JP2000305441A - Hologram recording medium with releasing layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hologram recording medium having high diffraction efficiency, transparency and preservation stability, not causing the blurring of a reproduced image, free from surface roughening and scuffing, capable of manufacturing holograms formed in various shapes and excellent in mass productivity. SOLUTION: A photosensitive layer 2 capable of manufacturing a hologram and consisting of (A) a solvent-soluble and cationic-polymerizable thermosetting epoxy oligomer having one or more glycidyl groups in its unit structure, (B) a compound which is liquid at normal temperature and normal pressure, has >=100 deg.C boiling point at normal pressure and has one or more radical polymerizable ethylenically unsaturated bonds, (C) an aromatic onium salt which generates a radical species which activates radical polymerization and Broensted acid or Lewis acid which activates cationic polymerization when the salt is exposed to actinic radiation, (D) a photoinitiator and (D) a sensitizing dye which sensitizes the component C is disposed on one face of a film substrate 1 and a releasing layer 3 is disposed on the other face to obtain the objective hologram recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a layer structure when a volume phase type hologram recording material is used as a recording medium, and more particularly to a hologram capable of forming holograms in various shapes and excellent in mass productivity. It relates to a recording medium.

[0002]

2. Description of the Related Art Holograms, which reproduce a three-dimensional image, are preferred for their excellent design, and are used for covers of books and magazines, POP displays, gifts and the like.
Further, since the hologram is equivalent to recording information on the order of submicron, it is also used to prevent forgery of securities, credit cards and the like. Further, in recent years, in addition to display applications, application to a hologram optical element (HOE) typified by a combiner for a head-up display (HUD) mounted on an automobile or a reflector for a reflective liquid crystal display device is expected. ing. The hologram recording material is required to be sensitive to a laser beam having a visible oscillation wavelength with high sensitivity and exhibit high resolution.
In actual use, it is required that characteristics such as diffraction efficiency of the hologram, reproducibility of the wavelength of the reproduction light, bandwidth (half-width of the reproduction light peak), chromatic aberration (blur), etc. meet the purpose. Specifically, in order to obtain a recording material for HOE, the diffraction efficiency is 90% or more at 5000 to 6000 spatial frequencies, and the half width (band width) of the peak of the reproduction light is 1
The peak wavelength of the reproduction wavelength is preferably within 5 nm from the photographing wavelength.
Light resistance, solvent resistance, durability such as scratch resistance are required,
It is also necessary to have excellent storage stability over a long period of time.

[0003] The general principle of hologram fabrication is described in several documents and technical books, for example, Chapter 2 of “Holographic Display” (edited by Junpei Tsujiuchi; Sangyo Tosho). According to these, generally, a photosensitive recording medium, for example, a photographic dry plate, is placed at a position where one of two coherent laser beams of a light beam is irradiated onto a recording object and the light totally reflected therefrom can be received. The recording medium is irradiated directly with the other coherent light in addition to the reflected light from the object without hitting the object. The light reflected from the object is referred to as target light, and the light directly illuminating the medium is referred to as reference light, and interference fringes between the reference light and the target light are recorded as image information.
Next, when the processed recording medium is exposed to light and observed at an appropriate eye position, the light from the illumination light source emits the wavefront of the reflected light that first arrived at the recording medium from the object during recording. Is diffracted by the hologram so as to reproduce the object, and as a result, an object image similar to the real image of the object is observed three-dimensionally. A hologram formed by causing the reference light and the target light to enter the recording medium from the same direction is known as a transmission hologram. On the other hand, holograms formed by making incident from opposite sides of a recording medium are generally known as reflection holograms.

Hitherto, as a hologram material, a photosensitive material based on a bleached silver salt and gelatin dichromate has been generally used. However, these hologram recording materials are
In each case, complicated processing is required after the production and recording of the photosensitive plate, and further, there is a problem that environmental resistance properties, for example, moisture resistance and weather resistance are inferior.

On the other hand, it has excellent environmental resistance characteristics and
As a material having characteristics that a hologram recording material should have, such as high resolution and high diffraction efficiency, there is a dry-processed recording material having no voids in a hologram layer, specifically, a solvent-soluble and cationically polymerizable material. Holographic recording materials comprising a thermosetting resin having at least one ethylene oxide ring in the structural unit and a radically polymerizable ethylenic monomer (JP-A-8-1676, JP-A-8-1677, JP-A-8-1678, Kaihei 8-1679).
The hologram made of the recording material has a thickness of 10 to 40 μm.
When a hologram is to be formed, a substrate having a smooth surface and being not eroded by the solvent of the photosensitive liquid is required. A glass substrate is one that satisfies these conditions. However, when a hologram is produced using a glass substrate, it must be produced in a batch method,
In this case, mass productivity is not good, and there are problems such as an increase in cost. Furthermore, it is difficult to form the hologram into an arbitrary shape. In order to solve these problems, there is a method of providing a hologram photosensitive layer on a long film substrate without using a glass substrate as a substrate. And the above disadvantages can be overcome. Furthermore, in the case of application to a hologram optical element, by producing a hologram, transferring the hologram layer from a film substrate to a glass substrate or another film via an adhesive or the like, and then peeling the hologram layer from the film substrate. Since various hologram optical elements can be obtained, there is an advantage that the base material of the hologram optical element can be arbitrarily selected.

[0006] By making the substrate a film substrate,
Although it is very useful because it has the above advantages, it has the following problems in producing a hologram. When producing a hologram recording medium by providing a photosensitive layer on a film substrate having no release treatment layer, since the hologram layer has tackiness, the hologram recording medium is wound up in a roll without blocking. Requires a cover film as a protective layer. In order to produce a hologram using the hologram recording material having the protective layer, it is necessary to bring the hologram layer into close contact with the master hologram at the time of hologram exposure, so that the hologram exposure is performed. The Rukoto. However, it is difficult to reuse the peeled protective layer due to problems such as dust and scratches. Further, after the hologram exposure, the film substrate having the hologram layer is wound again in a roll shape in order to pass through a heating step and a fixing step which are later steps. However, at this time, since the hologram layer still has tackiness, if the film substrate is wound up in a roll form, blocking occurs. As a method for preventing this blocking, it is necessary to laminate the protective layer again when winding up in a roll. In such a hologram recording medium using a film base material without a release treatment layer, it is necessary to laminate the protective layer twice, which further increases the cost, and also results in surface roughening, scratches, etc. due to lamination failure. Disadvantages such as generation of

[0007]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, by selecting a specific layer configuration for the hologram recording medium developed by the present inventors. It has been found that a hologram recording medium excellent in mass productivity can be obtained without the need for a cover film, and the present invention has been completed.

That is, the invention of claim 1 comprises (A) a solvent-soluble, thermosetting epoxy oligomer capable of cationic polymerization having at least one glycidyl group in a unit structure, and (B) a liquid at room temperature and normal pressure. And boiling point at normal pressure
A compound having at least one radically polymerizable ethylenically unsaturated bond having a temperature of at least 00 ° C., (C) a radical species that activates radical polymerization when exposed to actinic radiation, and a brane that activates cationic polymerization A hologram-producible photosensitive layer (2) comprising an aromatic onium salt generating a Sted acid or a Lewis acid and (D) a sensitizing dye for sensitizing a photoinitiator (C) is formed on a film substrate (1). And a release processing layer (3) provided on the opposite surface of the hologram recording medium.

According to a second aspect of the present invention, there is provided an aromatic compound which generates a Bronsted acid or a Lewis acid which activates a radical species and a cationic polymerization when exposed to the actinic radiation according to the first aspect. A hologram recording medium, wherein the onium salt (C) is a diaryliodonium salt.

According to a third aspect of the present invention, the film substrate (1) according to the first aspect is a polyethylene terephthalate resin,
A hologram recording medium comprising a polypropylene resin or a polyethylene resin.

According to a fourth aspect of the present invention, there is provided a hologram recording medium wherein the release treatment layer (3) according to the first aspect is made of a silicone resin.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
FIG. 1 is a schematic diagram illustrating the configuration of a hologram recording medium having a release processing layer according to the present invention, and FIG. 2 is a schematic diagram illustrating a hologram exposing machine for hologram duplication.

As shown in FIG. 1, a hologram recording medium (10) having a release treatment layer of the present invention comprises a film base (1) containing a hologram photosensitive recording material on a photosensitive layer (2).
And a release processing layer (3) formed on the back surface of the hologram. Usually, as shown in FIG. 2, the hologram is held in the form of a long take-up roll. A hologram image is recorded using an exposure machine.

First, a hologram photosensitive recording material constituting a photosensitive layer of the hologram recording medium of the present invention is used.
Component (A) The thermosetting epoxy oligomer which is solvent-soluble and cationically polymerizable and has at least one glycidyl group in a unit structure includes bisphenol A, bisphenol AD, bisphenol B, and bisphenol A.
F, bisphenol S, brominated bisphenol A, novolak, o-cresol novolak, p-alkylphenol novolak, hydrogenated bisphenol A, hydrogenated bisphenol AD, hydrogenated bisphenol B, hydrogenated bisphenol AF, hydrogenated bisphenol S, hydrogenated bromide The following epoxy compounds produced by a condensation reaction of various phenol compounds such as bisphenol A and epichlorohydrin can be exemplified. However, the present invention is not limited to these.

[0015]

Embedded image

(Where n = 1 to 20)

[0017]

Embedded image

(Wherein R represents an alkyl group, and n = 1
-20. )

[0019]

Embedded image

(Where n = 1 to 20)

The molecular weight of the above-mentioned thermosetting epoxy oligomer is preferably from 900 to 6000. If it is smaller than this, the film-forming property is deteriorated and uniform coating cannot be performed. Further, a molecular weight larger than this range generally makes synthesis difficult. The epoxy equivalent of the thermosetting epoxy oligomer is 400
To 6000, and other than this, good cationic polymerization does not proceed.

Next, as the component (B) used in the present invention, a compound which is liquid at normal temperature and normal pressure and has at least one ethylenically unsaturated bond capable of radical polymerization and having a boiling point of 100 ° C. or higher at normal pressure includes: It contains at least one ethylenically unsaturated bond in the structural unit, contains a polyfunctional vinyl monomer in addition to a monofunctional vinyl monomer, or may be a mixture thereof.

More specifically, high-boiling vinyl monomers such as (meth) acrylic acid, itaconic acid, maleic acid, (meth) acrylamide, diacetone acrylamide, 2-hydroxyethyl (meth) acrylate, and aliphatic Hydroxy compounds, such as ethylene glycol,
Diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, neopentyl glycol, 1,
3-propanediol, 1,4-butanediol, 1,
5-pentanediol, 1,6-hexanediol,
1,10-decanediol, trimethylolpropane,
Di- or poly (meta) such as pentaerythritol, dipentaerythritol, sorbitol, mannitol
Acrylic esters or alicyclic polyhydroxy compounds, for example, mono- or di (meth) acrylic esters such as dicyclopentanol, dicyclopentenol, tricyclodecane dimethylol, etc., are preferred. Is polyethylene glycol di (meth) acrylate or polypropylene glycol di (meth)
Acrylates may be mentioned, but are not limited thereto.

The component (C) used in the present invention, as a photoinitiator system which activates radical polymerization and cationic polymerization when exposed to actinic radiation, simultaneously generates a radical species and a Bronsted acid or Lewis acid upon irradiation with light. As the aromatic onium salt to be used, a diaryliodonium salt or the like is preferable. The diaryliodonium salts used in the present invention include Macromolecules, 1
0,1307 (1977). Compounds described in, for example,
Chlorides and bromides of iodonium such as diphenyliodonium, ditolyliodonium, phenyl (p-anisyl) iodonium, bis (m-nitrophenyl) iodonium, bis (pt-butylphenyl) iodonium and bis (p-chlorophenyl) iodonium; Alternatively, a tetrafluoroborate salt, a hexafluorophosphate salt, a hexafluoroarsenate salt and the like can be mentioned, but it is not limited to these.

Further, the sensitizing dye of component (D) used in the present invention includes, for example, organic compounds such as cyanine or merocyanine derivatives, coumarin derivatives, chalcone derivatives, xanthene derivatives, thioxanthene derivatives, azurenium derivatives, squarylium derivatives, and porphyrin derivatives. Dye compounds can be used. In addition, "Dye Handbook" (Shin Okawara et al., Kodansha 1986), "Chemistry of Functional Dyes" (Shin Okawara et al., CMC 1986),
"Special Functional Materials" (CMC 198, edited by Chuzaburo Ikemori and others)
6) can be used. It should be noted that the dye and the sensitizer are not limited thereto, and any dye or sensitizer that absorbs light in the other visible region can be used.If necessary, these dyes and sensitizers may be used. Two or more kinds can be used in combination at any ratio.

The amount of the component (B) contained in the hologram recording material of the present invention can be in the range of 20 to 200 parts by weight, preferably 30 to 100 parts by weight, per 100 parts by weight of (A). Parts by weight. The amount of the photoinitiator of component (C) is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of component (A). The amount of component (D) can range from 0.01 to 5 parts by weight, preferably from 0.1 to 1 part by weight, per 100 parts by weight of (A). The amount used is limited by the thickness of the photosensitive layer and the optical density of the thickness. That is, it is preferable to use the optical density within a range not exceeding 2.

The hologram recording material composed of the above components includes, for example, toluene, xylene, chlorobenzene,
Chloroform, dichloroethane, dichloroethylene, trichloroethylene, methyl isobutyl ketone, dioxane, tetrahydrofuran, isopropanol, n-butanol, 2-methoxyethanol, 2-methoxyethyl acetate, propylene glycol monomethyl ether, 3-methoxypropanol, 3-methoxypropyl acetate, methyl ethyl ketone And an appropriate solvent such as acetone, or a mixture thereof in an appropriate combination, can be dissolved and applied on the film substrate (1).

In the present invention, various additives for solving various practical problems can be used in combination with the hologram recording material. For example, for the purpose of preventing thermal polymerization during storage, addition of a thermal polymerization inhibitor such as p-methoxyphenol, hydroquinone, catechol, and phenothiazine, and for the purpose of promoting polymerization, amines, thiols, and chain transfer agents such as disulfides. Addition or addition of an antifoaming agent, a leveling agent, a plasticizer, an antioxidant, a flame retardant, an antistatic agent, an antihalation agent and the like are possible.

As described above, these components are appropriately selected, and the photosensitive solution obtained by mixing them at an arbitrary ratio is mixed with a bar coater.
FIG. 1 shows a hologram recording medium obtained by applying a photosensitive layer (2) capable of producing a hologram on a film substrate (1) using a known coating means such as a roll coater, a die coater, a comma coater, and a gravure coater. It is a hologram recording medium (10) for hologram photographing shown. When the photosensitive liquid is applied, it may be diluted with an appropriate solvent, if necessary, but in that case, drying is required after application on the film substrate. Further, the transmittance of the irradiation light at the time of shooting is 1
% Is desirable.

Examples of the film substrate (1) used for the hologram recording medium of the present invention include polyethylene terephthalate resin, polypropylene resin and polyethylene resin. Specifically, Melinex (PET)
Film, trade name of ICI Japan Co., Ltd.), Diafoil (PET film, trade name of Diafoil Co., Ltd.), Teijin Tetoron Film (P
ET film, trade name, manufactured by Teijin Limited), Lumirror (PE
T film, trade name, manufactured by Toray Industries, Inc., Ester Espet (trade name, PET film, trade name, manufactured by Toyobo Co., Ltd.), Alphan (PP film, trade name, manufactured by Honshu Paper Co., Ltd.),
Pyren (PP film, Toyobo Co., Ltd. product name),
Tocelo OP (PP film, Toyo Cellophane Paper Co., Ltd.)
Brand name), Purelay (PP film, trade name made by Idemitsu Petrochemical Co., Ltd.), Hybron film (PE film, trade name made by Mitsui Toatsu Platec Co., Ltd.), Lamilon (PE film, Seishiyo Packaging Co. ), And Toyobo Rix film (PE film, trade name, manufactured by Toyobo Co., Ltd.), but are not limited thereto.

As the film substrate (1) having the release treatment layer (3) on the back surface used in the hologram recording medium of the present invention, a bar coater, a roll coater, a die coater, Using a known coating means such as a comma coater or a gravure coater, a silicone resin or the like is applied to form a release treatment layer (3), or a commercially available release treated film or the like is used. Is also good.

The release layer (3) used in the hologram recording medium of the present invention is preferably a silicone resin. Specific examples of the silicone resin used in the present invention include SD7223, SD7226, and SD722.
9 (silicone for film release paper, trade name of Dow Corning Silicone Toray Co., Ltd.), KS774, KS
3703 (release agent for release paper for film, brand name manufactured by Shin-Etsu Chemical Co., Ltd.), TSM620, TSM6281, T
SR144 (release silicone, trade name, manufactured by Toshiba Silicone Co., Ltd.) can be mentioned, but not limited thereto.

As the film substrate having the release treatment layer (3) of the hologram recording medium of the present invention, there is a release treated film on the market.
Polyethylene film (PE film, Tamapoli Co., Ltd.)
Product name), Lupic (PE film, Tonen Chemical Co., Ltd.)
Brand name), Pyren (PP film, Toyobo Co., Ltd.)
Brand name), Trefane BO (PP film, trade name, manufactured by Toray Industries, Inc.), Alphan (PP film, trade name, manufactured by Honshu Paper Co., Ltd.), Taiko FO (PP film, manufactured by Mimura Nisho) (Trade name), Teijin Tetron film (PET film, trade name, manufactured by Teijin Limited), Taiko polyester film (PET film, Nimura Chemical Co., Ltd.)
And the like, but are not limited to these.

As a light source suitable for the hologram recording material used in the present invention in the step of exposing an interference pattern in producing a hologram using the hologram recording medium of the present invention, a helium-cadmium laser, an argon laser, a krypton laser, A coherent light source such as a helium-neon laser or a semiconductor laser can be used, but is not limited thereto.

In the hologram recording exposure step,
(B) a monomer having at least one or more radically polymerizable ethylenically unsaturated bonds which is liquid at normal temperature and pressure and has a boiling point of 100 ° C. or higher at normal pressure is (A) a solvent-soluble glycidyl in the unit structure The polymerizable recording material is uniformly distributed in the cationically polymerizable thermosetting epoxy oligomer having at least one group, but the polymerizable recording material is irradiated with laser interference light to cause light interference in the laser irradiation site. In a site having strong acidity, the photoinitiator (C) simultaneously generates a radical species that activates radical polymerization and cationic polymerization and a Brnsted acid or Lewis acid by the action of the sensitizing dye (D). The monomer (B) is polymerized by the radical species generated here, and a concentration difference occurs as the monomer (B) is polymerized, whereby the monomer (B) diffuses and moves from the surroundings. Therefore, the monomer concentration is high in a portion of the laser irradiation portion where the light interference is strong, and is low in a portion of the laser irradiation portion where the light interference is weak. By multiplying this, the epoxy oligomer (A)
Is extruded to a portion of the laser irradiation portion where the light interference effect is weak, and the concentration at that portion increases, while the concentration at the portion of the laser irradiation portion where the light interference effect is strong decreases. As a result, it is presumed that a refractive index difference occurs between the two portions, and a latent image of the hologram is recorded. Further, the remaining monomer (B) has a concentration difference between a portion where the light interference effect is strong and a portion where the light interference action is weak in the laser irradiation portion, and the monomer (B) is further diffused by heating after hologram exposure. The epoxy oligomer (A), which is a support around the interference fringes formed by the polymerization of the monomer (B) by the strong acid generated simultaneously with the radical species, is caused by the migration and the difference in the refractive index, and the epoxy oligomer (A) is cationically polymerized. As a result, a crosslinked structure is formed, the refractive index increases, and the refractive index modulation is enhanced. In addition, weather resistance is also improved by this crosslinking reaction. Further, it is presumed that the unreacted monomer (B) and photoinitiator (C) remain in the polymerizable recording material after heating, and by irradiating a sufficient amount of ultraviolet light there, The monomer (B) in the reaction can be cured and fixed, and the sensitizing dye (D) can be decolored, so that the hologram produced can have improved weather resistance and colorless transparency.

[0036]

Hereinafter, the present invention will be described in more detail with reference to specific examples. <Example 1> Bisphenol-based epoxy resin epicoat 1007 (degree of polymerization n = 10.8, epoxy equivalent: 175)
0-2200, Yuka Shell Epoxy Co., Ltd. product name) 1
00 parts by weight, triethylene glycol diacrylate 5
0 parts by weight, 4,4'-bis (tert-butylphenyl) iodonium hexafluorophosphate, 5 parts by weight, 3,3'-carbonylbis (7-diethylamino) coumarin, 0.5 part by weight, 100 parts by weight of 2-butanone Was dissolved and used as a photosensitive solution. A PET film having a release treatment layer formed as a release treatment layer (3) as a film substrate (1) using a die coater so as to have a thickness of about 20 μm using this photosensitive solution: Teijin Tetron.
A hologram recording medium 10 was produced by applying a film O type to a thickness of 100 μm (trade name, manufactured by Teijin Limited) to form a photosensitive layer (2). This hologram recording medium 1
Since 0 is formed in a long shape, it is usually wound up and stored.

The hologram recording medium manufactured with the above-mentioned layer structure is exposed using an argon laser (488 nm) as a light source by a hologram exposing machine for hologram replication shown in FIG. The material was wound up without lamination on a new film substrate. In order to perform the developing / fixing step, the wound hologram recording material was heated at 100 ° C. for 30 minutes using a scroll oven to form a developing step. As a result, when heated in a scroll oven, the hologram recording material subjected to hologram exposure can be unwound and heated without causing blocking and without deteriorating the surface properties of the hologram layer. Was. Further, as a fixing step, UV curing was performed using a UV irradiation apparatus (a conveyor type ultraviolet curing apparatus manufactured by Eye Graphics Co., Ltd., a high-pressure mercury lamp, 1 J / cm 2) to perform fixing, and a hologram having excellent hologram characteristics was obtained. .

<Example 2-3> The release-treated P of the film substrate (1) having the release treatment layer (3) on the back surface of Example 1
ET film: Teijin Tetron film O type 100 μm thick (trade name, manufactured by Teijin Limited); PE film: Tamapoly polyethylene M series 100 μm
A hologram was obtained by the same material and operation as in Example 1 except that the thickness (trade name of Tamapoli Co., Ltd.) and the PP film: Alphan Alphan R were 50 μm thick (trade name of Honshu Paper Co., Ltd.). . Both of the above hologram recording materials provided good holograms without blocking and deterioration of the surface properties of the hologram layer.

Example 4 PET film: Diafoil S type 100 μm thick (trade name of Diafoil Co., Ltd.) as a film substrate (1) having a release treatment layer (3) on the back surface of Example 1 As a release treatment layer (3), a 5% toluene solution of a release agent KS774 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) for a release paper for a film is coated with a gravure coater to a thickness of 0.5 μm. Example 1 except that a heat treatment (80 ° C., 1 minute) was performed to install the release treatment layer (3), and the film substrate (1) having the release treatment layer (3) on the back surface was used. A hologram was obtained by using the same materials and operations as described above. The above hologram recording materials are both blocking,
A good hologram was obtained without deteriorating the surface properties of the hologram layer.

<Example 5-6> PET of the film substrate (1) having the release treatment layer (3) on the back surface of Example 4
Film: Diafoil S type 100 μm thickness (trade name, manufactured by Diafoil Co., Ltd.), PE film: Lamilon II-F grade 80 μm thickness (trade name, manufactured by Sumiishi Packaging Co., Ltd.), PP film: Trefane BO 2500
A hologram was obtained by the same material and operation as in Example 1 except that the type was 60 μm thick (trade name, manufactured by Toray Industries, Inc.). The above hologram recording materials are both blocking,
A good hologram was obtained without deteriorating the surface properties of the hologram layer.

<Comparative Example 1> As a film substrate of Example 1, a film substrate PET whose back surface was not subjected to a release treatment was used.
Film: Example 4 except that Diafoil S type was 100 μm thick (trade name of Diafoil Co., Ltd.)
An attempt was made to produce a hologram using the same materials and operations. As a result, the wound hologram recording material is blocking, and if it is forcibly peeled off, the surface property of the hologram layer is deteriorated, and a terrible portion is shifted to the back surface of the base film. It was impossible. Therefore, a good hologram could not be obtained with the hologram recording material.

<Comparative Example 2-3> Film base PET film in which the back surface of Comparative Example 1 was not subjected to a release treatment: Diafoil S type 100 μm thick (Diafoil Co., Ltd.)
Product name), PE film: Lamilon II-F8
0 μm thickness (trade name, manufactured by Sekiryo Packaging), PP film:
The production of a hologram was attempted using the same materials and operation as in Comparative Example 1, except that the Trefan BO 2500 type was 60 μm thick (trade name, manufactured by Toray Industries, Inc.). as a result,
As in the case of Comparative Example 1, blocking and deterioration of the surface properties of the hologram layer occurred. Therefore, the hologram recording material could not obtain a good hologram.

[0043]

According to the present invention, in a hologram recording medium in which a photosensitive layer capable of forming a hologram is provided on a film substrate, a film substrate having a release treatment layer on the back surface is used, thereby eliminating the need for a cover film. A hologram recording medium excellent in mass productivity can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a hologram recording medium having a release processing layer according to the present invention.

FIG. 2 is a schematic diagram illustrating a hologram exposing machine for hologram duplication.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film base material 2 Photosensitive layer 3 Release processing layer 10 Hologram recording medium having release processing layer 11 Hologram recording material unwinding 12 Hologram recording material winding 13 Master hologram 14 Laser beam

Continued on front page F-term (reference) 2H025 AA00 AA13 AB20 AC01 AC08 AD01 BC13 BC31 BD23 CA00 CA41 CA48 CB30 DA19 DA40 2K008 AA16 DD13 EE01 FF17 GG01 4F100 AK02A AK04B AK07B AK42B AK53A AT00B BA03BA02A13 J10B12A13 J10A JN17A JN30

Claims (4)

[Claims] 1. A thermosetting epoxy oligomer which is solvent-soluble and cationically polymerizable and has at least one glycidyl group in a unit structure, and (B) a liquid which is liquid at normal temperature and normal pressure and has a boiling point at normal pressure. A compound having at least one radically polymerizable ethylenically unsaturated bond at a temperature of 100 ° C. or higher, (C) a radical species that activates radical polymerization when exposed to actinic radiation, and a brane that activates cationic polymerization A hologram-producible photosensitive layer comprising an aromatic onium salt generating a Sted acid or a Lewis acid and (D) a sensitizing dye for sensitizing a photoinitiator (C) is provided on a film substrate (1). A hologram recording medium having a release processing layer, comprising a release processing layer (3) provided on the opposite surface. 2. An aromatic onium salt that generates a radical species that activates radical polymerization and a Bronsted acid or Lewis acid that activates cationic polymerization upon exposure to actinic radiation is a diaryliodonium salt. 2. A hologram recording medium having a release treatment layer according to claim 1. 3. The hologram recording medium having a release treatment layer according to claim 1, wherein said film substrate (1) is made of any one of polyethylene terephthalate resin, polypropylene resin and polyethylene resin. 4. The hologram recording medium having a release processing layer according to claim 1, wherein said release processing layer (3) is made of a silicone resin.