JP2006003387A - Photosensitive composition for volume phase type hologram recording, hologram recording medium and method for manufacturing same, and hologram recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive composition for volume phase type hologram recording, a hologram recording medium and a method for manufacturing the same, and a hologram recording method. <P>SOLUTION: The photosensitive composition for volume phase type hologram recording comprises a radical polymerization system (A), a cationic polymerization system (B) and a binder polymer (C) and is used for recording the intensity distribution of brightness of interference fringes obtained by interference of light as changes of refractive index, wherein a cationic polymerization initiator (b2) as a component of the cationic polymerization system (B) is a thermally latent cationic polymerization initiator comprising an aluminum complex and an arylsilanol. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a volume phase hologram recording material. More specifically, a novel composition for volume phase hologram recording material used for recording the intensity distribution of light and dark of the light interference pattern as a change in refractive index, in particular, transparency which is a basic characteristic required for holograms, The present invention relates to a hologram recording material composition capable of producing a recording medium excellent in diffraction efficiency, refractive index modulation and processability, and further relates to a hologram recording medium obtained therefrom, a method for producing the medium, and a hologram recording method.

  A composition for a hologram recording material containing a binder polymer as a base resin and combining a radical polymerization system and a cationic polymerization system is known. In particular, as a radical polymerizable monomer constituting the radical polymerization system, a composition using a radical polymerizable compound having a 9,9-diarylfluorene skeleton at room temperature and solid is represented as one that gives good results (Patent Literature). 1). However, the hologram after recording is subjected to a heat treatment in order to amplify the diffraction efficiency and then is irradiated with light such as UV in order to cure the cationically polymerizable compound.

  On the other hand, the method by the thermal cationic polymerization by heating is known conventionally rather than the photocationic polymerization by light irradiation (patent documents 2-6). According to this, the complexity of the process can be avoided, but when using, for example, diazonium salts disclosed in the prior art as the thermal cationic polymerization initiator, there is a drawback that the reaction proceeds in the dark, and is representative of iodonium salts. In the case of using onium salts, acid anhydrides, and the like, there are practical problems such as the fact that ionic impurities are easily released and the moisture resistance is lowered (Non-patent Document 1).

Japanese Patent Laid-Open No. 13-109360 Japanese Patent Laid-Open No. 08-101501 Japanese Patent Laid-Open No. 05-94014 JP 05-210343 A JP 05-107999 A Japanese Patent Laid-Open No. 05-181271 Polymer No. 35 February Issue 116-119 (1986)

  An object of the present invention is to obtain a hologram having high transparency, diffraction efficiency, and refractive index modulation as in the prior art, a simple post-processing step after hologram recording, and moisture resistance of the hologram. It is an object of the present invention to provide a novel photosensitive composition for volume phase hologram recording, which gives an excellent hologram.

As a result of repeated studies to solve the above problems, the present inventors have found the following novel hologram recording material composition and have completed the present invention.
That is, it consists of a radical polymerization system (A), a cationic polymerization system (B), and a binder polymer (C), and records the intensity distribution of light and darkness of interference fringes obtained by causing light interference as a change in refractive index. In the composition for volume phase type hologram recording material used, the cationic polymerization initiator (b2), which is one component of the cationic polymerization system (B), is a thermal latent cationic polymerization initiator composed of an aluminum complex and an arylsilanol. It is a photosensitive composition for volume phase hologram recording characterized by being.

  A photosensitive composition for volume phase hologram recording capable of providing high transparency, diffraction efficiency and refractive index modulation as in the prior art, and a hologram recording medium produced therefrom is diffracted only by a heat treatment step after exposure. Since the efficiency and refractive index modulation can be increased and the cationic polymerizable monomer and the unreacted radical polymerizable compound can be cured, the operation is simplified. In addition, the moisture resistance of the medium itself can be improved, and the coloring of the medium is reduced.

The radical polymerization system (A) used in the present invention is a curing system substantially comprising a radical polymerizable compound (a1) and a radical polymerization initiator (a2), and other necessary sensitizing dyes (a3). Etc. may be contained.
The cationic polymerization system (B) is a curing system substantially composed of a cationic polymerizable compound (b1) and a cationic polymerization initiator (b2).
The novel hologram recording material composition according to the present invention is a mixture consisting essentially of these radical polymerization system (A), cationic polymerization system (B) and binder polymer (C), but contains other additives. Good. The composition must be a composition having sufficient transparency that a hologram recording medium produced using the composition can exhibit hologram performance.

In the present invention, in the composition for volume phase type hologram recording material used to record the intensity distribution of the interference fringes obtained by causing the light to interfere as a change in refractive index,
(1) The basic composition is a mixture of the radical polymerizable compound (a1), the cationic polymerizable compound (b1), and the binder polymer (C).
(2) As a polymerization initiator, a photo radical polymerization initiator that polymerizes the radical polymerizable compound (a1) by exposing an interference fringe (first light) obtained by interference of coherent light in the visible light region. (a2), a sensitizing dye (a3) used in combination with a radical photopolymerization initiator, a thermal latent cationic polymerization initiator (b2) composed of an aluminum complex and an arylsilanol,
(3) Volume phase hologram recording characterized in that the refractive index of the radical polymerizable compound (a1) is larger than the weighted average value of the refractive indexes of the cationic polymerizable compound (b1) and the binder polymer (C). The photosensitive composition for use is preferred.

Radical polymerizable compound (a1)
The radically polymerizable compound (a1) used in the present invention is not limited as long as it is compatible with the binder polymer (C) and the cationically polymerizable compound (b1), and is an acrylate having an ethylenically unsaturated double bond. It may be selected from the group consisting of monomers, methacrylic monomers, vinyl monomers, and combinations of two or more thereof.

Specific examples of the (meth) acrylate monomer include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl methacrylate, n-stearyl methacrylate, methoxydiethylene glycol methacrylate, cyclohexyl meta Crate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate, isobornyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl methacrylate , Dimethylaminoethyl methacrylate , Diethylaminoethyl methacrylate, glycidyl methacrylate, tert-butyl methacrylate, isostearyl methacrylate, n-butoxyethyl methacrylate, isoamyl acrylate, lauryl acrylate, stearyl acrylate, butoxyethyl acrylate, ethoxyethylene glycol acrylate, methoxytriethylene glycol acrylate, phenoxyethyl acrylate , Tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl phthalic acid , Isooctyl acrylate, isomyristyl Relate, isostearyl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, nonaethylene glycol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate 1,9-nonanediol dimethacrylate, glycerin dimethacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, neopentyl glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,10-decanediol dimethacrylate, Ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate , Tetraethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, glycerin diacrylate, 2-hydroxy-3-acryloyloxypropyl Acrylate, neopentyl glycol diacrylate, 1,3-butanediol diacrylate, 1,10-decanediol diacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol Tetramethacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetramethacrylate, ditrimethylol B bread tetraacrylate, tetramethylolmethane tetraacrylate, dipentaerythritol hexamethacrylate, dipentaerythritol hexaacrylate, and the like.
Further, it may be a dimer or trimer oligomer of the above compound, and may be used alone or in combination of two or more.

Specific examples of the vinyl monomer include vinyl acetate, 4-vinylaniline, 9-vinylanthracene, 4-vinylanisole, vinylbenzaldehyde, vinylbenzoate, vinylbenzyl chloride, 4-vinylbiphenyl, vinyl bromide, N-vinylcaprolactam, Vinyl chloroformate, vinyl crotonate, vinyl cyclohexane, 4-vinyl-1-cyclohexene diepoxide, vinyl cyclopentane, vinyl decanoate, 4-vinyl-1,3-dioxolan-2-one, vinyl carbonate, vinyl Trithiocarbonate, vinyl 2-ethylhexanoate, vinyl ferrocene, vinylidene chloride, vinyl formate, 1-vinyl imidazole, 2-vinyl naphthalene, vinyl neodecanoate, 5-vinyl Lu-2-norbornene, 4- (vinyloxy) butylbenzoate, 2- (vinyloxy) ethanol, 4-vinylphenyl acetate, vinyl pivalate, vinyl propionate, 2-vinylpyridine, 1-vinyl-2-pyrrolidinone, vinylsulfone, vinyl Examples include trimethylsilane.
Further, it may be a dimer or trimer oligomer of the above compound, and may be used alone or in combination of two or more.

  As the radical polymerizable compound (a1), the larger the difference from the refractive index of the cationic polymerizable compound (b1), the larger the change in the refractive index of interference fringe recording. The refractive index of the radical polymerizable compound is preferably larger than the refractive index of the cationic polymerizable compound. More preferably, the radically polymerizable compound has a refractive index of 1.55 or more, for example, the following compounds.

The radical polymerizable compound (a1) may have a bis (thiophenyl) sulfide skeleton, a halogenated phenyl skeleton, a carbazole skeleton, or a fluorene skeleton.
Specific examples of monomers having a bis (thiophenyl) sulfide skeleton include bis (4-acryloylthiophenyl) sulfide, bis (4-acryloylthio-2-cyclohexen-1-yl) sulfide, and bis (2-acryloylthienyl) sulfide. Bis (3-acryloylthiopyridyl) sulfide, bis (5-acryloylthiopyranyl) sulfide, bis (5- (meth) acryloylthio-1,4-dithianyl) sulfide, and the like.
Further, it may be a dimer or trimer oligomer of the above compound, and may be used alone or in combination of two or more.

Specific examples of the monomer having a halogenated phenyl skeleton include 2,4-dibromophenyl (meth) acrylate, 2,6-dibromophenyl (meth) acrylate, 4,6-dichloro-1-vinylbenzene, 2,6- Dibromo-3-hydroxy-phenyl acrylate, 2,4,6-tribromophenyl (meth) acrylate, 2,4,6-trichloro-1-vinylbenzene, 2,4,6-tribromophenoxyethyl (meth) acrylate 2,4-dibromo-1,3-di (meth) acryloyloxybenzene, 2,4-dibromo-6-methyl-1,3,5-tri (meth) acryloyloxybenzene, 2,4,6-trichloro -1,3,5-tri (meth) acryloyloxyben etc. are mentioned.
Further, it may be a dimer or trimer oligomer of the above compound, and may be used alone or in combination of two or more.

Specific examples of the monomer having a carbazole skeleton include 1-vinylcarbazole, 2-vinylcarbazole, 3-vinylcarbazole, 4-vinylcarbazole, 9-vinylcarbazole, 1- (meth) acryloyloxycarbazole, 2- (meth). Acryloyloxycarbazole, 3- (meth) acryloyloxycarbazole, 4- (meth) acryloyloxycarbazole, 9- (meth) acryloyloxycarbazole, 1,9-divinylcarbazole, 1,5,9-trivinylcarbazole, 2, Examples include 7-di (meth) acryloyloxycarbazole, 2-methyl-1,9-divinylcarbazole, 1,9-di (meth) acryloyloxycarbazole.
Further, it may be a dimer or trimer oligomer of the above compound, and may be used alone or in combination of two or more.

[式中、Ｒ₁およびＲ₂は互いに同一もしくは異なる１価の有機基を意味し、そのうち少なくとも一方は末端に（メタ）アクリロイル基または（メタ）アクリロイルオキシ基を有する。Ｍ₁およびＭ₂は、互いに同一もしくは異なり、−（ＯＲ₃）_n−（Ｒ₃は水酸基を有してもよい低級アルキレン基、ｎは０、１または２）で示される２価の有機基または単結合を意味する。Ｘ₁およびＸ₂は、互いに同一もしくは異なり、水素原子または低級アルキル基を意味する。] The monomer having a fluorene skeleton may be represented by the following general formula [I].

[Wherein, R ₁ and R ₂ are the same or different monovalent organic groups, and at least one of them has a (meth) acryloyl group or a (meth) acryloyloxy group at the terminal. M ₁ and M ₂ are the same or different from each other, and are a divalent organic group represented by — (OR ₃ ) _n — (R ₃ is a lower alkylene group which may have a hydroxyl group, n is 0, 1 or 2). Or it means a single bond. X ₁ and X ₂ are the same or different from each other and each represents a hydrogen atom or a lower alkyl group. ]

Here, among R ₁ and R ₂ , the organic group having no (meth) acryloyl group may be a lower alkyl group having 1 to 3 carbon atoms.
Of M ₁ and _{M 2 - (OR 3) n} - in, when n is 1 or 2, carbon atoms in the lower alkylene R is preferably 1-3, more preferably 1-2. Examples of OR ₃ include oxymethylene, oxyethylene, oxypropylene, and oxybutylene. Examples of — (OR ₃ ) _n — include dioxymethylene and dioxyethylene. When the lower alkylene group R has a hydroxyl group, the hydroxyl group may be at any position of the alkylene group, but the alkylene having a hydroxyl group is, for example, (2-hydroxy) propylene.
The organic groups X ₁ and X ₂ may be alkyl groups having 1 to 5 carbon atoms such as methyl, ethyl, propyl and the like.

Specific examples of the monomer having a fluorene skeleton of the radical polymerizable compound (a1) include 9,9-bis (4- (meth) acryloyloxyphenyl) fluorene, 9,9-bis (4- (meth) acryloyloxymethoxy). Phenyl) fluorene, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene, 9,9-bis [4- (meth) acryloyloxy-3-methylphenyl] fluorene, 9,9 -Bis [4- (meth) acryloyloxymethoxy-3-methylphenyl] fluorene, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) -3-methylphenyl] fluorene, 9,9-bis (4- (meth) acryloyloxy-3-ethylphenyl) fluorene, 9,9-bis (4- (meth) acryloyloxymeth) Cy-3-ethylphenyl) fluorene, 9,9-bis [4- (2- (meth) acryloyloxyethoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (2- (meth) acryloyl) Oxypropoxy) -3-ethylphenyl] fluorene, 9,9-bis [4- (3- (meth) acryloyloxy-2-hydroxy) propoxyphenyl] fluorene, 9,9-bis [4- (3- (meta ) Acryloyloxy-2-hydroxy) propoxy-3-methylphenyl] fluorene, 9,9-bis {4- [2- (3-acryloyloxy-2-hydroxy-propoxy) -ethoxy] phenyl} fluorene, and the like. .
Further, it may be a dimer or trimer oligomer of the above compound, and may be used alone or in combination of two or more.

In order to obtain good film forming properties and optical properties such as diffraction efficiency, the organic groups R ₁ and R ₂ are both an acryloyl group and an acryloyloxy group, and — (OR ₃ ) n of M ₁ and M ₂ In the formula, n is 0, 1 or 2, and when n is 1 or 2, the lower alkylene group R has 1 to 2 carbon atoms, and X ₁ and X ₂ are preferably hydrogen atoms. .

  Among the compounds satisfying the above conditions, preferred compounds include 9,9-bis [4- (3-acryloyloxy-2-hydroxy) propoxyphenyl] fluorene (manufactured by Nippon Steel Chemical Co., Ltd., “9,9-bis (4 Acrylic acid adduct of glycidyl ether of hydroxyphenyl) fluorene, ASF400 "), 9,9-bis (4-methacryloyloxyphenyl) fluorene (manufactured by Nippon Steel Chemical Co., Ltd.," Bisphenol fluorenedimethacrylate "), 9,9-bis (4-acryloyloxyphenyl) fluorene, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene (Osaka Gas Co., Ltd., “Bisphenoxyethanol fluorene acrylate, BPEF-A”), 9,9- Bis [4- (2-methacryloyloxyethoxy) phenyl] fluoro (“Bisphenoxyethanol full orange methacrylate, BPEF-MA” manufactured by Osaka Gas Co., Ltd.), 9,9-bis [4- [2- (3-acryloyloxy-2-hydroxy-propoxy) -ethoxy] phenyl] fluorene (Osaka Gas Co., Ltd., “Bisphenoxyethanol full orange epoxy acrylate, BPEF-GA”), 9,9-bis [4- (3-acryloyloxy-2-hydroxy) propoxy-3-methylphenyl] fluorene (Osaka Gas Co., Ltd.) "Biscresol full orange epoxy acrylate, BCF-GA").

Particularly preferable compounds include 9,9-bis [4- (3-acryloyloxy-2-hydroxy) propoxyphenyl] fluorene, 9,9-bis (4-methacryloyloxyphenyl) fluorene, and 9,9-bis (4 Examples include -acryloyloxyphenyl) fluorene, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, and 9,9-bis [4- (2-methacryloyloxyethoxy) phenyl] fluorene.
Further, it may be a dimer or trimer oligomer of the above compound, and may be used alone or in combination of two or more.

Photoradical polymerization initiator (a2)
The radical photopolymerization initiator (a2) used in the present invention is one that generates radicals by irradiating the first light interference fringe with excellent coherence in the visible light region. For example, a carbonyl compound, an amine compound, an arylaminoacetic acid compound, an organic tin compound, an alkylaryl boron salt, a trihalogenomethyl-substituted triazine compound, an organic peroxide, a bisimidazole derivative, and a titanocene compound are preferable, and an organic peroxide, a bisimidazole Derivatives are particularly preferred.
These may be used alone or in combination of two or more.

  For example, 3,3 ', 4,4'-tetra (tert-butylperoxycarbonyl) benzophenone as the organic peroxide and 2,2'-bis (o-chlorophenyl) -4,4' as the bisimidazole derivative , 5,5'-tetraphenyl-1,1'-biimidazole, bis (2,4,5-triphenyl) imidazolyl, and bis (η5-2,4-cyclopentadien-1-yl as a titanocene compound ) -Bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium is preferably exemplified. Organic peroxides are particularly preferred.

Photosensitizing dye (a3)
The photosensitizing dye (a3) is used as a composite photoradical polymerization initiator in combination with the photoradical polymerization initiator (a2) in order to efficiently absorb light in the ultraviolet to visible light region.
Preferred photosensitizers (a3) include mihiraketone, acridine yellow, merocyanine, methylene blue, camphorquinone, eosin, decarboxylated rose bengal and the like.
The photosensitizing dye is not particularly limited as long as it absorbs light in the visible region. For example, cyanine derivatives, merocyanine derivatives, phthalocyanine derivatives, xanthene derivatives, thioxanthene derivatives, acridine derivatives, porphyrin derivatives, coumarin derivatives. Base styryl derivatives, ketocoumarin derivatives, quinolone derivatives, stilbene derivatives, oxazine derivatives, thiazine dyes, etc. can also be used. Furthermore, “Dye Handbook” (Okawara Shin et al., Kodansha, 1986) Photosensitizing dyes described in “Chemicals” (Shin Okawara et al., CMC, 1983) and “Special functional materials” (Tadaburo Ikemori et al., CMC, 1986) can also be used. These may be used alone or in combination of two or more.

  As a coumarin derivative, 3- (2-benzothiazolyl) -7-diethylamino) coumarin, 3- (2-benzothiazolyl) -7-dibutylamino) coumarin, 3- (2-benzothiazolyl) -7-dioctylamino) coumarin, 3- (2-Benzimidazolyl) -7-diethylamino) coumarin is exemplified.

  Ketocoumarin derivatives include 3,3′-carbonylbis (7-diethylaminocoumarin), 3,3′-carbonylbis-7-diethylaminocoumarin-7′-bis (butoxyethyl) aminocoumarin, and 3,3′-carbonylbis. (7-dibutylaminocoumarin) is exemplified.

  Base styryl derivatives include 2- [p- (dimethylamino) styryl] benzothiazole, 2- [p- (dimethylamino) styryl] naphtho [1,2-d] thiazole, 2-[(m-hydroxy-p -Methoxy) styryl] benzothiazole.

  Merocyanine derivatives include 3-ethyl-5-[(3-ethyl-2 (3H) -benzothiazolylidene) ethylidene] -2-thioxo-4-oxazolidinone, 5-[(1,3-dihydro-1, 3,3-trimethyl-2H-indole-2-ylidene) ethylidene] -3-ethyl-2-thioxo-4-oxazolidinone is exemplified.

  In the present invention, a particularly preferable composite photoradical polymerization initiator is a case where an organic peroxide or a bisimidazole derivative is used as a photoradical polymerization initiator in combination with a photosensitizing dye.

  Specific examples of organic peroxide-photosensitizing dye combinations include 3, 3 ', 4,4'-tetra (tert-butylperoxycarbonyl) benzophenone and photosensitization by Hayashibara Biochemical Laboratories. NKX653, NKX3883, NKX1880, NKX1595, NKX1695, NK4256, NK1886, NK1473, NK1474, NK4795, NK4276, NK4278, NK91, NK1046, NK1237, NK1420, NK1590, NK1590, and NK3590.

  The photosensitizing dye when an organic peroxide or a bisimidazole derivative is used as the photoradical polymerization initiator is preferably a coumarin dye.

Cationic polymerizable compound (b1)
The cationically polymerizable compound (b1) used in the present invention is preferably compatible with any of the components, has a refractive index as low as that of the radically polymerizable compound (a1), and is liquid at normal temperature and pressure. By using such a cationically polymerizable compound, the entire composition is sufficiently compatible before hologram recording, but diffusion transfer of the radical polymerizable compound (a1) is likely to occur as hologram recording is started. . Furthermore, by selecting a material having a low refractive index, it is possible to separate it from the cationically polymerizable compound (b1) by diffusion transfer of the radically polymerizable compound (a1). A refractive index difference (refractive index modulation) can be obtained.
The cationic polymerizable compound (b1) can be polymerized by heating at a temperature of preferably 60 ° C. or higher in the presence of the cationic polymerization initiator (b2).

  Examples of the cationically polymerizable compound (b1) include compounds containing at least one of oxirane structure and oxetane structure in one molecule, or at least one of each of them.

  Glycidyl ethers include phenyl glycidyl ether, 2-ethylhexyl glycol glycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol di Glycidyl ether, Neonentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, Glycerin diglycidyl ether, Totimethylolpropane triglycidyl ether, Hydrogenated bisphenol A diglycidyl ether, 2,2-Dibromoneopentyl glycol di A glycidyl ether can be illustrated.

  Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis {[(3-ethyl-3-oxetanyl) methoxy] methyl] benzene, 3-ethyl-3- (phenoxymethyl) oxetane, Di [1-ethyl (3-oxetanyl)] methyl ether, 3-ethyl-3- (2 ethylhexyloxymethyl) oxetane, 3-ethyl-3-{[3- (triethoxysilyl) propoxy] methyl} oxetane, Examples thereof include oxetanylsilsesquioxysan and phenol novolac oxetane.

  Further, as other usable compounds, spiro orthoesters, spiro ortho carbonates, bicycloorthocarbonates and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (CY179) having little polymerization shrinkage are also useful. is there.

  The exemplified compound may be a dimer or a trimer oligomer. Moreover, you may use individually or in combination of 2 or more. In particular, when an oxirane compound and an oxetane compound are mixed and used, the cationic polymerization rate increases and a high molecular weight polymer is formed, which can be preferably used.

Thermally latent cationic polymerization initiator (b2)
The cationic polymerization initiator (b2) characteristically used in the present invention is a thermal latent cationic polymerization initiator composed of a combination of an aluminum complex and an arylsilanol.

  The thermal latent cationic polymerization initiator (b2) composed of an aluminum complex and an arylsilanol used in the present invention has no function as an initiator at room temperature on the premise that it does not have a photoinitiating function in the interference exposure process. It is sufficient that it exhibits a cationic polymerization initiating ability capable of polymerizing the cationically polymerizable compound (b1) at a temperature higher than that, for example, preferably 60 ° C. or higher. A combination of aluminum complex [II] and arylsilanol [III] is exemplified.

[式中、Ｒ₄、Ｒ₆は互いに同一または異なって炭素数が１から１２の置換基を有してもよいアルキル基を意味し、Ｒ₅は置換基を有していてよい炭素原子を意味する。]

[Wherein R ₄ and R ₆ are the same or different from each other and each represents an alkyl group which may have a substituent having 1 to 12 carbon atoms, and R ₅ represents a carbon atom which may have a substituent. means. ]

[式中、Ｒ₇、Ｒ₈は互いに同一または異なって炭素数が１から１２の置換基を有してもよいアルキル基またはアリール基を意味する。ｍは０から３の整数である。]

[Wherein, R ₇ and R ₈ are the same or different from each other and each represents an alkyl group or an aryl group which may have a substituent having 1 to 12 carbon atoms. m is an integer of 0 to 3. ]

In the aluminum complex, R ₄ and R ₅ include those that form an aryl group in cooperation with carbon atoms and other atoms sandwiched between them. The formed aryl group may have a substituent.

As specific examples of the aluminum complex, i) tris (acetylacetonato) aluminum, ii) tris (ethylacetoacetate) aluminum, and iii) tris (salicylaldehyde) aluminum specifically represented by the following formula are preferable. Can be mentioned.

When a plurality of R ₇ are contained in the arylsilanol, they may be the same or different. The same applies to the OR _8. R ₇ is preferably a phenyl group.

  Specific examples of the arylsilanol include diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldipropoxysilane, diphenyldiacetoxysilane, diphenyldiphenoxysilane, triphenylmethoxysilane, and triphenylethoxysilane.

Binder polymer (C)
The binder polymer (C) used in the present invention has good compatibility with the radically polymerizable compound (a1) and the cationically polymerizable compound (b1), and can be completely dissolved without containing an insoluble part in an organic solvent. I just need it. Typical examples include a homopolymer of a monomer having an ethylenically unsaturated double bond, or a copolymer of the monomer and a copolymerizable monomer copolymerizable therewith, a diphenol compound and a dicarboxylic acid compound. Selected from the group consisting of a condensation polymer, a polymer having a carbonate group in the molecule, a polymer having a —SO ₂ — group in the molecule, a cellulose derivative, and a combination of two or more thereof.

Specific examples of the binder polymer (C) include polyvinyl acetate, polyvinyl butyrate, polyvinyl formal, polyvinyl carbazole, polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate, polyethyl acrylate, polybutyl acrylate, polymethacrylate. Ronitrile, polyethyl methacrylate, polybutyl methacrylate, polyacrylonitrile, poly-1,2-dichloroethylene, ethylene-vinyl acetate copolymer, syndiotactic polymethyl methacrylate, poly-α-vinyl naphthalate, polycarbonate, cellulose acetate , Cellulose triacetate, cellulose acetate butyrate, polystyrene, poly-α-methylstyrene, poly-o-methylstyrene, poly-p -Methylstyrene, poly-p-phenylstyrene, poly-2,5-dichlorostyrene, poly-p-chlorostyrene, poly-2,5-dichlorostyrene, polyarylate, polysulfone, polyethersulfone, styrene-acrylonitrile Copolymer, styrene-divinylbenzene copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, ABS resin, polyethylene, polyvinyl chloride, polypropylene, polyethylene terephthalate, polyvinyl pyrrolidone, polyvinylidene chloride, hydrogen Styrene-butadiene-styrene copolymer, transparent polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, a copolymer of (meth) acrylic acid cycloaliphatic ester and methyl (meth) acrylate, and the like.
The above exemplary compounds of the binder polymer (C) may be used alone or in combination of two or more.

  The binder polymer (C) can be variously selected depending on the use and application of the hologram. In order to obtain optical properties such as good film formability and diffraction efficiency, polyvinyl acetate, polyvinyl butyrate, cellulose acetate butyrate, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polystyrene, polyvinyl formal, etc. are preferably used. It is done.

In order to obtain optical characteristics such as better heat resistance, film formability and diffraction efficiency, the binder polymer (C) preferably has a glass transition temperature (Tg) of 100 ° C. or higher. A copolymer of (meth) acrylic acid cyclic aliphatic ester and methyl (meth) acrylate is preferably used. The cyclic aliphatic portion of the (meth) acrylic acid cyclic aliphatic ester constituting the copolymer of (meth) acrylic acid cyclic aliphatic ester and methyl (meth) acrylate has a bornyl skeleton, isobornyl skeleton or norbornyl skeleton. It may be. Examples of (meth) acrylic acid cyclic aliphatic ester constituting a copolymer of (meth) acrylic acid cycloaliphatic ester and methyl (meth) acrylate include bornyl (meth) acrylate, isobornyl (meth) acrylate, norbornyl ( And (meth) acrylate.
1 type may be sufficient as (meth) acrylic-acid cyclic aliphatic ester, and 2 or more types may be sufficient as it. In the latter case, the copolymer is a ternary or higher copolymer of two or more (meth) acrylic acid cycloaliphatic esters and methyl (meth) acrylate.
In order to obtain a hologram having better heat resistance, the glass transition temperature of the copolymer of (meth) acrylic acid cycloaliphatic ester and methyl (meth) acrylate is preferably 130 ° C. or higher.
As the copolymer of (meth) acrylic acid cycloaliphatic ester and methyl (meth) acrylate, one kind thereof may be used, or a combination of two or more kinds may be used.

Composition ratio The composition ratio of each component of the photosensitive composition for volume phase hologram recording of the present invention is a radical polymerizable compound (a1), a cationic polymerizable compound (b1), a binder polymer (C), a photo radical polymerization initiator. (a1) is 10 to 70, and (b1) is 10 to 100 parts by weight in total of (a2), a sensitizing dye (a3), and a thermal latent cationic polymerization initiator (b2) composed of an aluminum complex and an arylsilanol. -70, (C) is preferably 10-70, (a2) is preferably 0.5-15, (a3) is preferably 0.01-1 and (b2) is preferably 0.5-15. More preferably, (a1) is 15-50, (b1) is 15-50, (C) is 15-50, (a2) is 1-8, (a3) is 0.05-0.5, (b2) is 1- 8 is desirable.

Other Additives The hologram recording material composition according to the present invention can contain additives such as a thickener, a thermal polymerization inhibitor, a chain transfer agent, a solvent, and the like, if necessary.
As thickeners, inorganic fine particles such as silica gel “Daiso Gel SP Series”, Fuji Silysia Chemical “Silysia” and “Fuji Silica Gel”, Shionogi Pharmaceutical “Carplex”, Japan “Aerosil” manufactured by Aerosil Co., “Leolo Seal”, “Toc Seal”, “Fine Seal” manufactured by Tokuyama Co., Ltd., etc. can be used. Or organic fine particles, for example, diallyl phthalate polymers that can be prepared by the methods described in JP-A-10-72510 and JP-A-10-310684, or “New Material Series“ Cutting-edge Technology of Ultrafine Particles Polymer ”” (CMC, "PB, 200 series" manufactured by Kao Corporation, supervised by Soichi Muroi, 1991), "Bellpearl series" manufactured by Kanebo Co., Ltd., "Techpolymer series" manufactured by Sekisui Plastics Co., Ltd., "Micropearl series" manufactured by Sekisui Fine Chemical Co., Ltd. "MR series""MPseries" manufactured by Soken Chemical Co., Ltd. can be used. The particle size of these fine particles is only required to be smaller than the film thickness of the hologram, and is usually preferably in the range of 0.1 to 20 nm.

The organic solvent is effective for improving the film-forming property, etc., in addition to adjusting the viscosity and compatibility, for example, ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, ester solvents such as ethyl acetate, butyl acetate, Aromatic solvents such as xylene and toluene, cellosolve solvents such as methyl cellosolve and ethyl cellosolve, alcohol solvents such as methanol and ethanol, ether solvents such as tetrahydrofuran and dioxane, and halogen solvents such as dichloromethane and chloroform are preferred. Used. In this case, it may be either a solution or a suspension by adding a solvent, but a solution is preferred. However, water cannot be used because it inhibits viscosity adjustment, compatibility adjustment, film forming property, and the like. Water cannot be used as a medium even in emulsion form.
The amount of the solvent used is about 0.5 to 1000 parts by weight with respect to 100 parts by weight in total of the radical polymerizable compound (a1), the cationic polymerizable compound (b1) and the binder polymer (C).

  Examples of the thermal polymerization inhibitor include hydroquinone, p-methoxyphenol, tert-butylcatechol, naphthylamine, diphenylpicrylhydrazine, diphenylamine and the like, which have a function of eliminating generated radicals.

  Examples of chain transfer agents include α-methylstyrene dimer, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, tert-butyl alcohol, n-butanol, isobutanol, isopropylbenzene, ethylbenzene, chloroform, methyl ethyl ketone, propylene, chloride. Vinyl etc. are mentioned.

Preparation method of composition To prepare a hologram recording material composition, for example, radical polymerizable compound (a1), cationic polymerizable compound (b1), binder polymer (C), radical polymerization initiator (a2), sensitization The dye (a3) and the heat-latent cationic polymerization initiator (b2) or the above optional components are put into an organic solvent-resistant container such as a glass beaker, and the whole is stirred. In this case, in order to promote dissolution of the solid component, it may be heated to, for example, about 40 to 90 ° C. within a range in which the composition is not denatured.

Method for Producing Medium In order to produce a hologram recording medium using the volume phase hologram recording material composition according to the present invention, the recording material composition is applied to one side of a substrate, and the resulting coating film, that is, a recording layer (for recording) A recording medium having a two-layer structure comprising a photosensitive film) and a substrate is obtained. If necessary, a three-layer structure is obtained by covering a recording layer on the substrate with a film-like, sheet-like or plate-like protective material. It is preferable to use an organic solvent in the recording layer forming step. In this case, radically polymerizable compound (a1), cationically polymerizable compound (b1), binder polymer (C), photoradical polymerization initiator (a2), sensitizing dye (a3), and thermal latent cationic polymerization initiator ( b2) Alternatively, the above optional additional components are dissolved in a solvent, and the obtained solution is applied onto a substrate, and then the solvent is stripped to form a recording layer. When the recording layer is covered with a protective material, it is preferable to remove the solvent by air drying or heating under reduced pressure before coating the protective material. The substrate is made of a plastic plate or a film such as a glass plate, a polyethylene terephthalate plate, a polycarbonate plate, or a polymethyl methacrylate plate. The thickness of the substrate is preferably 0.02 to 10 mm. The substrate does not have to be flat, and may be bent, curved, or have an uneven structure on the surface. The thickness of the protective material is preferably 0.02 to 10 mm. Examples of the coating method include gravure coating, roll coating coating, bar coating coating, and spin coating coating. The thickness of the recording layer after removing the solvent is preferably 1 to 100 μm.

Recording Method / General Method A normal recording method can be employed to record a recording object as a hologram on the hologram recording medium according to the present invention. In other words, the coherent light having a wavelength in the range of 400 to 700 nm is divided into two, and the reflection from the object obtained by irradiating the object to be recorded with one light beam (reference light) and the other light beam. Light (object light) (or transmitted light (object light) from a master hologram obtained by irradiating a volume phase master hologram on which information on the object has been recorded in advance) are in the same plane with respect to the recording medium. Alternatively, the volume phase hologram recording material medium is arranged at a position where the interference fringes obtained by making the light incident from the front and back surfaces can interfere with each other, and the object is recorded on the medium. More specifically, the laser beam is divided into two light beams using a beam splitter or the like, and interference fringes are obtained by using a mirror or the like to match the two again (two-beam exposure method). Alternatively, one laser beam is reflected by a mirror, and interference fringes are obtained by combining both incident light and reflected light again (one-beam exposure method). When obtaining such an interference pattern, a separately produced hologram may be arranged on the optical path as a master hologram, and interference fringes may be obtained by a one-beam and / or two-beam exposure method. The recording medium is installed at a position where the intensity distribution of the interference pattern formed in this way can be captured. In this state, when laser light irradiation is normally performed for several seconds to several minutes, interference fringes that become holograms are recorded on the recording medium. In order to minimize vibration during hologram recording, these recordings should be performed on an optical vibration isolation table. The amount of laser light used is represented by the product of light intensity and irradiation time, and is preferably about 10,000 to 10,000 mJ / cm ² . If the amount of light is less than this range, it is difficult to record, and if it exceeds this range, the diffraction efficiency of the hologram may decrease.

Types of light sources The light sources used in the present invention will be described.
As a preferable light source for obtaining interference fringes of coherent light in the visible light region and performing volume phase hologram recording, a laser can be used. A laser has a single wavelength and has coherence, and thus is a preferable light source in hologram recording. The most preferable light source is a light source excellent in coherence, for example, a laser in which an optical element such as an etalon is attached to the laser. This is particularly preferable because the frequency of the single wavelength is a single frequency, and the interference distance can be increased. Specific examples of typical lasers include Kr (wavelength 647 nm, 413 nm, 407 nm), He-Ne (wavelength 633 nm), Ar (wavelength 514.5 nm, 488 nm), YAG (wavelength 532 nm), He-Cd (wavelength 442 nm). ) Etc. can be illustrated. These light sources may be used alone or in combination of two or more. Further, the light source may be continuous light or may oscillate in pulses at a certain or arbitrary interval.

Description of action Next, using a volume phase hologram recording medium of the present invention, will be described a method of forming the volume phase hologram of the present invention. Here, a case where a radical photopolymerization initiator that reacts with a visible light laser and a cationic polymerization initiator that reacts with ultraviolet light are included will be described as an example. In this case, in the volume phase hologram recording medium, before exposure, the radical polymerizable compound (a1), the cationic polymerizable compound (b1), the binder polymer (C), the radical photopolymerization initiator (a2), the photosensitizing dye. (a3) and the heat-latent cationic polymerization initiator (b2) are compatible with each other, but the radical polymerizable compound (a1) is preferentially photopolymerized with interference fringe exposure of visible laser light to form a polymer. As a result, a hologram recording layer is obtained.

  That is, the intensity distribution of light / darkness of light in the visible light region on a two-layer structure formed by applying the recording material composition according to the present invention on a substrate, or a three-layer structure formed by covering the recording layer with a protective material. First, radicals are generated from the photoradical polymerization initiator (a2) in the portion with a large amount of light in the interference fringes, and the radically polymerizable compound (a1) rich in photoradical polymerization reactivity is photopolymerized. And the concentration of the radical polymerizable compound (a1) decreases at the same time as the portion shrinks in volume. In order to compensate for the dent and concentration gradient caused by this, an unreacted polymer flows from a portion with a small amount of light, and the cationic polymerizable monomer (b1) and the binder polymer (C) are phased from the radical polymerizable compound (a1). Separated and eliminated to the part with less light. The photopolymerization of the radical polymerizable compound (a1) that has diffused and moved to the portion with a large amount of light further proceeds. As a result of these, a structure in which the polymer of the radically polymerizable compound (a1) having a high refractive index is accumulated in a portion having a large amount of light and a binder polymer (C) having a low refractive index is accumulated in a portion having a small amount of light. Form.

  Here, the cationic polymerizable monomer (b1) mainly functions as a component for promoting the separation of the radical polymerizable compound (a1) and the binder polymer (C). This is uniformly present in the system at the initial stage of exposure, but is finally eliminated to a portion with a small amount of light, that is, to the binder polymer (C) side. Thus, an interference fringe based on the difference in refractive index between the composition distribution according to the amount of light, that is, the portion having a large amount of the radical polymerizable compound (a1) and the portion having a large amount of the cationic polymerizable monomer (b1) and the binder polymer (C). It is formed as a hologram.

  The volume phase hologram thus obtained has sufficient refractive index modulation, but can be further enhanced by heat treatment. By performing the heat treatment, it is possible to promote the movement of the unreacted radical polymerizable compound (a1), which has been unable to diffuse and move at the temperature at the time of recording, to the interference fringe portion, and as a result, the refractive index modulation is further increased. A bright hologram with high diffraction efficiency is obtained.

  Subsequently, by continuing the heat treatment as it is, by polymerizing the cation polymerizable monomer mainly remaining as an unreacted component, a complicated post-treatment step such as ultraviolet irradiation is not required, and the entire composition is obtained. A cured volume phase hologram with good moisture resistance is formed.

  The above-described heat treatment may be performed by heating the recording medium in the temperature range of 60 to 150 ° C. for 0.5 to 24 hours under light shielding. It is preferable to heat for 6 to 12 hours in a temperature range of 80 ° C to 100 ° C.

Using the volume phase hologram recording medium according to the present invention for hologram reproduction , an object as a recording object can be recorded and reproduced. An ordinary photograph can only record information on the amplitude of the object, so the object recorded on the photograph can only be viewed as two-dimensional, but the recording medium can simultaneously record the information on the phase and amplitude of the object, That is, since complete three-dimensional information can be recorded, the recorded object can also be viewed as complete three-dimensional. In the embodiment of the present invention, recording by a one-beam exposure method using a mirror is described. In this case, the object to be recorded is the mirror surface of the mirror. In order to obtain interference fringes, the object light and the reference light can be incident on the recording surface of the recording medium from the same surface, or can be incident from the front and back surfaces to cause interference. At this time, a transmission hologram is recorded in the former, and a reflection hologram is recorded in the latter. In the one-beam exposure method, the mirror surface of the mirror becomes a recording object, but another recording object is used instead of the mirror, and light having a coherence property such as laser light is used as a light source, and incident light (reference light) is used. The recording medium can be arranged at a position where an interference fringe formed by interference with reflected light (object light) from the object can be captured, and the object can be recorded on the medium. When reproducing the recording, white light or a light source used during recording can be used as the reference light, and the object light is preferably efficiently irradiated by irradiating the latter light source at the same angle as the reference light during hologram recording. Is played. Further, in order to obtain object light, a volume phase hologram in which object information is recorded in advance may be used. In this method, a recorded hologram is used as a master hologram, and information on the hologram can be copied by a single beam exposure method. In this case, the one-beam exposure method uses interference between reference light (transmitted light from the master hologram (not including object information)) and object light (diffracted transmitted light from the master hologram (including object information)). Can be recorded. This method has the advantage of being easily mass-produced. The diffraction efficiency evaluated in the embodiment of the present invention is the brightness of the mirror surface reconstructed with respect to the intensity of the reference light, that is, the intensity of the object light, how the object can be recorded brightly, and This is an index indicating whether or not the reproduction was possible.

  Hereinafter, the present invention will be specifically described with reference to several examples of the present invention. However, these examples do not limit the present invention.

Example 1
1) Acrylic acid addition of glycidyl ether of 9,9-bis (4-hydroxyphenyl) fluorene as a radically polymerizable compound (a1) having a 9,9-diarylfluorene skeleton and solid at normal temperature and pressure Product (manufactured by Nippon Steel Chemical Co., Ltd., “ASF400”, simple substance refractive index: 1.63) 1.00 g (weight percentage with respect to the total composition: 27.8 wt%), 3, 4 as the cationically polymerizable compound (b1) -Epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Bantico, "CY-179", single index of refraction: 1.50) 1.00 g (27.8 wt%), poly as binder polymer (C) 1.25 g (34.8 wt%) of methylmethyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd., “methyl methacrylate polymer”, simple substance refractive index: 1.49), photoradical 0.25 g (7.0 wt%) of 3,3 ′, 4,4′-tetra (tert-butylperoxycarbonyl) benzophenone (manufactured by NOF Corporation, “BTTB-25”) as a light initiator (a2), light As a sensitizing dye (a3), a coumarin-based dye (manufactured by Hayashibara Biochemical Co., Ltd., NK1538) 0.005 g (0.1 wt%), a thermal latent cationic polymerization initiator (b2) composed of an aluminum complex and an arylsilanol (b2) as tris (2, 4-pentadionato) aluminum (III) (Tokyo Kasei) and arylsilanol LS-5900 (Shin-Etsu Chemical) 0.05 g (1.4 wt%), 0.04 g (1.1 wt%)), respectively, and solvent A composition for recording material was prepared by mixing 5 g of acetone at room temperature.
2) This composition was applied to one side of a 60 mm × 60 mm glass substrate by spin coating so that the thickness after drying was 15 to 20 μm, and the solvent was removed from the coating layer by heat treatment under reduced pressure. A recording medium having a two-layer structure comprising a substrate and a recording layer was prepared.
3) The recording layer of this recording medium was covered with a PET film having a thickness of 50 μm to produce a photosensitive layer for volume phase type hologram recording having a three-layer structure.
4) Next, the glass surface of the photosensitive plate was overlapped with a mirror through xylene as a solvent. The layer structure is, in order, a mirror, xylene, glass, a photosensitive composition, and a PET film.
5) In this state, a 514.5 nm Ar ion laser having a single frequency with excellent coherence was incident vertically from the PET surface, and a one-beam reflection hologram was recorded. The interference fringes formed at this time are formed by the incident light and the reflected light from the mirror.
6) FIG. 1 shows an example of recording a reflection hologram of one beam. In the figure, (A) is a laser generator, (CL) is a collimator lens, and (B1) is incident light. A sample used for recording is shown in FIG. (M) is a mirror, (K) is xylene, (G) is glass, (H) is a composition, (P) is a PET film, (B1) is the incident light of the laser, (B2) is the reflected light of the laser is there.
7) The photosensitive plate was exposed in this state, and interference fringes to be a hologram were recorded on the photosensitive plate.
The light-reflective hologram was exposed for 40 seconds at an exposure amount of 40 mJ / cm ² with the light intensity of the beam being 1.0 mW / cm ² .
8) The obtained reflection hologram was heated at 100 ° C. for 4 hours.

Example 2
The PET film was peeled off from the reflection hologram obtained in Example 1 (diffraction efficiency: 85%, reproduction wavelength: 485 nm) (layer constitution: PET / recording layer / glass substrate from above), and an adhesive film (manufactured by Sumitomo 3M, Scotch clear tape, “CK-24”) was bonded so that the adhesive layer adhered to the hologram layer. Hologram performance such as diffraction efficiency and reproduction wavelength was maintained even when an adhesive film was laminated. The reason why the hologram performance does not change as a result of sticking the adhesive is that there is almost no unreacted component remaining in the hologram film, and cationic polymerization is proceeding.

Example 3
An adhesive film similar to that of Example 2 is bonded to the reflection hologram obtained in Example 1 (layer structure: PET / adhesive layer / recording layer / glass substrate from above), and the PET film derived from the adhesive film is peeled off from here. , Aluminum vapor-deposited film (Kimura Aluminum Foil Co., Ltd., no polycoat) was laminated so that the aluminum vapor-deposited surface was adhered to the adhesive layer (layer structure: PET / aluminum vapor-deposited layer / adhesive layer / recording layer / glass substrate from above) ). This sample was placed in an environment of 60 ° C./95% RH for 10 days. When the appearance of the aluminum layer of the sample exposed to this high temperature and high humidity environment for a long time was examined, there was no change. This shows that the aluminum deposition layer was not eroded by the acid.

Example 4
In the blending composition of Example 1, an experiment was conducted using (B) ethylene glycol diglycidyl ether (Kyoeisha Chemical Co., Ltd., “40E”, simple refractive index: 1.46) as the cationic polymerizable compound.

Example 5
The PET film was peeled off from the reflection hologram obtained in Example 4 (diffraction efficiency: 88%, reproduction wavelength: 487 nm) (layer structure: PET / recording layer / glass substrate from above), and an adhesive film (Sumitomo 3M, Scotch clear tape, “CK-24”) was bonded so that the adhesive layer adhered to the hologram layer. Hologram performance such as diffraction efficiency and reproduction wavelength was maintained even when an adhesive film was laminated. The reason why the hologram performance does not change as a result of sticking the adhesive is that there is almost no unreacted component remaining in the hologram film, and cationic polymerization is proceeding.

Example 6
An adhesive film similar to that of Example 2 is bonded to the reflection hologram obtained in Example 4 (layer structure: PET / adhesive layer / recording layer / glass substrate from above), and the PET film derived from the adhesive film is peeled off from here. , Aluminum vapor-deposited film (Kimura Aluminum Foil Co., Ltd., no polycoat) was laminated so that the aluminum vapor-deposited surface was adhered to the adhesive layer (layer structure: PET / aluminum vapor-deposited layer / adhesive layer / recording layer / glass substrate from above) ). This sample was placed in an environment of 60 ° C./95% RH for 10 days. When the appearance of the aluminum layer of the sample exposed to this high temperature and high humidity environment for a long time was examined, there was no change. This shows that the aluminum deposition layer was not eroded by the acid.

Example 7
In the formulation composition of Example 1, an experiment was performed using (C) vinyl acetate polymer (manufactured by Kishida Chemical Co., “vinyl acetate polymer”, polymer refractive index: 1.43) as the binder polymer.

Example 8
The PET film was peeled off from the reflection hologram obtained in Example 7 (diffraction efficiency: 91%, reproduction wavelength: 483 nm) (layer structure: PET / recording layer / glass substrate from above), and an adhesive film (manufactured by Sumitomo 3M, Scotch clear tape, “CK-24”) was bonded so that the adhesive layer adhered to the hologram layer. Hologram performance such as diffraction efficiency and reproduction wavelength was maintained even when an adhesive film was laminated. The reason why the hologram performance does not change as a result of sticking the adhesive is that there is almost no unreacted component remaining in the hologram film, and cationic polymerization is proceeding.

Example 9
An adhesive film similar to that of Example 2 is bonded to the reflection hologram obtained in Example 7 (layer structure: PET / adhesive layer / recording layer / glass substrate from above), and the PET film derived from the adhesive film is peeled off from here. , Aluminum vapor-deposited film (Kimura Aluminum Foil Co., Ltd., no polycoat) was laminated so that the aluminum vapor-deposited surface was adhered to the adhesive layer (layer structure: PET / aluminum vapor-deposited layer / adhesive layer / recording layer / glass substrate from above) ). This sample was placed in an environment of 60 ° C./95% RH for 10 days. When the appearance of the aluminum layer of the sample exposed to this high temperature and high humidity environment for a long time was examined, there was no change. This shows that the aluminum deposition layer was not eroded by the acid.

Comparative Example 1
In the formulation composition of Example 1, an experiment was conducted using a triarylsulfonium compound (“SP-170” manufactured by Asahi Denka Kogyo Co., Ltd.) as a cationic polymerization initiator. The recording method was the same, and in the case where the post-treatment process was a comparative example, UV irradiation was performed after the heat treatment to cure the cationically polymerizable compound.

Comparative Example 2
The same adhesive film as in Example 2 was bonded to the reflection hologram obtained in Comparative Example 1 (diffraction efficiency: 83%, reproduction wavelength: 483 nm). Hologram performance such as diffraction efficiency and reproduction wavelength was maintained even when an adhesive film was laminated. There was no change in the reactivity of the cationic photopolymerization initiator and the thermal latent cationic polymerization initiator.

Comparative Example 3
In the same manner as in Example 3, an adhesive film and an aluminum vapor deposition film were bonded to the reflective hologram obtained in Comparative Example 1. This sample was placed in an environment of 60 ° C./95% RH for 10 days. When the appearance of the aluminum layer of the sample exposed to this high temperature and high humidity environment for a long time was examined, a pinhole was opened in the aluminum deposition layer. This is because the aluminum deposition layer was eroded by acid.

Comparative Example 4
In the formulation composition of Example 4, an experiment was performed using a triarylsulfonium salt (“SP-150” manufactured by Asahi Denka Kogyo Co., Ltd.) as a cationic polymerization initiator. The recording method was the same, and in the case where the post-treatment process was a comparative example, UV irradiation was performed after the heat treatment to cure the cationically polymerizable compound.

Comparative Example 5
The same adhesive film as in Example 2 was bonded to the reflection hologram obtained in Comparative Example 4 (diffraction efficiency: 85%, reproduction wavelength: 486 nm). Hologram performance such as diffraction efficiency and reproduction wavelength was maintained even when an adhesive film was laminated. There was no change in the reactivity of the cationic photopolymerization initiator and the thermal latent cationic polymerization initiator.

Comparative Example 6
In the same manner as in Example 3, an adhesive film and an aluminum vapor deposition film were bonded to the reflective hologram obtained in Comparative Example 1. This sample was placed in an environment of 60 ° C./95% RH for 10 days. When the appearance of the aluminum layer of the sample exposed to this high temperature and high humidity environment for a long time was examined, a pinhole was opened in the aluminum deposition layer. This is because the aluminum deposition layer was eroded by acid.

Comparative Example 7
In the formulation composition of Example 7, an experiment was conducted using a diphenyliodonium salt (manufactured by Midori Chemical Co., “BBI-102”) as a cationic polymerization initiator. The recording method was the same, and in the case where the post-treatment process was a comparative example, UV irradiation was performed after the heat treatment to cure the cationically polymerizable compound.

Comparative Example 8
The same adhesive film as in Example 2 was bonded to the reflection hologram obtained in Comparative Example 7 (diffraction efficiency: 89%, reproduction wavelength: 481 nm). Hologram performance such as diffraction efficiency and reproduction wavelength was maintained even when an adhesive film was laminated. There was no change in the reactivity of the cationic photopolymerization initiator and the thermal latent cationic polymerization initiator.

Comparative Example 9
In the same manner as in Example 3, an adhesive film and an aluminum vapor deposition film were bonded to the reflective hologram obtained in Comparative Example 1. This sample was placed in an environment of 60 ° C./95% RH for 10 days. When the appearance of the aluminum layer of the sample exposed to this high temperature and high humidity environment for a long time was examined, a pinhole was opened in the aluminum deposition layer. This is because the aluminum deposition layer was eroded by acid.

Performance Evaluation Regarding the holograms obtained in the above examples and comparative examples, the film thickness and diffraction efficiency of the hologram after recording were measured.
a) Film thickness The film thickness of the hologram after recording was measured using a micrometer.
b) The diffraction efficiency of the reflection hologram was determined by measuring the transmittance with an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, “V-550”). A method for calculating the diffraction efficiency is shown in FIG. When the obtained reflection hologram is measured with an ultraviolet-visible spectrophotometer, a chart as shown in FIG. 3 is obtained. In the figure, (T) is the transmittance of the sample, and (P) is the peak height of the diffracted light. The diffraction efficiency of the reflection hologram was calculated from the following equation based on the peak height of the diffracted light with respect to the overall transmittance.
Diffraction efficiency (%) = (Diffraction light peak (height) / Overall transmittance (height)) × 100

The obtained results are shown in Table 1.

  As is clear from Table 1, the recordability of the reflection hologram obtained in Example 1 is not different from that obtained in Comparative Example 1. Moreover, also from the point of curability, since the result of Example 2 did not change to Comparative Example 2, it was shown that sufficient curing was performed even in the formulation containing the latent thermal cationic polymerization initiator. In Example 3, there was no change in the laminated aluminum vapor deposition layer, whereas in Comparative Example 3, a small hole was formed in the aluminum vapor deposition layer, and corrosion of aluminum by acid occurred. Moreover, when visually observed under natural light, all of the media of the comparative examples showed a pale yellow coloration, and the media of the present invention was colorless.

  The photosensitive composition for hologram recording according to the present invention requires a simple production process and can be used in the field of producing a hologram recording medium requiring sufficient moisture resistance.

It is the schematic which showed the example of the reflection type hologram. It is the conceptual diagram which showed the calculation method of diffraction efficiency.

Explanation of symbols

(A): Laser generator (BS): Beam splitter (M): Mirror (S): Photosensitive plate (B1): Object light (B2): Reference light

Claims (6)

Consisting of radical polymerization system (A), cationic polymerization system (B), and binder polymer (C), it is used to record the intensity distribution of light and darkness of interference fringes obtained by making light interfere as a change in refractive index. In the composition for volume phase hologram recording material,
Photosensitive for volume phase hologram recording, wherein the cationic polymerization initiator (b2), which is a constituent of the cationic polymerization system (B), is a thermal latent cationic polymerization initiator composed of an aluminum complex and an arylsilanol. Composition. In the composition for volume phase type hologram recording material used for recording the intensity distribution of light and darkness of interference fringes obtained by making light interfere as a change in refractive index,
(1) The basic composition is a mixture of the radical polymerizable compound (a1), the cationic polymerizable compound (b1), and the binder polymer (C).
(2) As a polymerization initiator, a photo radical polymerization initiator that polymerizes the radical polymerizable compound (a1) by exposing an interference fringe (first light) obtained by interference of coherent light in the visible light region. (a2), a sensitizing dye (a3) used in combination with a radical photopolymerization initiator, and a thermal latent cationic polymerization initiator (b2) composed of an aluminum complex and an arylsilanol,
(3) The refractive index of the radical polymerizable compound (a1) is larger than the weighted average value of the refractive indexes of the cationic polymerizable compound (b1) and the binder polymer (C),
A photosensitive composition for volume phase hologram recording. 3. The volume phase type according to claim 1, wherein the aluminum complex is a compound represented by the following formula [II], and the arylsilanol is a compound represented by the following formula [III]. Photosensitive composition for hologram recording.

[Wherein R ₄ and R ₆ are the same or different from each other and each represents an alkyl group which may have a substituent having 1 to 12 carbon atoms, and R ₅ represents a carbon atom which may have a substituent. means. ]

[Wherein, R ₇ and R ₈ are the same or different from each other and each represents an alkyl group or an aryl group which may have a substituent having 1 to 12 carbon atoms. m is an integer of 0 to 3. ]   A hologram recording medium comprising the photosensitive composition for volume phase hologram recording according to any one of claims 1 to 3 formed on a substrate, wherein the photosensitive film is covered with a protective material as necessary.   A hologram recording comprising: dissolving or suspending the composition according to claim 1 in an organic solvent; applying the obtained solution or suspension on a substrate; and then evaporating the solvent. A method for manufacturing a medium.   5. When recording a volume phase hologram on the hologram recording medium according to claim 4, first, an interference fringe (first light) obtained by interference of coherent light in the visible light region is exposed to the hologram recording medium, and then shielded. A method for recording a hologram recording medium, comprising heating the recording medium at a temperature range of 60 to 150 ° C. for 0.5 to 24 hours.

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