formed in a pattern by a similar method can also be used as the optical diffraction structure.
The thickness of the relief hologram forming layer 4 is 1 μm to 30 μm, particularly 3 μm to 10 μm.
If this thickness is less than 1 μm, it is difficult to form a “hologram relief 5 shape”, and if it exceeds 30 μm, “relief hologram forming layer 4 due to thermal expansion or thermal deformation due to the processing process or use environment of the hologram sheet”. Deterioration of the “re-hologram leaf 5 shape” is likely to occur. When the thickness of the relief hologram forming layer 4 is 3 μm to 10 μm, it is excellent in handling suitability during the processing step and in use, and the uniformity can be improved.
The relief hologram is a recording of interference fringes due to the interference of light between the object beam and the reference beam in an uneven relief shape, for example, a laser reproduction hologram such as a Fresnel hologram, and a white light reproduction hologram such as a rainbow hologram, There are color holograms utilizing these principles, computer generated holograms (CGH), holographic diffraction gratings, and the like. Further, like a machine readable hologram, the reproduction light may be converted into data by a light receiving unit and transmitted as predetermined information, or authenticity may be determined. (The relief hologram forming process is not shown.)

The hologram relief 5 shape of the relief hologram forming layer 4 creates not only an optical method but also an electron beam drawing device to precisely create fine irregularities, thereby creating a precisely designed relief structure and making it more precise. It is also possible to create complicated reproduction light. The relief shape is designed to have a pitch, depth, or specific periodic shape of the unevenness according to the wavelength (range) of the light or light source for reproducing or reproducing the hologram, the direction and the intensity of reproduction or reproduction.
In addition, a color hologram image is formed by a diffraction grating pixel consisting of diffraction grating lines (a minimum unit of a single diffraction grating area consisting of the same diffraction grating line. A set of light emitted from these pixels as diffracted light is one color hologram image. Such a hologram relief 5 is an example including a diffraction grating group corresponding to a hologram image), and a predetermined pixel size, grating line pitch, and grating line angle are assigned to each element. It is also possible to form using an image processing method of assigning and reproducing.
The pitch (period) of the unevenness depends on the reproduction or reproduction angle, but is usually 0.1 μm to several μm, and the depth of the unevenness is a factor that greatly affects the reproduction or reproduction intensity, but is usually 0.01 μm. ˜0.5 μm.
As in the case of a single diffraction grating, when the unevenness of exactly the same shape is repeated, as the adjacent unevenness is the same shape, the degree of interference of reflected light increases and the intensity increases, and the maximum value is reached. Converge. The blur in the diffraction direction is also minimized. When a single point of an image converges to a focal point, such as a stereoscopic image, the convergence accuracy to the focal point is improved, and a reproduced or reproduced image becomes clear.
The method of shaping (also referred to as replicating) the shape of the hologram relief 5 uses a master on which diffraction gratings and interference fringes are recorded in a concavo-convex shape as a press mold (also referred to as a stamper), and forms on the relief hologram forming layer 4. In addition, the concavo-convex pattern of the original plate can be duplicated by stacking the original plate and heat-pressing both of them with an appropriate means such as a heating roll. The hologram pattern to be formed may be single or plural.

In order to accurately reproduce the above ultrafine shape, to suppress damage to the volume hologram forming layers 2 and 3 at the time of replication, and further minimize distortion and deformation such as heat shrinkage after replication. For this reason, the original plate is made of metal and duplicated at low temperature and high pressure.
For the original plate, a metal having high hardness such as Ni is used. After a Cr or Ni thin film layer is formed on the surface of a glass master or the like formed by optical imaging or electron beam drawing or the like by vacuum deposition or sputtering, Ni or the like is electrodeposited (electroplating, electroless plating) Further, it can be made by peeling the metal after forming 50 to 1000 μm by composite plating or the like.
The duplication method uses a flat plate type or a rotary type, the linear pressure is 0.1 ton / m to 10 ton / m, and the duplication temperature is 50 ° C. to 150 ° C. (The replication process is not shown.)
Then, using the above-described method for shaping (replicating) the hologram relief 5 shape, a “transparent layer having a uniform thickness” is previously formed on the laminate of the transparent base material 1 / volume hologram forming layers 2 and 3. (Not shown. This “transparent layer” becomes the relief hologram forming layer 4 of the hologram sheet A of the present invention.), And “a uniform thickness electroluminescent element” is formed on the transparent layer. A layer "(not shown. This electroluminescent element layer becomes the electroluminescent element layer 4 of the hologram sheet A of the present invention) is formed, but the above-described original plate is formed on the electroluminescent element layer having a uniform thickness. By applying heat and pressure by appropriate means such as a heating roll, the concavo-convex pattern of the original is provided on the “transparent layer of uniform thickness” by applying relief relief. A beam forming layer 4, it is preferable to electroluminescent element layer 4 is provided on the "electroluminescent element layer of uniform thickness."

(Electroluminescence element layer)
The electroluminescence element layer 6 is formed by sequentially providing constituent layers on the hologram relief 5 of the relief hologram forming layer 4. (See FIG. 3. The electroluminescence element layer 6 is represented as one “integrated layer”, and each layer (individual layer) constituting the electroluminescence element layer 6 is not shown.)
In either the organic electroluminescence element or the inorganic electroluminescence element, first, the electrode is formed from an anode or a cathode. Below, the example formed from an anode is demonstrated. It can be easily guessed that the cathode is provided in the same manner as this method.
Examples of the anode material include transparent conductive materials such as ITO thin film (indium / tin oxide thin film), indium oxide, tin-doped tin oxide, antimony-doped tin oxide, zinc-doped tin oxide, fluorine-doped tin oxide, and zinc oxide. , Conductive polymers such as polyaniline, polypyrrole, polyacetylene, polyalkylthiophene derivatives, polysilane derivatives, and the like can be used.
The formation method of the anode is a sputtering method, a vacuum deposition method, a chemical vapor deposition method (CVD method), a spin coating method, a sol-gel method using a casting method, a spray pyrolysis method, an ion plating method, etc. A method of applying and forming a coating solution having a desired composition can be employed.
In particular, it is preferable to employ an electron beam heating vacuum deposition method or a high-frequency magnetron sputtering method. Specifically, the film is formed under the conditions of a degree of vacuum of 1 × 10 ⁻⁷ to 1 × 10 ⁻³ Pa, a film formation rate of 0.1 to 50 nm / second, and a substrate temperature of −10 to 100 ° C.
A typical anode is an ITO thin film, which is a transparent conductive thin film, and is formed on the hologram relief 5 by, for example, about 300 nm by an electron beam heating vacuum deposition method.
The conductivity of the transparent conductive thin film is controlled by its surface resistance value, and the heating rate of indium and tin and the amount of oxygen gas introduced are controlled so as to be 0.1Ω / □ or less.

The hologram relief 5 has a fine asperity depth of 0.01 μm, and the subtle change in the curve itself contains hologram reproduction information. The hologram forming layer and the transparent substrate are sufficiently cooled and processed at a high speed so that the curve is not changed by an impact such as a collision. Therefore, the film thickness is reduced.
Thoroughly control the film thickness of the transparent conductive thin film and keep the film thickness variation within a few percent (several% of 300 nm → 10 nm level), and the surface of the transparent conductive thin film (the surface bonded to the relief) (Opposite surface) is made to have substantially the same shape as the hologram forming surface.
In order to further reduce damage to the volume hologram forming layer 2 and the relief hologram forming layer 4, a CVD method (chemical vapor deposition method) or the like can also be used. In the case of the CVD method, there is almost no damage to the relief hologram forming layer 4, but additional processing such as heat treatment after forming the thin film is required, and the surface property of the thin film is somewhat rough as the relief shape of the hologram relief 5. It becomes.
Next, as for the layer to be formed, in the case of an inorganic electroluminescence element, as the simplest configuration, an insulating layer is provided on this transparent conductive thin film.
Specifically, the material used for the insulating layer is an amorphous oxide such as Y ₂ O ₃ , Al ₂ O ₃ , Ta ₂ O ₅ , SiO ₂ , Si ₃ O ₄ , BaTiO ₃ , PbTiO _3, etc. Ferroelectric, SiNx, SiOF, SiOC, Pb (Zr, Ti) O ₃ , (Pb, La) (Zr, Ti) O ₃ , Bi ₄ Ti ₃ O1 ₂ , and perovskite ferroelectric, tungsten Examples thereof include a bronze ferroelectric and a bismuth layer structure ferroelectric.
Furthermore, organic ferroelectrics using π-electron acid-base two-component organic substances, such as dihydroxy having a hydroxyl group with strong acidity (H + (proton) donating ability) such as chloranic acid and bromanilic acid. -P-benzoquinones, or chloranilic acid as an acid, phenazine (Phz) in which a nitrogen atom of a proton accepting group is incorporated into a benzene ring as a base to form a 1: 1 molecular compound, and the like It is also possible to use these aggregated molecules in which hydrogen bonds are formed between them to form a one-dimensional network.

The formation method includes sputtering, vacuum deposition, chemical vapor deposition (CVD), spin coating, sol-gel method using cast method, spray pyrolysis method, ion plating method, and the like. A method of applying and forming a coating liquid having a composition can be employed.
As a dielectric film which is an insulating layer, a BaTiO ₃ thin film is typically formed with a thickness of, for example, 500 nm by using a sputtering (using Ar gas) method. In this case, since the metal oxide thin film has already been formed on the relief hologram forming layer 4, the heat resistance of the relief is relatively high, and the thin film can be formed relatively easily.
This layer is preferably thicker (˜2 μm) in order to ensure insulation, but in order to maintain the shape of the hologram relief 5 surface of the hologram forming layer, it is still uniform and its surface. Therefore, it is preferable to set the thickness to 100 nm to 500 nm.
Here, if the insulating layer is formed to every corner on the transparent conductive thin film, the anode terminal cannot be provided. Therefore, a part of the transparent conductive thin film is considered by the masking method in consideration of the balance with the size of the hologram. For example, in the case of a hologram having a size of 50 mm × 40 mm, masking of a size of 2 mm × 4 mm is performed to form an insulating layer.
Furthermore, the light emitting layer for inorganic electroluminescent elements is provided on it.
The light emitting layer is formed using a light emitting phosphor having a desired light emission color. For example, ZnS, Mn / CdSe or the like is used as a red light emitting phosphor, and ZnS: TbOF or ZnS: Tb is used as a green light emitting phosphor. Examples of the blue light emitting phosphor include SrS: Ce, (SrS: Ce / ZnS) n, CaGa ₂ S ₄ : Ce, and Sr ₂ Ga ₂ S ₅ : Ce. Moreover, SrS: Ce / ZnS: Mn etc. are mentioned as a white light emission fluorescent substance, These fluorescent substances can be selected suitably and can be used.
As the light-emitting layer, typically, a base material using ZnS and Mn added to the light emission center is formed with a thickness of, for example, 1 μm by using a sputtering (using Ar gas) method.
Since this light emitting layer emits light including the phase information of the hologram relief 5, both surfaces (both interfaces) of this layer must faithfully reproduce the relief shape of the relief hologram forming layer 4.

Therefore, a film forming method that can ensure the uniformity of the thickness of each layer and the smoothness of the interface is adopted.
The same masking process is performed on the above-described position also when the light emitting layer is formed.
The cathode provided thereon can be formed using the same material as the anode and using the same method as the anode.
The surface of the cathode in contact with the light emitting layer follows the relief shape of the light emitting layer, and the shape of the light emitting layer itself can be reproduced. The opposite surface also follows the relief shape, and the shape of the light emitting layer itself can be reproduced.
As described above, the relief hologram forming layer 3 and the electroluminescence element layer 6 made of an inorganic electroluminescence element are formed on the surface of the hologram relief 5 on the laminate of the transparent base material 1 / volume hologram formation layer 2. The hologram sheet A of the present invention can be formed so as to contact and follow. (See Figure 3.)
When an alternating voltage having a voltage of 100 V and a frequency of 100 to 1000 Hz is applied 11 between the anode and the cathode of the hologram sheet A, the volume hologram reproduction image 8 or 10 is visually recognized under the natural light 7 or 9. The electroluminescence element layer 6 emits light, and on the anode side, the relief hologram reproduction image 12 can be visually recognized through the relief hologram forming layer 4, the volume hologram forming layer 2 or 3, and the transparent substrate 1. (See Figure 4.)
Further, the recording area of the volume hologram and the formation area of the hologram relief are band-like areas having a width of 100 μm to 300 μm, so that a voltage of 100 V and a frequency of 100 to When an alternating voltage of 1000 Hz is applied 16, the volume hologram reproduction image 14 that has been viewed under natural light 13 emits light in the electroluminescence element layer 6, and the two hologram reproduction images interfere with each other. This hologram reproduction image is not reproduced, and it is observed as if the hologram reproduction image disappeared 17. (See Figure 5.)
Next, an organic electroluminescence device will be described. An electroluminescence device in which an organic thin film serving as a light emitting layer is formed on the transparent conductive thin film layer and sandwiched between cathodes is the simplest organic electroluminescence device. The element layer 6 is formed.
The light-emitting layer is a two-component system of a main material (host material) and an impurity material (dopant material), and the impurity material that emits light is uniformly dispersed in the main material with addition of 0.1 to 1%.
Since the electron mobility of the organic thin film is not intended for high-speed response, it can be used even if it is relatively small, and is preferably set to a value of 1 × 10 ⁻⁶ cm ² / V · s or more.

When using a low molecular system for the organic thin film that is the light emitting layer,
A CVD method is performed using ZnPBO (bis [2- (2-benzoxazolyl) phenolato] zinc) as a light emitting layer material and Coumarin 6 (3- (2-benzothiazolyl) -7- (diethylamino) coumarin as a doping dye material. And formed to a thickness of 50 nm.
When using a polymer system for the organic thin film that is the light emitting layer,
As a light emitting layer material, PPV (polyparaphenylene vinylene) system, as a hole layer material, PEDOT (poly-3,4-ethylenedioxythiophene) + PSS (polystyrene sulfonic acid: dopant) copolymer, The solid content is 0.5%, and the thickness after drying is 100 nm.
In addition, it is also preferable to use an organic thin film in combination with a fluorescent whitening agent such as benzothiazole, benzimidazole or benzoxazole, a metal complex having a styrylbenzene compound or an 8-quinolinol derivative as a ligand. In addition, a distyrylarylene skeleton such as 4,4′-bis (2,2-diphenylvinyl) biphenyl is used as a host, and a strong fluorescent dye from blue to red, for example, a coumarin or a fluorescent dye similar to the host is doped. It is also suitable to use those used together.
As a formation method, methods such as a vacuum deposition method, a spin coating method, a casting method, an LB (Langmuir-Blodget) method, and a sputtering method can be employed. For example, when forming by a vacuum evaporation method, the conditions of a degree of vacuum of 1 × 10 ⁻⁷ to 1 × 10 ⁻³ Pa, a film forming speed of 0.1 to 50 nm / second, and a substrate temperature of −10 to 100 ° C. may be adopted. preferable.
An organic thin film can also be formed by dissolving an appropriate resin functioning as a binder and a material for an organic thin film in a predetermined solvent to form a solution and then reducing the film by a spin coating method or the like. be able to. In addition, the organic thin film is a film formed by selecting a formation method and formation conditions as appropriate and deposited from a gas phase material compound, or a film formed by solidification from a solution state or liquid phase material compound. It is preferable to use a molecular deposited film.

On these, a transparent conductive thin film etc. are similarly used as a cathode layer.
Also in the organic electroluminescence element, the method of exposing the anode terminal can be taken similarly to the inorganic electroluminescence element, and the hologram sheet A of the present invention can be formed. (See FIG. 3. The anode terminal is not shown.)
When a DC voltage of 10 V is applied 11 between the anode and the cathode of the hologram sheet A, the volume hologram reproduction image 8 or 10 is visually recognized under the natural light 7 or 9, and the electroluminescence element layer 6 emits light, and the relief hologram reproduction image 12 can be viewed through the relief hologram forming layer 4, the volume hologram forming layer 2 or 3, and the transparent substrate 1 (from the anode side). (See Figure 4.)
Further, the recording area of the volume hologram and the formation area of the hologram relief are band-like areas having a width of 100 μm to 300 μm, so that a DC voltage of 10 V is applied between the anode and the cathode of the hologram sheet A. When the application 16 is applied, the volume hologram reproduction image 14 that has been viewed under the natural light 13 emits light in the electroluminescence element layer 6, and the two hologram reproduction images interfere with each other, so that any hologram reproduction image is obtained. Is not reproduced, and it is observed as if the hologram reproduction image disappeared 17. (See Figure 5.)
From these phenomena, it can be determined that the hologram sheet A is authentic.

Example 1
A photopolymer (thickness hologram forming layer 2 or 3) having a film thickness of 20 μm is laminated, and a photopolymer (“HRF705” manufactured by DuPont) having a 23 μm thick polyethylene terephthalate film laminated thereon as a protective film. Used as a volume hologram, an argon laser (emission wavelength: 488 nm) is used as a light source, the optical systems (1) and (2) in FIG. 2 are used, and a rectangle of 2.0 mm × 3.0 mm size is used as a unit shape. A masking process is performed on the pattern (in FIG. 2 (2), the shielding plate with the unit shape alternately shielded is photographed so as to be in contact with both sides of the recording material. Not shown), 30 mm × 50 mm size The "painting motif" was a reflection type volume hologram, and the imaging position was taken at a position 2 mm from the recording surface.
That is, the area where the reflective volume hologram is recorded becomes the volume hologram forming layer 3, and the area where no reflection is recorded becomes the volume hologram forming layer 2.
At this time, at an exposure intensity of 4.0 mW, the recording angle (the angle of the reference light in FIG. 2 (2)) is set to 20 degrees with respect to the volume hologram forming layer 2 (relative to the perpendicular direction of the sheet surface). after the irradiation so that the exposure amount of 70 mJ / cm ^2, was irradiated with ultraviolet rays at 500 mJ / cm ² using a high pressure mercury lamp was then heated for 120 minutes at 120 ° C., the volume hologram layer 2 or 3 side , A polyethylene terephthalate film sheet (also referred to as a PET film) having a thickness of 50 μm and a size of 40 mm × 60 mm, which is bonded to the transparent substrate 1, and then the protective film is peeled off. / Volume hologram forming layer 2 or 3 ”was produced. (See FIG. 3. In FIG. 4, this “painting motif” is displayed as “holo” (8 or 10) for convenience.)
At this time, the diffraction efficiency was 50%.
On the volume hologram forming layer 2 or 3, a melamine resin composition is applied, and a mold surface for a relief mold (“H” character image: see FIG. 4) with a hologram image position detection pattern (above and above) is used. Similarly, the hologram relief 5 is formed in a checkered pattern having a rectangular shape of 2.0 mm × 3.0 mm as the unit shape.) The position of the volume hologram forming layer 2 and the position of the hologram relief 5 are Correspondingly, the hologram relief 5 is formed by aligning the position of the volume hologram forming layer 3 and the “position of the planar region of the hologram forming layer 4” to correspond to each other, and heating and curing in contact with each other. A relief hologram forming layer 4 having a thickness of 3 μm was obtained. (See Figure 3.)
The dielectric breakdown strengths of the PET film and melamine resin were 50 MV / m and 20 MV / m, respectively.

On the hologram forming layer 4, an ITO thin film as an anode was formed to a thickness of 300 nm by an electron beam heating vacuum deposition method so as to cover the hologram relief 5 formation region and the planar region. (Not shown.) The surface resistance of the ITO thin film was 0.1Ω / □.
On top of that, BaTiO3 is used as a dielectric film, which is an insulating layer, and a masking process is performed in the area of 3 mm × 3 mm under the right end of the hologram image to leave an anode terminal, and a sputtering (using Ar gas) method is used. And 0.7 μm thick. (Not shown)
On top of that, a light-emitting layer having ZnS as the base material and Mn added to the light emission center was formed with a thickness of 1 μm by sputtering (using Ar gas). Zinc sulfide (ZnS) added with 0.5 mol% of manganese sulfide (MnS) was used as the target, and high-purity argon gas was used as the target gas. At this time, in order to leave the anode terminal, a masking process was performed in a 3 mm × 3 mm region below the right end of the hologram image. (Not shown)
On this light emitting layer, an ITO thin film as a cathode layer was subjected to masking treatment at the same position, and formed with a thickness of 500 nm by electron beam heating vacuum deposition.
The four layers of the anode layer, the insulating layer, the light emitting layer, and the cathode layer constitute an electroluminescence element layer 4 (inorganic electroluminescence element layer). The hologram sheet A of the present invention was produced by being formed so as to follow and follow the flat area. (See Figure 3.)
When the hologram sheet A was placed under the natural light 7 as shown in FIG. 4, a clear reflection type volume hologram reproduction image “painting motif” 8 could be visually recognized. (See FIG. 4. In FIG. 4, this “painting motif” is displayed as “holo” for convenience.)
When an AC voltage of 100 V and 100 Hz is applied 11 between the anode terminal portion and the cathode terminal portion of the hologram sheet A, green light emission is generated, and a relief hologram reproduction image “H” 12 by this emission color is generated. And the reflection type volume hologram reproduction image "painting motif" 10 by natural light illumination light 9 was obtained. (See FIG. 4. In FIG. 4, this “painting motif” is displayed as “holo” for convenience.)
An appropriate pressure-sensitive adhesive is left on the hologram sheet A, leaving the anode terminal portion and further a part of the ITO thin film layer as the cathode layer (a 3 mm square region different from the anode terminal region, which becomes the cathode terminal). Apply, cut out to 35mm x 55mm size, paste on passport, and apply 100V / 100Hz AC voltage between the anode terminal part and the cathode terminal part in the dark environment. A relief hologram reconstructed image was generated by light emission, and it was confirmed that this passport was authentic. (Not shown)

(Example 2)
The anode on the relief hologram forming layer 4 is formed with a thickness of 100 nm, the insulating layer thereon is formed with a thickness of 300 nm, the light emitting layer thereon is formed with a thickness of 500 nm, and further thereon A hologram sheet A of Example 2 was obtained in the same manner as in Example 1 except that the cathode was formed with a thickness of 100 nm. (See Figure 3.)
When evaluated in the same manner as in Example 1, the same good results as in Example 1 were obtained except that the sharpness of the relief hologram reproduction image 12 at the time of light emission was improved and it was thought that the determination could be made more reliably. It was. (See Figure 3.)
(Example 3)
The volume hologram forming layers 3 and 2 are formed by masking a reflective volume hologram (“painting motif 2”) into a striped checkered pattern of 200 μm × 1.0 mm size with an oscillation wavelength of an argon laser of 514.5 nm. Was recorded. (See Figure 3.)
The diffraction efficiency at this time was 30%.
Further, the position of the hologram relief 5 was also set to a position corresponding to the volume hologram forming layer 2.
Then, an ITO thin film is formed as an anode with a thickness of 300 nm by an electron beam heating vacuum deposition method, and a TPAC (1,1-bis [4- [N, N-dioxide] is formed thereon as a hole transport material. (P-tolyl) amino] phenyl] cyclohexane) with a thickness of 100 nm, as the light emitting layer, ZnPBO (bis [2- (2-benzoxazolyl) phenolato] zinc) as the light emitting material and Coumarin 6 (3- (2-benzothiazolyl) -7- (diethylamino) coumarin) 3% mixed, with a thickness of 200 nm, and as an electron transport material, BND (2,5-bis (1-naphthyl) -1,3,4- Oxadiazole) was formed to a thickness of 100 nm by the same masking treatment as in Example 1 by vacuum deposition.
On top of that, as a cathode, an ITO thin film was masked at the same position, and formed with a thickness of 300 nm by an electron beam heating vacuum deposition method.
As described above, except that the electroluminescence element layer 6 (organic electroluminescence element layer) composed of the anode, the hole transport layer, the light emitting layer, the electron transport layer, and the cathode, and the volume hologram forming layers 2 and 3 were formed. In the same manner as in Example 1, a hologram sheet A of Example 3 was produced. (See Figure 3.)
When this hologram sheet A was placed under the natural light illumination light 13, a clear reflection type volume hologram reproduction image “painting motif” 14 was visually recognized, but between the anode terminal portion and the cathode terminal portion of this hologram sheet A In addition, when a DC voltage of 6 V was applied 16 to emit light (center emission wavelength 520 nm), the hologram reproduction image disappeared 17 under the natural light illumination light 15, and the authenticity of the hologram sheet A was ensured. I was able to judge. (See Figure 5.)
(Comparative example)

A hologram sheet was formed without forming an electroluminescence element layer, and was used as a comparative example.
When observed in the same manner as in Example 1, it was possible to visually confirm the reflection type volume hologram reproduction image, but even if a predetermined electric field was applied, there was no change and this hologram sheet was a fake. I was able to judge.
Further, the hologram relief provided on the relief hologram forming layer was filled with an adhesive, and the relief hologram reproduction image could not be visually recognized under fluorescent lamp illumination.

A hologram sheet 1 transparent substrate 2 volume hologram forming layer (area where volume hologram is not recorded)
3 Volume hologram formation layer (area where volume hologram is recorded)
4 Relief hologram forming layer 5 Relief hologram forming layer (region with hologram relief)
6 Electroluminescence element layer 7 Natural light (volume hologram illumination light)
6 Volume hologram reproduction image (in the case of a reflection type volume hologram)
7 Natural light (volume hologram illumination light)
8 Volume hologram reproduction image (in the case of a reflection type volume hologram)
9 Natural light (volume hologram illumination light)
10 Volume hologram reproduction image (in the case of a reflection type volume hologram)
11 Application of predetermined electric field 12 Relief hologram reproduction image by light emission of electroluminescence element layer 13 Natural light (volume hologram illumination light)
14 Volume hologram reproduction image (in the case of a reflection type volume hologram)
15 Natural light 16 Application of a predetermined electric field 17 State in which a hologram reproduction image has disappeared

Claims (3)

A volume hologram forming layer, a relief hologram forming layer provided with a hologram relief, and an electroluminescence element layer provided following the hologram relief of the relief hologram forming layer in this order on one surface of the transparent substrate. The hologram sheet provided in
A hologram sheet comprising a volume hologram recording area recorded on the volume hologram forming layer and a hologram relief forming area alternately.
2. The hologram sheet according to claim 1, wherein the recording area of the volume hologram and the formation area of the hologram relief are band-like areas having a width of 100 μm to 300 μm.
  3. The hologram sheet according to claim 1, wherein a thickness of the electroluminescence element layer is 0.01 μm to 2.0 μm.

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