JPH0962169A - Hologram recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a hologram excellent in weather resistance, heat resistance, chemical stability, storage stability, high resolution by a dry process, high diffraction efficiency, high transparency, and reproducibility for reproducing wavelength by using a laminated material of a polyvinylalcohol resin in such a manner that the polyvinylalchol resin is in contact with a hologram recording layer. SOLUTION: This hologram recording medium 1 consists of a supporting body 2, a hologram recording layer 3 and a coating layer 4. The hologram recording layer 3 consists of a thermosetting resin which is soluble a solvent and has an ethylene oxide ring in the structural unit which is cation- polymerizable with other material, a radical polymerizable ethylene monomer, a photohardening agent which activates radical polymn. and cation polymn when exposed to radiation rays having a chemical function, and a sensitizing dye which sensitizes the photosetting agent. The coating layer 4 consists of a polyvinylalcohol resin or essentially consists of a polyvinylalcohol resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is highly sensitive to visible light, particularly argon laser light, or electron beams,
Further, the present invention relates to a layer structure of a hologram recording medium used for forming a volume phase hologram having excellent weather resistance, heat resistance, storage stability, and excellent hologram characteristic values such as resolution, diffraction efficiency, and transparency.

[0002]

2. Description of the Related Art Conventionally, since holograms can reproduce three-dimensional stereoscopic images, they have been used for books, covers for magazines, displays for POPs, gifts, etc. because of their excellent design and decorative effects. . Since holograms can be said to be equivalent to the recording of information in submicron units, they are also used for counterfeit prevention marks such as securities and credit cards.

Particularly, the volume phase hologram modulates the phase without absorbing the light beam passing through the image by forming spatial interference fringes having different refractive indexes in the hologram recording medium, not by optical absorption. Therefore, in recent years, application to a hologram optical element (hereinafter, referred to as HOE) represented by a head-up display (HUD) mounted on an automobile is expected in addition to a display application.

By the way, the volume phase hologram recording material constituting the volume phase hologram is required to be highly sensitive to a laser beam having a visible oscillation wavelength and exhibit a high resolution. Further, when actually used for forming a hologram, it is required that characteristics such as diffraction efficiency of hologram, wavelength reproducibility of reproduced light, band width (half-value width of reproduced light peak) and the like are suitable for the purpose. Especially, the hologram recording material for HOE has a diffraction efficiency of 500 spatial frequency.
90% or more at 0 to 6000 lines / mm, half-value width (bandwidth) of reproduction light peak is 20 to 30 nm, peak wavelength of reproduction wavelength is preferably within 5 nm from photographing wavelength, and further stored for a long time There is also a need for good stability.

Hitherto, as a recording material for such a volume phase hologram, a bleached silver salt and a dichromate gelatin type photosensitive material have been generally used. This dichromated gelatin-based photosensitive material is most widely used for recording volume phase holograms because of its high diffraction efficiency and low noise characteristics, but this photosensitive material has a short shelf life,
Problems that must be adjusted each time a hologram is made, and problems that hologram reproducibility is poor due to deformation of the hologram during the swelling and shrinking process of gelatin that is required when making a hologram by wet development It also has points. Further, the silver salt sensitive material requires complicated processing after recording, and is not a photosensitive material which is satisfactory from the viewpoint of stability and workability. Furthermore, all of these above-mentioned light-sensitive materials have a problem that they are inferior in environmental resistance characteristics such as moisture resistance and weather resistance.

Therefore, as a material having excellent environmental resistance and having the characteristics that a hologram recording material should have, such as high resolution and high diffraction efficiency, a hologram recording material using poly-N-vinylcarbazole, for example, a crosslinking agent. As a hologram recording material comprising a cyclic cis-α-dicarbonyl compound and a sensitizer (JP-A-60-45283), 1,
4,5,6,7,7-hexachloro-5-nobornene-
Holographic recording material composed of anhydrous-2,3-dicarboxylic acid and a dye (JP-A-60-227280), 2, 3
-A hologram recording material composed of bornandione and thioflavin (JP-A-60-260080), a hologram recording material composed of thioflavin T and iodoform (JP-A-62-123489), and the like are described.

Further, as a hologram recording material which can be photocured with high sensitivity, a photocurable resin composition comprising a combination of 3-ketocoumarins and a diaryl iodonium salt, which are constituent components of a photopolymerization initiator, (Japanese Patent Laid-Open No. 60- 88005) and a hologram recording material (JP-A-4-31590) in which a photopolymerization initiator and polymethylmethacrylate as a supporting polymer are combined.

Further, a photopolymerizable photosensitive material capable of producing a hologram in one processing step without wet processing is disclosed in US Pat. No. 3,993,485 and US Pat. No. 3,658.
No. 39934 of the former, which is described in Japanese Patent No. 526.
In Japanese Patent Publication No. 85, a combination of two polymerizable unsaturated ethylenic monomers having different reactivity and refractive index and a photopolymerization initiator, a polymerizable unsaturated ethylenic monomer having a similar refractive index, and the same are disclosed. Is a combination of an unsaturated ethylenic monomer that acts as a cross-linking agent when polymerizing, and a non-reactive compound having a different refractive index from these two monomers and a polymerization initiator, and the latter US Pat.
Japanese Unexamined Patent Publication (Kokai) No. 6 describes a method for producing a stable hologram comprising a hologram recording material containing a photopolymerizable ethylenic monomer and a photopolymerization initiator in a polymer matrix.

US Pat. No. 4,942,112 and US Pat. No. 5,098,803 are described as improved techniques including the method for producing the hologram recording material disclosed in US Pat. No. 3,658,526, and thermoplastic resins are described therein. , A polymerizable unsaturated ethylenic monomer and a photopolymerization initiator as a basic composition, and a compound having an aromatic ring in either the thermoplastic resin or the polymerizable unsaturated ethylenic monomer for improving the refractive index modulation. As a technique for improving this, Japanese Patent Application Laid-Open No. 5-107999 describes a hologram recording material in which a cationically polymerizable monomer and a cationic polymerization initiator are blended in place of the plasticizer in the above patent.

Japanese Patent Laid-Open No. 5-94014 discloses that
A hologram recording material comprising an epoxy resin, a radically polymerizable unsaturated ethylenic monomer and a photoradical polymerization agent is described.

[0011]

The above various hologram recording materials require complicated processing steps when wet development is required, poor reproducibility, high refractive index modulation cannot be obtained, and storage stability is high. There is no. Poor workability, poor heat resistance, or large exposure dose, and various problems of film strength and storage stability due to addition of non-reactive plasticizer,
In addition, the photopolymerizable photosensitive material capable of producing a hologram in a single processing step without wet processing is a problem of the polymerizability or dispersibility of the monomer for obtaining the refractive index modulation, and the carrier and non-support of the monomer. There is a problem of storage stability due to the addition of a reactive additive, and there is a demand for a hologram recording material having excellent hologram properties such as workability during hologram production, diffraction efficiency of the obtained hologram, transparency, and reproducibility. Especially, in the HOE which uses it, the necessity is increasing. A hologram image is formed by exposure on a hologram recording medium produced by applying a hologram recording material having such hologram characteristics. A protective layer provided on the outermost layer of the hologram recording medium or a coating formed as a support layer. Depending on the material forming the layers, the diffraction efficiency of the hologram image to be obtained is reduced. Therefore, the present invention is a volume phase which is excellent in weather resistance, heat resistance, chemical stability, and storage stability, and has high resolution, high diffraction efficiency, high transparency, and reproduction wavelength reproducibility by dry processing. An object of the present invention is to provide a hologram recording medium that uses a hologram recording material capable of forming a hologram and that has a coating layer that does not cause a reduction in diffraction efficiency.

[0012]

The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 provides (A) a solvent-soluble, cationically polymerizable ethylene oxide ring on a support. Thermosetting resin having at least one in the structural unit, (B) radically polymerizable ethylenic monomer, (C) photoinitiator that activates radical polymerization and cationic polymerization when exposed to actinic radiation, (D) light A hologram recording medium comprising: a hologram recording layer made of a sensitizing dye for sensitizing the initiator (C); and a coating layer made of a polyvinyl alcohol resin or a polyvinyl alcohol resin as a main component. Is.

According to a second aspect of the invention, in the hologram recording medium according to the first aspect, the coating layer is a laminated body formed by coating a polyvinyl alcohol resin on a support material, and the polyvinyl alcohol of the laminated body. It is characterized in that a laminate is laminated so that the resin is in contact with the hologram recording layer.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
1A and 1B are schematic cross-sectional views illustrating the configuration of the hologram recording medium of the present invention, and FIG. 2 is a schematic explanatory view illustrating an optical system for hologram recording.

The component (A) constituting the hologram recording layer of the hologram recording medium of the present invention is a thermosetting resin having at least one solvent-soluble, cationically polymerizable ethylene oxide ring in its structural unit, for example, bisphenol A. , Bisphenol AD, bisphenol B, bisphenol AF, bisphenol S, brominated bisphenol A, novolac, o-cresol novolac, p-
Alkylphenol novolac, hydrogenated bisphenol A, hydrogenated bisphenol AD, hydrogenated bisphenol B,
An epoxy compound represented by the following chemical formula, which is produced by a condensation reaction of various phenol compounds such as hydrogenated bisphenol AF, hydrogenated bisphenol S, hydrogenated brominated bisphenol A, and epichlorohydrin, can be given. In addition,
It is not limited to these.

[0016]

Embedded image (In the formula, n = 1 to 20.)

[0017]

Embedded image (In the formula, n = 1 to 20.)

[0018]

Embedded image (In the formula, n = 1 to 20.)

The thermosetting resin as the component (A) preferably has a molecular weight in the range of 900 to 6000. When the molecular weight is smaller than this range, the film-forming property deteriorates and uniform coating is difficult. When the molecular weight is larger than the range, it is generally difficult to synthesize. Further, the thermosetting resin preferably has an epoxy equivalent of 400 to 6700, and there is a problem that good cationic polymerization does not proceed outside this range.

The radical-polymerizable aliphatic monomer as the component (B) has at least one ethylenic unsaturated bond in the structural unit, and is a polyfunctional monomer in addition to the monofunctional vinyl monomer. It contains a vinyl monomer, and may be a mixture thereof. Specifically, (meth) acrylic acid, itaconic acid, maleic acid,
(Meth) acrylamide, diacetone acrylamide,
High-boiling-point vinyl monomers such as 2-hydroxyethyl (meth) acrylate, and aliphatic polyhydroxy 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 And di- or poly (meth) acrylic acid esters such as pentaerythritol, dipentaerythritol, sorbitol, and mannitol. However, the present invention is not limited to these.

Chemistry of component (C) of the present invention As a photoinitiator which activates radical polymerization and cationic polymerization when exposed to radiation, there are described J. Photochem. Sci. Te
chnol. , 2,283 (1987). And an iron arene complex, a trihalogenomethyl-substituted s-triazine, a sulfonium salt, a diazonium salt, a selenonium salt, an arsonium salt, an iodonium salt, and the like. As this iodonium salt, Mac
romolecules, 10 , 1307 (197)
7). And compounds such as diphenyliodonium, ditolyliodonium, phenyl (p-anisyl) iodonium, phenyl (m-nitrophenyl) iodonium, bis (p-tert-butylphenyl) iodonium, bis (p-chlorophenyl). Chlorides of iodonium such as iodonium, bromide, or borofluoride salts, hexafluorophosphate salts, hexafluoroarsenate salts, aromatic sulfonates and the like can be mentioned, but if they satisfy the above characteristics, these It is not limited to.

Further, as the sensitizing dye of the component (D) of the present invention, organic dyes such as cyanine or merocyanine derivatives, coumarin derivatives, chalcone derivatives, xanthene derivatives, thioxanthene derivatives, azurenium derivatives, squarylium derivatives, porphyrin derivatives, etc. Compounds can be used. In addition, "Dye Handbook"
(Okawara Shin et al., Kodansha 1986), "Chemistry of functional dyes" (Okawara Shin, et al. CMC 1986),
"Special Functional Materials" (Ceisaburo Ikemori et al. CMC 1
986) and the sensitizers described above can be used. Note that the dye and the sensitizer are not limited to these, and any other dye or sensitizer that absorbs light in the visible region can be used, and if necessary, these dyes and sensitizers can be used. Two or more kinds can be used in combination at an arbitrary ratio.

The coating layer 4 laminated on the hologram recording layer 3 of the hologram recording medium 1 of the present invention contains a polyvinyl alcohol resin or a polyvinyl alcohol resin as a main component as shown in FIG. ) A film-shaped, sheet-shaped, or formed by coating, and a laminate 6 formed by coating and forming a polyvinyl alcohol resin on an arbitrary supporting material 5 as shown in FIG. The cover layer 4 is formed by laminating the surface 5a so as to contact the hologram recording layer 3. The coating layer 4 of the hologram recording medium 1 of the present invention as described above is
A function as an oxygen barrier film during the polymerization of ethylenic monomers by radical species generated by hologram exposure in the hologram recording material used for the hologram recording layer 3,
When used in the form of a roll, it has a function of preventing blocking on the contact surface of the hologram recording medium 1, a function of protecting the hologram recording layer 3 at the time of hologram duplication, etc. Further, according to this coating layer 4, a hologram image is produced. The hologram recording layer 3 thus formed exhibits high diffraction efficiency.

The coating layer 4 is specifically an unstretched film (thickness: 50 to 1 made of polyvinyl alcohol resin.
00 μm) · Biaxially stretched film (film thickness: 12 to 25 μm
m), a coating film formed by coating and drying a polyvinyl alcohol resin, a coating liquid containing a polyvinyl alcohol resin as a main component, or an arbitrary film-shaped support material 5 such as polyethylene terephthalate, polymethacrylate, cellulose triacetate, polypropylene, or polyethylene. Polyvinyl alcohol resin aqueous solution, for example, saponification degree 87-89%, medium degree of polymerization (viscosity of 4% aqueous solution at 20 ° C. is 20-30 cp.
The polyvinyl alcohol resin of s) is preferable, and 5 to
A 10% aqueous solution is especially preferred. It is the laminated body 6 formed in polyvinyl alcohol resin (PVA) dry film thickness 0.5-5 micrometers.

The hologram recording material having the above composition is obtained by mixing 20 to 200 parts by weight of the ethylenic monomer (B) with 100 parts by weight of the thermosetting resin (A), preferably , 30 to 100 parts by weight. If the amount is less than 20 parts by weight, the amount of monomers polymerized by holographic exposure with a laser is insufficient,
Even after the heat treatment, a high refractive index modulation cannot be obtained and a bright hologram cannot be obtained. Further, when the amount exceeds 200 parts by weight, the amount of the monomer becomes excessive, and the amount of the monomer remaining in the system increases without being polymerized in the first holographic exposure. As a result, it remains while diffusing in the heat treatment in the manufacturing process. The amount of monomer causes polymerization, the interference fringes of the hologram once formed are disturbed, high refractive index modulation cannot be obtained, and a bright hologram cannot be obtained. The amount of the photoinitiator (C) is 0.1 to 20 relative to 100 parts by weight of the thermosetting resin (A).
Parts by weight, preferably 1 to 10 parts by weight. Further, the amount of the sensitizing dye (D) is 0.1 to 5 parts by weight, preferably 0.2 to 0.5 parts by weight, based on 100 parts by weight of the thermosetting resin (A). Since the amount used is limited by the optical density of the hologram recording layer to be formed and its thickness, it is preferable to use the optical density within a range not exceeding 2. If it deviates from this range, it becomes difficult to obtain a high diffraction efficiency and the sensitivity characteristic deteriorates.

As described above, the photosensitive liquid of the hologram recording material obtained by appropriately selecting each of these components and mixing them at an arbitrary ratio is used by a known coating means such as a spin coater, a roll coater or a bar coater. A hologram recording layer 3 is formed by coating in a film form on a support 2 such as a glass plate, a polycarbonate plate, a polymethylmethacrylate plate, or a polyester film, and then the coating layer 4 having the above-mentioned structure is laminated and laminated by an extruder or the like. The hologram recording medium 1 shown in FIG. 1 is manufactured by forming a solution by coating. Although it is possible to dilute the hologram recording material with an appropriate solvent when applying the hologram recording layer 3, it is necessary to dry the hologram recording material after applying it to the support, and as described above, the irradiation light at the time of photographing is transmitted. It is desirable to prepare such that the rate is 1% or more. As the solvent, dichloromethane, chloroform, acetone, 2-butanone, cyclohexanone, ethyl acetate, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2- Methoxyethyl ether,
2-ethoxyethyl ether, 2- (2-ethoxyethoxy) ethanol, 2- (2-butoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethyl acetate, 2- (2-butoxyethoxy) ethyl acetate,
Tetrahydrofuran, 1,4-dioxane and the like can be mentioned.

If desired, various additives such as known binders, plasticizers, thermal polymerization inhibitors, chain transfer agents and antioxidants may be added to the hologram recording material constituting the hologram recording layer 3 of the present invention. May be.

Further, a hologram master or mirror 1 used when producing a hologram by an optical duplication method.
The intermediate liquid 13 may be used between the four and the hologram recording medium of the present invention in order to improve the adhesion. Specifically, those having a relatively high boiling point and having a refractive index of about 1.4 to 1.5 that do not attack the hologram master and the hologram recording material are preferable. Specific examples thereof include saturated hydrocarbons such as n-heptane, n-octane, isooctane, n-nonane, and n-decane, and isoper, which is a mixture thereof, or aromatic hydrocarbons such as toluene and xylene. It is not limited to.

The process of holographically exposing the hologram recording medium 1 using the hologram recording material to form a latent image is shown in FIG. A laser beam 8 oscillated from a hologram recording medium 1 passes through a mirror 9, a lens 10, a lens 11 and a spatial filter 12.
The light entering the hologram recording medium 1 is reflected by the hologram master or the mirror 14 and again enters the hologram recording medium 1, whereby interference fringes are formed and a hologram image is recorded. Further, in the present invention, after the hologram is photographed by exposure, the fixing process is performed by a dry process.

When a hologram image is recorded on the hologram recording medium 1, laser irradiation is applied to the hologram recording layer 3 in accordance with a desired image so that a portion of the laser irradiation portion having a strong optical interference action is thermally cured. Resin (A)
When the radically polymerizable ethylenic monomer (B) uniformly dispersed therein is exposed to laser (laser interference light) to be exposed to light, it is polymerized and polymerized by the action of the photopolymerization initiator. The transfer of the polymerizable ethylenic monomer (B) occurs. Therefore, the concentration of the radical-polymerizable aliphatic monomer (B) is high in the laser-irradiated portion where the optical interference is strong, and the concentration of the radical-polymerizable ethylenic monomer (B) is high in the portion where the light interference action is weak. Is decreased, the refractive index modulation occurs due to the difference in the refractive index due to the density difference between the portion of the hologram recording medium 1 where the optical interference is strong and the portion where the optical interference action is weak, whereby the hologram image recording is performed. . The coating layer 4 laminated on the hologram recording layer 3 of the holographic recording medium 1 functions as an oxygen blocking film when the ethylenic monomer is polymerized by radical species generated by hologram exposure, and the hologram master or the mirror 14. In order to improve the adhesiveness with the hologram recording medium 1 of the present invention, the hologram recording layer 3 can have a function as a protective film that protects the hologram recording layer 3 from the intermediate liquid 13, and the hologram recording layer 3 can have high diffraction efficiency. Furthermore, the residual monomer (B) is fixed by polymerization by the ultraviolet light overall exposure treatment and heat treatment after hologram exposure, and the thermosetting resin (A) that is the support becomes a crosslinked structure by cationic polymerization. The weather resistance, heat resistance, and chemical stability of the hologram recording medium 1 are improved.

In the exposure process of the interference pattern,
As a light source suitable for the hologram recording material of the present invention, a helium-cadmium laser, an argon laser, a krypton laser, a helium neon laser, or the like can be used, but the light source is not limited thereto.

Further, the hologram recording medium of the present invention is superior to the conventional hologram recording medium in the reproducibility of the peak wavelength of reproduction light and its bandwidth, and is also excellent in environment resistance. Can be applied to.

[0033]

EXAMPLES The present invention will be described in detail below based on specific examples. <Example 1-4> Bisphenol-based epoxy oligomer Epicoat 1007 (degree of polymerization n = 10.8, epoxy equivalent: 1750 to 2100 manufactured by Yuka Shell Epoxy Co., Ltd.) 1
00 parts by weight, triethylene glycol diacrylate (TEGDA) 50 parts by weight and diphenyliodonium hexafluorophosphate 5 parts by weight, 3,3′-
Carbonyl bis (7-diethylamino) coumarin 0.5
By mixing 1 part by weight with 100 parts by weight of 2-butanone, a hologram recording material was prepared and used as a photosensitive solution. This sensitizing solution was applied to a polyethylene terephthalate film (thickness: 50 μm
mm width "Lumirror 60T50" product name manufactured by Toray)
To a thickness of about 20 μm and a width of 250 mm, and dried to form a hologram recording layer, and then a biaxially stretched polyvinyl alcohol film (25 μm thickness 300 mm width “Boblon # 250” product name on the hologram recording layer. (Higo Film Co., Ltd.) was laminated to prepare a hologram recording medium.

The hologram recording medium was brought into close contact with a polyvinyl alcohol film surface using a surface vapor deposition mirror using Isopar as an intermediate liquid, and an argon laser (51) was used as a light source by an optical system for hologram photographing shown in FIG.
(4.5 nm) and exposed to form a hologram,
The entire surface is irradiated with a high-pressure mercury lamp, and then at 80 ° C for 30
The heat treatment was performed for minutes to fix the hologram.

The diffraction efficiency of the obtained hologram was measured by a spectrophotometer manufactured by Shimadzu Corporation. This spectrophotometer can measure the relative specular reflectance with respect to an aluminum vapor deposition mirror at an incident angle of 5 °. Measurement condition is 5mmφ
The monochromatic light of is incident on the sample at an angle of 5 °, the transmittance when the diffracted light from the sample is detected is defined as the diffraction efficiency, and the angle (θ) between the light flux and the hologram recording medium / reflection mirror is changed. The diffraction efficiency of the produced hologram was similarly measured, and the evaluation results are shown in Table 1.

[0036]

[Table 1]

<Example 5-8> The hologram recording medium prepared in Example 1-4 was stored in the dark at 40 ° C for 30 days, and a hologram was prepared and fixed in the same manner as in Example 1-4. The diffraction efficiency was measured. Table 2 shows the evaluation results.

[0038]

[Table 2]

<Examples 9-13> 1,6-hexanediol diacrylate (HDOD) was used in place of the triethylene glycol diacrylate (TEGDA) of Example 1 above.
A), diethylene glycol diacrylate (DEGD
A), neopentyl glycol diacrylate (NPG
DA), trimethylolpropane triacrylate (T
A hologram was prepared and fixed in the same manner as in Example 1 except that MPTA) and pentaerythritol triacrylate (PETA) were used, and the diffraction efficiency was measured.
Table 3 shows the evaluation results.

[0040]

[Table 3]

HDODA; 1,6-hexanediol diacrylate DEGDA; diethylene glycol diacrylate NPGDA; neopentyl glycol diacrylate TMPTA; trimethylolpropane triacrylate PETA; pentaerythritol triacrylate

<Example 14-17> In place of the biaxially stretched polyvinyl alcohol film (25 μm thick, 300 mm width "Boblon # 250", trade name, manufactured by Nigo Film Co., Ltd.), which is the coating layer of the above Examples 1-4, A hologram was prepared and fixed in the same manner as in Example 1-4, except that a stretched polyvinyl alcohol film (50 μm thick, 300 mm width “Vinylon # 500” manufactured by Nigo Film Co., Ltd.) was used, and its diffraction efficiency was measured. . The evaluation results are shown in Table 4.
Shown in

[0043]

[Table 4]

Comparative Example 1-5 A biaxially stretched polyvinyl alcohol film (25 μm thick 3
00 mm width "Boblon # 250" Product name: Polyethylene terephthalate (50
μm thickness 300 mm width “Lumirror T50” product name Toray Industries, Inc., cellulose triacetate film (50 μm thickness 3
00mm width "Fujitac" product name Fuji Photo Film Co., Ltd., polypropylene film (50μm thickness 300m)
m width "Trefan NO" product name Toray Synthetic Film Co., Ltd., polyethylene film (50 μm thickness 300 mm)
Width “TUX LDPE” product name, manufactured by Tohcello Co., Ltd., polyvinyl chloride film (50 μm thickness 300 m)
A hologram was prepared and fixed in the same manner as in Example 1 except that m width "BYC" (trade name, manufactured by Gunze Co., Ltd.) was used, and the diffraction efficiency was measured. The evaluation results are shown in Table 5.
Shown in

[0045]

[Table 5]

PET: Polyethylene terephthalate TAC: Cellulose triacetate film PP: Polypropylene film PE: Polyethylene film PVC: Polyvinyl chloride film

<Example 18-21> A 10% aqueous solution of polyvinyl alcohol (Kuraray Poval PVA-217, manufactured by Kuraray Co., Ltd.) aqueous solution was applied to each film of Comparative Example 1-4 to a thickness of about 2 μm and dried. A hologram was prepared in the same manner as in Comparative Example 1-4, except that the coating layer was formed by using the thus obtained laminated body so that the polyvinyl alcohol aqueous solution coated surface was in contact with the hologram recording layer as shown in FIG. 1 (b). It was prepared, fixed, and its diffraction efficiency was measured. The evaluation results are shown in Table 6.

[0048]

[Table 6]

PET: Polyethylene terephthalate TAC: Cellulose triacetate film PP: Polypropylene film PE: Polyethylene film

In the hologram recording medium according to the present invention shown in Example 1-21, no decrease in diffraction efficiency was observed even when left in an environment of 25 ° C., 60% RH for 180 days and 150 ° C. for 10 hours. .

[0051]

As described above, the present invention is a thermosetting resin having at least one solvent-soluble cationically polymerizable ethylene oxide ring in a structural unit as described above,
A radical-polymerizable ethylenic monomer, a photoinitiator that activates radical polymerization and cationic polymerization when exposed to actinic radiation, a hologram recording layer composed of a sensitizing dye, and a polyvinyl alcohol resin, or a polyvinyl alcohol resin as a main component. It is a hologram recording medium formed by laminating a coating layer with and having excellent sensitivity in the visible light region, resolution, diffraction efficiency, transparency, heat resistance, excellent weather resistance, and chemically stable, Excellent storage stability, oxygen blocking function during polymerization of ethylenic monomer by radical species generated by hologram exposure in hologram recording material, blocking prevention function between hologram recording layers when used in superposition, hologram duplication In this case, it has a function of protecting the hologram recording layer 3 and forms a hologram. Program recording layer shows a high diffraction efficiency.

[Brief description of drawings]

1A and 1B are schematic cross-sectional views each illustrating a configuration of a hologram recording medium of the present invention.

FIG. 2 is a schematic explanatory diagram illustrating an optical system for hologram imaging.

[Explanation of symbols]

1 hologram recording medium 2 support 3 hologram recording layer 4 coating layer 5 support 5a polyvinyl alcohol resin surface 6 laminate 7 laser 8 laser light 9 mirror 10 lens 11 lens 12 spatial filter 13 intermediate liquid 14 hologram master or mirror

Claims (2)

[Claims] 1. A thermosetting resin having at least one solvent-soluble, cationically polymerizable ethylene oxide ring in a structural unit, (B) a radically polymerizable ethylenic monomer, and (C) on a support. A photoinitiator that activates radical and cationic polymerization when exposed to actinic radiation,
(D) A hologram recording layer made of a sensitizing dye for sensitizing the photoinitiator (C), and a coating layer made of a polyvinyl alcohol resin or containing a polyvinyl alcohol resin as a main component are laminated. Hologram recording medium. 2. The coating layer comprises a laminated body formed by coating a polyvinyl alcohol resin on a support material, and laminating the laminated body so that the polyvinyl alcohol resin of the laminated body is in contact with the hologram recording layer. The hologram recording medium according to claim 1, wherein