JP6089867B2 - Composition for hologram recording medium, hologram recording medium using the same, and polymerizable compound - Google Patents

Description

The present invention relates to a novel polymerizable compound having high diffraction efficiency and high light transmittance, little shrinkage due to crosslinking, and high solubility.
The present invention also relates to a composition containing the novel compound and a hologram recording medium comprising the composition.

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.
General principles regarding hologram production are described in several documents and technical books (see Non-Patent Document 1). According to these, a photosensitive hologram recording material is placed at a position where one of the two light speed coherent laser beams is irradiated onto the recording object and the light can be received. The hologram recording material is directly irradiated with the other coherent light in addition to the light from the object without hitting the object. The light from the object is called object light, and the light directly irradiated onto the recording material is called reference light, and interference fringes between the reference light and the object light are recorded as image information.
In particular, a hologram whose film pressure is sufficiently thick with respect to the interference fringe interval (usually a film thickness of 5 times or more of the interference fringe interval or 1 μm or more) is called a volume hologram and can be recorded in the film thickness direction. Therefore, higher capacity recording is possible with a larger film thickness.

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, a photopolymer method in which a resin matrix is combined with a monomer capable of radical polymerization or cationic polymerization as a photoactive compound is mentioned (see Patent Documents 1 to 4).
The photopolymer here refers to a material comprising at least a matrix resin, a polymerizable reactive compound, and a photopolymerization initiator.
When recording a hologram, if there is a recording layer in the part where two lights intersect and become strong, the photoinitiator causes a chemical reaction and becomes an active substance, which acts on the polymerizable reactive compound and reacts with it. Polymerizes. At this time, if there is a difference in refractive index between the matrix resin and the polymer purified from the polymerizable reactive compound, the interference fringes become a refractive index difference and are fixed in the recording layer. Further, when the polymerizable reactive compound is polymerized, the reactive compound is diffused from the periphery, and the concentration distribution of the reactive compound or the polymer of the reactive compound is generated inside the photopolymer. When only the reference light is irradiated, the recording based on the object light or information light is reproduced from the interference fringes. However, when the reference light having the same wavelength is used, an unreacted polymerizable reactive compound is recorded by irradiating the recording layer during reproduction. It should polymerize like time. However, as described above, there is a concentration distribution of the reactive compound or the polymer of the reactive compound inside the photopolymer, so that the portion where the two lights cross and become weak, that is, the unrecorded portion, Since the concentration of the reactive compound is relatively lowered, even if this portion of the reactive compound is polymerized, there remains a difference in refractive index from the recorded portion. Therefore, the recording does not disappear even when the same wavelength is irradiated during reproduction.

  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, and high S / N ratio for recording, and achieves high multiplicity. A composition is required, and 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.

  As a typical polymerizable monomer as a reactive compound for such a photopolymer, N-vinylcarbazole and tribromophenyl acrylate have been studied (for example, Patent Documents 1 and 2). These polymers have a refractive index sufficiently higher than that of the matrix resin produced by polymerization, and are highly compatible with the matrix resin before polymerization, and are highly compatible with the matrix resin even after polymerization. Since the required scattering is small, it is a compound suitable for hologram recording with high diffraction efficiency even if recording is repeated.

  Patent Documents 3 to 5 report that a hologram recording material and a recording medium having high diffraction efficiency and sensitivity can be obtained by using a polymerizable sulfur atom-containing compound or the like. Further, Patent Document 6 proposes a polymerizable compound to solve the above problem.

JP-A-10-105030 JP-T-2005-502918 JP 2005-114848 A JP 2005-43507 A JP 2005-114849 A JP 2010-18606 A

Junpei Uchiuchi, Chapter 2, “Holographic Display”, Industrial Books

However, in general, the diffraction efficiency and the shrinkage ratio are in a trade-off relationship, and the polymerization shrinkage accompanying recording increases when the concentration of the polymerizable compound is increased to improve the diffraction efficiency. Even when a polymerizable sulfur atom-containing compound or the like is used, it is insufficient in terms of diffraction efficiency, light transmittance, and shrinkage rate, and it is necessary to create a further polymerizable compound.
Moreover, in the polymeric compound shown by patent document 6, there exists a problem that solubility is not enough from the bulkiness.

The present invention solves the above-mentioned problems, and a compound having a new polymerizable property as an optical material, particularly a reactive compound used for hologram recording, and by using this compound, has high diffraction efficiency and light transmittance. An object of the present invention is to provide a hologram recording medium having a high shrinkage and a low shrinkage rate.
The diffraction efficiency of the hologram recording medium is proportional to the recording density per medium surface and is a numerical value converted from the difference in refractive index. Here, the difference in refractive index is the difference in refractive index between the recorded portion and the unrecorded portion. The recorded part is a part polymerized by light, and the unrecorded part is a non-recorded part.

In the hologram recording medium before recording, a uniform state is ensured to such an extent that the matrix resin and the reactive compound have transparency at the recording wavelength. By irradiating the hologram recording medium with light for recording, the reactive compound becomes a corresponding polymer under the influence of the activated initiator.
In general, since the density increases as the molecules approach due to polymerization, the refractive index of the recorded part changes to the corresponding polymer (polymer) due to the polymerization of the reactive compound due to the recording, so that the refractive index of the recorded part is not recorded. Relative to the refractive index. Further, at that time, the reactive compound moves from the non-irradiated portion to the irradiated portion due to the change in density accompanying polymerization.
Therefore, when the refractive index of the reactive compound exceeds the refractive index of the matrix resin, the refractive index further increases in the irradiated portion relative to the unrecorded portion and the state before recording due to the formation of the polymer and the increase in the concentration of the reactive compound. To rise. On the other hand, in the non-irradiated portion, the refractive index is further lowered than the state before recording due to the decrease in the concentration of the reactive compound. Therefore, the difference in refractive index between the irradiated part and the non-irradiated part becomes larger. On the other hand, when the refractive index of the reactive compound is lower than the refractive index of the matrix resin, the refractive index of the irradiated portion is higher than that of the unrecorded portion or the state before recording due to the formation of polymer, but the increase in the concentration of the reactive compound is refracted. Since it works to reduce the rate, the rise is suppressed.

  Furthermore, since the refractive index increases in the non-irradiated part due to the decrease in the concentration of the reactive compound, the difference in refractive index between the irradiated part and the non-irradiated part is that the reactive compound has a higher refractive index than the matrix resin. It is smaller than when it is large. Therefore, in order to increase the refractive index difference between the irradiated part (recording part) and the non-irradiated part (unrecorded part), the refractive index of the matrix resin must be smaller than the refractive index of the reactive compound, and the difference should be large. is important. It is considered that the multiplicity can be increased because the difference in refractive index between the recorded portion and the unrecorded portion is larger, and a higher diffraction efficiency can be achieved.

The present invention has found that a specific compound has a high refractive index, less shrinkage due to crosslinking, and further excellent solubility, and by using a composition using the compound for a hologram recording medium, It has been found that the recording efficiency and recording stability of the hologram recording medium can be obtained.
That is, the gist of the present invention is as follows [1] to [5].
[1] A composition for a hologram recording medium, comprising at least a compound having an isocyanate group and / or a compound having an isocyanate-reactive functional group, and a polymerizable compound represented by the following general formula (1).

(In the formula (1),
X is an alkylene group which may have a substituent, n ₁ is an integer of ₁ to 3, and R ¹ is a (hetero) aryl group in which two or more rings which may have a substituent are condensed. N ₂ is an integer of ₂ to 5, and R ² is hydrogen or a methyl group. A plurality of R ¹ may be the same or different. )
[2] The composition for a hologram recording medium according to [1], wherein R ¹ is a heteroaryl group in which two or more rings optionally having a substituent are condensed
[3] The hologram medium composition according to [1] or [2], further comprising a photopolymerization initiator.
[4] A hologram recording medium comprising the composition for a hologram recording medium according to any one of [1] to [3].
[5] A compound represented by the following general formula (2):

(In Formula (2), X ¹ is an alkylene group which may have a substituent, n ₁₁ is an integer of 1 to 3, and R ¹¹ has two or more rings which may have a substituent. A condensed (hetero) aryl group, n ₂₁ is an integer of 2 to 5, R ²¹ is hydrogen or a methyl group, and a plurality of R ¹¹ may be the same or different.

According to the present invention, a hologram recording medium composition using a novel polymerizable compound having excellent solubility, and a hologram recording medium having high diffraction efficiency and low shrinkage using the composition are obtained.
According to the present invention, a polymerizable compound having excellent solubility, a high refractive index and less shrinkage due to crosslinking can be obtained.

In an Example, 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) A figure shows the surface of an LED unit, (c) A figure is It is a figure which shows the arrangement | sequence of LED.

  Embodiments of the present invention will be specifically described below, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

In the present invention, “(hetero) aryl” means both “aryl” and “heteroaryl”.
In the present invention, “(meth) acrylate” means both “acrylate” and “methacrylate”.

1. Composition for hologram recording medium The composition for hologram recording medium of the present invention comprises at least a compound having an isocyanate group and / or a compound having an isocyanate-reactive functional group, and a polymerizable compound represented by the general formula (1). . By using the composition for hologram recording medium, a hologram recording medium having high diffraction efficiency and low shrinkage can be obtained.
As the composition for a hologram recording medium of the present invention, the presence or absence and combination of a compound having an isocyanate group and a compound having an isocyanate-reactive functional group can be determined by storing the composition for a hologram recording medium or a method for producing a hologram recording medium. It can select suitably, It does not specifically limit in this invention.

1-1. Compound having isocyanate group The proportion 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, 0.1 mass% or more is preferable and 1 mass% or more is more preferable. When the ratio of the isocyanate group is less than the above upper limit, turbidity is less likely to occur when the hologram recording medium is used, and optical uniformity tends to be obtained. Further, when the ratio is higher than the lower limit, the hardness of the resin matrix and the glass transition temperature are increased, and the recording tends to be prevented from being lost.
Moreover, the ratio of the isocyanate group in this invention shows the ratio of the isocyanate group in the whole compound which has the 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, aliphatic, or alicyclic skeleton. Moreover, the compound which has an isocyanate group may have one isocyanate group in a molecule | numerator, and may have multiple, but it is preferable to have two or more. Further, the number of isocyanate groups in the molecule is preferably 8 or less, and more preferably 7 or less. This range is preferred because it tends to be a three-dimensional crosslinked matrix and a recording layer having excellent record retention can be obtained.
Moreover, since it is hard to color among the above, the compound which has an isocyanate group which has an aliphatic skeleton is preferable.

  A combination of a compound having an isocyanate group and a compound having an isocyanate-reactive functional group is a combination of 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 combination of a compound having three or more isocyanate groups in the molecule and a compound having two or more isocyanate-reactive functional groups in the molecule is preferable. According to the three-dimensional crosslinked matrix obtained by these combinations, there is a tendency that a recording layer having excellent record retention can be obtained.

  Examples of the compound having an isocyanate group include isocyanic acid, 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 Aliphatic hydrocarbon compounds such as isocyanatomethyl-1,8-octane diisocyanate, 1,4-cyclohexylene diisocyanate, isomer cyclohexanedimethylene diisocyanate; 1,4-phenylene diisocyanate, 2,4- and / or 2, 6 Aromatic compounds such as toluene diisocyanate, 1,5-naphthylene diisocyanate, 2,4′- or 4,4′-diphenylmethane diisocyanate and / or triphenylmethane 4,4 ′, 4 ″ -triisocyanate; It is done.

  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.

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 or more isocyanate-reactive groups in the molecule, but preferably has two or more. Further, the number of isocyanate-reactive groups in the molecule is preferably 8 or less, and more preferably 7 or less. This range is preferred because it tends to be a three-dimensional crosslinked matrix and a recording layer having excellent record retention can be obtained.
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 a number average molecular weight, preferably 50 or more, more preferably 100 or more, more preferably 150 or more. Further, it is preferably 50000 or less, more preferably 10,000 or less, and even more preferably 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 tends to 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. There is a tendency.

<Compound having a hydroxyl group as an isocyanate-reactive functional group>
The compound having a hydroxyl group as an isocyanate-reactive functional group may be any compound having one or more hydroxyl groups in one molecule, but preferably has two or more hydroxyl groups. Further, the hydroxyl group in the molecule is preferably 8 or less, and more preferably 7 or less. This range is preferred because it tends to be a three-dimensional crosslinked matrix and a recording layer having excellent record retention can be obtained.

  Examples of compounds having a hydroxyl group include glycols such as ethylene glycol, triethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, neopentyl glycol; butanediol, pentanediol, hexanediol, heptanediol, tetramethylene glycol Diols such as: bisphenols, or compounds obtained by modifying these polyfunctional alcohols with polyethyleneoxy chain or polypropyleneoxy chain; triols such as glycerin, trimethylolpropane, butanetriol, pentanetriol, hexanetriol, decanetriol, etc. Compounds in which these polyfunctional alcohols are modified with polyethyleneoxy chain or polypropyleneoxy chain; polyfunctional polyoxy Butylene; polyfunctional polycaprolactone; 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 preferably a number average molecular weight of 50 or more, more preferably 100 or more, and more preferably 150 or more. Further, it is preferably 50000 or less, more preferably 10,000 or less, and even more preferably 5000 or less. In the case where 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 tends to be prevented from being lowered. In addition, 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 or the crosslinking density is increased, so that the loss of recorded contents tends to be prevented. .

<Compound having an amino group as an isocyanate-reactive functional group>
The compound having an amino group as an isocyanate-reactive functional group may be any compound having at least one amino group in one molecule, but preferably has two or more amino groups. Further, the amino group in the molecule is preferably 8 or less, and more preferably 7 or less. This range is preferred because it tends to be a three-dimensional crosslinked matrix and a recording layer having excellent record retention can be obtained.

  Examples of the compound having an amino group include aliphatic amines such as ethylenediamine, diethylenetriamine, triethylenetetramine, and hexamethylenediamine; alicyclic amines such as isophoronediamine, menthanediamine, and 4,4′-diaminodicyclohexylmethane; And aromatic amines such as xylylenediamine, diaminodiphenylmethane, 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 preferably a number average molecular weight of 50 or more, more preferably 100 or more, more preferably 150 or more. Further, it is preferably 50000 or less, more preferably 10,000 or less, and even more preferably 5000 or less. In the case where 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 tends to 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, the compatibility with other components is improved or the crosslinking density is increased, so that the recorded content tends to be prevented from disappearing. .

<Compound having a mercapto group as an isocyanate-reactive functional group>
A compound having a mercapto group as the isocyanate-reactive functional group may be any compound having at least one mercapto group in one molecule, but preferably has two or more mercapto groups. Further, the mercapto group in the molecule is preferably 8 or less, and more preferably 7 or less. This range is preferred because it tends to be a three-dimensional crosslinked matrix and a recording layer having excellent record retention can be obtained.

Examples of compounds having a mercapto group include 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzene Dithiol, 1,10-decanedithiol, 1,2-ethanedithiol, 1,6-hexanedithiol, 1,9-nonanedithiol, 1,4-
Dithiol compounds such as bis (3-mercaptobutyryloxy) butane; tetrathiol compounds such as pentaerythritol tetrakis (3-mercaptopropionate) and pentaerythritol tetrakis (2-mercaptoacetate); pentaerythritol tetrakis (3-mercaptobuty Rate), trithiol compounds such as trimethylolpropane tris (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate); and the like. 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 preferably a number average molecular weight of 50 or more, more preferably 100 or more, more preferably 150 or more. Further, it is preferably 50000 or less, more preferably 10,000 or less, and even more preferably 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 tends to be prevented from being lowered. In addition, 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, or the crosslinking density is increased, so that the loss of recorded contents tends to be prevented. .

1-3. Polymerizable compound The polymerizable compound of the present invention is a compound represented by the following general formula (1).

(In the formula (1),
X is an alkylene group which may have a substituent, n ₁ is an integer of ₁ to 3, and R ¹ is a (hetero) aryl group in which two or more rings which may have a substituent are condensed. N ₂ is an integer of ₂ to 5, and R ² is hydrogen or a methyl group. A plurality of R ¹ may be the same or different. )

In formula (1), X is an alkylene group which may have a substituent. Although not particularly limited, in order to obtain sufficient diffraction efficiency, the number of carbon atoms is preferably 1 or more, preferably 20 or less, more preferably 10 or less, and still more preferably 5 or less.
Examples of X include methylene, ethylene, propylene, isopropylene, butylene, isobutylene, t-butylene, pentylene, isopentylene, t-pentylene, hexylene, polymethylene, trimethylene, pentamethylene, octamethylene and the like.

R ¹ may have a substituent, and is a (hetero) aryl group in which two or more rings are condensed, and preferably has a structure having a high refractive index. Here, the refractive index as R ¹ can be estimated by the Lorentz-Lorentz equation. The refractive index of R ¹ is preferably 1.55 or more, more preferably 1.60 or more, and further preferably 1.65 or more. Moreover, Preferably it is 1.95 or less, More preferably, it is 1.90 or less.
In addition, R ¹ preferably has a molecular weight that is somewhat large from the viewpoint of reducing shrinkage due to polymerization, and the molecular weight of R ¹ is preferably 50 or more, and more preferably 70 or more. From the viewpoint of securing mobility during recording, the molecular weight is preferably 300 or less, more preferably 250 or less.

The (hetero) aryl group in which two or more rings of R ¹ are condensed is 3 to 8 members, preferably 5
Examples thereof include groups in which two to six-membered aromatic hydrocarbon rings and / or heterocycles having one or more unsaturated bonds are condensed. The number of rings constituting R ¹ is preferably 2 or more, preferably 5 or less, more preferably 3 or less. Further, since R ¹ tends to lower the refractive index, it is preferable not to contain spiro carbon.

Hereinafter, specific examples of R ¹ include an aryl group in which two or more rings are condensed and a heteroaryl group in which two or more rings are condensed, but are not limited thereto.
R ¹ may be either an aryl group in which two or more rings are condensed or a heteroaryl group in which two or more rings are condensed, but a heteroaryl group is particularly preferable because it tends to obtain a high refractive index. .

<Aryl group fused with two or more rings>
Specifically, an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, an acenaphthylene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, etc., preferably 6 to 14 carbon atoms,
More preferably, 6-12 groups etc. are mentioned. Among them, from the viewpoint of refractive index, the larger the number of rings, the better. However, since a structure in which conjugation is long tends to lead to coloring, a twisted structure is preferable.

<Heteroaryl group in which two or more rings are condensed>
A group containing a heterocyclic structure containing one or more heteroatoms in the ring, and further condensed with an aromatic hydrocarbon ring and / or a ring having one or more unsaturated bonds. The delocalization of π electrons is not necessarily high, but it is preferable that the number of unsaturated bonds is large and / or that a hetero atom is included because it tends to greatly contribute to a high refractive index.
The hetero atom contained in the ring is not particularly limited, and each atom such as S, O, N, and P can be used. From the viewpoint of securing the refractive index, each atom of S, O, and N is preferable. Of these, S or O is preferred. In order to suppress coloring, the number of heteroatoms is preferably 1 to 2 in R1.

Specific examples of heteroaryl groups in which two or more rings are fused include indole ring, indoline ring, benzothiazole ring, benzofuran ring, benzothiophene ring, benzothiazole ring, benzoxazole ring, benzothioxan ring, benzodioxin ring A group in which three rings such as thianthrene ring, dibenzofuran ring, dibenzothiophene ring, dibenzothioxan ring, and dibenzodioxin ring are condensed; and the like.
Among these, from the viewpoint of refractive index, a thianthrene ring, a benzothiophene ring, and a dibenzothiophene ring are preferable, and a thianthrene ring and a dibenzothiophene ring are more preferable.

The substituent that R ¹ may have is not particularly limited as long as it does not lower the compatibility or does not decrease the refractive index. Specifically, C1-C3 alkylthio groups, such as a methylthio group, C2-C6 alkylthioalkyl groups, such as a methylthiomethyl group, etc. are mentioned.
A plurality of R ¹ may be the same or different.

n ₂ is an integer from 2 to 5. Among these, in order to further improve the solubility, it is preferably 4 or less, and more preferably 3 or less.

Benzene ring to which R ¹ is substituted may have a substituent group other than R ^1. For example, in order to further improve the solubility, an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkoxycarbonyl group, an alkoxyalkoxy group, an alkanoyloxy group, etc., in order to increase the refractive index, an aryl group, an alkylthioalkyl group, an aryl An oxy group, an arylalkoxyl group or the like may be substituted. However, in order to achieve an economical synthesis, it is preferably unsubstituted.

Here, the alkyl group is preferably a linear alkyl group having 1 to 4 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a secondary butyl group, and the like. It is done.
The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, and specific examples include a methoxy group and an ethoxy group.

The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 6 carbon atoms, and specifically includes a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, a butoxymethyl group, a methoxyethyl group, an ethoxyethyl group, and a propoxyethyl group. Group, butoxyethyl group and the like.
The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 2 to 5 carbon atoms, and specific examples include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, and a butoxycarbonyl group.

The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 3 to 6 carbon atoms, and specific examples thereof include a methoxyethoxy group, an ethoxyethoxy group, a propoxyethoxy group, and a butoxyethoxy group.
The alkanoyloxy group is preferably an alkanoyloxy group having 2 to 5 carbon atoms, and specific examples include an acetoxy group, a propionoxy group, a butyroxy group, and a valeroxy group.

The aryl group is preferably an aryl group composed of a monocyclic or condensed ring having 6 to 14 carbon atoms, and specific examples thereof include a phenyl group, a naphthyl group, and an anthranyl group.
The alkylthioalkyl group is preferably an alkylthioalkyl group having 2 to 4 carbon atoms, and specific examples include a methylthiomethyl group, a methylthioethyl group, an ethylthiomethyl group, and an ethylthioethyl group.

The aryloxy group is an aryloxy group having a monocyclic or condensed ring having 6 to 14 carbon atoms, and specific examples include a phenoxy group.
The arylalkoxy group is an arylalkoxy group having 7 to 5 carbon atoms, and specific examples include a benzyloxy group.

The bonding position of the benzene ring and —O— and the substitution position of R ¹ and the benzene ring are not particularly limited, but are preferably not adjacent to each other from the viewpoint of synthesis yield.
Also preferred is one having no SP3 carbon from the viewpoint of solubility in the substitution position of the benzene ring and R ^1.

The reactive compound represented by the formula (1) preferably has a molecular weight of 200 or more, more preferably 300 or more, from the viewpoint of reducing shrinkage due to crosslinking during light irradiation. Moreover, 800 or less is preferable and it is more preferable that it is 700 or less.
The polymerizable compound represented by the formula (1) has a refractive index or an apparent refractive index at an irradiation light wavelength (recording wavelength, etc.) of preferably 1.55 or more, more preferably 1.60 or more, more preferably 1.62 or more. Further, it is preferably 1.78 or less, more preferably 1.77 or less, and more preferably 1.75 or less. For example, when the polymerizable compound represented by the formula (1) is used as a hologram recording material, the refractive index is larger than 1.55, so that the diffraction efficiency tends to be large and the multiplicity tends to be sufficient. In addition, since the refractive index is less than 1.78, the difference in refractive index from the matrix resin does not become too large, that is, the scattering does not become too large, so that the transmittance does not decrease and is larger during recording and reproduction. It tends not to require energy.
Although the 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 or apparent refractive index at a wavelength other than the recording wavelength, and predict the refractive index at the recording wavelength.

  Here, the apparent refractive index means that when the compound is a solid, the refractive index cannot be measured as it is. Therefore, as described in Synthesis Example 1 described later, the compound is dissolved in an appropriate solvent to form a solution. The refractive index of the solution is measured, and the value obtained by extrapolating the refractive index when the compound is 100% is indicated.

The polymerizable compound used in the composition for a hologram recording medium of the present invention preferably has a molar extinction 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, the transmittance of the medium is prevented from being lowered, and sufficient diffraction efficiency with respect to the thickness tends to be obtained.

The solubility of the polymerizable compound constituting the composition for forming a hologram recording layer of the present invention is preferably 5 (g / 100 g) or more in acetone under the conditions of 25 ° C. and 1 atm. g / 100 g) or more.
When trying to realize low shrinkage at a high refractive index, generally, the solubility in a solvent such as toluene, THF (tetrahydrofuran), MEK (methyl ethyl ketone), acetone, or the composition for hologram recording layer is often poor. The polymerizable compound represented by the formula (1) used in the above has excellent solubility in solvents such as toluene, THF, MEK, and acetone, and the composition for hologram recording layer. It can be suitably used for products.

  The compound represented by the following formula (2) has a large refractive index, little shrinkage due to crosslinking, and excellent solubility.

(In Formula (2), X ¹ is an alkylene group which may have a substituent, n ₁₁ is an integer of 1 to 3, and R ¹¹ has two or more rings which may have a substituent. A condensed (hetero) aryl group, n ₂₁ is an integer of 2 to 5, R ²¹ is hydrogen or a methyl group, and a plurality of R ¹¹ may be the same or different.

X ¹ has the same meaning as X in formula (1), and the preferred range and the substituent that may be present are also synonymous. Similarly, n ₁ has the same meaning as n ₁₁ , R ¹¹ has the same meaning as R ¹ , n ₂₁ has the same meaning as n ₂ , and R ²¹ has the same meaning as R ² .

  Specific examples of the compounds represented by the above formulas (1) and (2) are illustrated below, but the present invention is not limited to these unless it exceeds the gist.

The composition for forming a hologram recording layer of the present invention has the polymerizable compound represented by the above formula (1), but the polymerizable compounds other than the above-described polymerizable compounds are used without departing from the gist of the present invention. These compounds may be included.
Examples of the polymerizable compound include a cation polymerizable monomer, an anion polymerizable monomer, and a radical polymerizable monomer. Any one of these polymerizable compounds may be used alone, or two or more thereof may be used in any combination and ratio.

<Cationically polymerizable monomer>
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, ethylenically unsaturated bond compounds, cyclic ether compounds. , Cyclic thioether compounds, vinyl compounds and the like. 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 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, 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.

<Radically 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.

1-4. Photopolymerization initiator The composition for a hologram recording medium of the present invention may further contain a photopolymerization initiator. As the photopolymerization initiator, any known radical polymerization 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, acylphosphine oxide compounds. In addition, oxime ester compounds and the like are used. Any one of these may be used alone, or two or more may be used in any combination and ratio. Among these, titanocene compounds, acylphosphine oxide compounds, oxime ester compounds, and the like are preferable because a polymerization reaction occurs in the visible light region.

  Specific examples of the oxime ester compound include those having the following structures (I) and (III).

(In the formula (I),
X ¹⁰ has a single bond, an alkylene group having 1 to 20 carbon atoms which may have a substituent, an alkenylene group (— (CH═CH) n— group) which may have a substituent, or a substituent. An alkynylene group (-(C≡C) n-), which may be a divalent group selected from the group consisting of a combination thereof (n represents an integer of 1 to 5),
R ¹⁰⁰ represents a monovalent organic group containing an aromatic ring and / or a heteroaromatic ring,
R ¹⁰¹ may have a substituent, each having 1 to 12 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 12 carbon atoms, an alkenyloxycarbonyl group having 3 to 12 carbon atoms, and 3 to 12 carbon atoms. Alkynyloxycarbonyl group, C7-12 aryloxycarbonyl group, C3-12 heteroaryloxycarbonyl group, C2-12 alkylthiocarbonyl group, C3-12 alkenylthiocarbonyl group, carbon An alkynylthiocarbonyl group having 3 to 12 carbon atoms, an arylthiocarbonyl group having 7 to 12 carbon atoms, a heteroarylthiocarbonyl group having 3 to 12 carbon atoms, an alkylthioalkoxy group, -O-N = C
R ¹¹⁰ R ¹¹¹ group, —N (OR ¹¹⁴ ) —CO—R ¹¹⁵ group and groups represented by the following general formula (II) (R ³⁰ and R ³¹ , R ³² and R ³³ , and R ³⁴ and R ³⁵ are: each represent optionally substituted good C1-12 alkyl group, a group selected from the group consisting of each other may be different.), R ¹⁰² may be each substituted, carbon An alkanoyl group having 2 to 12 carbon atoms, an alkenoyl group having 3 to 25 carbon atoms, a cycloalkanoyl group having 3 to 8 carbon atoms, an aryloyl group having 7 to 20 carbon atoms, a heteroarylloyl group having 3 to 20 carbon atoms, and 2 carbon atoms Represents a group selected from the group consisting of a C-10 alkoxycarbonyl group and a C7-20 aryloxycarbonyl group. )

[In the formula (III),
X ¹⁰ and Y ¹⁰ are any groups,
Z ¹⁰ represents a direct bond, an alkylene group which may have a substituent, an alkenylene group which may have a substituent, an alkynylene group which may have a substituent, a —C (═O) — group. , -C (= S)-group or a divalent group obtained by combining two or more of these.
R ²⁰¹ represents a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or a cycloalkyl group that may have a substituent.

X ¹⁰ and Y ^{10 in} the formula (III) are not particularly limited and are arbitrary groups. X ¹⁰ is preferably such that the number of elements other than hydrogen constituting X ¹⁰ is 1 or more, preferably 10 or less, from the sensitivity of hologram recording performance and the high activity of radicals generated. What is below is more preferable, What is 6 or less is more preferable, What is 4 or less is further more preferable.

X ¹⁰ is not particularly limited, and specifically includes an alkyl group that may have a substituent, an alkenyl group that may have a substituent, a cycloalkyl group that may have a substituent, and a substituent. It may be an aromatic ring having 3 to 20 carbon atoms, a heterocyclic ring having 3 to 20 carbon atoms that may have a substituent, or a —C (═O) —X ¹¹ —R ²⁰² group. However, it is preferable because the polymerization efficiency, the stability of the photopolymerization initiator, and the light emission characteristics after photocleavage of the photopolymerization initiator can be improved.

Y ¹⁰ is not particularly limited, and specifically, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, a cycloalkyl group that may have a substituent, and a substituent. which may have an aromatic ring, which may have a substituent group a heterocyclic ^ring, -Y 11 ^{-R 56} groups, -O-N = ^{CR 52}
R ⁵³ group, —N (OR ⁵⁴ ) — (C═O) —R ⁵⁵ group, or a group represented by the following formula (IV).

Y ² represents a direct bond, an alkylene group which may have a substituent, an alkenylene group which may have a substituent, an alkynylene group which may have a substituent, an —O— group or an —S— group. , -C (= O)-group, -C (= S)-group, and a divalent group obtained by combining two or more of these.
R ⁵⁶ specifically has an alkyl group which may have a substituent, an alkenyl group which may have a substituent, a cycloalkyl group which may have a substituent, and a substituent. May be an aromatic ring, an optionally substituted heterocyclic ring, -OR ⁵⁷ group, -SR ⁵⁸ group, -N = CR ⁵⁹
R ⁶⁰ group, —N (OR ⁶¹ ) —C (═O) —R ⁶² group, or a group represented by formula (IV).

R ⁵⁰ and R ⁵¹ represent an alkyl group which may have a substituent. R ⁵² , R ⁵³ , R ⁵⁷ and R ⁵⁸ each independently have an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. It represents an alkynyl group, an aromatic ring which may have a substituent, or a heterocyclic ring which may have a substituent.
R ⁵⁴ , R ⁵⁵ , R ⁵⁹ , R ⁶⁰ , R ⁶¹ and R ⁶² each independently represents an alkyl group which may have a substituent.

The compounds represented by the formulas (I) and (III) can be obtained by known methods described in JP 2010-008713 A and the like.

1-5. Catalyst The composition for a hologram recording medium of the present invention includes at least a compound having an isocyanate group and / or a compound having an isocyanate-reactive functional group, and a polymerizable compound represented by the general formula (1), and is described below. The compound having an isocyanate group and the compound having an isocyanate-reactive functional group are reacted. In this reaction, an appropriate catalyst can be used. Examples of catalysts are bis (4-t-butylphenyl) iodonium perfluoro-1-butanesulfonic acid, bis (4-t-butylphenyl) iodonium p-
Toluenesulfonic acid, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonic acid, (4-bromophenyl) diphenylsulfonium triflate, (4-t-
Butylphenyl) diphenylsulfonium trifluoromethanesulfonic acid, diphenyliodonium perfluoro-1-butanesulfonic acid, (4-fluorophenyl) diphenylsulfonium trifluoromethanesulfonic acid, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonic acid, tri Catalysts based on Lewis acids such as phenylsulfonium trifluoromethanesulfonic acid, onium salts such as bis (alkylphenyl) iodonium hexafluorophosphonic acid, zinc chloride, tin chloride, iron chloride, aluminum chloride, BF3, hydrochloric acid Protonic acids such as phosphoric acid, trimethylamine, triethylamine, triethylenediamine, dimethylbenzylamine, diazabicycloundecene and other amines, 2-methyli Imidazoles such as midazole, 2-ethyl-4-methylimidazole, trimellitic acid 1-cyanoethyl-2-undecylimidazolylum, bases such as sodium hydroxide, potassium hydroxide, potassium carbonate, dibutyltin laurate, Tin catalysts such as dioctyltin laurate and dibutyltin octoate, bismuth catalysts such as tris (2-ethylhexanato) bismuth and tribenzoyloxybismuth, tetrakis (ethylacetoacetate) zirconium, 1,1′-isopropylidenezirconocene dichloride, Zirconium catalysts such as tetrakis (2,4-pentanedionato) zirconium and the like can be mentioned.
Of these, a bismuth catalyst and a zirconium catalyst are preferable for improving storage stability.

The bismuth-based catalyst is not particularly limited as long as it is a catalyst containing a bismuth element and promotes the reaction of a compound having an isocyanate group and a compound having an isocyanate-reactive functional group.
Examples of bismuth-based catalysts include tris (2-ethylhexanato) bismuth, tribenzoyloxybismuth, bismuth triacetate, bismuth tris (dimethyldiocarbamate), bismuth hydroxide, triphenylbismuth (V) bis (trichloroarate ), Tris (4-methylphenyl) oxobismuth (V), triphenylbis (3-chlorobenzoyloxy) bismuth (V), and the like.
Among them, trivalent bismuth compounds are preferable from the viewpoint of catalytic activity, and bismuth carboxylate, general formula Bi (OCOR) ₃ (R is a linear or branched alkyl group, cycloalkyl group, or substituted or unsubstituted aromatic group). Is more preferable. Any one of the above bismuth catalysts may be used alone, or two or more thereof may be used in any combination and ratio.

The zirconium-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, dichloride (indenyl) zirconium, zirconium carbonate and the like can be mentioned.
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.
Further, the bismuth-based catalyst and the zirconium-based catalyst may be used alone or in combination.

1-6. Others The composition for a hologram recording medium in the present invention can contain other components as long as it does not contradict the gist of the present invention.

<Other catalysts>
In the composition for a hologram recording medium of the present invention, another curing catalyst can be used together with the catalyst in order to adjust the 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 or a rare earth compound. . Rare earth elements are 17 elements of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium belonging to group 3A of the periodic table. is there. Among these, from the viewpoint of storage stability (shelf life) of the hologram recording medium, a catalyst containing an element belonging to a lanthanoid is preferable. Among these, a catalyst containing light rare earth is preferable, and a catalyst containing lanthanum (La) and praseodymium (Pr) is more preferable.
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), triethylenediamine (TEDA), N-methylmorpholine (NMMO), N · (N ′, N′-dimethylaminoethyl) -morpholine (DMAEMO), bis (2-dimethylamino) Examples include amine compounds such as ethyl) ether (BDMEE), ethylene glycol bis (3-dimethyl) -aminopropyl ether (TMEGDA), and diisopropylethylamine (DIEA). Any of these may be used alone, or two or more of these may be used in any combination and ratio.

Other components include a solvent, a plasticizer, a dispersant, a leveling agent, an antifoaming agent, an adhesion promoter, etc. for preparing a recording layer of a hologram recording medium, and a chain transfer agent for recording reaction control. , 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. When the composition for a hologram recording medium of the present invention contains a compound having an isocyanate group, the compound having an isocyanate group is preferably 0.1% by mass or more, more preferably 10% by mass or more, and further preferably 35% by mass. % Or more. Moreover, Preferably it is 99.9 mass% or less, More preferably, it is 99 mass% or less, More preferably, it is 95 mass% or more.
When the hologram recording medium composition of the present invention contains a compound having an isocyanate-reactive functional group, the compound having an isocyanate-reactive functional group is preferably 0.1% by mass or more, more preferably 10% by mass or more. More preferably, it is 35% by mass or more. Moreover, Preferably it is 99.9 mass% or less, More preferably, it is 99 mass% or less, More preferably, it is 95 mass% or more.
When the composition for a hologram recording medium of the present invention has both an isocyanate group-containing compound and an isocyanate-reactive functional group, the total is preferably 0.1% by mass or more, more preferably 10% by mass or more, Preferably it is 35 mass% or more. Moreover, Preferably it is 99.9 mass% or less, More 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.

When the hologram recording medium composition of the present invention includes a compound having an isocyanate group and a compound having an isocyanate-reactive functional group, the ratio of the number of isocyanate-reactive functional groups of the compound having an isocyanate-reactive functional group to the number of isocyanate groups is Preferably it is 0.1 or more, More preferably, it is 0.5 or more. Moreover, Preferably it is 10.0 or less, Preferably it is 2.0 or less. When this ratio is within the above range, there are few unreacted functional groups, and the storage stability tends to be improved.
The amount of the polymerizable compound used is preferably 0.1% by mass or more, more preferably 1% by mass or more, more preferably 2% by mass or more. Moreover, it is 80 mass% or less preferably, More preferably, it is 50 mass% or less, More preferably, it is 30 mass% or less. When the amount of the polymerizable compound is larger than the above lower limit value, sufficient diffraction efficiency is obtained, and when the amount is less than the upper limit value, the compatibility of the recording layer tends to be maintained.

  The amount of the photopolymerization initiator used is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less. When the amount of the photopolymerization initiator is larger than the above lower limit, sufficient recording sensitivity tends to be obtained.

In the present invention, the amount of the catalyst used is preferably determined in consideration of the reaction rate of the compound having an isocyanate group and the compound having an isocyanate-reactive functional group, preferably 5% by mass or less, more preferably 4% by mass or less. More preferably, it is 1 mass% or less. Moreover, it is preferable to use 0.005 mass% or more.
The total amount of other components other than the above components may be 30% by mass or less, preferably 15% by mass or less, and more preferably 5% by mass.

1-8. Method for producing composition for hologram recording medium In the composition for hologram recording medium of the present invention, the components contained in the composition for hologram recording medium may be mixed in any combination and order. Further, other components may be combined and mixed.
For example, a composition (liquid) containing a compound having an isocyanate group and a compound having an isocyanate-reactive functional group may be prepared separately from the liquid A and the liquid B and mixed at the time of molding the hologram recording medium. The composition for a hologram recording medium of the present invention includes at least a compound having an isocyanate group and / or a compound having an isocyanate-reactive functional group, and a polymerizable compound represented by the general formula (1), and a liquid A and / or It refers to a mixture of B liquid and further A liquid and B liquid. The composition for a hologram recording medium of the present invention can be obtained by the following method, but the present invention is not limited to this.

As a composition for hologram recording medium (liquid A), a compound having an isocyanate group and a polymerizable compound represented by the formula (1) and all components other than the catalyst are mixed; a compound having an isocyanate group and the formula (1) Prepared by a method such as mixing a polymerizable compound represented by a catalyst and a catalyst; mixing a compound having an isocyanate group, a polymerizable compound represented by formula (1) and a compound having an isocyanate-reactive functional group; can do.
Also, as the composition for hologram recording medium (liquid B), all components other than the compound having an isocyanate-reactive functional group and the catalyst are mixed; the compound having an isocyanate-reactive functional group and the polymerization represented by the formula (1) It can be prepared by a method such as mixing a compound having a reactive compound and a catalyst; mixing a compound having an isocyanate-reactive functional group, a polymerizable compound represented by formula (1) and a compound having an isocyanate group; .
Components other than the compound having an isocyanate group and the compound having an isocyanate-reactive functional group contained in the composition for hologram recording medium (liquid A, liquid B) (polymerizable compound, catalyst, other components, etc.) It may be contained in both B liquids, and may be contained in one side. From the viewpoint of solubility, the polymerizable compound is preferably contained in a composition for a hologram recording medium containing a compound having an isocyanate group.
Moreover, the quantity and ratio of each component mentioned above mean the quantity and ratio as a composition which combined A liquid and B liquid.

  The liquid A and liquid B described above are preferably dehydrated and degassed during or after mixing. 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.

The mixing of the A liquid and the B liquid is preferably 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.
Moreover, the isocyanate functional prepolymer by reaction of the compound which has an excess isocyanate group, and the compound which has an isocyanate reactive functional group can also be used as a compound which has an isocyanate group. Furthermore, an isocyanate-reactive prepolymer obtained by reacting a compound having an excess isocyanate-reactive functional group with a compound having an isocyanate group can also be used as the compound having an isocyanate-reactive functional group.

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, but is preferably 1 μm or more, more preferably 10 μm or more, and preferably 3000 μm or less, more preferably 2000 μm or less. It is. 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 at the time of multiplex recording on the hologram recording medium, and the degree of multiplex recording tends to be increased. 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. There is a tendency to be able to.
Further, the shrinkage ratio of the recording layer due to exposure during recording and reproduction of information is preferably 0.25% or less, more preferably 0.20% or less, from the viewpoint of recording reproducibility. More preferably, it is 18 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 acrylic, polyethylene terephthalate, polyethylene naphthoate, polycarbonate, polyethylene, polypropylene, amorphous polyolefin, polystyrene, polycycloolefin, cellulose acetate, and other organic materials; glass, silicon, quartz, etc. An inorganic material is mentioned. Among these, polycarbonate, acrylic, polyester, amorphous polyolefin, glass and the like are preferable, and polycarbonate, acrylic, amorphous polyolefin, polycycloolefin, and glass are more 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, 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.

As a method for measuring the light emission intensity of a hologram medium, a laser having a recording wavelength is irradiated at right angles to the medium, light emission at an angle of 45 degrees formed from the laser light is measured using a USB4000 manufactured by Ocean Optics, and the light receiving time is It is obtained by integrating the emission spectrum when performed in 100 milliseconds.

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. The solvent is 1
You may use a seed | species independently 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, 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. Among these lights, for example, solid lasers such as ruby, glass, Nd-YAG and Nd-YVO4; diode lasers such as GaAs, InGaAs and GaN; helium-neon, argon, krypton, excimer, CO 2 Gas lasers such as: 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.

[Synthesis Example 1]

  A solution of 3.0 g of 4-dibenzothiophene boric acid, 0.41 g of tetrakis (triphenylphosphine) palladium and 1.58 g of 2,4-dibromophenol was added to a round bottom flask, and 40 ml of dimethoxyethane was added and stirred. 15 ml of sodium bicarbonate water was added, and the flask was placed in an oil bath at 80 ° C. and heated for 3 hours. The mixture was cooled to room temperature and concentrated with an evaporator until it became two layers, and 50 ml of methylene chloride was added to separate from the aqueous layer. The aqueous layer was washed with methylene chloride, combined with the previous methylene chloride solution, and dried by adding magnesium sulfate. After filtering through filter paper and concentrating, separation with a silica gel column (eluent: hexane: ethyl acetate = 80: 20 (volume ratio)) to concentrate Rf0.27 component, 1.02 g of the above compound 1 (white solid) ( Yield 35%) was obtained (EMS = 458).

  To a solution in which 1.0 g of Compound 1 synthesized in a round bottom flask was added and 10 mL of DMF was added, 0.55 g of 2-bromoethanol and 1.8 g of potassium carbonate were added, and the mixture was heated and stirred at 60 ° C. for 48 hours in an oil bath. The reaction solution cooled to room temperature was added to 150 g of ice and stirred, and the precipitated solid was filtered off to obtain 1.13 g (97% yield) of Compound 2 as a white solid (EMS = 502).

To a solution in which 2.0 g of Compound 2 synthesized in a round bottom flask was added and 20 mL of THF was added, 0.56 g of triethylamine was added and stirred in an ice bath. To this mixture, 0.47 g of acryloyl chloride was added dropwise at an internal temperature of 0 ° C. to 5 ° C., and the mixture was stirred as it was for 30 minutes. The reaction mixture was poured into 30 mL of water and extracted twice with 50 mL of ethyl acetate. The organic layer was washed with 1% aqueous sodium hydroxide solution, water and saturated brine, and dried by adding sodium sulfate. After the sodium sulfate was filtered off, a solution obtained by adding 5 mL of ethyl acetate to the concentrated solution was added dropwise to ethanol, and the produced solid was filtered off to obtain 1.68 g (yield 76%) of Compound 3 as a white solid. Obtained (EMS = 556).

[Synthesis Example 2]

To a solution obtained by dissolving 2.0 g of Compound 1 synthesized in Synthesis Example 1 in 20 mL of DMF in a round bottom flask was added 0.6 g of 3-bromopropanol and 1.8 g of potassium carbonate, and the mixture was heated and stirred at 60 ° C. for 7 hours in an oil bath. The reaction mixture was cooled to room temperature and then poured into 150 mL of ice water, and the precipitated solid was filtered off to obtain 2.2 g of a white solid (yield 98%). (EMS = 516)

To a solution in which 2.0 g of Compound 4 synthesized in a round bottom flask was added and 20 mL of THF was added, 0.55 g of triethylamine was added and stirred in an ice bath. To this mixture, 0.46 g of acryloyl chloride was added dropwise at an internal temperature of 0 ° C. to 5 ° C., and the mixture was stirred as it was for 30 minutes. The reaction mixture was poured into 30 mL of water and extracted twice with 50 mL of ethyl acetate. The organic layer was washed with 1% aqueous sodium hydroxide solution, water and saturated brine, and dried by adding sodium sulfate. A solution obtained by adding 5 mL of ethyl acetate to the concentrated solution after filtering out sodium sulfate was added dropwise to ethanol, and the resulting solid was filtered to obtain 1.71 g (yield 77%) of Compound 5 as a white solid. Obtained (EMS = 570).

[Synthesis Example 3]

To a solution obtained by dissolving 3.0 g of Compound 1 synthesized in Synthesis Example 1 in 30 mL of DMF in a round bottom flask, 1.0 g of 4-bromopropanol and 3.2 g of cesium carbonate were added, and the mixture was heated and stirred at 60 ° C. for 30 hours in an oil bath. The reaction mixture was cooled to room temperature, then poured into 300 mL of ice water, and the precipitated solid was filtered off to obtain 3.4 g of a white solid (yield 99%). (EMS = 530)

  To a solution in which 3.0 g of Compound 6 synthesized in a round bottom flask was added and 30 mL of THF was added, 0.8 g of triethylamine was added and stirred in an ice bath. To this mixed solution, 0.7 g of acryloyl chloride was added dropwise at an internal temperature of 0 ° C. to 5 ° C., and the mixture was stirred as it was for 30 minutes. The reaction mixture was poured into 50 mL of water and extracted twice with 50 mL of ethyl acetate. The organic layer was washed with 1% aqueous sodium hydroxide solution, water and saturated brine, and dried by adding sodium sulfate. A solution in which 5 mL of ethyl acetate was added to the concentrated sodium sulfate after filtration was added dropwise to ethanol, and the resulting solid was filtered to obtain Compound 7 as a white solid (EMS = 584).

[Synthesis Example 4]

Add 0.5 g of Compound 1 synthesized in a round bottom flask, add 0.6 g of 2-bromoethanol and 0.9 g of potassium carbonate to a solution containing 20 mL of DMF, and add 4 g at 60 ° C. in an oil bath.
The mixture was stirred for 8 hours. The reaction liquid cooled to room temperature was added to 150 g of ice and stirred, and the precipitated solid was filtered off to obtain 0.55 g (yield 92%) of Compound 8 as a white solid (EMS = 546).

To a solution containing 0.5 g of Compound 8 synthesized in a round bottom flask and 5 mL of THF, 0.13 g of triethylamine was added and stirred in an ice bath. To this mixture, 0.11 g of acryloyl chloride was added dropwise at an internal temperature of 0 ° C. to 5 ° C., and the mixture was stirred as it was for 30 minutes. The reaction mixture was poured into 30 mL of water and extracted twice with 20 mL of ethyl acetate. The organic layer was washed with 1% aqueous sodium hydroxide solution, water and saturated brine, and dried by adding sodium sulfate. After the sodium sulfate was filtered off, a solution obtained by adding 2 mL of ethyl acetate to the concentrated solution was added dropwise to ethanol, and the produced solid was filtered off to obtain 0.47 g (yield 86%) of Compound 9 as a white solid. Obtained (EMS = 600).

Synthesis Comparative Example 1

To a solution in which 2.0 g of Compound 1 was added to a round bottom flask and 20 L of THF was added, 0.5 g of triethylamine was added and stirred in greed. To this mixed solution, 0.4 g of acryloyl chloride was added dropwise at an internal temperature of 0 ° C. to 5 ° C., followed by stirring for 30 minutes. The reaction mixture was poured into 30 mL of water and extracted twice with 50 mL of ethyl acetate. The organic layer was washed with 1% aqueous sodium hydroxide solution, water and saturated brine, and dried by adding sodium sulfate. A solution obtained by adding 5 mL of ethyl acetate to the concentrated solution after filtering out sodium sulfate was added dropwise to ethanol, and the resulting solid was filtered to obtain compound 10 as a white solid in 2.10 g (yield 93%). (EMS = 512).

Synthesis Comparative Example 2

  When 1.5 g of 4-dibenzothiophene boric acid, 0.22 g of tetrakis (triphenylphosphine) palladium, and 1.2 g of 3-bromophenol were placed in a round bottom flask and 50 ml of dimethoxyethane was added and stirred, 1M sodium bicarbonate was added. 7.5 ml of water was added and the flask was placed in an 80 ° C. oil bath and heated for 6 hours. The mixture was cooled to room temperature and concentrated with an evaporator until it became two layers, and 20 ml of methylene chloride was added to separate from the aqueous layer. The aqueous layer was washed with methylene chloride, combined with the previous methylene chloride solution, and dried by adding magnesium sulfate. After filtering through a filter paper and concentrating, it was separated with a silica gel column as an eluent, hexane: ethyl acetate = 70: 30, and concentrated to obtain 1.03 g (yield 68%) of Compound 11 as a white solid (EMS = 276). .

0.43 g of triethylamine was added to a solution obtained by adding 1.03 g of Compound 11 to a round bottom flask and 15 mL of THF, and the mixture was stirred in greed. To this mixture, 0.40 g of acryloyl chloride was added dropwise at an internal temperature of 0 ° C. to 5 ° C., and the mixture was stirred as it was for 30 minutes. The reaction mixture was poured into 10 mL of water and extracted twice with 20 mL of ethyl acetate. The organic layer is 1% aqueous sodium hydroxide, water,
After washing with saturated brine, sodium sulfate was added and dried. Sodium sulfate was filtered off, and a solution obtained by adding 5 mL of ethyl acetate to the concentrated solution was added dropwise to ethanol, and the resulting solid was filtered off to obtain 0.90 g (yield 73%) as a white solid. (EMS = 330
).

[Example 1]
<Preparation of composition for hologram recording medium>
Hexamethylene diisocyanate adduct (NCO% (isocyanate group ratio): 17.9%) 6.23 g, compound 3 0.46 g, and 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole -3-yl] -1- (O-acetyloxime)
A solution A was prepared by dissolving 0.023 g of ethyl glutarate.
Next, 0.001 g of an octylic acid solution of tris (2-ethylhexanoate) bismuth was dissolved in 8.76 g of polyoxypropylene glycol having a molecular weight of about 1000 to obtain a solution 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>
Subsequently, the above mixed solution degassed in vacuum was poured onto a slide glass on which a spacer sheet having a thickness of 500 μm was placed on the two ends, and the slide glass was placed thereon, and the periphery was fixed with a clip at 60 ° C. Was measured for 15 hours to prepare a hologram recording medium for measurement. 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.

[Example 2]
It was prepared and evaluated in the same manner as in Example 1 except that Compound 3 used in Example 1 was changed to Compound 5.

[Comparative Example 1]
It was produced and evaluated in the same manner as in Example 1 except that Compound 3 used in Example 1 was changed to Compound 10.

[Comparative Example 2]
It was produced and evaluated in the same manner as in Example 1 except that Compound 3 used in Example 1 was changed to Compound 12.

[Comparative Example 3]
The compound 3 used in Example 1 was added to 0.186 g of 2,4,6-tribromophenyl acrylate and 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1 It was produced and evaluated in the same manner as in Example 1 except that ethyl-(O-acetyloxime) glutarate was changed to 0.046 g of 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

[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 with 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 shows a single-mode laser diode manufactured by Sony that can obtain light around 405 nm (“L1” in FIG. 1A)), L2 indicates a laser light source for reproducing light that emits light having a wavelength of 633 nm, and PD1, PD2 Indicates a photodetector. Also, 1
Indicates an LED unit, 2 indicates an arm, and 3 indicates 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 hologram recording, using a He-Ne laser that can obtain light with a wavelength of 633 nm (V05-LHP151 manufactured by Meles 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. 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.
In addition, M / # made 15 or more A, 10 or more and less than 15 B, and less than 10 C.

(sensitivity)
The sensitivity of the sample for measurement is 8 of the maximum M / # indicated by the sample in the above M / # measurement.
This represents the average sensitivity until it reaches 0%, 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).
The sensitivity was set to A for 1.0 or more, B for 0.5 or more and less than 1.0, and C for less than 0.5.

(Shrinkage factor)
By rotating the sample with respect to the optical axis, the angle formed by the bisector of the inner angle at the point where the two light beams intersect and the normal of the medium is moved in increments of −28 degrees to 28 degrees and 4 degrees, and 15 times multiplexed. Recording was performed with a diffraction efficiency of 0.1% or less at one time, uniform irradiation by the LED unit was 6 mW / cm ² , and the time was 5 minutes. For the medium after multiple recording, the angle selectivity of diffraction efficiency is plotted, and the deviation from the originally recorded angular position is measured for each recording angle. The obtained angle deviation value (= difference in diffraction grating spacing) is expressed in the relational expression regarding angle deviation and shrinkage rate described in Applied Physics Letters, Vol. 73, No. 10, pp. 1337-1339 (1998). By substituting, the shrinkage value satisfying the relational expression was obtained.

(Solubility)
A compound was dissolved in acetone so as to be 5 g / 100 g.

In Comparative Example 1 and Comparative Example 2, the evaluation media were not dissolved and could not be evaluated.
Further, in Comparative Example 3 in which the polymerizable compound was generally 2,4,6-tribromophenyl acrylate, which is generally referred to as a high refractive index, the diffraction efficiency was not sufficiently high, and the shrinkage ratio was large.
From the above, high diffraction efficiency and low shrinkage can be realized by using the polymerizable compound of the present invention.

Claims (5)

A composition for a hologram recording medium, comprising at least a compound having an isocyanate group and / or a compound having an isocyanate-reactive functional group, and a polymerizable compound represented by the following general formula (1).

(In the formula (1),
X is an alkylene group which may have a substituent, n ₁ is an integer of ₁ to 3, and R ¹ is a (hetero) aryl group in which two or more rings which may have a substituent are condensed. N ₂ is an integer of ₂ to 5, and R ² is hydrogen or a methyl group. A plurality of R ¹ may be the same or different. ) 2. The composition for a hologram recording medium according to claim 1, wherein R ¹ is a heteroaryl group in which two or more rings optionally having a substituent are condensed. The composition for a hologram medium according to claim 1, further comprising a photopolymerization initiator. A hologram recording medium comprising the composition for a hologram recording medium according to claim 1. A compound represented by the following general formula (2):

(In Formula (2), X ¹ is an alkylene group which may have a substituent, n ₁₁ is an integer of 1 to 3, and R ¹¹ has two or more rings which may have a substituent. A condensed (hetero) aryl group, n ₂₁ is an integer of 2 to 5, R ²¹ is hydrogen or a methyl group, and a plurality of R ¹¹ may be the same or different.

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