JP2007316570A - Composition for volume hologram recording material, and volume hologram recording material using the same, volume hologram optical recording medium and volume hologram optical recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for a volume hologram recording material having low hygroscopicity and excellent storage stability. <P>SOLUTION: The composition comprises: a thermosetting matrix (A) containing polyether (A1) having two or more epoxy groups in one molecule and having an alkylene oxide chain having four or more carbon atoms and a hardening agent (A2); and a photo-active compound (B). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a composition for volume hologram recording material, a volume hologram recording material using the composition, a volume hologram optical recording medium, and a volume hologram optical recording method. Specifically, a composition for volume hologram recording material suitably used as a polyether matrix of a photopolymer type volume hologram recording material, a volume hologram recording material using the volume hologram recording material composition, and a volume hologram optical recording The present invention relates to a medium and a volume hologram optical recording method.

  As an example of a known volume phase hologram recording material, there is a write-once type that does not require wet treatment or bleaching treatment, and its composition is generally a material in which a photoreactive compound is compatible with a matrix. For example, a photopolymer system in which a monomer that can be radically polymerized or cationically polymerized is combined with a polyether matrix (see Patent Documents 1 and 2, etc.).

  The photopolymer method is a very simple method with very wide selectivity of monomers that cause a change in refractive index. In addition, the polyether matrix is highly compatible with the monomer and has a low glass transition temperature (hereinafter sometimes referred to as “Tg” as appropriate). Therefore, in the photopolymer method using a polyether matrix, a volume hologram recording material having high transparency and excellent recording speed can be obtained.

JP 2005-43862 A JP 11-352303 A

  However, since the polyether matrix made of propylene oxide is used in the conventional polyether matrix, the hygroscopicity is high, there is a problem in the storage stability of the visible light polymerization initiator (the shelf life is short), and the practicality is high. Low and further improvements were sought.

  The present invention has been made in view of the above problems, and its object is to provide a composition for a volume hologram recording material having low hygroscopicity and excellent storage stability, and a volume hologram recording material and volume hologram using the same. An optical recording medium and a volume hologram optical recording method are provided.

  As a result of intensive studies to solve the above problems, the present inventors have used a thermosetting matrix containing a polyether having a C 4 or more alkylene oxide chain and a curing agent in combination with a photoactive compound. The inventors have found that a composition for a volume hologram recording material having low hygroscopicity and excellent storage stability can be obtained, and the present invention has been completed by finding that the above problems can be solved.

  That is, the gist of the present invention is a heat containing a polyether (A1) having two or more epoxy groups in one molecule and an alkylene oxide chain having 4 or more carbon atoms, and a curing agent (A2). A composition for volume hologram recording material, comprising a curable matrix (A) and a photoactive compound (B) (claim 1).

  Here, it is preferable that carbon number of the alkylene oxide chain which the said polyether (A1) has is 4 or more and 10 or less (Claim 2).

  Moreover, it is preferable that the ratio with respect to the said photoactive compound (B) of the said thermosetting matrix (A) is 10 to 5000 weight part (Claim 3).

  Moreover, it is preferable that the number average molecular weights of the said polyether (A1) are 200 or more and 50000 or less (Claim 4).

  The curing agent (A2) is preferably at least one selected from the group consisting of amines, acid anhydrides, thiols, anionic polymerization initiators and cationic polymerization initiators (Claim 5).

  The photoactive compound (B) is preferably a radical polymerizable monomer (claim 6).

  Another gist of the present invention resides in a volume hologram recording material comprising at least the composition for volume hologram recording material described above (claim 7).

  Another gist of the present invention resides in a volume hologram optical recording medium comprising at least a layer containing the volume hologram recording material described above (claim 8).

  Another aspect of the present invention is that the layer of the volume hologram optical recording medium is irradiated with excitation light and reference light, and volume hologram recording is performed on the layer by interference between the excitation light and the reference light. The present invention resides in a volume hologram optical recording method characterized in that:

  According to the present invention, a composition for a volume hologram recording material having low hygroscopicity and excellent storage stability, and a volume hologram recording material, a volume hologram optical recording medium and a volume hologram optical recording method using the same are provided. Can do.

  Hereinafter, embodiments of the present invention will be described in detail. The following description is an example (representative example) of an embodiment of the present invention, and the present invention is specified by these contents as long as the gist thereof is not exceeded. It is not a thing.

  In the following description, “these derivatives” refer to compounds obtained by substituting a part of the structure of the exemplified compound with another structure without departing from the spirit of the present invention.

  In addition, in the following description, the description “(meth) acrylic acid” is a general term for acrylic acid and methacrylic acid. The same applies to “(meth) acrylamide” and “(meth) acrylate”.

[I. Volume hologram recording material composition]
The composition for volume hologram recording material of the present invention contains at least a thermosetting matrix (A) described below and a photoactive compound (B).

[I-1. Thermosetting matrix (A)]
The thermosetting matrix (A) used in the composition for volume hologram recording material of the present invention has a polyether having two or more epoxy groups in one molecule and an alkylene oxide chain having 4 or more carbon atoms. (A1) (hereinafter sometimes simply referred to as “polyether (A1)”) and at least a curing agent (A2).

<I-1-1. Polyether (A1)>
The polyether (A1) used in the thermosetting matrix (A) is a polyether having two or more epoxy groups in one molecule and an alkylene oxide chain having 4 or more carbon atoms. The type is not particularly limited.

  The number of epoxy groups possessed by the polyether (A1) is not particularly limited as long as it is usually 2 or more. If the number of epoxy groups is small, the hardness required for the matrix may not be obtained. On the other hand, the upper limit of the number of epoxy groups is not particularly limited, but is usually 8 or less, preferably 4 or less. When the number of epoxy groups is too large, it takes a long time to consume the epoxy groups, and it may take too much time for heat curing.

  The number of carbon atoms of the alkylene oxide chain of the polyether (A1) is usually 4 or more, and usually 10 or less, preferably 8 or less, and more preferably 6 or less. When the number of carbon atoms is too large, the hydrophobicity is improved, but the polarity of the molecule is lowered, so that the compatibility with a photoactive compound, a polymerization initiator, a catalyst and the like may be lowered. In addition, since the glass transition temperature rises and crystallization is likely to occur, the recording speed may decrease, optical non-uniformity may occur, and this may cause data errors during hologram recording.

  Examples of the alkylene oxide chain having 4 to 10 carbon atoms include alkyl trimethylene oxide chain formed by opening oxetane having a substituent containing a carbon atom, and tetramethylene oxide formed by opening tetrahydrofuran. Examples include chains. Among these, a tetramethylene oxide chain is particularly preferable from the viewpoint of balance between hydrophobicity, compatibility, and glass transition temperature.

  The amount of the alkylene oxide chain of the polyether (A1) is usually 10% by weight or more, preferably 50% by weight or more based on the polyether (A1). If the amount of the alkylene oxide chain is small, the Tg of the matrix becomes too high, and the recording speed may decrease. On the other hand, the upper limit is not particularly limited and is less than 100%.

  In addition, polyether (A1) may contain components other than an alkylene oxide chain and an epoxy group in the range which does not impair the effect of this invention remarkably.

  The number average molecular weight of the polyether (A1) is usually 200 or more, particularly 300 or more, and usually 50000 or less, preferably 20000 or less, and particularly preferably 10,000 or less. If the number average molecular weight of the polyether (A1) is too small, the hardness of the matrix becomes too high, and the recording speed may decrease. On the other hand, if the number average molecular weight of the polyether (A1) is too large, the hardness of the matrix is too small and the recorded content may be lost.

  Polyether (A1) satisfying the above conditions can be synthesized by a known method. In general, it can be synthesized using glycol having an alkylene oxide chain having 4 or more carbon atoms and epichlorohydrin.

  Examples of glycols having an alkylene oxide chain having 4 or more carbon atoms include glycols obtained by ring-opening polymerization of one or more cyclic ethers having 4 or more carbon atoms.

<I-1-2. Curing agent (A2)>
The kind of the curing agent (A2) used in the thermosetting matrix (A) is not particularly limited as long as it is a compound having a functional group that reacts with an epoxy group, and is appropriately selected from known compounds. Is possible.

  Examples of the curing agent (A2) include polyfunctional phenols, amines, acid anhydrides, thiols, anionic polymerization initiators, and cationic polymerization initiators.

・ Polyfunctional phenol:
Examples of the polyfunctional phenol include bisphenol, novolac type phenol resin, resol type phenol resin, and the like.

・ Amines:
As the amines, those containing a primary amine group or a secondary amine group can be used. Examples of such amines include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, polyamides, and imidazole compounds.

  Examples of the aliphatic polyamine include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and derivatives thereof.

  Examples of alicyclic polyamines include isophorone diamine, menthane diamine, N-aminoethylpiperazine, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro (5,5) undecane adduct, Examples thereof include bis (4-amino-3-methylcyclohexyl) methane, bis (4-aminocyclohexyl) methane, and derivatives thereof.

  Examples of the aromatic polyamine include m-xylylenediamine, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, and derivatives thereof.

  Examples of polyamides include condensation products of dicarboxylic acids such as dimer acid and the above-mentioned polyamines.

  Examples of imidazole compounds include imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and derivatives thereof.

  Examples of other polyamines include dicyandiimide and adipic acid dihydrazide.

・ Anhydride:
Examples of acid anhydrides include monofunctional acid anhydrides and bifunctional acid anhydrides.

  Examples of monofunctional acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and derivatives thereof.

  Examples of the bifunctional acid anhydride include pyromellitic anhydride, benzophenone tetracarboxylic anhydride, and derivatives thereof.

・ Thiols:
Specific examples of thiols include 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 1,10-decanedithiol, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,9-nonanedithiol, 1,8-octanedithiol, 1,5-pentanedithiol, 1,2-propanedithiol, 1 , 3-propadithiol, toluene-3,4-dithiol, 3,6-dichloro-1,2-benzenedithiol, 1,3,5-triazine-2,4,6-trithiol (trimercapto-triazine), 1 , 5-Naphthalenedithiol, 1,2-benzenedimethanethiol, 1,3-benzenedimethanethiol, 1, -Benzenedimethanethiol, 4,4'-thiobisbenzenethiol, 2-di-n-butylamino-4,6-dimercapto-s-triazine, trimethylolpropane tris (β-thiopropionate), 2, 5-dimercapto-1,3,4-thiadiazole, 1,8-dimercapto-3,6-dioxaoctane, 1,5-dimercapto-3-thiapentane, Epomate QX10 (manufactured by Japan Epoxy Resin), Epomate QX11 (Japan) Dithiols such as Epoxy Resin); Thiols such as Thiocol (Toray Fine Chemical), Cupcure 3-800 (Japan Epoxy Resin), and Epicure QX40 (Japan Epoxy Resin) and other thiol compounds . Among these, commercially available fast-curing polythiols such as Epomate QX10, Epomate QX11, Cup Cure 3-800, EpiCure QX40, etc. are preferably used.

Anionic polymerization initiator:
An anionic polymerization initiator generates an anion by irradiation with heat or active energy rays, and examples thereof include a tertiary amine. Examples of tertiary amines include tertiary amines such as dimethylbenzylamine, dimethylaminomethylphenol, 2,4,6-trisdimethylaminomethylphenol, 1,8-diazabicyclo [5.4.0] undecene-7. Examples include amino group-containing compounds and derivatives thereof; imidazole compounds such as imidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole; and derivatives thereof.

・ Cation polymerization initiator:
Cationic polymerization initiators generate cations when irradiated with heat or active energy rays, and examples include aromatic onium salts. Specific examples include anion components such as SbF ₆ ⁻ , BF ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , CF ₃ SO ₃ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , iodine, sulfur, nitrogen, phosphorus and the like. The compound which consists of an aromatic cation component containing these atoms is mentioned. Of these, diaryl iodonium salts, triaryl sulfonium salts and the like are preferable. Further, San-Aid SI series manufactured by Sanshin Chemical Co., Ltd. is also suitably used as the cationic polymerization initiator.

  Among these, the curing agent (A2) is preferably at least one selected from the group consisting of amines, acid anhydrides, thiols, anionic polymerization initiators, and cationic polymerization initiators. This is because these have a high curing rate and are excellent in matrix productivity.

  The usage-amount of a hardening | curing agent (A2) differs with the case where a hardening | curing agent (A2) is an anionic initiator or a cationic initiator, and other cases.

  When the curing agent (A2) is a compound other than an anionic initiator or a cationic initiator (amines, acid anhydrides, thiols, etc.), the amount used is usually a ratio of 0.1 to the number of moles of epoxy groups. Equivalents or more, especially 0.7 equivalents or more, and usually 2.0 equivalents or less, especially 1.5 equivalents or less is preferred. If the amount of the curing agent (A2) used is too small or too large, the number of unreacted functional groups is large, and storage stability may be impaired.

  On the other hand, when the curing agent (A2) is an anionic initiator or a cationic initiator, the amount used is usually 0.001% by weight or more, particularly 0.01% by weight or more, based on the ratio to the thermosetting matrix (A). Moreover, the range of usually 50% by weight or less, particularly 10% by weight or less is preferable. If the amount of the curing agent (A2) used is too small, the concentration of the initiator is too low, so that the polymerization reaction may take too long. On the other hand, when there is too much usage-amount of a hardening | curing agent (A2), continuous ring-opening reaction may not be produced as a polymerization reaction.

  In addition, any one of the various curing agents (A2) illustrated above may be used alone, or two or more may be used in any combination and ratio. When using 2 or more types of hardening | curing agents (A2) together, those total amounts are made to satisfy | fill the said range.

  Further, the imidazole compound can function as an anionic initiator or can function as an amine. That is, when an imidazole compound is used in an amount within a preferred range as an anionic initiator, it functions as an anionic initiator, and when used in an amount within a preferred range as amines, it functions as an amine. Therefore, in consideration of this point, the usage amount may be selected according to the target function.

<I-1-3. Other>
The thermosetting matrix (A) of the present invention may contain other components in addition to the above-mentioned polyether (A1) and curing agent (A2) as long as it does not contradict the gist of the present invention.
For example, various additives can be blended in the thermosetting matrix (A) of the present invention as necessary. Examples of the additive include a curing accelerator.

  Examples of curing accelerators include tertiary amines such as benzyldimethylamine, imidazoles such as 2-ethyl-4-methylimidazole, tertiary phosphines such as triphenylphosphine, and tetrabutylphosphonium bromide. Quaternary ammonium salts such as quaternary phosphonium salts and tetramethylammonium bromide. Any one of these curing accelerators may be used alone, or two or more thereof may be used in any combination and ratio.

  The amount of the curing accelerator used is usually in the range of 0.0001% by weight or more, especially 0.001% by weight or more, and usually 10% by weight or less, especially 5% by weight or less as a ratio to the thermosetting matrix (A). Is preferred. If the amount of curing accelerator used is too small, curing may take too long. On the other hand, if the amount of the curing accelerator used is too large, it may be difficult to control the curing reaction. In addition, when using together 2 or more types of hardening accelerators, those total amounts are made to satisfy | fill the said range.

[I-2. Photoactive compound (B)]
The type of the photoactive compound (B) used in the composition for volume hologram recording material of the present invention is not particularly limited and can be appropriately selected from known compounds. The monomer which has is used. Examples of the polymerizable monomer include a cation polymerizable monomer, an anion polymerizable monomer, and a radical polymerizable monomer.

<I-2-1. Cationic polymerizable monomer>
Examples of the cationic polymerizable monomer include (1) a compound having an oxirane ring, (2) styrene and derivatives thereof, (3) vinyl naphthalene and derivatives thereof, (4) vinyl ethers, (5) N-vinyl compounds, ( 6) A compound having an oxetane ring can be exemplified. Among these, it is preferable to use a compound having at least an oxetane ring, and it is more preferable to use a compound having an oxirane ring together with a compound having an oxetane ring.

  (1) Examples of the compound having an oxirane ring include a prepolymer containing two or more oxirane rings in one molecule. Examples of such prepolymers include cycloaliphatic polyepoxies, polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyhydric alcohols, polyglycidyl ethers of polyoxyalkylene glycols, poly (aromatic polyols). Examples thereof include glycidyl ethers, hydrogenated compounds of polyglycidyl ethers of aromatic polyols, urethane polyepoxy compounds, and epoxidized polybutadienes. Any of these prepolymers may be used alone, or two or more thereof may be used in any combination and ratio.

  (2) Examples of styrene and its derivatives include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-methyl. Examples include styrene.

  (3) Examples of vinylnaphthalene and derivatives thereof include 1-vinylnaphthalene, α-methyl-1-vinylnaphthalene, β-methyl-1-vinylnaphthalene, 4-methyl-1-vinylnaphthalene, 4-methoxy-1 -Vinyl naphthalene etc. are mentioned.

  (4) Examples of vinyl ethers include isobutyl ether, ethyl vinyl ether, phenyl vinyl ether, p-methylphenyl vinyl ether, p-methoxyphenyl vinyl ether, α-methylphenyl vinyl ether, β-methylisobutyl vinyl ether, β-chloroisobutyl vinyl ether, and the like. Can be mentioned.

  (5) Examples of N-vinyl compounds include N-vinylcarbazole, N-vinylpyrrolidone, N-vinylindole, N-vinylpyrrole, N-vinylphenothiazine, N-vinylacetanilide, N-vinylethylacetamide, N- Examples include vinyl succinimide, N-vinyl phthalimide, N-vinyl caprolactam, and N-vinyl imidazole.

  (6) Examples of the compound having an oxetane ring include various known oxetane compounds described in JP-A Nos. 2001-220526 and 2001-310937.

  Any one of the above-exemplified cationic polymerizable monomers may be used alone, or two or more may be used in any combination and ratio.

<I-2-2. Anionic polymerizable monomer>
Examples of anionic polymerizable monomers include hydrocarbon monomers and polar monomers.

  Examples of the hydrocarbon monomer include styrene, α-methylstyrene, butadiene, isoprene, vinyl pyridine, vinyl anthracene, and derivatives thereof.

  Examples of polar monomers include methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, and isopropyl methacrylate; acrylic acid esters such as methyl acrylate and ethyl acrylate; methyl vinyl ketone, isopropyl vinyl ketone, and cyclohexyl vinyl ketone. , Vinyl ketones such as phenyl vinyl ketone; isopropenyl ketones such as methyl isopropenyl ketone and phenyl isopropenyl ketone; other polarities such as acrylonitrile, acrylamide, nitroethylene, methylenemalonate, cyanoacrylate, vinylidene cyanide Monomer; and the like.

  Any one of the above-exemplified anionic polymerizable monomers may be used alone, or two or more thereof may be used in any combination and ratio.

<I-2-3. Radical polymerizable monomer>
Examples of the radical polymerizable monomer include (meth) acrylic acid esters, (meth) acrylamides, vinyl esters, styrenes and the like.

  Examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, (n- or i-) propyl (meth) acrylate, (n-, i-, sec- or t-). Butyl (meth) acrylate, amyl (meth) acrylate, adamantyl (meth) acrylate, chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxypentyl (meth) Acrylate, cyclohexyl (meth) acrylate, allyl (meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, benzyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenze (Meth) acrylate, hydroxybenzyl (meth) acrylate, hydroxyphenethyl (meth) acrylate, dihydroxyphenethyl (meth) acrylate, furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenyl (meth) acrylate, hydroxyphenyl (meth ) Acrylate, chlorophenyl (meth) acrylate, sulfamoylphenyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 2- (hydroxyphenylcarbonyloxy) ethyl (meth) acrylate, and the like.

  Examples of (meth) acrylamides include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-butyl (meth) acrylamide, and N-benzyl. (Meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-phenyl (meth) acrylamide, N-tolyl (meth) acrylamide, N- (hydroxyphenyl) (meth) acrylamide, N- (sulfamoylphenyl) ( (Meth) acrylamide, N- (phenylsulfonyl) (meth) acrylamide, N- (tolylsulfonyl) (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-methyl-N-phenyl (meth) acrylamide, N- Hydroxyethyl-N- Chill (meth) acrylamide.

  Examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate, vinyl benzoate, vinyl t-butyl benzoate, vinyl chlorobenzoate, vinyl 4-ethoxybenzoate, vinyl 4-ethylbenzoate, 4- Examples include vinyl methylbenzoate, vinyl 3-methylbenzoate, vinyl 2-methylbenzoate, vinyl 4-phenylbenzoate, and vinyl pivalate.

  Examples of styrenes include styrene, p-acetylstyrene, p-benzoylstyrene, 2-butoxymethylstyrene, 4-butylstyrene, 4-sec-butylstyrene, 4-tert-butylstyrene, 2-chlorostyrene, 3 -Chlorostyrene, 4-chlorostyrene, dichlorostyrene, 2,4-diisopropylstyrene, dimethylstyrene, p-ethoxystyrene, 2-ethylstyrene, 2-methoxystyrene, 4-methoxystyrene, 2-methylstyrene, 3-methyl Examples thereof include styrene, 4-methylstyrene, p-methylstyrene, p-phenoxystyrene, p-phenylstyrene, and the like.

  Any one of the radically polymerizable monomers exemplified above may be used alone, or two or more thereof may be used in any combination and ratio.

<I-2-4. Other>
Any one of the above-exemplified cationically polymerizable monomers, anionic polymerizable monomers, and radically polymerizable monomers may be used alone, or two or more of them may be used in combination in any combination and ratio. . However, since it is difficult to inhibit the reaction between the epoxy forming the matrix and the epoxy curing agent, it is preferable to use a radical polymerizable monomer as the photoactive compound (B).

[I-3. Mixing ratio of thermosetting matrix (A) and photoactive compound (B)]
The amount of the thermosetting matrix (A) used is usually 10 parts by weight or more, especially 100 parts by weight or more, more preferably 200 parts by weight or more, especially 300 parts by weight, when the photoactive compound (B) is 100 parts by weight. In addition, the range is usually 5000 parts by weight or less, particularly 2000 parts by weight or less, and more preferably 1500 parts by weight or less. If the amount of the thermosetting matrix (A) used is too large, the change in the refractive index is small and the recording efficiency may be low. On the other hand, if the amount of the thermosetting matrix (A) used is too small, a large amount of unreacted photoactive compound remains and causes bleed out when stored as a recording material for a long period of time. It may become.

[I-4. Other ingredients]
The composition for volume hologram recording material of the present invention may contain other components in addition to the above-mentioned thermosetting matrix (A) and photoactive compound (B) as long as it does not contradict the gist of the present invention. Good.
For example, the composition for volume hologram recording material of the present invention is blended with optional additives as necessary for controlling the excitation wavelength and excitation energy of the photoactive compound (B), controlling the reaction, improving the characteristics, etc. can do.

Examples of the additive include the following compounds.
Examples of the compound that controls excitation of the sensitizer include a sensitization aid.
Examples of the compound used for controlling the reaction include a polymerization initiator, a chain transfer agent, a polymerization terminator, a compatibilizing agent, a reaction aid and the like.
Other examples of additives that may be required for improving properties include dispersants, antifoaming agents, plasticizers, preservatives, and stabilizers.
Any one of these additives may be used alone, or two or more thereof may be used in any combination and ratio.

  The amount of the additive used is usually 0.001% by weight or more, particularly 0.01% by weight or more, and usually 30% by weight or less, especially 10% by weight or less, based on the ratio to the composition for volume hologram recording material of the present invention. It is preferable to set it as the range. When two or more additives are used in combination, the total amount thereof is set to satisfy the above range.

  In particular, examples of suitable additives when the photoactive compound (B) is a radical polymerizable monomer include a polymerization initiator and a sensitizer. These will be described in detail below.

<I-4-1. Polymerization initiator>
As the polymerization initiator, any known radical photopolymerization initiator can be used. Examples include azo compounds, azide compounds, organic peroxides, organoborates, onium salts, bisimidazole derivatives, titanocene compounds, iodonium salts, organic thiol compounds, halogenated hydrocarbon derivatives, and the like. Any of these may be used alone, or two or more of these may be used in any combination and ratio. Among these, as the polymerization initiator, a titanocene compound is preferable because a polymerization reaction occurs with visible light.

  When a titanocene compound is used as a polymerization initiator, the kind thereof is not particularly limited. For example, among various titanocene compounds described in JP-A Nos. 59-152396 and 61-151197, etc. Can be selected and used as appropriate.

  Specific examples of the titanocene compound include di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, and di-cyclopentadienyl-Ti-bis-2,3,4. , 5,6-pentafluorophen-1-yl, dicyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophen-1-yl, di-cyclopentadienyl-Ti-bis- 2,4,6-trifluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2,6-di-fluorophen-1-yl, di-cyclopentadienyl-Ti-bis-2 , 4-di-fluorophen-1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophen-1-yl, di-methylcyclopentadienyl- T -Bis-2,3,5,6-tetrafluorophen-1-yl, -methylcyclopentadienyl-Ti-bis-2,6-difluorophen-1-yl, di-cyclopentadienyl-Ti- Bis-2,6-difluoro-3- (pyrid-1-yl) -phen-1-yl and the like can be mentioned.

  In particular, since di-cyclopentadienyl-Ti-bis-2,6-difluoro-3- (pyridin-1-yl) -phen-1-yl has absorption up to about 550 nm, an argon ion laser is used as a light source. (488 nm) and FD-Nd / YAG laser (532 nm) can be used, and since it is highly versatile, it is preferably used as a polymerization initiator.

  Any one of the various polymerization initiators described above may be used alone, or two or more thereof may be used in any combination and ratio.

  The amount of the polymerization initiator used is usually 0.1% by weight or more, particularly 0.5% by weight or more, and usually 10% by weight or less, especially 5% by weight based on the total solid content of the composition for volume hologram recording material. % Or less is preferable. If the amount of the polymerization initiator used is too small, the amount of radicals generated will be small, so that the rate of photopolymerization will be slow and the hologram recording sensitivity may be low. On the other hand, if the polymerization initiator is used in an excessive amount, radicals generated by light irradiation recombine with each other or disproportionate, so that the contribution to photopolymerization is reduced, and the hologram recording sensitivity is also lowered. There is a case. When two or more polymerization initiators are used in combination, the total amount thereof satisfies the above range.

<I-4-2. Sensitizer>
As a sensitizer, it can select arbitrarily from well-known various sensitizers, and can use it. Among these, specific examples of preferred sensitizers include the following compounds.

2,6-diethyl-1,3,5,7,8-pentamethylpyromethene-BF2 complex, 1,3,5,7,8-pentamethyl described in JP-A-5-241338 A pyromethene complex such as a pyromethene-BF2 complex;
Xanthene dyes such as eosin, ethyl eosin, erythrosine, fluorescein, rose bengal;
1- (1-Methylnaphtho [1,2-d] thiazole-2 (1H) -ylidene-4- (2,3,6,7) tetrahydro-1H described in JP-A-2-69 , 5H-benzo [ij] quinolizin-9-yl) -3-buten-2-one, and 1- (3-methylbenzothiazol-2 (3H) -ylidene-4- (p-dimethylaminophenyl) -3 A ketothiazoline compound such as buten-2-one;
2- (p-dimethylaminostyryl) -naphtho [1,2-d] thiazole, 2- [4- (p-) described in JP-B-2-55446, JP-B-2-30321, and the like. Styryl or phenylbutadienyl heterocyclic compounds such as dimethylaminophenyl) -1,3-butadienyl] -naphtho [1,2-d] thiazole;
2,4-diphenyl-6- (p-dimethylaminostyryl) -1,3,5-triazine and 2,4-diphenyl-6-(([2,3,6,7] tetrahydro-1H, 5H- Triazine compounds such as benzo [ij] quinolizin-9-yl) -1-ethen-2-yl) -1,3,5-triazine;
Nanthryl-(([2,3,6,7] tetrahydro-1H, 5H-benzo [ij] quinolidine-9-, as described in JP-A-6-116313, JP-A-47-2528, and the like. Yl) -1-ethen-2-yl) ketone, aminophenyl unsaturated ketone compounds such as 2,5-bis (p-dimethylaminocinnamylidene) cyclopentanone;
Porphyrins such as 5,10,15,20 tetraphenylporphyrin and hematoporphyrin.

  Any of the various sensitizers exemplified above may be used alone, or two or more may be used in any combination and ratio.

  In general, as a sensitizer, a colored compound such as a dye as described above is often used to absorb visible laser light, but the final hologram optical recording medium is required to be colorless and transparent. In some cases, it is preferable to use a cyanine dye as a sensitizer. Since cyanine dyes are generally easily decomposed by light, post-exposure is performed, that is, by leaving them for several hours to several days under room light or sunlight, the cyanine dyes in the volume hologram recording material are decomposed. A colorless and transparent holographic optical recording medium is obtained which has no absorption in the visible range.

  Specific examples of the cyanine dye include anhydro-3,3′-dicarboxyxymethyl-9-ethyl-2,2′thiacarbocyanine betaine, anhydro-3-carboxymethyl-3 ′, 9-diethyl-2,2 'Thiacarbocyanine betaine, 3,3', 9-triethyl-2,2'-thiacarbocyanine iodine salt, 3,9-diethyl-3'-carboxymethyl-2,2'-thiacarbocyanine iodine salt 3,3 ′, 9-triethyl-2,2 ′-(4,5,4 ′, 5′-dibenzo) thiacarbocyanine iodine salt, 2- [3- (3-ethyl-2-benzothiazolidine) -1-propenyl] -6- [2- (3-ethyl-2-benzothiazolidine) ethylideneimino] -3-ethyl-1,3,5-thiadiazolium iodine salt, 2-[[3-allyl 4-oxo-5- (3-n-propyl-5,6-dimethyl-2-benzothiazolidine) -ethylidene-2-thiazolidine] methyl] 3-ethyl-4,5-diphenylthiazolinium iodine salt, 1 , 1 ′, 3,3,3 ′, 3′-hexamethyl-2,2′-indotricarbocyanine / iodine salt, 3,3′-diethyl-2,2′-thiatricarbocyanine / perchlorate Anhydro-1-ethyl-4-methoxy-3′-carboxymethyl-5′-chloro-2,2′-quinothiaciamine betaine, anhydro-5,5′-diphenyl-9-ethyl-3,3 ′ -Disulfopropyloxacarbocyanine hydroxide triethylamine salt, 2- [3- (3-ethyl-2-benzothiazolidine) -1-propenyl] -6- [2- (3-ethyl-2- Down zone thiazolidine) ethylidene imino] -3-ethyl-1,3,5-thiadiazolium-iodine salt and the like. Any of these cyanine dyes may be used alone, or two or more thereof may be used in any combination and ratio.

  The amount of the sensitizer needs to be increased or decreased depending on the thickness of the layer containing the volume hologram recording material of the present invention, but is usually 0.01% by weight or more, particularly 0.1% by weight with respect to the polymerization initiator. In addition, it is usually preferably 10% by weight or less, particularly preferably 5% by weight or less. If the amount of the sensitizer used is too small, the initiator efficiency is reduced, and recording may take a long time. On the other hand, if the amount of the sensitizer used is too large, the absorption of light used for recording and reproduction increases, which may make it difficult for light to reach in the depth direction. When two or more sensitizers are used in combination, the total amount thereof should satisfy the above range.

[I-5. Others]
As described above, the composition for volume hologram recording material of the present invention has the effect of low hygroscopicity and excellent storage stability. The reason is not clear, but is presumed as follows. That is, the C4 or higher polyether (A1) contained in the composition for volume hologram recording material has a lower molecular polarity than a polyether composed only of C2 and C3, so that the hydrophilicity can be lowered. It is presumed that the storage stability is improved because the polymerization property can be prevented and the polymerization initiator and the like can be prevented from being broken by moisture.

[I-6. (Use)
The composition for volume hologram recording material of the present invention is used for a volume hologram recording material. Thereby, the characteristics (characteristics such as low hygroscopicity and excellent storage stability) possessed by the composition for volume hologram recording material of the present invention can be effectively utilized. The volume hologram recording material using the composition for volume hologram recording material of the present invention is hereinafter referred to as “volume hologram recording material of the present invention”.

  The volume hologram recording material of the present invention may consist only of the composition for volume hologram recording material of the present invention, and may contain other components. Although there is no restriction | limiting in particular in another component, As an example, various additives, such as a light dispersing agent and a coloring material, are mentioned. The content of other components is arbitrary as long as the effects of the present invention are not significantly impaired.

[II. Volume hologram optical recording medium]
The volume hologram optical recording medium of the present invention comprises at least a layer containing the volume hologram recording material of the present invention described above. The layer containing the volume hologram recording material of the present invention is arbitrary, but is usually a layer on which information is recorded (this is referred to as “recording layer”). There is no restriction | limiting in the other specific structure in the volume hologram optical recording medium of this invention, It is arbitrary. Hereinafter, a volume hologram optical recording medium according to an embodiment of the present invention (this may be referred to as “optical recording medium of the present embodiment”) will be described in detail.

  The optical recording medium of this embodiment is configured to include at least a recording layer formed using the volume hologram recording material of the present invention. Further, the optical recording medium of the present embodiment includes a support and other layers as necessary.

[II-1. (Recording layer)
The recording layer is a layer on which information is recorded. Information is usually recorded as a hologram. In the optical recording medium of this embodiment, the recording layer is not particularly limited as long as it is formed using the volume hologram recording material of the present invention.

  The thickness of the recording layer is not particularly limited and may be appropriately determined in consideration of the recording method and the like. Generally, it is usually 1 μm or more, preferably 10 μm or more, and usually 1 cm or less, preferably 2000 μm or less. It is a range. If the recording layer is too thick, the selectivity of each hologram is lowered during multiplex recording on the optical recording medium, and the degree of multiplex recording may be reduced. If the recording layer is too thin, it is difficult to uniformly form the entire recording layer, and it may be difficult to perform multiplex recording with uniform diffraction efficiency of each hologram and a high S / N ratio.

[II-2. (Support)
Usually, the optical recording medium has a support, and the recording layer and other layers are laminated on the support to constitute the optical recording medium. However, when the recording layer or other layers have the necessary strength and durability, the optical recording medium may not have a support.
The support is not particularly limited in detail as long as it has the required strength and durability, and any support can be used.
Specifically, although there is no restriction | limiting in the shape of a support body, Usually, it forms in flat form or a film form.

Moreover, there is no restriction | limiting in the material which comprises a support body, Transparent or opaque may be sufficient.
As a material for the support, transparent materials include organic materials such as acrylic, polyethylene terephthalate film, polyethylene naphthoate, polycarbonate, polyethylene, polystyrene, and cellulose acetate; and inorganic materials such as glass, silicon, and quartz. Among these, polycarbonate, acrylic, polyester, glass and the like are preferable, and acrylic, polycarbonate, and glass are particularly preferable.

  On the other hand, if the material of the support is opaque, a metal such as aluminum; a metal such as gold, silver or aluminum, or a dielectric such as magnesium fluoride or zirconium oxide is coated on the transparent support. And the like.

  Although there is no restriction | limiting in particular also in the thickness of a support body, Usually, it is preferable to set it as the range of 0.1 mm or more and 1 mm or less. If the support is too thin, the mechanical strength of the optical recording medium may be insufficient, and if it is too thick, the cost may increase.

  Moreover, you may surface-treat on the surface of a support body. This surface treatment is usually performed to improve the adhesion between the support and the recording layer. Examples of the surface treatment include subjecting the support to corona discharge treatment or forming an undercoat layer on the support in advance. Here, examples of the composition of the undercoat layer include halogenated phenols and partially hydrolyzed vinyl chloride-vinyl acetate copolymers.

  Furthermore, the surface treatment may be performed for purposes other than the improvement of adhesiveness. Examples thereof include a reflective coating treatment for forming a reflective coating layer made of a metal such as gold, silver, and aluminum; a dielectric coating treatment for forming a dielectric layer such as magnesium fluoride and zirconium oxide, and the like. It is done. These layers may be formed as a single layer or two or more layers.

  Further, the support may be provided only on either the upper side or the lower side of the recording layer of the optical recording medium of the present invention, or may be provided on both. However, when providing a support on both the upper and lower sides of the recording layer, at least one of the supports is configured to be transparent so as to transmit active energy rays (excitation light, reference light, reproduction light, etc.).

  In the case of an optical recording medium having a transparent support on one side or both sides of the recording layer, a transmissive or reflective hologram can be recorded. When a support having reflection characteristics on one side is used, a reflection type hologram can be recorded.

  Furthermore, patterning for data addresses may be provided on the support. Although there is no restriction | limiting in the patterning method, For example, an unevenness | corrugation may be formed in support body itself, a pattern may be formed in a reflective layer (after-mentioned), and you may form by the method of combining these.

[II-3. Other layers]
In addition to the recording layer and the support described above, other layers may be provided on the optical recording medium of the present embodiment. Examples of other layers include a protective layer, a reflective layer, an antireflection layer (antireflection film), and the like.

  The protective layer is a layer for preventing adverse effects such as a decrease in sensitivity due to oxygen and deterioration in storage stability. There is no restriction | limiting in the specific structure of a protective layer, It is possible to apply a well-known thing arbitrarily. For example, a layer made of a water-soluble polymer or the like can be formed as a protective layer.

  The reflective layer is formed when the optical recording medium is configured to be reflective. In the case of a reflective optical recording medium, the reflective layer may be formed between the support and the recording layer, or may be formed on the outer surface of the support. Usually, the support and the recording layer are used. It is preferable to be between.

  Further, in any of the transmission type and reflection type optical recording media, an antireflection film may be provided on the side on which recording light and readout light enter and exit, or between the recording layer and the support. The antireflection film functions to improve light utilization efficiency and suppress the generation of ghost images.

[II-4. Production method〕
There is no particular limitation on the method of manufacturing the optical recording medium of the present embodiment, and it can be manufactured by any method. As an example, the volume hologram recording material of the present invention can be produced by applying a solvent-free material on a support to form a recording layer. At this time, any method can be used as a coating method. Specific examples include spray method, spin coating method, wire bar method, dip method, air knife coating method, roll coating method, blade coating method, doctor roll coating method and the like.

  In addition, when forming a recording layer having a particularly large film thickness, a method of molding the volume hologram recording material of the present invention into a mold, or a method of coating on a release film and punching the mold, A recording layer can also be formed.

  Further, the volume hologram recording material of the present invention may be mixed with a solvent to prepare a coating solution, which may be coated on a support and dried to form a recording layer. Also in this case, any method can be used as a coating method. As an example, a method similar to the above-described coating method may be mentioned.

  Also, the type of solvent is not particularly limited, but usually a solvent that has sufficient solubility for the components used, gives good coating properties, and does not attack a support such as a resin substrate is used. It is preferable.

  Examples of solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and methyl amyl ketone; aromatic solvents such as toluene and xylene; methanol, ethanol, propanol, n-butanol, heptanol, hexanol, Alcohol solvents such as diacetone alcohol and furfuryl alcohol; ketone alcohol solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone; ether solvents such as tetrahydrofuran and dioxane; dichloromethane, dichloroethane and chloroform Halogen solvents of: Cellosolve solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate; Propylene glycol solvents such as methyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol dimethyl ether; ethyl acetate, butyl acetate, Amyl acetate, butyl acetate, ethylene glycol diacetate, diethyl oxalate, ethyl pyruvate, ethyl-2-hydroxybutyrate ethyl acetoacetate, methyl lactate, ethyl lactate, methyl 2-hydroxyisobutyrate, methyl 3-methoxypropionate, etc. Ester solvents: tetrafluoropropanol, octafluoropentanol, hexafluo Perfluoroalkyl alcohol solvents such as butanol; highly polar solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone and dimethylsulfoxide; chain hydrocarbon solvents such as n-hexane and n-octane; cyclohexane, methylcyclohexane, Examples thereof include cyclic hydrocarbon solvents such as ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, tert-butylcyclohexane and cyclooctane; or a mixed solvent thereof.

  In addition, any one of these solvents may be used alone, or two or more thereof may be used in any combination and ratio.

  Moreover, there is no restriction | limiting in particular also in the usage-amount of a solvent. However, it is preferable to adjust the amount of the solvent used so that the solid content concentration of the coating solution is about 1% by weight or more and 1000% by weight or less from the viewpoints of coating efficiency and handleability.

  Furthermore, when the volume hologram recording material of the present invention has a small amount of volatile components, the volume hologram recording material of the present invention can be produced by molding by, for example, an injection molding method or a hot press method. In this case, when the molded body has sufficient thickness, rigidity, strength, etc., the molded body can be used as it is as the optical recording medium of the present embodiment.

  The recording layer made of the volume hologram recording material of the present invention is formed by molding the thermosetting matrix (A) described above into a desired shape and then impregnating with the photoactive compound (B) or other additives. May be produced.

  The optical recording medium of the present embodiment manufactured by the above procedure can take the form of a self-supporting slab or a disk, and can be used for applications such as a three-dimensional image display device, a diffractive optical element, and a large capacity memory.

[II-5. (Recording / playback method)
Both writing (recording) and reading (reproducing) information on the optical recording medium of the present embodiment are performed by light irradiation.

  First, when recording information, light that can cause a chemical change of the photoactive compound (B) (for example, polymerization and concentration change when the photoactive compound (B) is a polymerizable monomer) is recorded. Used as light (also called object light). In particular, in the optical recording medium of this embodiment, in order to record information as a volume hologram, the recording light is irradiated onto the recording layer together with the reference light so that the recording light and the reference light interfere with each other in the recording layer. As a result, the interference light causes a change in the photoactive compound (B) in the recording layer (for example, when the photoactive compound (B) is a polymerizable monomer, its polymerization and concentration change), resulting in interference. The fringes cause a refractive index difference in the recording layer, and the interference fringes recorded in the recording layer record the hologram on the recording layer.

  On the other hand, when reproducing the volume hologram recorded on the recording layer, the recording layer is irradiated with predetermined reproduction light (usually reference light). The irradiated reproduction light is diffracted according to the interference fringes. Since the diffracted light contains the same information as the recording layer, the information recorded on the recording layer can be reproduced by reading the diffracted light with an appropriate detection means.

Note that the wavelength range of the recording light, the reproduction light, and the reference light is arbitrary depending on each application, and may be the visible light region or the ultraviolet region. Among these lights, for example, solid lasers such as ruby, glass, Nd-YAG, and Nd-YVO ₄ ; diode lasers such as GaAs and InGaAs; helium-neon, argon, krypton, excimer, CO ₂ Gas lasers, etc .; lasers excellent in monochromaticity and directivity, such as dye lasers having pigments.

Further, there is no limitation on the irradiation amount of the recording light, the reproduction light, and the reference light, and the irradiation amount is arbitrary as long as the recording and reproduction can be performed. However, if the amount is extremely small, the chemical change of the photoactive compound (B) may be incomplete, and the heat resistance and mechanical properties of the recording layer may not be sufficiently expressed. The component (volume hologram recording material of the present invention) may be deteriorated. Therefore, the recording light, the reproducing light and the reference light are usually 0.1 J / cm ² in accordance with the composition of the volume hologram recording material of the present invention used for forming the recording layer, the kind and blending amount of the polymerization initiator, and the like. As described above, irradiation is performed in a range of 20 J / cm ² or less.

EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.
In the following description, “parts” refers to parts by weight unless otherwise specified.

[Synthesis Example 1]
A 1 L glassy flask equipped with a stirrer, a dropping funnel and a thermometer was charged with 250 parts of polytetramethylene glycol having a number average molecular weight of 1000 heated to 45 ° C. and 1 part of boron trifluoride ethyl ether, and heated to 80 ° C. did. 51 parts of epichlorohydrin (1.1 equivalents per hydroxyl group of diol) was added dropwise while adjusting so that the temperature during dropping and aging did not exceed 85 ° C., and after aging for 1 hour, the mixture was cooled to 40 ° C. 80 parts of 50% aqueous sodium hydroxide solution was added, heated to 70 ° C. and stirred for 4 hours. After cooling to 50 ° C., methyl isobutyl ketone was added, washed with water, desolvated, dehydrated and filtered. As a result, a colorless and transparent polyether glycol diglycidyl ether having an epoxy equivalent of 480 g / eq was obtained. This is hereinafter referred to as “PTMG-epoxy”.

[Synthesis Example 2]
The synthesis was performed in the same procedure as in Synthesis Example 1 except that polytetramethylene glycol having a number average molecular weight of 1000 used in Synthesis Example 1 was replaced with polypropylene glycol having a number average molecular weight of 1000. As a result, a colorless and transparent polyether glycol diglycidyl ether having an epoxy equivalent of 480 g / eq was obtained. This is hereinafter referred to as “PPG-epoxy”.

[Example 1]
<Formation of matrix>
As the polyether (A1), PTMG-epoxy obtained in [Synthesis Example 1] was used. This PTMG-epoxy 3.0 g was mixed with 0.09 g of a cationic initiator (Sun Shine SI-60 manufactured by Sanshin Chemical Co., Ltd.) as a curing agent (A2), and placed in a 30 cm ² Teflon (registered trademark) container. A film-like thermosetting matrix (hereinafter abbreviated as “matrix” where appropriate) having a thickness of 1 mm was prepared by heating to 0 ° C. for 5 hours to cure.

<Impregnation with photoactive compounds, etc.>
3.0 g of methyl methacrylate as the photoactive compound (B) and di-cyclopentadienyl-Ti-bis-2,6-difluoro-3- (pyridin-1-yl) -phen-1- as the initiator A solution consisting of 0.06 g of Ir (IRGACURE 784 manufactured by Ciba Specialty Chemicals) was prepared. The obtained solution was put into a container containing the above-mentioned membrane matrix and impregnated into the matrix at room temperature. Ten hours later, the matrix was taken out and weighed, and it was 3.86 g. By the above procedure, a volume hologram recording material in which a matrix was impregnated with 20% by weight of methyl methacrylate and an initiator (IRGACURE784) was obtained.

<Hygroscopic test>
The above-mentioned volume hologram recording material was allowed to stand for 1 day or 10 days in an environment of humidity 60 MH% and temperature 40 ° C. to obtain a sample for use in hologram recording described later. These are hereinafter referred to as “one-day sample” and “10-day sample”, respectively.

<Hologram recording>
Using the volume hologram recording material samples described above (samples left for 1 day and samples left for 10 days), hologram recording was performed according to the procedure described below, and whether or not recording was possible was determined.

  An outline of the apparatus used for hologram recording is shown in FIG. 1, S represents a sample of volume hologram recording material, M1 to M3 all represent mirrors, PBS represents a polarizing beam splitter, L1 represents a laser light source for recording light that emits light having a wavelength of 532 nm, and L2 Indicates a laser light source for reproducing light that emits light having a wavelength of 633 nm, and PD1 and PD2 indicate photodetectors.

As a light source for holographic recording, an Nd: YVO ₄ crystal was excited by a diode, and a light of 532 nm was obtained using a nonlinear optical crystal LBO (Verdi-V2 manufactured by Coherent: “L1” in the figure). . The light of 532 nm was divided by a polarizing beam splitter (“PBS” in the figure) and crossed on the recording surface so that the angle formed by the two beams was 50.00 degrees. At this time, the bisector of the angle formed by the two beams is perpendicular to the recording surface, and the vibration planes of the electric field vectors of the two beams obtained by the division are two intersecting lines. Irradiation was carried out so as to be parallel to the plane including the beam. After holographic recording, using a He-Ne laser that can obtain 633 nm light (Melesgrio V05-LHP151: “L2” in the figure), the light is irradiated at an angle of 30.19 degrees with respect to the recording surface. Whether or not hologram recording is correctly performed by detecting the diffracted light using a power meter and a detector (2930-C, 918-SL manufactured by Newport Co., Ltd .: “PD1” and “PD2” in the figure). It was judged. The diffraction efficiency of a hologram is given by the ratio of the intensity of diffracted light to the intensity of incident light.

[Comparative Example 1]
Except that the PTMG-epoxy used in Example 1 was replaced with the PPG-epoxy obtained in [Synthesis Example 2] above, formation of a matrix, impregnation with a photoactive compound, and the like were performed in the same procedure as in Example 1. A moisture absorption test and hologram recording were performed.

[Evaluation]
The results of Example 1 and Comparative Example 1 are shown in Table 1 below.

  As shown in Table 1, the volume hologram recording material of Example 1 was able to record holograms for both the 1-day sample and the 10-day sample, whereas the volume hologram recording material of Comparative Example 1 was left for 1 day. Hologram recording was possible with the sample, but hologram recording was not possible with the sample left for 10 days. Therefore, Example 1 using PTMG-epoxy, which is a polyether having an alkylene oxide chain having 4 carbon atoms, is a polyether having an alkylene oxide chain having less than 4 carbon atoms, PPG-epoxy. It was found that the volume hologram recording material was superior in hydrophobicity to Comparative Example 1 used.

  The composition for volume hologram recording material of the present invention and the volume hologram recording material using the composition are suitably used for applications such as a volume hologram optical recording medium.

It is a figure for demonstrating the outline | summary of the apparatus used for the hologram recording in an Example.

Explanation of symbols

S Sample M1 to M3 Mirror PBS Polarizing beam splitter L1 Laser light source for recording light L2 Laser light source for reproduction light PD1, PD2 Photo detector

Claims (9)

A thermosetting matrix (A) containing a polyether (A1) having two or more epoxy groups in one molecule and an alkylene oxide chain having 4 or more carbon atoms, and a curing agent (A2); A composition for a volume hologram recording material, comprising a photoactive compound (B). The composition for a volume hologram recording material according to claim 1, wherein the alkylene oxide chain of the polyether (A1) has 4 to 10 carbon atoms. The volume according to claim 1 or 2, wherein a ratio of the thermosetting matrix (A) to 100 parts by weight of the photoactive compound (B) is 10 parts by weight or more and 5000 parts by weight or less. Composition for hologram recording material. 4. The volume hologram recording material composition according to claim 1, wherein the polyether (A1) has a number average molecular weight of 200 or more and 50000 or less. The curing agent (A2) is at least one selected from the group consisting of amines, acid anhydrides, thiols, anionic polymerization initiators, and cationic polymerization initiators. The composition for volume hologram recording materials according to any one of the above. The composition for volume hologram recording material according to claim 1, wherein the photoactive compound (B) is a radical polymerizable monomer. A volume hologram recording material comprising at least the composition for volume hologram recording material according to any one of claims 1 to 6. A volume hologram optical recording medium comprising at least a layer containing the volume hologram recording material according to claim 7. The volume hologram optical recording medium according to claim 8, wherein the layer is irradiated with excitation light and reference light, and volume hologram recording is performed on the layer by interference between the excitation light and the reference light. Volume hologram optical recording method.

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