JP2013167873A - Composition for hologram recording medium and hologram recording medium using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for hologram recording medium that has excellent registration properties, reduces a change of recording performance due to its storage, and has excellent storage stability, and a hologram recording medium using the same.SOLUTION: A composition for hologram recording medium contains a compound having an isocyanate group, a compound having an isocyanate reactive functional group, a polymerizable monomer, an oxime ester photopolymerization initiator having a condensed ring, and a zirconium-based catalyst.

Description

  The present invention relates to a composition for a hologram recording medium and a hologram recording medium using the same.

2. Description of the Related Art In recent years, a hologram type optical recording medium that records information as a hologram by changing the refractive index of the recording layer according to the light intensity distribution due to the interference of light toward further increase in capacity and density of the optical recording medium. Has been developed.
Among them, a hologram whose film thickness is sufficiently thick with respect to the interference fringe interval (usually having a film thickness of about 5 times the interference fringe interval or about 1 μm or more) is called a volume hologram. In addition, since the one where a film thickness is larger can perform recording in the film thickness direction, recording at a high density is possible. As an example of a known volume hologram recording material, there is a write-once type that does not require wet treatment or bleaching treatment, and its composition is generally a resin matrix in which a photoactive compound is compatible. For example, there is a photopolymer method in which a resin matrix is combined with a monomer capable of radical polymerization or cationic polymerization as a photoactive compound (see, for example, Patent Document 1).

  At the time of recording information in hologram recording, when object light and reference light are irradiated, interference fringes composed of a bright part and a dark part are formed on the recording layer. For example, when the photoactive compound is a radical polymerizable compound, in the bright part, the photopolymerization initiator absorbs light, becomes a radical active species, and polymerization of the radical polymerizable compound occurs. As radical polymerization proceeds, a concentration gradient of the radical polymerizable compound is produced in the light and dark portions. This concentration gradient causes the radical polymerizable compound to diffuse from the dark part to the bright part, and the bright part and the dark part are composed of different chemical species and have different refractive indexes. The hologram recording medium holds this refractive index difference as information.

  The photopolymer method is a practical and promising method that can achieve both high diffraction efficiency and dry processing, but has high sensitivity, sufficient diffraction efficiency, high S / N ratio, and high multiplicity. A composition to be achieved is demanded, and further, a hologram recording medium having excellent stability and reliability is desired. In order to achieve these, various studies have been made on the composition of the hologram recording composition and the method of producing the hologram recording medium.

  For example, in Patent Document 2, by optimizing the chain length and structure in the three-dimensional crosslinked matrix (resin matrix) structure, without sacrificing the compatibility of the matrix polymer and the writing monomer (photoactive compound), It is described that it enables a better contrast ratio and improved brightness of the hologram.

JP 11-352303 A JP 2010-84147 A

However, according to the study by the present inventors, when the tin (Sn) -based curing catalyst described in Patent Documents 1 and 2 is used as the matrix curing catalyst, the Zr catalyst described in Patent Document 2 is used. Even in such a case, it has been found that further improvement in recording characteristics and storage stability (shelf life) of the hologram recording medium is necessary during storage of the hologram recording medium.
In view of the above, the problems of the present invention are excellent in recording characteristics, less change in recording characteristics due to storage,
An object of the present invention is to provide a composition for a hologram recording medium excellent in storage stability and a hologram recording medium using the same.

As a result of intensive studies by the present inventors, a combination of a zirconium-based catalyst and an oxime ester-based photopolymerization initiator having a condensed ring provides excellent recording characteristics and little change in recording characteristics due to storage. It discovered that it could be set as the composition for media.
The gist of the present invention is characterized by containing a compound having an isocyanate group, a compound having an isocyanate-reactive functional group, a polymerizable monomer, an oxime ester photopolymerization initiator having a condensed ring, and a zirconium catalyst. And a composition for a hologram recording medium.

The polymerizable monomer is preferably a radical polymerizable monomer. The molecular weight of the polymerizable monomer is preferably 300 or more.
Another gist of the present invention resides in a hologram recording medium characterized by using the above-mentioned composition for a hologram recording medium in a recording layer.

  According to the present invention, a composition for a hologram recording medium and a hologram recording medium using the composition can be excellent in recording characteristics and storage stability.

In Example 1, 2, and the comparative example 1, it is a schematic diagram which shows the outline | summary of the structure of the apparatus used for hologram recording, (a) A figure shows the whole apparatus, (b) The figure shows the surface of an LED unit. The figure shown and (c) figure are figures which show the arrangement | sequence of LED.

The items and methods exemplified below are examples (representative examples) of embodiments of the present invention, and the present invention is not specified in these contents unless departing from the gist thereof.
1. Composition for hologram recording medium Composition for hologram recording medium of the present invention,
(1) Compound having an isocyanate group (hereinafter sometimes referred to as “component (1)”),
(2) a compound having an isocyanate-reactive functional group (hereinafter sometimes referred to as “component (2)”),
(3) a polymerizable monomer (hereinafter sometimes referred to as “component (3)”),
(4) an oxime ester-based photopolymerization initiator having a condensed ring (hereinafter sometimes referred to as “component (4)”),
(5) A zirconium-based catalyst (hereinafter sometimes referred to as “component (5)”) is contained.
Each will be described below.

1-1. Compound having an isocyanate group The compound having an isocyanate group reacts with a compound having an isocyanate-reactive functional group (component (2)) in the presence of a zirconium-based catalyst (component (5)) described later to form a resin matrix. To do.

The ratio of the isocyanate group in the molecule of the compound having an isocyanate group is preferably 50% by mass or less, more preferably 47% by mass or less, and further preferably 45% by mass or less. Moreover, it is 0.1 mass% or more normally, Preferably it is 1 mass% or more. When the ratio of isocyanate groups is less than the above upper limit, turbidity is less likely to occur when a hologram recording medium is produced, and optical uniformity is obtained. Further, when the ratio is larger than the lower limit, the hardness of the resin matrix and the glass transition temperature are increased, and the loss of recording can be prevented. The ratio of the isocyanate group in this invention shows the ratio of the isocyanate group in the whole compound which has an isocyanate group to be used.

The ratio of the isocyanate group in the compound having an isocyanate group can be obtained from the following formula.
42 (molecular weight of isocyanate group) × number of isocyanate groups / molecular weight of compound having isocyanate groups × 100
There is no restriction | limiting in particular in the kind of compound which has an isocyanate group, For example, it may have an aromatic, araliphatic, aliphatic, or alicyclic frame | skeleton. Moreover, the compound which has an isocyanate group may have one isocyanate group in a molecule | numerator, and may have two or more, but it is preferable to have two or more. A compound having two or more isocyanate groups in the molecule and a compound having three or more isocyanate-reactive functional groups in the molecule, or a compound having three or more isocyanate groups in the molecule and two or more in the molecule According to the three-dimensional cross-linked matrix obtained from a compound having an isocyanate-reactive functional group, a recording layer having excellent record retention can be obtained.

  Examples of the compound having an isocyanate group include isocyanate, butyl isocyanate, octyl isocyanate, butyl diisocyanate, hexyl diisocyanate (HMDI), isophorodiisocyanate (IPDI), 1,8-diisocyanato-4- (isocyanato). Methyl) octane, 2,2,4- and / or 2,4,4-trimethylhexamethylene diisocyanate, isomeric bis (4,4'-isocyanatocyclohexyl) methane and mixtures thereof having any desired isomeric content , Isocyanatomethyl-1,8-octane diisocyanate, 1,4-cyclohexylene diisocyanate, isomer cyclohexane dimethylene diisocyanate, 1,4-phenylene diisocyanate, 2,4- and / or 2,6-toluene diisocyanate , 1,5 Nafure Ji diisocyanate, 2,4'- or 4,4'-diphenylmethane diisocyanate and / or triphenylmethane 4,4 ', 4' '- such as triisocyanate.

It is also possible to use an isocyanate derivative having a urethane, urea, carbodiimied, acrylic urea, isocyanurate, allophanate, biuret, oxadiazinetrione, uretdione and / or iminooxadiazinedione structure. Any of these may be used alone, or two or more of these may be used in any combination and ratio.
Of these, aliphatic ones are preferred because they are difficult to color.

1-2. Compound having an isocyanate-reactive functional group The compound having an isocyanate-reactive functional group in the present invention is a compound having an active hydrogen (isocyanate-reactive functional group) involved in a chain extension reaction with a compound having an isocyanate group. is there. Examples of the isocyanate-reactive functional group include a hydroxyl group, an amino group, and a mercapto group. The compound having an isocyanate-reactive functional group may have one isocyanate-reactive functional group in the molecule, or may have two or more, but preferably has two or more. In addition, when it has two or more isocyanate-reactive functional groups, the number of isocyanate-reactive functional groups contained in one molecule may be one or more. The average molecular weight of the compound having an isocyanate-reactive functional group is usually 50 or more in terms of number average molecular weight, preferably 100 or more, more preferably 150 or more. Moreover, it is 50000 or less normally, it is 10,000 or less, More preferably, it is 5000 or less. When the average molecular weight of the compound having an isocyanate-reactive functional group is not less than the above lower limit value, the crosslinking density is lowered and the recording speed can be prevented from being lowered. In addition, when the average molecular weight of the compound having an isocyanate-reactive functional group is not more than the above upper limit, compatibility with other components is improved and the crosslinking density is increased, thereby preventing loss of recorded contents. be able to.

  As described above, a compound having two or more isocyanate groups and a compound having three or more isocyanate-reactive functional groups, or a compound having three or more isocyanate groups and two or more isocyanate-reactive functional groups According to the three-dimensional cross-linked matrix obtained from the compound, a recording layer having excellent record retention can be obtained.

-Compound having a hydroxyl group The compound having a hydroxyl group may be one having one or more hydroxyl groups in one molecule, but one having two or more hydroxyl groups is preferable. Examples thereof include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, and neopentyl glycol; diols such as butanediol, pentanediol, hexanediol, heptanediol, and tetramethylene glycol; Bisphenols, or compounds obtained by modifying these polyfunctional alcohols with polyethyleneoxy chain or polypropyleneoxy chain; these polyfunctional alcohols such as triols such as glycerin, trimethylolpropane, butanetriol, pentanetriol, hexanetriol, decanetriol, etc. Compound modified with polyethyleneoxy chain or polypropyleneoxy chain; polyfunctional polyoxybutylene; Caprolactone; polyfunctional polyesters, polyfunctional polycarbonate; and polyfunctional polypropylene glycol. Any of these may be used alone, or two or more of these may be used in any combination and ratio.

  The average molecular weight of the compound having a hydroxyl group is usually 50 or more in terms of number average molecular weight, preferably 100 or more, more preferably 150 or more. Moreover, it is 50000 or less normally, Preferably it is 10,000 or less, More preferably, it is 5000 or less. When the average molecular weight of the compound having a hydroxyl group is not less than the above lower limit value, the crosslinking density is lowered, and the recording speed can be prevented from being lowered. Further, when the average molecular weight of the compound having a hydroxyl group is not more than the above upper limit value, compatibility with other components is improved and the crosslinking density is increased, so that loss of recorded contents can be prevented.

-Compound having an amino group The compound having an amino group may be any compound having at least one amino group in one molecule, but preferably has two or more amino groups. Examples thereof include aliphatic amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and hexamethylenediamine; alicyclic amines such as isophoronediamine, menthanediamine, and 4,4′-diaminodicyclohexylmethane; m-xylylenediamine, diamino Aromatic amines such as diphenylmethane and m-phenylenediamine; Any of these may be used alone, or two or more of these may be used in any combination and ratio.

  The average molecular weight of the compound having an amino group is usually 50 or more in terms of number average molecular weight, preferably 100 or more, more preferably 150 or more. Moreover, it is 50000 or less normally, Preferably it is 10,000 or less, More preferably, it is 5000 or less. When the average molecular weight of the compound having an amino group is not less than the above lower limit value, the crosslinking density is lowered and the recording speed can be prevented from being lowered. In addition, when the average molecular weight of the compound having an amino group is not more than the above upper limit, compatibility with other components is improved and the crosslinking density is increased, so that loss of recorded contents can be prevented. .

Compound having a mercapto group The compound having a mercapto group may be any compound having one or more mercapto groups in one molecule, but preferably has two or more mercapto groups. Examples thereof 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, pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (2-mercaptoacetate), pentaerythritol tetrakis (3-mercaptobutyrate), trimethylolpropane tris (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), 1,4-bis (3-mercaptobutyryloxy) butane, etc. Is mentioned. Any of these may be used alone, or two or more of these may be used in any combination and ratio.

  The average molecular weight of the compound having a mercapto group is usually 50 or more in terms of number average molecular weight, preferably 100 or more, more preferably 150 or more. Moreover, it is 50000 or less normally, Preferably it is 10,000 or less, More preferably, it is 5000 or less. When the average molecular weight of the compound having a mercapto group is not less than the above lower limit value, the crosslinking density is lowered and the recording speed can be prevented from being lowered. Further, when the average molecular weight of the compound having a mercapto group is not more than the above upper limit value, compatibility with other components is improved and the crosslinking density is increased, so that loss of recorded contents can be prevented. .

1-3. Polymerizable monomer The polymerizable monomer means a compound that can be polymerized by a photopolymerization initiator described later. The kind of the polymerizable monomer used in the composition for a hologram recording medium of the present invention is not particularly limited, and can be appropriately selected from known compounds. Examples of the polymerizable monomer include a cation polymerizable monomer, an anion polymerizable monomer, and a radical polymerizable monomer. Any of these may be used, or two or more of these may be used in combination. However, it is preferable to use a radically polymerizable monomer because the compound having an isocyanate group and the compound having an isocyanate-reactive functional group are unlikely to inhibit the reaction forming the matrix.

・ Cationically polymerizable monomers Examples of cationically polymerizable monomers include epoxy compounds, oxetane compounds, oxolane compounds, cyclic acetal compounds, cyclic lactone compounds, thiirane compounds, thietane compounds, vinyl ether compounds, spiro orthoester compounds, and ethylenically unsaturated bonds. Examples thereof include a compound, a cyclic ether compound, a cyclic thioether compound, and a vinyl compound. Any one of the above cationic polymerizable monomers may be used alone, or two or more of them may be used in any combination and ratio.

Anionic polymerizable monomer Examples of the anionic polymerizable monomer 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, acrylic acid esters, vinyl ketones, isopropenyl ketones, and other polar monomers.
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.

-Radical polymerizable monomer Examples of the radical polymerizable monomer include compounds having a (meth) acryloyl group, (meth) acrylamides, vinyl esters, vinyl compounds, styrenes, spiro ring-containing compounds, 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. In this specification, a general term for methacryl and acryl is referred to as (meth) acryl.
Among these, a compound having a (meth) acryloyl group is more preferable from the viewpoint of steric hindrance during radical polymerization.

-Molecular weight of polymerizable monomer The polymerizable monomer used in the composition for a hologram recording medium of the present invention usually has a molecular weight of 80 or more, preferably 150 or more, more preferably 300 or more, more preferably 400 or more. Moreover, it is 3000 or less normally, Preferably it is 2500 or less, More preferably, it is 2000 or less. When the molecular weight is equal to or more than the above lower limit value, it is possible to reduce the shrinkage rate associated with the polymerization of light irradiation during hologram information recording. Further, when the molecular weight is not more than the above upper limit value, the mobility of the polymerizable monomer in the recording layer using the composition for hologram recording medium is high, diffusion is likely to occur, and sufficient diffraction efficiency can be obtained. it can.

-Refractive index of polymerizable monomer The polymerizable monomer has a refractive index of usually 1.50 or more, preferably 1.52 or more, more preferably 1.55 or more at the wavelength of light irradiated to the hologram recording medium (recording wavelength, etc.). Usually, it is 1.80 or less, preferably 1.78 or less. When the refractive index is not excessively small, sufficient diffraction efficiency is obtained, and sufficient multiplicity tends to be obtained. In addition, since the refractive index is not excessively large, the difference in refractive index from the resin matrix does not become too large, and appropriate scattering tends to result in no need for excessive energy for recording and reproduction. In addition, although a refractive index shows a large value when evaluated at a short wavelength, a sample showing a relatively large refractive index at a short wavelength shows a relatively large refractive index even at a long wavelength, and the relationship is not reversed. . Therefore, it is possible to evaluate the refractive index at a wavelength other than the recording wavelength and predict the refractive index at the recording wavelength.

As the polymerizable monomer having a high refractive index, a compound having a halogen atom (iodine, chlorine, bromine, etc.) or a compound having a hetero atom (nitrogen, sulfur, oxygen, etc.) in the molecule is preferable. Among them, those having a heterocyclic structure are more preferable.
These compounds preferably have 2 or less heteroatoms in the heterocyclic structure contained in the molecule in order to ensure solubility in a solvent or a matrix. By being two or less, solubility is improved and a uniform recording layer can be obtained. In addition, when the structure regularity of the heterocycle in the molecule is high, coloring or reduction in solubility may occur due to stacking. Therefore, a heteroaryl group in which two or more rings are condensed is more preferable.

  Examples of preferable polymerizable monomers include compounds represented by the following (formula a) described in JP 2010-018606 A.

(In (Formula a), A is a ring which may have a substituent, Ar is a (hetero) aryl group in which two or more rings may be substituted, and R ¹ is Hydrogen or a methyl group, n is an integer of 1 to 7, and when n is 2 or more, a plurality of Ars may be the same or different, provided that A is an aromatic heterocycle, And when Ar is a heteroaryl group in which two or more rings optionally having a substituent are fused, in the structure in which each of A and Ar is linked, A And the partial structure in each structure of Ar and Ar does not contain a hetero atom.)
Examples of the compound represented by the above (formula a) include 2- (1-thianthrenyl) -1-phenyl (meth) acrylate, 2- (2-benzothiophenyl) -1-phenyl (meth) acrylate, 2 -(4-dibenzofuranyl) -1-phenyl (meth) acrylate, 2- (4-dibenzothiophenyl) -1-phenyl (meth) acrylate, 3- (3-benzothiophenyl) -1-phenyl (meth) ) Acrylate, 3- (4-dibenzofuranyl) -1-phenyl (meth) acrylate, 3- (4-dibenzothiophenyl) -1-phenyl (meth) acrylate, 4- (1-thianthrenyl) -1-phenyl (Meth) acrylate, 4- (4-dibenzothiophenyl) -1-phenyl (meth) acrylate, 2,4-bis (1-thianthrenyl) -1-phenyl (meth) acrylate, 2,4-bis (2-dibenzothiophenyl) -1-phenyl (meth) acrylate, 2,4-bis (3-benzothiophenyl) -1-phenyl (meth) acrylate 2,4-bis (4-dibenzofuranyl) -1-phenyl (meth) acrylate, 2,4-bis (4-dibenzothiophenyl) -1-phenyl (meth) acrylate, 4-methyl-2,6 -Bis (1-thianthrenyl) -1-phenyl (meth) acrylate, 4-methyl-2,6-bis (2-benzothiophenyl) -1-phenyl (meth) acrylate, 4-methyl-2,6-bis (3-benzothiophenyl) -1-phenyl (meth) acrylate, 4-methyl-2,6-bis (4-dibenzofuranyl) -1-phenyl (meth) acryl Over DOO, 4-methyl-2,6-bis (4-dibenzothiophenyl) -1-phenyl (meth) acrylate.

-Molar Absorption Coefficient of Polymerizable Monomer The polymerizable monomer preferably has a molar absorption coefficient of 100 L · mol ⁻¹ · cm ⁻¹ or less at the hologram recording wavelength. When the molar extinction coefficient is 100 L · mol ⁻¹ · cm ⁻¹ or less, it is possible to prevent the transmittance of the medium from being lowered and to obtain a sufficient diffraction efficiency with respect to the thickness.

1-4. Oxime ester compound having a condensed ring The oxime ester compound having a condensed ring of the present invention functions as a photopolymerization initiator.
The photopolymerization initiator refers to a substance that generates a cation, anion, or radical that causes a chemical reaction by light, and contributes to the polymerization of the above-described polymerizable monomer. There is no restriction | limiting in particular in the kind of photoinitiator, According to the kind etc. of polymerizable monomer, it can select suitably.

In the present invention, at least one oxime ester photopolymerization initiator having at least a condensed ring (hereinafter also referred to as oxime ester compound according to the present invention) is used as the photopolymerization initiator.
It is preferable to use 0.003% by mass or more of the oxime ester photopolymerization initiator having a condensed ring with respect to the total amount of the photopolymerization initiator, more preferably 0.03% by mass or more, and further preferably 0.05% by mass. % Or more.

The oxime ester-based photopolymerization initiator having a condensed ring only needs to have a structure represented by> C═N—O— and a condensed ring, and the composition of the present invention is used in the process of producing a hologram recording medium. It is not limited as long as it can be mixed with other components that constitute and does not inhibit the reaction of the other components.
Specifically, what has a structure represented by a following formula (d) is preferable.

In the formula (d), X represents a group having a condensed ring. Carbon number is 9 or more normally, 10 or more are preferable and 14 or more are more preferable. On the other hand, it is usually 40 or less, preferably 30 or less, and more preferably 20 or less.
As the group having a condensed ring, a monovalent condensed ring group which may have a substituent, or a condensed ring which may have a substituent, from the ease of adjusting the absorption wavelength of the photopolymerization initiator. A group bonded to a divalent substituent that maintains conjugation between> C═N—O— and the condensed ring is preferred.

  As the condensed ring, a condensed heterocyclic ring is preferable. Examples of the fused heterocyclic ring in the fused heterocyclic group that may have a substituent include an indole ring, an isoindole ring, a benzimidazole ring, a purine ring, an indazole ring, and a quinoline ring, each of which may have a substituent. , Isoquinoline ring, quinoxaline ring, cinnoline ring, pteridine ring, acridine ring, carbazole ring, benzocinnoline ring, benzotriazole ring, benzothiazine ring, hypoxanthine ring, phenanthrin ring, dibenzopyridine ring, acridone ring, carbamazepine ring, perimidine ring , Pyridazine ring, phthalazine ring, naphthididine ring, quinazoline ring, acridine ring, tripyrazoline ring, piperazine ring, indoline ring, isocindalin ring, quinacridine ring, pyridine ring, indolizine ring, etc .; Ring, xanthene ring, coumarin ring, benzofuran ring, isobenzofuran ring, dibenzofuran ring, benzopyriumion ring, chroman ring, dibenzodioxane ring and other oxygen-containing condensed heterocycles; thianthrene ring, benzothiophene ring, dibenzothiophene ring, etc. Sulfur-containing fused heterocycles; fused heterocycles containing different heteroatoms such as benzoxazole rings, benzoisoxazole rings, benzothiazole rings, benzothiadiazole rings, phenoxathiin rings, phenoxazine rings, phenothiazine rings, etc .; Can be mentioned.

Examples of the substituent that the condensed ring may have include an alkyl group, an alkenyl group, an alkynyl group, an alkylamino group, an alkenylamino group, an alkynylamino group, an alkyloxy group, an alkenyloxy group, an alkynyloxy group, an alkylthio group, and an alkenyl group. Thio group, alkynylthio group, each may have a substituent, cycloalkyl group, aryl group, heteroaryl group, cycloalkylamino group, arylamino group, heteroarylamino group, cycloalkyloxy group, aryloxy group , Heteroaryloxy group, cycloalkylthio group, arylthio group, heteroarylthio group and the like.

These substituents may be directly bonded to the condensed ring or may be bonded via a divalent group. Examples of the divalent substituent that connects the condensed ring and the substituent include a carbonyl group, a thiocarbonyl group, an amide group,-(CH = CH) a-,-(C≡C) a-, or a combination thereof ( a is 1 to
Represents an integer of 5).
In addition, in the following description, the substituent illustrated as a substituent which a condensed ring may have is preferably used for the substituent in the case of having a substituent.

As the divalent substituent that maintains conjugation between> C═N—O— and the condensed ring, a carbonyl group, a thiocarbonyl group, — (CH═CH) a—, — (C≡C) a—, or A combination of them (a
Represents an integer of 1 to 5).
Among these, X is preferably a monovalent condensed heterocyclic group or a group in which a condensed heterocyclic ring and a carbonyl group are bonded.

Z is a direct bond or a divalent organic group.
The carbon number of the divalent organic group is usually 1 or more and 20 or less. As the divalent organic group, a divalent hydrocarbon group which may have a substituent is preferable.
Examples of the divalent hydrocarbon group which may have a substituent include an alkylene group having 1 to 20 carbon atoms which may have a substituent,-(CH = CH) a-,-(C≡C). A divalent group consisting of a- or a combination thereof (a represents an integer of 1 to 5) is preferred.
R ₁ is a monovalent organic group.
The carbon number of the monovalent organic group is usually 1 or more and 40 or less. Preferred examples of the organic group include substituents represented by the following formula (d-1) or formula (d-2).

-C (= O) R Formula ₂₁ (d-1)
In the formula (d-1), R ₂₁ represents a hydrocarbon group that may have a hetero atom. The number of carbon atoms is not limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and usually 40 or less, preferably 30 or less, more preferably 25 or less.

  The number of carbon atoms of the hydrocarbon group which may have a hetero atom is not limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and usually 40 or less, preferably 30 or less, more preferably 25 or less. It is. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be either a chain hydrocarbon group or a cyclic hydrocarbon group, and may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. As a hetero atom, sulfur, oxygen, and / or nitrogen are preferable, and sulfur or oxygen is more preferable. Specifically, for example, alkyl group, alkenyl group, alkynyl group, cycloalkyl group, arylalkyl group, aryl group, heteroaryl group, alkylthio group, alkyloxy group, alkylamino group, arylthio group, aryloxy group, arylamino Group and the like.

Among the groups represented by the formula (d-1), an alkanoyl group having 2 to 20 carbon atoms, an alkenoyl group having 3 to 25 carbon atoms, and 3 to 8 carbon atoms, each of which may have a substituent. And a cycloalkanoyl group, and a benzoyl group having 3 to 8 carbon atoms are preferred.
R ₂ is a monovalent organic group.
The carbon number of the monovalent organic group is usually 1 or more and 40 or less. The organic group is a hydrocarbon group that may have a hetero atom, and is represented by the following formula (d-3), formula (d-4), formula (d-5), or formula (d-6). A group represented by the group, —O—N═CR ₃ R ₄ or —N (OR ₃ ) —OCOR ₄ is preferred.

  The number of carbon atoms of the hydrocarbon group which may have a hetero atom is not limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and usually 40 or less, preferably 30 or less, more preferably 25 or less. It is. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be either a chain hydrocarbon group or a cyclic hydrocarbon group, and may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. As a hetero atom, sulfur, oxygen, and / or nitrogen are preferable, sulfur or oxygen is more preferable, and oxygen is still more preferable. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an arylalkyl group, an aryl group, and a heteroaryl group.

  Among the hydrocarbon groups which may have a hetero atom, each of which may have a substituent, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, and 5 to 12 carbon atoms. The following aryl groups, arylalkyl groups having 6 to 20 carbon atoms, and heteroaryl groups having 3 to 20 carbon atoms are preferable.

-UR ₂₂ formula (d-2)
In the formula (d-2), U is sulfur or oxygen.
R ₂₂ represents a hydrocarbon group which may have a hetero atom. The number of carbon atoms is not limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and usually 40 or less, preferably 30 or less, more preferably 25 or less. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be either a chain hydrocarbon group or a cyclic hydrocarbon group, and may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. As a hetero atom, sulfur, oxygen, and / or nitrogen are preferable, sulfur or oxygen is more preferable, and oxygen is still more preferable. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an arylalkyl group, an aryl group, a heteroaryl group, an alkylthioalkyl group, and an alkyloxyalkyl group.

  Specific examples of the group represented by the formula (d-2) include an alkylthio group, an alkyloxy group, an arylthio group, an aryloxy group, and an alkylthioalkyloxy group. Especially, the C1-C12 alkylthio group and C2-C12 alkylthioalkyloxy group which may respectively have a substituent are illustrated preferably.

—NR ₂₃ R ₂₄ formula (d-3)
In Formula (d-3), R ₂₃ and R ₂₄ represent a hydrocarbon group that may have a hetero atom. The number of carbon atoms is not limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and usually 40 or less, preferably 30 or less, more preferably 25 or less. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be either a chain hydrocarbon group or a cyclic hydrocarbon group, and may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. As a hetero atom, sulfur, oxygen, and / or nitrogen are preferable, sulfur or oxygen is more preferable, and oxygen is still more preferable. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an arylalkyl group, and a heteroaryl group.
Preferred examples of the group represented by the formula (d-3) include an amino group having 1 to 20 carbon atoms.

-C (= O) TR formula ₂₅ (d-4)
In the formula (d-4), T is sulfur or oxygen.
R ₂₅ represents a hydrocarbon group which may have a hetero atom. The number of carbon atoms is not limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and usually 40 or less, preferably 30 or less, more preferably 25 or less.

  The hydrocarbon group of the hydrocarbon group which may have a hetero atom may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be either a chain hydrocarbon group or a cyclic hydrocarbon group, and may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. As the hetero atom of the hydrocarbon group which may have a hetero atom, sulfur, oxygen, and / or nitrogen are preferable. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an arylalkyl group, and a heteroaryl group.

Among the groups represented by formula (d-4), each of which may have a substituent, an alkoxycarbonyl group having 2 to 12 carbon atoms, an alkenyloxycarbonyl group having 3 to 12 carbon atoms, and 3 to 12 carbon atoms. An alkynyloxycarbonyl group, an aryloxycarbonyl group having 7 to 12 carbon atoms and a heteroaryloxycarbonyl group having 3 to 12 carbon atoms, and an alkylthiocarbonyl group having 2 to 12 carbon atoms, each of which may have a substituent. Alkenylthiocarbonyl group having 3 to 12 carbon atoms, alkynylthiocarbonyl group having 3 to 12 carbon atoms, arylthiocarbonyl group having 7 to 12 carbon atoms, and heteroarylthiocarbonyl group having 3 to 12 carbon atoms are preferably exemplified. The

_{-C (= O) -NR 26 R} 27 Formula (d-5)
In the formula (d-5), R ₂₆ and R ₂₇ represent a hydrocarbon group that may have a hetero atom. The number of carbon atoms is not limited, but is usually 1 or more, preferably 2 or more, more preferably 3 or more, and usually 40 or less, preferably 30 or less, more preferably 25 or less. The hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be either a chain hydrocarbon group or a cyclic hydrocarbon group, and may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. As a hetero atom, sulfur, oxygen, and / or nitrogen are preferable, sulfur or oxygen is more preferable, and oxygen is still more preferable. Specific examples include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, an arylalkyl group, and a heteroaryl group.
Preferred examples of the group represented by the formula (d-5) include an aminocarbonyl group having 1 to 20 carbon atoms.

R ₃ and R ₄ each independently represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms, each of which may have a substituent.
Specific examples of the oxime ester polymerization initiator having a condensed ring include 1- [9-ethyl- (6-diphenylamino) -9H-carbazol-3-yl] -2- (O-acetyloxime) -1,2- Hexanedione, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -2- (O-acetyloxime) ethanone, 1- [9-ethyl- (6-benzoyl)- 9H-carbazol-3-yl] -1- (O-acetyloxime) ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-chloroacetyloxime) Methyl glutarate, 1- (9-ethyl-9H-carbazol-3-yl) -2- (O-acetyloxime) -3,3-dimethyl-1,2-butanedione, 1 [9-Ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime) ethyl glutarate, 1- [9-ethyl-6- (2-methylbenzoyl)- 9H-carbazol-3-yl] -1- (O
-Acetyloxime) -3-phenyl-1,2-propanedione, 1- [9- (2-ethylhexane) -6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (
O-acetyloxime) -3-phenyl-1,2-butanedione, 1- (9-ethyl-9
H-carbazol-3-yl) -1- (O-acetyloxime) -3-dimethyl-1,2-propanedione, 1- [9-ethyl-6- (3-methylphenyl) -9H-carbazol-3-yl]- 2- (O-acetyloxime) -3-phenyl-1,2-propanedione, 1- [9- (2-ethylhexyl) -9H-carbazol-3-yl] -2- (O-thiophen-2-yl-carboxy Oxime) -3-phenyl-1,2-propanedione, 1- (9
-Ethyl-9H-carbazol-3-yl) -4- (2,6-diisobutoxy) phenyl-3- (O-acetyloxime) -2-butene, 1- (9-ethyl-9H-carbazol-3-yl) -2- ( O-3-thiophenylmethylcarboxyoxime) -1,2-hexanedione, 1- [9-ethyl- (6-diphenylamino) -9H-carbazol-3-yl] -1- (2-methoxyphenyl) -1- (O-acetyloxime) methanone, 6- (9-ethyl-9H-carbazol-3-yl) -2- (O-butoxycarbonyloxime) -1,2-hexanedione, 1- [9-ethyl-6- (2- Methylbenzoyl) -9H-carbazol-3-yl] -1- (O-benzoyloxime) glutarate methyl, 1- (9-ethyl-9H-carbazol) Ru-3-yl) -1- (O-acetyloxime) -4-phenyl-1,2-butanedione, 1- [7- (2-methylbenzoyl) -thioxanthone-2-yl] -2- (O— Acetyloxime) ethanone, 1- [7- (2-methylbenzoyl) -thioxanthone-2-yl] -1- (O-acetyloxime) ethyl glutarate, 1- (thioxanthone-2-yl) -1- (O -Acetyloxime) -3-phenyl-1
, 2-butanedione, 1- (thioxanthone-2-yl) -4- (2,6-diisobutoxy) phenyl-3- (O-acetyloxime) -2-butene, 1- (thioxanthone-2-yl) -2- (O-thiophen-2-yl-carboxyoxime) -3-phenyl-1,2
-Propanedione or compounds described in JP2010-8713A and JP2009-271502A.

-Other photoinitiators As a photoinitiator, photoinitiators other than the said oxime ester system photoinitiator can be used together. For example, any of the following cationic photopolymerization initiators, anionic photopolymerization initiators, and radical photopolymerization initiators can be used as long as they correspond to the polymerizable monomers to be used. Any of these may be used alone or in combination of two or more.

However, it is preferable to use a radical photopolymerization initiator because it is difficult to inhibit the reaction forming the matrix. Of these, phosphine oxide compounds are more preferred.
The photopolymerization initiator is more preferably a compound having a molar extinction coefficient of 1000 L · mol ⁻¹ · cm ⁻¹ or less at the recording wavelength. When the molar extinction coefficient is 1000 L · mol ⁻¹ · cm ⁻¹ or less, the reduction in the transmittance of the hologram recording medium at the recording wavelength, which occurs when mixing an amount capable of obtaining sufficient diffraction efficiency, is suppressed. it can.

(Cationic photopolymerization initiator)
As the cationic photopolymerization initiator, any known cationic photopolymerization initiator can be used. 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. Any one of the above-exemplified cationic photopolymerization initiators may be used alone, or two or more thereof may be used in any combination and ratio.

(Anionic photopolymerization initiator)
Any anionic photopolymerization initiator may be used as long as it is a known anionic photopolymerization initiator. Examples include amines. Examples of amines include amino group-containing compounds such as dimethylbenzylamine, dimethylaminomethylphenol, 1,8-diazabicyclo [5.4.0] undecene-7, and derivatives thereof; imidazole, 2-methylimidazole, Imidazole compounds such as 2-ethyl-4-methylimidazole, and derivatives thereof; Any one of the anionic photopolymerization initiators exemplified above may be used alone, or two or more may be used in any combination and ratio.

(Radical photopolymerization initiator)
As the radical photopolymerization initiator, any known radical photopolymerization initiator can be used. Examples include phosphine oxide compounds, azo compounds, azide compounds, organic peroxides, organoborates, onium salts, bisimidazole derivatives, titanocene compounds, iodonium salts, organic thiol compounds, halogenated hydrocarbon derivatives, etc. . Any one of the radical photopolymerization initiators exemplified above may be used alone, or two or more of them may be used in any combination and ratio. As described above, phosphine oxide compounds are particularly preferable.

The type of the phosphine oxide compound is not particularly limited as long as the object and effect of the present invention are not impaired, and among them, an acyl phosphine oxide compound is preferable.
Examples of the acylphosphine oxide compound include monoacylphosphine oxide represented by the following (formula b) or diacylphosphine oxide represented by the following (formula c). Any of these may be used alone, or two or more of these may be used in any combination and ratio.

(In (Formula b), R ⁷ is an alkyl group having 1 to 18 carbon atoms; an alkyl group having 1 to 4 carbon atoms substituted with a halogen or an alkoxy group having 1 to 6 carbon atoms; A cycloalkyl group, a phenylalkyl group having 7 to 9 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group; selected from the group consisting of halogen, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms A phenyl group, a naphthyl group or a biphenyl group substituted with at least one; a 5- or 6-membered heterocyclic group containing monovalent N, O or S;

R ⁸ is a phenyl group; a naphthyl group; a biphenyl group; a phenyl group substituted with at least one selected from the group consisting of halogen, an alkyl group having 1 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms; Naphthyl group or biphenyl group; 5- or 6-membered heterocyclic group containing monovalent N, O or S; alkoxy group having 1 to 18 carbon atoms; phenoxy group; halogen, alkyl group having 1 to 4 carbon atoms Or a phenoxy group, a benzyloxy group, or a cyclohexyloxy group, which is substituted with an alkoxy group having 1 to 4 carbon atoms. R ⁸ and R ⁷ may form a ring together with a phosphorus atom.

R ⁹ is an alkyl group having 1 to 18 carbon atoms; substituted with a halogen or an alkoxy group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, or a carbon number 7-9 phenylalkyl group, phenyl group, naphthyl group, biphenyl group; substituted with at least one selected from the group consisting of halogen, alkyl group having 1 to 12 carbon atoms and alkoxy group having 1 to 12 carbon atoms A phenyl group, a naphthyl group or a biphenyl group; a 5- or 6-membered heterocyclic group containing monovalent N, O or S; or a group represented by the following (formula b-1):

(In (Formula b-1), B ¹ is an alkylene group having 2 to 8 carbon atoms or a cyclohexylene group; unsubstituted or substituted with a halogen, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. R ^{7 ′} and R ^{8 ′} represent the same groups as those described for R ⁷ and R ⁸ in the above (formula b), where (formula b) And R ⁷ and R ^{7 ′} , R ⁸ and R ^{8 ′} may be the same or different.))

(In (Formula c), R ¹⁰ is an alkyl group having 1 to 18 carbon atoms; an alkyl group having 1 to 4 carbon atoms substituted with a halogen or an alkoxy group having 1 to 6 carbon atoms; A cycloalkyl group, a phenylalkyl group having 7 to 9 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group; selected from the group consisting of halogen, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms A phenyl group, a naphthyl group or a biphenyl group substituted with at least one; a 5- or 6-membered heterocyclic group containing monovalent N, O or S, an alkoxy group having 1 to 18 carbon atoms, or A phenoxy group; a phenoxy group, a benzyloxy group, or a cyclohexyloxy group substituted with a halogen, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms A group;

R ¹¹ and R ¹² are each independently an alkyl group having 1 to 18 carbon atoms; an alkyl group having 1 to 4 carbon atoms substituted with a halogen or an alkoxy group having 1 to 6 carbon atoms; An alkyl group, a phenylalkyl group having 7 to 9 carbon atoms, a phenyl group, a naphthyl group, or a biphenyl group; at least one selected from the group consisting of halogen, an alkyl group having 1 to 12 carbon atoms, and an alkoxy group having 1 to 12 carbon atoms A phenyl group, a naphthyl group or a biphenyl group substituted with one group; a 5- or 6-membered heterocyclic group containing monovalent N, O or S; )

Specific examples of the compound represented by the above (formula b) or (formula c) include 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoylethoxyphenylphosphine oxide, 2,6-dimethoxy. Benzoylethoxyphenylphosphine oxide, 2,6-dichlorobenzoylethoxyphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl)-(2,4,4-trimethyl-pent-1-yl ) -Phosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (2,4,6- Trimethylbenzoyl)- 2,4-dipentyl-oxy phenyl) phosphine oxide and the like.
Among these, a monoacylphosphine oxide compound is preferable because excellent recording sensitivity can be obtained.

1-5. Zirconium-Based Catalyst In the present invention, a zirconium (Zr) -based catalyst can be used as a matrix curing catalyst.
The zirconium (Zr) -based catalyst is not particularly limited as long as it is a catalyst containing a zirconium element and promotes the reaction of a compound having an isocyanate group and a compound having an isocyanate-reactive functional group.

Examples include cyclopentadienylzirconium trichloride, decamethylzirconocene dichloride, 1,1′-dibutylzirconocene dichloride, 1,1′-isopropylidenezirconocene dichloride, tetrakis (2,4-pentanedionato) zirconium, tetrakis ( Trifluoro-2,4-pentanedionato) zirconium, tetrakis (hexafluoro-2,4-pentanedionato) zirconium, zirconium butoxide, zirconium-t-butoxide, zirconium propoxide, zirconium isopropoxide, zirconium ethoxide, bis ( Ethyl acetoacetate) dibutoxyzirconium, tetrakis (ethylacetoacetate) zirconium, zirconium oxide, barium zirconium oxide, calcium oxide di Koniumu, zirconium bromide, zirconium chloride, zirconium fluoride, 2 chloride (indenyl) zirconium, and the like zirconium carbonate is.

Among them, a compound having an organic ligand is preferable from the aspect of compatibility with other components, and more preferable than a compound having an alkoxide or acetylacetonate (2,4-pentanedionate) structure. Any one of the above zirconium compounds may be used alone, or two or more thereof may be used in any combination and ratio.

1-6. Others The composition for a hologram recording medium in the present invention is characterized by containing the above-mentioned components (1) to (5), but may contain other components unless contrary to the gist of the present invention.

-Other catalyst The composition for hologram recording media of this invention can also use another curing catalyst with the said zirconium-type catalyst for adjustment of reaction rate. The catalyst that can be used in combination is not particularly limited as long as it is not contrary to the gist of the present invention, but in order to obtain a synergistic effect of the catalyst, it is preferable to use a compound having an amino group in a part of the structure. Examples thereof include triethylamine (TEA), N, N-dimethylcyclohexylamine (DMEDA), N, N, N ′, N′-tetramethylethylenediamine (TMEDA), N, N, N ′, N′-tetramethyl. Propane-1,3-diamine (TMPDA), N, N, N ′, N′-tetramethylhexane-1,6-diamine (TMHMDA), N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (PMDETA), N, N, N ′, N ″, N ″ -pentamethyldipropylene-triamine (PMDPTA), triethylenediamine (TEDA), N, N′-dimethylpiperazine (DMP), N, -methyl, N '-(2dimethylamino) -ethylpiperazine (TMNAEP), N-methylmorpholine (NMMO), N · (N', N'-dimethylamino Mention may be made of amine compounds such as chill) -morpholine (DMAEMO), bis (2-dimethylaminoethyl) ether (BDMEE), ethylene glycol bis (3-dimethyl) -aminopropyl ether (TMEGDA), diisopropylethylamine (DIEA). it can. Any of these may be used alone, or two or more of these may be used in any combination and ratio.

Other components Other components include solvents, plasticizers, dispersants, leveling agents, antifoaming agents, adhesion promoters, etc. for preparing the recording layer of hologram recording media, and for recording reaction control. , Chain transfer agents, polymerization terminators, compatibilizers, reaction aids, sensitizers, antioxidants and the like. Any one of these components may be used alone, or two or more thereof may be used in any combination and ratio.

  Among them, it is preferable to use a leveling agent. Examples of the leveling agent include polycarboxylic acid sodium salt, polycarboxylic acid ammonium salt, polycarboxylic acid amine salt, silicon-based leveling agent, acrylic leveling agent, ester compound, ketone compound, and fluorine compound. Any one of these compounds may be used alone, or two or more thereof may be used in any combination and ratio.

1-7. Composition ratio of each component in the composition for hologram recording medium The amount of each component used in the composition for hologram recording medium of the present invention is arbitrary as long as it is not contrary to the gist of the present invention. The following ranges are preferable based on the total mass. The usage-amount of a component (1) and a component (2) is 0.1 mass% or more normally in total, Preferably it is 10 mass% or more, More preferably, it is 35 mass% or more. Moreover, it is 99.9 mass% or less normally, Preferably it is 99 mass% or less. By making this usage amount equal to or more than the above lower limit value, it becomes easy to form the recording layer.

The ratio of the number of isocyanate-reactive functional groups in component (2) to the number of isocyanate groups in component (1) is preferably 0.1 or more, more preferably 0.5 or more. Moreover, it is 10.0 or less normally, Preferably it is 2.0 or less. When this ratio is within the above range, the number of unreacted functional groups is small, and the storage stability is improved.
The usage-amount of a component (3) is 0.1 mass% or more normally, Preferably it is 1 mass% or more, More preferably, it is 2 mass% or more. Moreover, it is 80 mass% or less normally, Preferably it is 50 mass% or less, More preferably, it is 30 mass% or less. When the amount of the component (3) is larger than the above lower limit value, sufficient diffraction efficiency is obtained, and when the amount is smaller than the upper limit value, the compatibility of the recording layer is maintained.

The usage-amount of a component (4) is 0.001 mass% or more normally, Preferably it is 0.01 mass% or more, and is 5 mass% or less normally, Preferably it is 3 mass% or less. When the amount of component (4) is greater than the above lower limit, sufficient recording sensitivity can be obtained.
The amount of component (5) used is preferably determined in consideration of the reaction rates of component (1) and component (2), and is usually 5% by mass or less, preferably 4% by mass or less, more preferably 1% by mass or less. It is. Moreover, it is preferable to use 0.005 mass% or more.
The total amount of other components other than components (1) to (5) may be 30% by mass or less, preferably 15% by mass or less, and more preferably 5% by mass.

1-8. Method for Producing Hologram Recording Medium Composition In the present invention, the components (1) to (5) may be mixed in any combination and order, and at that time, other components may be combined and mixed. Good.
For example, it can be obtained by the following method, but the present invention is not limited thereto.
All components other than the component (2) and the component (5) are mixed to obtain a liquid A. A mixture of component (2) and component (5) is designated as B liquid. Each liquid is preferably dehydrated and degassed. If dehydration / deaeration is not performed or insufficient, bubbles may be generated when the medium is produced, and a uniform recording layer may not be obtained. In the dehydration / deaeration, heating and decompression may be performed as long as each component is not impaired.

  Mixing of liquid A and liquid B is performed immediately before molding. At this time, it is also possible to use a mixing technique by a conventional method. When mixing the liquid A and the liquid B, deaeration may be performed as necessary to remove the residual gas. Furthermore, in order to remove a foreign material and an impurity after mixing each of A liquid and B liquid, it is preferable to pass a filtration process, and it is more preferable to filter each liquid separately. As component (1) ', it is also possible to use an isocyanate-functional prepolymer resulting from the reaction of excess component (1) and component (2). Furthermore, an isocyanate-reactive prepolymer obtained by reacting an excess of component (2) with component (1) can also be used as component (2) '.

1-9. Preferred combination of photopolymerization initiator and zirconium-based catalyst In the present invention, the oxime ester-based photopolymerization initiator and other photopolymerization initiators and the zirconium-based catalyst can be arbitrarily combined. Preferred is an oxime ester photopolymerization initiator alone, or a combination of an oxime ester photopolymerization initiator and a phosphine oxide compound and a zirconium catalyst, more preferably an oxime ester photopolymerization initiator alone or an oxime ester light. A combination of a polymerization initiator and a phosphine oxide compound and a zirconium-based catalyst having an organic ligand.

2. About the hologram recording medium of the present invention The hologram recording medium of the present invention further comprises a recording layer and, if necessary, a support and other layers. Usually, the hologram recording medium has a support, and the recording layer and other layers are laminated on the support to constitute the hologram recording medium. However, when the recording layer or other layers have the strength and durability required for the medium, the hologram recording medium may not have a support. Examples of other layers include a protective layer, a reflective layer, an antireflection layer (antireflection film), and the like.
The recording layer of the hologram recording medium of the present invention is preferably formed from the composition for a hologram recording medium of the present invention.

2-1. Recording layer The recording layer of the hologram recording medium of the present invention is a layer formed from the composition for a hologram recording medium of the present invention, and is a layer on which information is recorded. Information is usually recorded as a hologram. As described in detail in the section of the recording method to be described later, a part of the polymerizable monomer contained in the recording layer causes a chemical change such as polymerization by hologram recording or the like. Therefore, in the hologram recording medium after recording, a part of the polymerizable monomer is consumed and exists as a compound after reaction such as a polymer.

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 generally 1 μm or more, preferably 10 μm or more, and usually 3000 μm or less, preferably 2000 μm or less. It is a range. By setting the thickness of the recording layer to be equal to or more than the above lower limit value, the selectivity of each hologram is increased and the degree of multiplex recording can be increased at the time of multiplex recording on the hologram recording medium. Further, by making the thickness of the recording layer equal to or less than the above upper limit value, the entire recording layer can be formed uniformly, and multiplex recording with uniform diffraction efficiency of each hologram and high S / N ratio is performed. Can do.
Further, it is preferable that the shrinkage rate of the recording layer due to exposure during recording and reproduction of information is 0.25% or less.

2-2. Support The support is not particularly limited in detail as long as it has the strength and durability required for the medium, and any support can be used. Moreover, although there is no restriction | limiting also 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. Examples of transparent materials for the support include organic materials such as acrylic, polyethylene terephthalate, polyethylene naphthoate, polycarbonate, polyethylene, polypropylene, amorphous polyolefin, polystyrene, and cellulose acetate; and inorganic materials such as glass, silicon, and quartz. It is done. Among these, polycarbonate, acrylic, polyester, amorphous polyolefin, glass, and the like are preferable, and polycarbonate, acrylic, amorphous polyolefin, and glass are particularly preferable.

On the other hand, when the opaque material is cited as the material of the support, 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. Things.
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 0.05 mm or more and 1 mm or less. When the thickness of the support is not less than the above lower limit, the mechanical strength of the hologram recording medium can be obtained, and the warpage of the substrate can be prevented. Further, when the thickness of the support is equal to or less than the above upper limit value, the light transmission amount can be maintained, and an increase in cost can be suppressed.

  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, partially hydrolyzed vinyl chloride-vinyl acetate copolymers, polyurethane resins, and the like.

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.
These surface treatments may be provided for the purpose of controlling the gas and moisture permeability of the substrate. For example, the reliability of the medium can be further improved by providing the support sandwiching the recording layer with the function of suppressing the permeability of gas and moisture.

Further, the support may be provided only on either the upper side or the lower side of the recording layer of the hologram 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 a hologram recording medium having a 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 is used on one side of the recording layer, a reflection 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 in this case, For example, an unevenness | corrugation may be formed in support body itself, a pattern may be formed in the reflective layer mentioned later, and you may form by the method of combining these.

2-3. Protective layer The protective layer is a layer for preventing the influence of deterioration of storage stability of the recording layer. 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, an organic / inorganic material, or the like can be formed as a protective layer.
The formation position of the protective layer is not particularly limited. For example, the protective layer may be formed on the surface of the recording layer, between the recording layer and the support, or on the outer surface side of the support. Moreover, you may form between a support body and another layer.

2-4. Reflective layer The reflective layer is formed when the hologram recording medium is configured to be reflective. In the case of a reflection-type hologram recording medium, the reflection 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.
As the reflective layer, a known layer can be arbitrarily applied. For example, a metal thin film or the like can be used.

2-5. Antireflection film For both transmissive and reflective hologram recording media, an antireflection film may be provided on the side on which object 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. Any known antireflection film can be used.

2-6. Method for producing hologram recording medium The method for producing the hologram recording medium of the present invention is not limited. For example, it can be produced by applying the composition for a hologram recording medium of the present invention on a support without solvent and forming a recording layer. At this time, any method can be used as a coating method. Specific examples include a spray method, a spin coat method, a wire bar method, a dip method, an air knife coat method, a roll coat method, a blade coat method, a doctor roll coat method, and the like. In forming the recording layer, when a recording layer having a particularly large thickness is formed, it is possible to use a method of molding in a mold or a method of coating on a release film and punching out of the mold. Alternatively, the composition for hologram recording medium of the present invention and a solvent or additive may be mixed to prepare a coating solution, which may be coated on a support and dried to form a recording layer. In this case as well, any method can be used as the coating method, and for example, the same method as described above can be adopted.

  Moreover, although there is no restriction | limiting in a solvent, Usually, it is preferable to use what has sufficient solubility with respect to a use component, gives favorable coating film property, and does not attack a support body, such as a resin substrate. Examples of solvents include ketone solvents such as acetone and methyl ethyl ketone; aromatic solvents such as toluene and xylene; alcohol solvents such as methanol and ethanol; ketone alcohol solvents such as diacetone alcohol; tetrahydrofuran, Ether solvents such as dichloromethane, halogen solvents such as chloroform, cellosolv solvents such as methyl cellosolve and ethyl cellosolve; propylene glycol solvents such as propylene glycol monomethyl ether and propylene glycol monoethyl ether; ethyl acetate, 3- Ester solvents such as methyl methoxypropionate; perfluoroalkyl alcohol solvents such as tetrafluoropropanol; highly polar solvents such as dimethylformamide and dimethyl sulfoxide; n-hexane, etc. Jo hydrocarbon solvents; cyclohexane, cyclic hydrocarbon solvents cyclooctane; and or a solvent mixture thereof. In addition, a solvent may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. Moreover, there is no restriction | limiting in the usage-amount of a solvent. However, it is preferable to prepare a coating solution having a solid content concentration of about 1% to 1000% by weight from the viewpoint of coating efficiency and handleability.

  Further, when the resin matrix comprising the components (1) and (2) of the composition for a hologram recording medium of the present invention is thermoplastic, the hologram recording of the present invention is performed by, for example, an injection molding method, a sheet molding method, a hot press method, or the like. A medium composition is formed. In the case where the resin matrix comprising the components (1) and (2) of the present invention is a (light) thermosetting with a small amount of volatile components, the photoreactive composition of the present invention can be obtained by, for example, reaction injection molding or liquid injection molding. The recording layer can be manufactured by molding a product. In this case, if the molded body has sufficient thickness, rigidity, strength, etc., the molded body can be used as it is as a hologram recording medium.

Further, as a method for producing a hologram recording medium, for example, a method for producing a hologram recording medium by forming a recording layer by applying a composition for a hologram recording medium melted by heat to a support and solidifying by cooling, a liquid hologram recording A method for producing a recording layer by applying a composition for a medium to a support and curing it by thermal polymerization, and curing by applying a liquid composition for a hologram recording medium to a support and photopolymerizing it. And a method of manufacturing the recording layer by forming the recording layer.
The hologram recording medium thus manufactured can take the form of a self-supporting slab or a disk, and can be used for a three-dimensional image display device, a diffractive optical element, a large-capacity memory, and the like.

2-7. Information Recording / Reproducing Method Information is written (recorded) and read (reproduced) on the hologram recording medium of the present invention by light irradiation.
First, when recording information, light capable of causing a chemical change of a polymerizable monomer, that is, polymerization and concentration change, is used as object light (also referred to as recording light).
For example, when recording information as a volume hologram, the object light is irradiated onto the recording layer together with the reference light so that the object light and the reference light interfere with each other in the recording layer. As a result, the interference light causes polymerization and concentration change of the polymerizable monomer in the recording layer, and as a result, the interference fringes cause a refractive index difference in the recording layer, and the interference recorded in the recording layer. A hologram is recorded on the recording layer by the stripes.

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 ranges of the object light, the reproduction light, and the reference light are arbitrary depending on each application, and may be a visible light region or an ultraviolet region. These as preferable even Among light, for example, ruby, glass, Nd-YAG, a solid-state laser such as a _{Nd-YVO 4; GaAs, InGaAs} , such as GaN diode lasers; helium - neon, argon, krypton, excimer, Examples thereof include a gas laser such as CO ₂ ; a laser having excellent monochromaticity and directivity, such as a dye laser having a dye.

Further, there is no limitation on the irradiation amounts of the object light, the reproduction light, and the reference light, and the irradiation amounts are arbitrary as long as they can be recorded and reproduced. However, if the amount is extremely small, the chemical change of the polymerizable monomer may be too incomplete, and the heat resistance and mechanical properties of the recording layer may not be sufficiently expressed. The component of the composition for a hologram recording medium of the present invention may deteriorate. Accordingly, the object light, the reproduction light, and the reference light are usually 0.1 J in accordance with the composition of the composition for hologram recording medium of the present invention used for forming the recording layer, the kind of photoinitiator, the blending amount, and the like. Irradiation is in the range of not less than / cm ^{2 and not} more than 20 J / cm ² .

  The hologram recording system includes a polarization collinear hologram recording system, a reference light incident angle multiplexing type hologram recording system, etc., but any recording system is satisfactory when the hologram recording medium of the present invention is used as a recording medium. It is possible to provide recording quality.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless it deviates from the summary.
[Hologram recording and evaluation method]
Using the evaluation sample of the hologram recording medium of the present invention, hologram recording and evaluation of the hologram recording performance of the hologram recording medium were performed according to the procedure described below.

Hologram recording was performed by using a semiconductor laser having a wavelength of 405 nm and using the exposure apparatus shown in FIG. 1 at an exposure power density of 6.0 mW / cm ² per beam, and performing two-beam plane wave hologram recording.
The medium was recorded 61 times at the same location from -30 ° to 30 ° at intervals of 1 °, and the sum of the square roots of diffraction efficiency at that time was defined as M / # (M number). The light transmittance at the recording wavelength was measured before and after the recording. Details will be described below.

(Hologram recording)
FIG. 1A is a configuration diagram showing an outline of the apparatus used for hologram recording, FIG. 1B is a configuration diagram showing the surface of the LED unit, and FIG. It is a block diagram which shows the arrangement | sequence of LED.
In FIG. 1A, S represents a sample of a hologram recording medium, M1 to M3 all represent mirrors, PBS represents a polarizing beam splitter, and L1 represents a laser light source for recording light (wavelength) that emits light having a wavelength of 405 nm. 1 represents a single-mode laser diode manufactured by Sony that can obtain light of around 405 nm (“L1” in FIG. 1A)), L2 represents a laser light source for reproduction light that emits light having a wavelength of 633 nm, and PD1, PD2 Indicates a photodetector. Reference numeral 1 denotes an LED unit, 2 denotes an arm, and 3 denotes a support.

  In the case of normal recording and reproduction, the LED unit is at the position of the solid line in FIG. 1A, and in the case of uniform exposure, as shown by the broken line, the arm 2 and the LED unit 1 to which the support column 3 is rotated and attached. After the LED moves to the front side of the recording portion of the sample S, the LED lights up for a certain period of time. As shown in FIG. 1C, the LEDs 1B are arranged on the LED unit surface 1A like dice 5 as dice. A power source is connected to the light sources L1 and L2, the photodetectors PD1 and PD2, and the LED unit 1.

  As shown in FIG. 1A, light having a wavelength of 405 nm is divided by a polarizing beam splitter (“PBS” in the figure), and the angle formed by the two beams is 37.0 ° on the recording surface. Crossed. 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 performed so as to be perpendicular to the plane including the beam.

  After recording the hologram, using a He-Ne laser that can obtain light having a wavelength of 633 nm (V05-LHP151 manufactured by Melles Griot: “L2” in the figure), the light is irradiated at an angle of 29.9 ° with respect to the recording surface. If the diffracted light is detected by using a power meter and a detector (Newport 2930-C, 918-SL: “PD1” and “PD2” in the figure), whether hologram recording is performed correctly. Judged whether or not. The diffraction efficiency of a hologram is given by the ratio of the intensity of diffracted light to the sum of transmitted light intensity and diffracted light intensity.

(Measurement of M / #)
The angle at which the sample is moved with respect to the optical axis (the angle between the two light beams, ie, the bisector of the internal angle at the point where the incident light from the mirrors M1 and M2 in FIG. 1A intersects) and the normal from the sample. 61 multiple recordings were performed in 1 degree increments from −30 ° to 30 °, and the sum of the obtained square roots of diffraction efficiency over the entire multiple recording region was defined as M / #.

  Specifically, for each example, using one of a plurality of optical recording media prepared first, the angle between the bisector of the inner angle at the point where the two light beams intersect and the normal of the medium is zero. Until the diffraction efficiency becomes constant, the two light beams, that is, the incident light from the mirrors M1 and M2 in FIG. 1A and the wavelength of 405 nm are irradiated, and the constant minimum energy is measured (in this case, evaluation of the diffraction efficiency) Is performed using light from the mirror M3 and a wavelength of 633 nm).

  Next, with respect to another sample, multiple recording is performed using the previously obtained minimum energy value as a measure of the total irradiation energy for 61 multiple recording. At this time, the irradiation energy is appropriately adjusted according to the number of times of recording, and a diffraction efficiency of several percent for each recording is maintained. After 61 multiple recording, the light (wavelength 405 nm) from the mirror M1 in FIG. 1A is subsequently irradiated, the diffraction efficiency from angles -30 ° to 30 ° is measured, and the sum of the square roots of the diffraction efficiency at each angle ( M / #).

  While changing the sample, performing multiple evaluations with different irradiation energy conditions such as increase / decrease in irradiation energy at the beginning of recording and increase / decrease in total irradiation energy, while maintaining diffraction efficiency of several percent or more for each recording, 61 A search was made for a condition in which the contained monomer was almost completely consumed before multiple recording (M / # almost reached equilibrium by 61 multiple recording), and the maximum value was obtained as M / #. The maximum value obtained was defined as M / # of the medium.

(sensitivity)
The sensitivity of the sample for measurement represents the average sensitivity until reaching 80% of the maximum M / # indicated by the sample in the M / # measurement, and is calculated as follows.
Sensitivity = (0.8 × (M / #)) / (I × ts × L)
Here, I is the incident light intensity (mW / cm ² ), ts is the total exposure time (seconds) until M / # reaches 80%, and L is the recording layer thickness (cm).
(Storage stability test)
In the sample storage stability test, an unrecorded sample was recorded after being stored at 80 ° C. and compared with that before storage. M / # and sensitivity were evaluated based on the remaining rate with 100% before storage.

[Example 1]
Preparation of composition for hologram recording medium 1.00 g of hexamethylene diisocyanate (NCO% (ratio of isocyanate group): 49.9%), 0.15 g of dibenzothiophenyl phenyl acrylate, and photopolymerization initiator (component (4)) ) 1- (9-ethyl-9H-carbazol-3-yl) -2- (O-acetyloxime) -3,3-dimethyl-1,2-butanedione was dissolved to give solution A.

Next, 0.4 mg of tetrakis (2,4-pentanedionato) zirconium as a zirconium-based catalyst (component (5)) was dissolved in 3.99 g of polyoxypropylene glycol having a molecular weight of about 1000 to prepare a liquid B.
Liquid B was degassed under reduced pressure for 3 hours, and then liquid A and liquid B were mixed and stirred and mixed, and further degassed in vacuum for several minutes.

・ Preparation of measurement sample Next, pour the above-mentioned vacuum degassed mixture onto a slide glass with a 500μm thick spacer sheet on the two ends, cover the slide glass on it, and use clips to surround it. Was fixed and heated at 60 ° C. for 15 hours to produce a measurement hologram recording medium. In this measurement sample, a recording layer having a thickness of 500 μm is formed between slide glasses as a cover.
The samples obtained in this manner were evaluated for hologram recording performance by the above method. The evaluation results are shown in Table 1. Table 1 shows the results when an unrecorded sample was stored at 80 ° C. for 168 hours.

[Example 2]
1- (9-Ethyl-9H-carbazol-3-yl) -2- (O-acetyloxime) -3,3-dimethyl-1,2-butanedione of Example 1 was treated with 1- (9- It was prepared in the same manner as in Example 1 except that it was changed to 0.003 g of ethyl-9H-carbazol-3-yl) -1- (O-acetyloxime) -4-phenyl-1,2-butanedione. went. The evaluation results are shown in Table 1. Table 1 shows the results when an unrecorded sample was stored at 80 ° C. for 168 hours.

[Comparative Example 1]
A tetrakis (2,4-pentanedionato) zirconium in Example 2 was prepared and evaluated in the same manner as in Example 2 except that the dioctyltin dilaurate was changed to 1.0 mg. The evaluation results are shown in Table 1. Table 1 shows the results when an unrecorded sample was stored at 60 ° C. for 168 hours.

[Comparative Example 2]
0.06 g of 1- (9-ethyl-9H-carbazol-3-yl) -2- (O-acetyloxime) -3,3-dimethyl-1,2-butanedione of Example 1 was added to 1.2-octanedione, It was produced and evaluated in the same manner as in Example 1 except that 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] was changed to 0.10 g. The evaluation results are shown in Table 1. Table 1 shows the results when an unrecorded sample was stored at 80 ° C. for 168 hours.
[Evaluation results]

  From the above table, the composition for a holographic recording medium prepared by combining a zirconium (Zr) -based catalyst with an oxime ester-based photopolymerization initiator having a specific structure has a storage stability ( It is clear that the residual ratio of M / # and the residual ratio of sensitivity are excellent.

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

1 LED unit
1A LED unit surface
1B LED
2 arms
3 props
S sample
M1, M2, 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 (5)

A compound having an isocyanate group,
A compound having an isocyanate-reactive functional group,
Polymerizable monomer,
An oxime ester-based photopolymerization initiator having a condensed ring,
And a composition for a holographic recording medium, comprising a zirconium-based catalyst.   The composition for a hologram recording medium according to claim 1, wherein the condensed ring is a condensed heterocyclic ring.   The composition for a hologram recording medium according to claim 1 or 2, wherein the polymerizable monomer is a radical polymerizable monomer.   The composition for a hologram recording medium according to any one of claims 1 to 3, wherein the molecular weight of the polymerizable monomer is 80 or more.   A hologram recording medium, wherein the composition for a hologram recording medium according to any one of claims 1 to 4 is used for a recording layer.

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