Composition for holographic recording medium, cured product for holographic recording medium, and holographic recording medium

Abstract

The present invention provides a composition for a holographic recording medium, the composition being capable of suppressing generation of a colored body or a light-emitting body that is derived from an oxime ester photopolymerization initiator and effectively suppressing undesirable phenomena such as loss of light and color change of a display image without greatly lowering hologram characteristics. Disclosed is a composition for a holographic recording medium, which contains the following components (a) to (f).　Component (a): an isocyanate compound which does not contain an aromatic ring or a methacrylate group; Component (b): a polycaprolactone polyol; Component (c): an acrylate monomer; Component (d): an oxime ester photopolymerization initiator; Component (e): a compound which has a nitroxyl radical group and an isocyanate-reactive functional group; Component (f): a compound which has an isocyanate group and a methacrylate group, or a compound which has an isocyanate-reactive functional group and a methacrylate group

Description

Composition for holographic recording medium, cured product for holographic recording medium, and holographic recording medium

[0001] The present invention relates to a composition for a holographic recording medium, a cured product for a holographic recording medium obtained by curing the composition for a holographic recording medium, and a holographic recording medium using the composition for a holographic recording medium.

[0002] In recent years, studies have been conducted into applying holographic recording media, which were developed for memory applications, to optical elements in AR (Augmented Reality) glass light guide plates. The light guide plate must deliver the projector's display image to the eye without loss or color change. Furthermore, since AR glasses are worn on the face, it is preferable for them to be colorless from an aesthetic perspective. Physically, the former is quantitatively evaluated by absorbance at blue light (450 nm), and the latter by the CIE DE2000 (ΔE00) color difference formula.

[0003] In conventional hologram materials, oxime ester photopolymerization initiators are preferably used as photopolymerization initiators due to their excellent sensitivity. However, light guide plates using hologram materials containing oxime ester photopolymerization initiators contain colorants or light-emitting materials (hereinafter referred to as "colorants / light-emitting materials") derived from the oxime ester photopolymerization initiators. Furthermore, it has been found that these colorants and light-emitting materials increase in amount during accelerated heat resistance testing. When a light guide plate contains colorants or light-emitting materials, light emitted from a projector experiences light loss and changes in the color of the displayed image as it passes through the light guide plate, which is undesirable from the perspective of performance as a light guide plate. It is also undesirable from an aesthetic standpoint.

[0004] To solve this problem, oxime ester photopolymerization initiators with specific structures have been used (for example, Patent Documents 1 to 3).

[0005] However, merely employing the oxime ester photopolymerization initiators having specific structures that have been proposed so far has not yet been sufficient to improve coloration.

[0006] Patent No. 6572608 Patent No. 6677330 Patent No. 7290072

[0007] An object of the present invention is to provide a composition for a holographic recording medium, a cured product thereof, and a holographic recording medium, which can suppress the generation of colored substances and light-emitting substances derived from oxime ester photopolymerization initiators and can effectively suppress undesirable phenomena such as light loss and changes in the color of displayed images without significantly deteriorating holographic properties.

[0008] As a result of extensive investigations aimed at solving the above-mentioned problems, the present inventors have found that by blending a compound having an isocyanate group or an isocyanate-reactive functional group and a methacrylate group into a hologram material, problems such as light loss due to colorants and light-emitting substances derived from oxime ester photopolymerization initiators and changes in the color of displayed images can be suppressed.

[0009] [1] A composition for a holographic recording medium, comprising the following components (a) to (f): component (a): an isocyanate compound not containing an aromatic ring or a methacrylate group; component (b): a polycaprolactone polyol; component (c): an acrylate monomer; component (d): an oxime ester photopolymerization initiator; component (e): a compound having a nitroxyl radical group and an isocyanate-reactive functional group; and component (f): a compound having an isocyanate group and a methacrylate group, or a compound having an isocyanate-reactive functional group and a methacrylate group.

[0010] [2] The composition for holographic recording media according to [1], wherein the isocyanate-reactive functional group in component (f) is a hydroxyl group, an amino group, or a mercapto group. [3] The composition for holographic recording media according to [1] or [2], wherein component (f) is a compound having an isocyanate group and a methacrylate group, or a compound having a hydroxyl group and a methacrylate group. [4] The composition for holographic recording media according to [3], wherein component (f) is a compound having a hydroxyl group and a methacrylate group. [5] The composition for holographic recording media according to any one of [1] to [4], wherein the content of component (f) relative to component (c) is 10 mol % or more and 100 mol % or less. [6] The composition for holographic recording media according to any one of [1] to [5], wherein the refractive index of the acrylate monomer in component (c) is 1.65 or more. [7] The composition for holographic recording media according to any one of [1] to [6], wherein component (d) is a ketoxime ester photopolymerization initiator. [8] The composition for a holographic recording medium according to any one of [1] to [7], further comprising the following component (g): a catalyst that promotes the reaction between an isocyanate group and an isocyanate-reactive functional group.

[0011] [9] A cured product for a holographic recording medium obtained by curing the composition for a holographic recording medium according to any one of [1] to [8].

[10] A laminate for a holographic recording medium having a support and a recording layer made of the cured product for a holographic recording medium according to [9].

[11] A holographic recording medium obtained by exposing the cured product for a holographic recording medium according to [9] or the laminate for a holographic recording medium according to

[10] .

[0012]

[12] An optical material comprising the cured product for a holographic recording medium according to [9].

[13] An optical component comprising the cured product for a holographic recording medium according to [9].

[14] A large-capacity memory comprising the holographic recording medium according to

[11] .

[15] An optical element obtained by holographic recording in the holographic recording medium according to

[11] .

[16] An AR light guide plate comprising the optical element according to

[15] .

[17] AR glasses comprising the optical element according to

[15] .

[0013]

[18] A composition solution set for a holographic recording medium, comprising a solution A and a solution B, wherein the solution A contains at least the following components (a), (c), (d), and (e), the solution B contains at least the following components (b) and (g), and either the solution A or the solution B, or both the solution A and the solution B, contain a component (f): component (a): an isocyanate compound not containing an aromatic ring and a methacrylate group, component (b): a polycaprolactone polyol, component (c): an acrylate monomer, component (d): an oxime ester photopolymerization initiator, component (e): a compound having a nitroxyl radical group and an isocyanate-reactive functional group, component (f): a compound having an isocyanate group and a methacrylate group, or a compound having an isocyanate-reactive functional group and a methacrylate group, component (g): a catalyst that promotes the reaction between an isocyanate group and an isocyanate-reactive functional group.

[0014] The composition for holographic recording media of the present invention can suppress the generation of colored substances and light-emitting substances derived from the oxime ester photopolymerization initiator, and can effectively suppress undesirable phenomena such as light loss and changes in the color of the displayed image without significantly deteriorating the holographic properties.

[0015] Fig. 1 is a schematic diagram showing the configuration of an apparatus used for PL measurement in the examples. Fig. 2 is a schematic diagram showing the configuration of an apparatus used for transmission hologram recording in the examples. Fig. 3 is a schematic diagram showing the configuration of an apparatus used for reflection hologram recording in the examples.

[0016] The following describes in detail the embodiments of the present invention. The products and methods exemplified below are examples (typical examples) of the embodiments of the present invention, and the present invention is not limited to these contents as long as they do not deviate from the gist of the present invention.

[0017] [Composition for Holographic Recording Media] The composition for holographic recording media of the present invention contains the following components (a) to (f), and more preferably contains the following component (g): Component (a): an isocyanate compound not containing an aromatic ring or a methacrylate group; Component (b): a polycaprolactone polyol; Component (c): an acrylate monomer; Component (d): an oxime ester photopolymerization initiator; Component (e): a compound having a nitroxyl radical group and an isocyanate-reactive functional group; Component (f): a compound having an isocyanate group and a methacrylate group, or a compound having an isocyanate-reactive functional group and a methacrylate group; Component (g): a catalyst that promotes the reaction between an isocyanate group and an isocyanate-reactive functional group.

[0018] <Mechanism> The mechanism by which the present invention can suppress the generation of colored bodies and light-emitting bodies derived from the oxime ester photopolymerization initiator and suppress undesirable phenomena such as light loss and changes in color of displayed images without significantly degrading holographic properties is believed to be as follows. That is, the oxime ester photopolymerization initiator generates iminyl radicals and acyl radicals (hereinafter referred to as "iminyl radicals and acyl radicals") upon irradiation with light. It is believed that these radicals form complexes with dimers or polymerizable monomers to become colored bodies or light-emitting bodies. In the composition for holographic recording media of the present invention, the compound having an isocyanate group and a methacrylate group (component (f)), or the methacrylate group of a compound having an isocyanate-reactive functional group and a methacrylate group, captures these radicals, thereby suppressing the generation of colored bodies and light-emitting bodies. As a result, it is believed that undesirable phenomena such as light loss and changes in color of displayed images due to the colored bodies and light-emitting bodies can be suppressed.

[0019] In addition, U.S. Patent No. 8,658,332 (hereinafter referred to as Patent Document 4) discloses a compound having both a functional group that chemically bonds to the matrix and a functional group that captures polymer radicals, and its effect is said to be to improve the holographic characteristic M / # (Δn) by 1.5 times or more. However, as mentioned above, the problem of the present invention is to capture iminyl radicals and acyl radicals, which are the cause of colored bodies and light-emitting bodies, and the problem to be solved is different. Patent Document 4 does not suggest how to solve the problem of the present invention, and the concept is different. In fact, Patent Document 4 also exemplifies aromatic compounds and nitroxy radical compounds, but the chemical structure of the fixing monomer of component (f) used in the present invention is limited to methacrylate compounds. Furthermore, the compound described in Patent Document 4 is characterized by improving M / # (Δn) by 1.5 times or more at a blending amount of less than 0.72 mass%, but this is because the compound described in Patent Document 4 and the methacrylate compound of component (f) of the present invention have different reactivity with iminyl radicals and acyl radicals, which are the cause of colored bodies and light-emitting bodies.

[0020] Furthermore, Japanese Patent Laid-Open Publication No. 2010-84148 (hereinafter referred to as Patent Document 5) exemplifies a urethane acrylate compound made from HEMA (hydroxyethyl methacrylate) as an acrylate monomer for hologram recording materials. While it is theoretically possible that unreacted HEMA remains in the hologram recording material, Patent Document 5 does not specifically describe or suggest the chemical structure or effect of component (f) as a fixing monomer in the present invention. Furthermore, there is no idea of ​​deliberately including HEMA as a fixing monomer for component (f) used in the present invention. Furthermore, International Publication No. 2015 / 012020 (hereinafter referred to as Patent Document 6) describes a urethane (meth)acrylate resin obtained by reacting an aromatic diisocyanate compound, a polyol compound, and a hydroxyl group-containing (meth)acrylate compound as essential raw materials, and a plastic lens obtained by curing the resin. However, Patent Document 6 is in a different field from the present invention, and the problem to be solved is clearly different, as well as the technical concept. As described above, Patent Documents 4 to 6 do not suggest the problems, configurations, and effects of the present invention at all.

[0021] Each component contained in the composition for holographic recording media of the present invention will be described below.

[0022] <Component (a)> Component (a) is an isocyanate compound containing neither an aromatic ring nor a methacrylate group, and is a component that reacts with a polycaprolactone polyol (component (b)) having a hydroxyl group as an isocyanate-reactive functional group, preferably in the presence of a curing catalyst (component (g)) described below, to form a resin matrix.

[0023] If the isocyanate compound of component (a) contains an aromatic ring, it will cause coloration. Therefore, in the present invention, an isocyanate compound that does not contain an aromatic ring is used as component (a).

[0024] The proportion of isocyanate groups in the molecules of the isocyanate compound of component (a) is preferably 50% by mass or less, more preferably 47% by mass or less, and even more preferably 45% by mass or less. The lower limit is usually 0.1% by mass or more, preferably 1% by mass or more. If the proportion of isocyanate groups is equal to or less than the above upper limit, turbidity is less likely to occur when the hologram recording medium is formed, and optical uniformity is obtained. Furthermore, if the proportion of isocyanate groups is equal to or more than the above lower limit, the hardness and glass transition temperature of the resin matrix are increased, and loss of recording information can be prevented.

[0025] The proportion of isocyanate groups in the present invention refers to the proportion of isocyanate groups in the entire isocyanate compound used, and the proportion of isocyanate groups in the isocyanate compound can be calculated using the following formula: (42 x number of isocyanate groups / molecular weight of isocyanate compound) x 100.

[0026] The isocyanate compound of component (a) is not particularly limited in type as long as it does not contain an aromatic ring or a methacrylate group, and may have, for example, an aliphatic or alicyclic skeleton. The isocyanate compound may have one or two or more isocyanate groups in the molecule, but preferably has two or more. This is because a crosslinked matrix obtained from an isocyanate compound (component (a)) having two or more isocyanate groups in the molecule and a polycaprolactone polyol (component (b)) having three or more hydroxyl groups as isocyanate-reactive functional groups in the molecule, or an isocyanate compound (component (a)) having three or more isocyanate groups in the molecule and a polycaprolactone polyol (component (b)) having two or more hydroxyl groups as isocyanate-reactive functional groups in the molecule, can provide a recording layer with excellent record retention properties.

[0027] Examples of isocyanate compounds that do not contain an aromatic ring or a methacrylate group include isocyanic acid, butyl isocyanate, octyl isocyanate, butyl diisocyanate, hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), 1,3-bis(isocyanatomethyl)cyclohexane, 1,8-diisocyanato-4-(isocyanatomethyl)octane, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, isomeric bis(4,4'-isocyanatocyclohexyl)methane and mixtures thereof having any desired isomer content, isocyanatomethyl-1,8-octane diisocyanate, 1,4-cyclohexylene diisocyanate, and isomeric cyclohexanedimethylene diisocyanates.

[0028] It is also possible to use isocyanate derivatives having a urethane, urea, carbodiimide, acrylic urea, isocyanurate, allophanate, biuret, oxadiazinetrione, uretdione and / or iminooxadiazinedione structure.

[0029] These may be used alone or in any combination of two or more in any ratio.

[0030] <Component (b)> The polycaprolactone polyol of component (b) is a compound having a hydroxyl group as an active hydrogen (isocyanate-reactive functional group) that participates in a chain extension reaction with the isocyanate compound of component (a) that does not contain an aromatic ring or a methacrylate group. Polycaprolactone polyol is preferable to alcohols, amines, and mercapto compounds that are used as compounds having an isocyanate-reactive functional group in ordinary hologram materials in that it can suppress coloration. Polycaprolactone polyol is also suitable from the viewpoints of material stability and structural flexibility.

[0031] Examples of polycaprolactone polyols used as component (b) include polycaprolactone polyols (such as polycaprolactone diols and polycaprolactone triols) obtained by ring-opening polymerization of ε-caprolactone in the presence of polyhydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, methylpentanediol, 2,4-diethylpentanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, trimethylolpropane, ditrimethylolpropane, pentaerythritol, and dipentaerythritol, and diols such as polypropylene glycol and polytetramethylene glycol (PTMG). Any of these may be used alone, or two or more may be used in any combination and ratio.

[0032] <Component (c)> The acrylate monomer of component (c) is a compound that can be polymerized by the oxime ester photopolymerization initiator of component (d) described below, and is a monomer compound that is polymerized during recording and / or post-exposure. The type of acrylate monomer used in the composition for holographic recording media of the present invention is not particularly limited, and can be appropriately selected from known compounds. The acrylate monomer is usually radically polymerizable.

[0033] In the present invention, the reason why acrylate monomers are used as polymerizable monomers, rather than other polymerizable compounds such as epoxy compounds or oxetane compounds, is that they have a high polymerization rate and can record signals with high sensitivity.

[0034] In the present invention, it is also possible to use a polymerizable monomer other than the acrylate monomer together with the acrylate monomer. In this case, the amount of the polymerizable monomer other than the acrylate monomer used is preferably 20% by mass or less, more preferably 10% by mass or less, and most preferably 0% by mass, i.e., no polymerizable monomer other than the acrylate monomer is used, based on the total amount of the acrylate monomer and the polymerizable monomer other than the acrylate monomer.

[0035] (Refractive Index of Acrylate Monomer) The refractive index of the acrylate monomer at the wavelengths of the AR glass light source (all three wavelengths: blue: 450 nm, green: 530 nm, red: 630 nm) is preferably 1.50 or more, more preferably 1.55 or more, even more preferably 1.65 or more, particularly preferably 1.68 or more, and preferably 1.80 or less, more preferably 1.78 or less, even more preferably 1.75 or less, particularly preferably 1.70 or less. When the refractive index is above the lower limit, the diffraction efficiency is sufficient, and the displayed image of the AR glass becomes bright. Furthermore, when the refractive index is below the upper limit, the difference in refractive index with the resin matrix becomes small, resulting in reduced scattering, thereby improving the quality of the displayed image. Note that the refractive index shows a large value when evaluated at short wavelengths, but samples that show a relatively large refractive index at short wavelengths also show a relatively large refractive index at long wavelengths, and this relationship is not reversed. Therefore, it is possible to evaluate the refractive index at wavelengths other than the recording wavelength and predict the refractive index at the recording wavelength. When the sample is a liquid, the refractive index of an acrylate monomer can be measured by the minimum deviation method, critical angle method, V-block method, etc. When the sample is a solid, the compound is dissolved in an appropriate solvent to prepare a solution, the refractive index of this solution is measured, and the refractive index when the compound is 100% can be determined by extrapolation.

[0036] As the acrylate monomer having a high refractive index, those having a heterocyclic structure containing a halogen atom (such as iodine, chlorine, or bromine) or a heteroatom (such as nitrogen, sulfur, or oxygen) are preferred. Another example is one having a condensed polycyclic aromatic ring structure. From the viewpoint of refractive index, it is preferred that the acrylate monomer have a plurality of these heterocyclic structures or condensed polycyclic aromatic ring structures.

[0037] (Molecular Weight of Acrylate Monomer) From the viewpoint of volumetric shrinkage, the molecular weight of the acrylate monomer used in the composition for holographic recording media of the present invention is preferably 80 or more, more preferably 150 or more, and even more preferably 300 or more. On the other hand, from the viewpoint of sensitivity, it is preferably 3000 or less, more preferably 2500 or less, and even more preferably 2000 or less. When the molecular weight is equal to or greater than the above lower limit, the shrinkage rate associated with polymerization due to light irradiation during holographic information recording can be reduced. Furthermore, when the molecular weight is equal to or less than the above upper limit, the mobility of the acrylate monomer in a recording layer using the composition for holographic recording media is high, facilitating diffusion, and sufficient diffraction efficiency can be obtained.

[0038] (Molar absorption coefficient of acrylate monomer) The acrylate monomer has a molar absorption coefficient of 100 L·mol at the hologram recording wavelength (405 nm). －１ ・cm －１ It is preferable that the concentration is 80 L mol or less. －１ ・cm －１ It is more preferable that the molar extinction coefficient is 100 L mol or less. －１ ・cm －１ By satisfying this condition, it is possible to prevent the transmittance of the medium from decreasing, and to obtain sufficient diffraction efficiency relative to the thickness.

[0039] (Suitable Structure of Acrylate Monomer) From the viewpoint of increasing the refractive index of the acrylate monomer, it is preferable that the acrylate monomer has an aromatic ring group. Aromatic ring groups are broadly classified into aromatic hydrocarbon groups and aromatic heterocyclic groups, and from the viewpoint of the ease of synthesis, aromatic hydrocarbon groups are preferred. The aromatic ring of these aromatic ring groups may have a monocyclic structure or a condensed ring structure. Alternatively, it may have a structure in which two or more aromatic rings are linked via a direct bond.

[0040] Examples of the aromatic hydrocarbon ring of the aromatic hydrocarbon group include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a biphenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring. Among these, from the viewpoints of ease of synthesis and availability, a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a biphenylene ring, and a fluorene ring are preferred, and a phenanthrene ring is more preferred.

[0041] Examples of the aromatic heterocyclic group include aromatic heterocyclic rings containing one heteroatom such as a furan ring, a benzofuran ring, a dibenzofuran ring, a naphthofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a naphthothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, a pyrrole ring, an indole ring, a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a pyridine ring, a quinoline ring, and an isoquinoline ring; aromatic heterocyclic rings containing two or more heteroatoms such as an imidazole ring, a triazole ring, a tetrazole ring, an oxazole ring, a thiazole ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, and a thiadiazole ring; a benzoxazole ring, and a thienoxazole ring. Examples of such a ring include a ring in which two or three rings are fused together, including an aromatic heterocycle containing two or more heteroatoms, such as a thiazolooxazole ring, an oxazolooxazole ring, an oxazoloimidazole ring, an oxazolopyridine ring, an oxazolopyridazine ring, an oxazolopyrimidine ring, an oxazolopyrazine ring, a naphthoxazole ring, a quinolinoxazole ring, a dioxazolopyrazine ring, a phenoxazine ring, a benzothiazole ring, a furothiazole ring, a thienothiazole ring, a thiazolothiazole ring, a thiazoloimidazole ring, a thienothiadiazole ring, a thiazolothiadiazole ring, a thiazolopyridine ring, a thiazolopyridazine ring, a thiazolopyrimidine ring, a thiazolopyrazine ring, a naphthothiazole ring, a quinolinothiazole ring, a thianthrene ring, and a phenothiazine ring. Among these, from the viewpoints of high refractive index and low coloration, a benzothiazole ring, a dibenzothiophene ring, a benzothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, and a thianthrene ring are preferred, and a dibenzothiophene ring is more preferred.

[0042] Preferred examples of the acrylate monomer include compounds represented by the following formula (1) or (2).

[0043]

[0044] [In formula (1) or (2), A represents an acryloyl group, n represents an integer of 1 to 3, L represents a linking group which may be branched, and m represents an integer of 0 or 1. R １１ ~R１３ each independently represents an aromatic heterocyclic group or a fused polycyclic aromatic hydrocarbon group which may have a substituent. １ ~X ３ each independently represents an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. p1 to p3 each independently represents an integer of 0 or 1.

[0045] (Regarding L in Formulas (1) and (2)) L represents a linking group which may be branched. L does not necessarily need to contain a heteroatom, but from the viewpoint of ease of synthesis, it preferably has an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. From the viewpoint of imparting high solubility to various media and avoiding coloration to the compound represented by Formula (1) or (2), L is preferably an aliphatic hydrocarbon group having an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent, and the number of carbon atoms (not including the number of carbon atoms of the substituent) is preferably 1 to 8. When the number of carbon atoms is 8 or less, the refractive index of the compound represented by Formula (1) or (2) is unlikely to decrease, and the viscosity is reduced due to the small molecular weight, which tends to improve processability. L may be a linking group containing a cyclic structure or a chain-like linking group, or a combination of these structures; however, from the viewpoint of alleviating steric hindrance around the acryloyl group A, a chain-like linking group is preferred.

[0046] Examples of the chain linking group include an oxomethylene group, an oxoethylene group, a 1,3-oxopropylene group, a 1,2-oxopropylene group, an oxobutylene group, a 2-hydroxyoxopropylene group, an oxohexylene group, an oxoheptylene group, a 3-oxopentylene group, and —OCH ２ CH ２ NHC(O)-, -OCH ２ CH ２ OCH ２ CH ２ NHC(O)-, -OCH ２ CH ２ SCH ２ CH ２ -, -OCH ２ CH ２ NHC(S)-,-OCH ２ CH ２ OCH ２ CH ２NHC(S)-,-OCH ２ CH ２ SCH ２ CH ２ NHC(S)-,-OCH ２ CH ２ Among these, —OCH(S)- and the like are preferred from the viewpoint of compatibility with components (a) and (b). ２ CH ２ NHC(O)-, -OCH ２ CH ２ OCH ２ CH ２ NHC(O)- is preferred.

[0047] (X in formulas (1) and (2) １ ~X ３ About X １ ~X ３ each independently represents an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. １ ~X ３ is preferably an oxygen atom or a sulfur atom from the viewpoint of keeping the water absorption low, and more preferably a sulfur atom which imparts a high refractive index. The substituent that the nitrogen atom may have is not particularly limited, but preferred examples include alkyl groups having 1 to 8 carbon atoms such as methyl groups and ethyl groups, and aromatic hydrocarbon groups such as phenyl groups and naphthyl groups.

[0048] (R in formulas (1) and (2) １１ ~R １３ About) R １１ ~R １３each independently represents an aromatic heterocyclic group or a fused polycyclic aromatic hydrocarbon group which may have a substituent. Examples of the aromatic heterocyclic group include an aromatic heterocyclic group containing one heteroatom such as a furan ring, a benzofuran ring, a dibenzofuran ring, a naphthofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a naphthothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, a pyrrole ring, an indole ring, a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a pyridine ring, a quinoline ring, or an isoquinoline ring; an aromatic heterocyclic group containing two or more heteroatoms such as an imidazole ring, a triazole ring, a tetrazole ring, an oxazole ring, a thiazole ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, or a thiadiazole ring; a benzoxazole ring, or a thienoxazole ring. Examples of the aromatic heterocycle include a condensed ring having two or three rings, including an aromatic heterocycle containing two or more heteroatoms, such as a thiazolooxazole ring, an oxazolooxazole ring, an oxazoloimidazole ring, an oxazolopyridine ring, an oxazolopyridazine ring, an oxazolopyrimidine ring, an oxazolopyrazine ring, a naphthoxazole ring, a quinolinoxazole ring, a dioxazolopyrazine ring, a phenoxazine ring, a benzothiazole ring, a furothiazole ring, a thienothiazole ring, a thiazolothiazole ring, a thiazoloimidazole ring, a thienothiadiazole ring, a thiazolothiadiazole ring, a thiazolopyridine ring, a thiazolopyridazine ring, a thiazolopyrimidine ring, a thiazolopyrazine ring, a naphthothiazole ring, a quinolinothiazole ring, a thianthrene ring, and a phenothiazine ring. In particular, from the viewpoints of achieving a high refractive index and low coloring, a benzothiazole ring, a dibenzothiophene ring, a benzothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, and a thianthrene ring are preferred.

[0049] Specific examples of the fused polycyclic aromatic hydrocarbon ring of the fused polycyclic aromatic hydrocarbon group include a naphthalene ring, an anthracene ring, a phenanthrene ring, a perylene ring, a tetracene ring, a pyrene ring, a benzpyrene ring, a chrysene ring, a biphenylene ring, a triphenylene ring, an acenaphthene ring, a fluoranthene ring, and a fluorene ring. In particular, from the viewpoints of ease of synthesis and availability, a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a biphenylene ring, and a fluorene ring are preferred, and from the viewpoint of fluorescence suppression, a naphthalene ring, a biphenylene ring, and a fluorene ring are more preferred.

[0050] These R １１ ~R １３ The aromatic heterocycle or fused polycyclic aromatic hydrocarbon ring constituting the formula (I) may have a substituent. Examples of the substituent include a halogen atom such as chlorine, bromine, or iodine, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a cyano group, an acetyloxy group, an alkylcarbonyloxy group having 2 to 9 carbon atoms, an alkoxycarbonyl group having 2 to 9 carbon atoms, a sulfamoyl group, an alkylsulfamoyl group having 2 to 9 carbon atoms, an alkylcarbonyl group having 2 to 9 carbon atoms, a phenethyl group, a hydroxyethyl group, an acetylamido group, a dialkylaminoethyl group formed by bonding alkyl groups having 1 to 4 carbon atoms, a trifluoromethyl group, an alkylthio group having 1 to 8 carbon atoms, an arylthio group having 6 to 10 carbon atoms, and a nitro group. Among these, preferred are alkyl groups having 1 to 8 carbon atoms, alkoxy groups having 1 to 8 carbon atoms, alkylthio groups having 1 to 8 carbon atoms, arylthio groups having 6 to 10 carbon atoms, cyano groups, acetyloxy groups, alkoxycarboxyl groups having 2 to 9 carbon atoms, sulfamoyl groups, alkylsulfamoyl groups having 2 to 9 carbon atoms, and nitro groups.

[0051] In formula (1), R １１ ~R １３ When p1 to p3=1, the aromatic ring constituting １ ~X ３ When p1 to p3=0, R １１ ~R １３The aromatic ring constituting the formula (2) may be bonded to the pentaerythritol skeleton in the formula (1) at any position. １１ ~R １３ When p1 to p3=1, the aromatic ring constituting the formula (2) is １ ~X ３ When p1 to p3=0, R １１ ~R １３ The aromatic ring constituting the formula (1) may be bonded to the benzene ring in formula (2) at any position.

[0052] (Regarding m and n in formulas (1) and (2)) m represents an integer of 0 or 1. This m can be selected as appropriate, but from the viewpoint of alleviating steric hindrance around the acryloyl group A and increasing the reactivity of the compound represented by formula (1) or (2), m=1 is preferred. n represents an integer of 1 to 3. This n can also be selected as appropriate, but from the viewpoint of increasing the refractive index of the compound represented by formula (1) or (2), n is preferably 1 or 2, and more preferably 1. Furthermore, from the viewpoint of making the compound represented by formula (1) or (2) more easily polymerizable, n is preferably 2 or 3.

[0053] Specific examples of the compounds represented by formula (1) or (2) are shown below. In the following, "Me" represents a methyl group, and "Et" represents an ethyl group.

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] <Component (d)> In the present invention, the oxime ester photopolymerization initiator used as component (d) is a radical photopolymerization initiator that generates radicals that initiate a chemical reaction when exposed to light. The oxime ester photopolymerization initiator of component (d) contributes to the polymerization of the acrylate monomer of component (c). There are no particular restrictions on the type of oxime ester photopolymerization initiator, and it can be appropriately selected depending on the type of acrylate monomer of component (c), etc.

[0062] The oxime ester photopolymerization initiator may have —C═N—O— as part of its structure. Among them, ketoxime ester photopolymerization initiators are preferred because they have excellent recording sensitivity, and compounds represented by the following formula (d) or (f) are more preferred.

[0063]

[0064] [In formula (d), X represents a single bond; an alkylene group having 1 to 20 carbon atoms which may have a substituent; or an alkenylene group -(CH=CH) which may have a substituent] ｓ -, an optionally substituted alkynylene group -(C≡C) ｓ -, and a divalent group selected from the group consisting of a combination thereof (wherein s is an integer of 1 to 5). ２ represents a monovalent organic group containing an aromatic ring and / or a heteroaromatic ring. ３ represents a hydrogen atom, or 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, an alkynyloxycarbonyl group having 3 to 12 carbon atoms, an aryloxycarbonyl group having 7 to 12 carbon atoms, a heteroaryloxycarbonyl group having 3 to 12 carbon atoms, an alkylthiocarbonyl group having 2 to 12 carbon atoms, an alkenylthiocarbonyl group having 3 to 12 carbon atoms, 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=CR ３２ R ３３ , -N(OR ３４ )-CO-R ３５ and represents a group selected from the group consisting of groups represented by the following formula (e):

[0065]

[0066] (In (formula e), R ３０ and R ３１ each independently represents an optionally substituted alkyl group having 1 to 12 carbon atoms.

[0067] R ４ represents a group selected from the group consisting of 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 heteroaryloyl group having 3 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 10 carbon atoms, and an aryloxycarbonyl group having 7 to 20 carbon atoms, each of which may be substituted.]

[0068]

[0069] [In (formula f), R ５ represents a hydrogen atom; an optionally substituted alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 25 carbon atoms, a heteroaryl group having 3 to 20 carbon atoms, or a heteroarylalkyl group having 4 to 25 carbon atoms; or Y １ or a group that bonds with Z to form a ring. ６ represents an alkanoyl group having 2 to 20 carbon atoms, an alkenoyl group having 3 to 25 carbon atoms, a cycloalkanoyl group having 4 to 8 carbon atoms, an aryloyl group having 7 to 20 carbon atoms, an alkoxycarbonyl group having 2 to 10 carbon atoms, an aryloxycarbonyl group having 7 to 20 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, a heteroaryloyl group having 3 to 20 carbon atoms, or an alkylaminocarbonyl group having 2 to 20 carbon atoms, any of which may have a substituent. Y １ represents a divalent aromatic hydrocarbon group and / or aromatic hetero group formed by condensing two or more rings, which may have a substituent; Z represents an aromatic group, which may have a substituent.

[0070] Specific examples of the oxime ester photopolymerization initiator include 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-benzoyloxime) methyl glutarate, 1-(9-ethyl-9H-carbazol-3-yl)-1-(O-benzoyloxime) methyl glutarate, 1-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-1-(O-acetyloxime) glutarate, and 1-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-1-(O-acetyloxime) glutarate. Methyl butyl ester, 1-[6-(cyclohexylcarbonyl)-9-ethyl-9H-carbazol-3-yl]-1,2-heptadione-2-(O-acetyloxime), 1-(9-ethyl-6-diphenylamino-9H-carbazol-3-yl)-1-(O-acetyloxime)hexane, 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-acetyloxime)ethanone , 1-(9-ethyl-6-benzoyl-9H-carbazol-3-yl)-1-(O-acetyloxime)ethanone, 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-chloroacetyloxime)methyl glutarate, 1-(9-ethyl-9H-carbazol-3-yl)-1-(O-acetyloxime)-3,3-dimethylbutanoic acid, 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-chloroacetyloxime)methyl glutarate benzoyl)-9H-carbazol-3-yl)-1-(O-acetyloxime)methyl glutarate, 1-(9-ethyl-9H-carbazol-3-yl)-1-(O-acetyloxime)methyl glutarate, 1-(4-(phenylthio)-2-(O-benzoyloxime))-1,2-octanedione, or the compounds described in JP-A Nos. 2010-8713 and 2009-271502.

[0071] Among the compounds represented by the above formula (d) or (f), methyl 1-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-1-(O-acetyloxime)glutarate, 1-[6-(cyclohexylcarbonyl)-9-ethyl-9H-carbazol-3-yl]-1,2-heptadione-2-(O-acetyloxime), 1-(9-ethyl-6-(2-methylbenzoyl) ...H-carbazol-3-yl]-1,2-heptadione-2-(O-acetyloxime), 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-acetyl oxime)ethyl glutarate and 1-(9-ethyl-9H-carbazol-3-yl)-1-(O-acetyloxime)ethyl glutarate are preferred, and from the viewpoint of photobleachability, 1-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-1-(O-acetyloxime)methyl glutarate and 1-[6-(cyclohexylcarbonyl)-9-ethyl-9H-carbazol-3-yl]-1,2-heptadione-2-(O-acetyloxime) are particularly preferred.

[0072] The absorption wavelength range of the oxime ester photopolymerization initiator is preferably 340 nm or more, more preferably 350 nm or more, and preferably 700 nm or less, and even more preferably 650 nm or less. For example, when the light source is a blue laser, it is preferable that the absorption range be at least 350 to 430 nm. When the light source is a green laser, it is preferable that the absorption range be at least 500 to 550 nm. When the absorption wavelength range is within the above range, the irradiated light energy can be used efficiently in the photopolymerization reaction, and therefore sensitivity tends to increase.

[0073] The oxime ester photopolymerization initiator has a molar absorption coefficient of 10 L mol at the hologram recording wavelength. －１ ・cm －１ It is preferable that the amount is 50 L / mol or more. －１ ・cm －１ It is more preferable that the molar extinction coefficient is 20,000 L mol or more. －１ ・cm －１ It is preferable that the concentration is 10,000 L mol or less. －１ ・cm －１When the molar absorption coefficient is in the above range, effective recording sensitivity can be obtained, the transmittance of the medium can be prevented from becoming too low, and sufficient diffraction efficiency relative to the thickness tends to be obtained.

[0074] The solubility of the oxime ester photopolymerization initiator in component (a) and component (b) under conditions of 25°C and 1 atmospheric pressure is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more.

[0075] In the present invention, a photopolymerization initiator other than the above-mentioned oxime ester photopolymerization initiator may be used in combination as the photopolymerization initiator. In this case, the amount of the oxime ester photopolymerization initiator is preferably 0.003 mass % or more, more preferably 0.03 mass % or more, even more preferably 0.05 mass % or more, and particularly preferably 0.1 to 100 mass %, based on the total amount of the photopolymerization initiators.

[0076] Examples of other photopolymerization initiators include the following radical photopolymerization initiators. Among these, it is preferable to use a radical photopolymerization initiator because it is less likely to inhibit the reaction that forms the matrix, and among these, a phosphine oxide compound is more preferable.

[0077] Any known radical photopolymerization initiator can be used as the radical photopolymerization initiator other than the oxime ester photopolymerization initiator. Examples include phosphine oxide compounds, azo compounds, azide compounds, organic peroxides, organic borates, onium salts, bisimidazole derivatives, titanocene compounds, iodonium salts, organic thiol compounds, and halogenated hydrocarbon derivatives. The above-listed radical photopolymerization initiators may be used alone or in any combination and ratio of two or more.

[0078] Other examples of the photopolymerization initiator include imidazole derivatives, oxadiazole derivatives, naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis(2-phenylethenyl)benzene and derivatives thereof, quinacridone derivatives, coumarin derivatives, Al(C ９ H６ No) ３ Examples of suitable materials include aluminum complexes such as those mentioned above, rubrene, perimidone derivatives, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, phenylpyridine complexes, porphyrin complexes, and polyphenylenevinylene-based materials.

[0079] In addition, as a photopolymerization initiator, a compound having a molar absorption coefficient of 1000 L·mol at the recording wavelength is particularly －１ ・cm －１ Compounds having a molar extinction coefficient of 1000 L mol or less are more preferred. －１ ・cm －１ By satisfying the above condition, it is possible to suppress a decrease in the transmittance of the holographic recording medium at the recording wavelength, which occurs when an amount sufficient to obtain a sufficient diffraction efficiency is mixed.

[0080] Among the oxime ester photopolymerization initiators, particularly preferred compounds are exemplified below.

[0081]

[0082] <Component (e)> Component (e) is a compound having a nitroxyl radical group and an isocyanate-reactive functional group. When the composition for holographic recording media of the present invention contains such component (e), the isocyanate-reactive functional group of component (e) reacts with the isocyanate group of component (a) to be fixed to the resin matrix, and the nitroxyl radical group contained in component (e) improves recording sensitivity, thereby achieving a high Δn.

[0083] Examples of the isocyanate-reactive functional group contained in component (e) include the hydroxyl group contained in component (b), as well as an amino group and a mercapto group.

[0084] The type of component (e) is not particularly limited, but specific examples include 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), 4-sulfanyl-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-mercapto-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl, oxyl, 4-carbamoyl-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-(2,3-epoxypropoxy)-2,2,6,6-tetramethylpiperidine-1-oxyl, 3-hydroxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-sulfanyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-amino-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-mercapto-2,2,5,5-tetramethylpyrrolidine pyrrolidine 1-oxyl, 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-(2,3-epoxypropoxy)-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-hydroxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-sulfanyl-2,2,5,5-tetramethylpyrrolidine-1-oxyl, 3-amino-2,2,5, Examples of stable nitroxyl radical compounds include 5-tetramethylpyrroline-1-oxyl, 3-mercapto-2,2,5,5-tetramethylpyrroline-1-oxyl, 3-carboxy-2,2,5,5-tetramethylpyrroline-1-oxyl, 3-carbamoyl-2,2,5,5-tetramethylpyrroline-1-oxyl, and 3-(2,3-epoxypropoxy)-2,2,5,5-tetramethylpyrroline-1-oxyl, but the present invention is not limited to these. Any one of these may be used alone, or two or more may be used in any combination and in any ratio. Furthermore, it is preferable that these nitroxyl radical groups are stable radical groups.

[0085] Of these, from the viewpoints of compound stability and reactivity with an isocyanate group, it is preferable to use TEMPOL, 4-sulfanyl-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, or 4-mercapto-2,2,6,6-tetramethylpiperidine-1-oxyl, and it is particularly preferable to use TEMPOL.

[0086] <Component (f)> The composition for holographic recording media of the present invention contains, as component (f), a compound having an isocyanate group and a methacrylate group (hereinafter, sometimes referred to as "component (f1)"), or a compound having an isocyanate-reactive functional group and a methacrylate group (hereinafter, sometimes referred to as "component (f2)"). As described above, component (f) functions as a fixing monomer that captures iminyl radicals and acyl radicals derived from oxime ester photopolymerization initiators that cause colorants and light-emitting materials, thereby suppressing undesirable phenomena such as light loss due to colorants and light-emitting materials and changes in the color of displayed images. Here, it is important that component (f) has a methacrylate group rather than an acrylate group in order to function as a fixing monomer. That is, after bonding with a radical compound to form a fixed radical, an acrylate group is highly reactive and then bonds with other polymer radicals, losing its activity, whereas a methacrylate group exists as a long-lived radical due to the radical stabilization effect of the α-methyl group, thereby capturing iminyl radicals and acyl radicals that cause colored bodies and color-developing bodies, thereby suppressing coloration and fluorescence. Furthermore, component (f1) having an isocyanate group can form a chemical bond with the polycaprolactone polyol of component (b) to chemically fix component (f1), and component (f2) having an isocyanate-reactive functional group can form a chemical bond with the isocyanate compound of component (a) that does not contain an aromatic ring and a methacrylate group, to chemically fix component (f2).

[0087] Component (f1) is not particularly limited as long as it has an isocyanate group and a methacrylate group, and examples thereof include 2-methacryloyloxyethyl isocyanate, 2-(2-methacryloyloxyethyloxy)ethyl isocyanate, etc. These components (f1) may be used alone or in any combination and ratio of two or more.

[0088] Examples of the isocyanate-reactive functional group contained in component (f2) include a hydroxyl group, an amino group, and a mercapto group, with a hydroxyl group being preferred. Component (f2) is not particularly limited as long as it has an isocyanate-reactive functional group and a methacrylate group, and examples thereof include hydroxyalkyl methacrylates such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, and 6-hydroxyhexyl methacrylate, 2-hydroxyethyl acryloyl phosphate, 2-methacryloyloxyethyl-2-hydroxypropyl phthalate, dipropylene glycol methacrylate, fatty acid-modified glycidyl methacrylate, and polyethylene glycol monomethacrylate. acrylate, polypropylene glycol monomethacrylate, 2-hydroxy-3-methacryloyloxypropyl methacrylate, glycerin dimethacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, pentaerythritol trimethacrylate, caprolactone-modified pentaerythritol trimethacrylate, ethylene oxide-modified pentaerythritol trimethacrylate, dipentaerythritol pentamethacrylate, caprolactone-modified dipentaerythritol pentamethacrylate, and ethylene oxide-modified dipentaerythritol pentamethacrylate.

[0089] Furthermore, compounds in which a cyclic ester compound is added to these hydroxyl group-containing methacrylate compounds can also be used. Examples of the cyclic ester compound include γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactone, ε-methylcaprolactone, ε-ethylcaprolactone, ε-propylcaprolactone, 3-penten-4-olide, 12-dodecanolide, and γ-dodecanolactone. When a compound in which a cyclic ester compound is added to a hydroxyl group-containing methacrylate compound is used, it is preferred from the viewpoint of compatibility with component (b) that 1 to 4 moles of the cyclic ester compound be added to 1 mole of the hydroxyl group-containing methacrylate compound.

[0090] Among these components (f2), from the viewpoint of compatibility with component (b), a hydroxyl group-containing methacrylate compound represented by the following formula (I) is preferred, and in the following formula (I), a hydroxyl group-containing methacrylate compound in which x=1 is particularly preferred from the viewpoint of low viscosity and easy handling.

[0091]

[0092] (In the above formula (I), x is an integer of 1 to 4.)

[0093] These components (f2) may be used either alone or as a mixture of two or more kinds in any combination and ratio.

[0094] One or more types of component (f1) and one or more types of component (f2) may be used in combination.

[0095] Of these, component (f2) is particularly preferred as component (f) from the viewpoints of safety, ease of handling, and economy, and a compound having a hydroxyl group as an isocyanate-reactive functional group, i.e., a compound having a hydroxyl group and a methacrylate group, is more preferred from the viewpoints of safety and ease of handling.

[0096] <Component (g)> The composition for holographic recording media of the present invention preferably further comprises, as component (g), a catalyst (hereinafter sometimes referred to as a "curing catalyst") that promotes the reaction between the isocyanate group contained in component (a) and the isocyanate-reactive functional group. As the curing catalyst for component (g), it is preferable to use a bismuth-based catalyst that acts as a Lewis acid.

[0097] Examples of bismuth catalysts include tris(2-ethylhexanato)bismuth, tribenzoyloxybismuth, bismuth triacetate, bismuth tris(dimethyldicarbamate), bismuth hydroxide, triphenylbismuth(V) bis(trichloroacetate), tris(4-methylphenyl)oxobismuth(V), and triphenylbis(3-chlorobenzoyloxy)bismuth(V).

[0098] Among these, trivalent bismuth compounds are preferred in terms of catalytic activity, and bismuth carboxylate, a compound represented by the general formula Bi(OCOR) ３ (R is a linear or branched alkyl group, a cycloalkyl group, or a substituted or unsubstituted aromatic group) is more preferred. The bismuth catalyst may be used alone or in any combination and ratio of two or more types.

[0099] Furthermore, as a curing catalyst, other curing catalysts can be used in combination with the above bismuth-based catalysts in order to adjust the reaction rate. There are no particular limitations on the catalysts that can be used in combination as long as they do not contradict the gist of the present invention, but in order to obtain a synergistic effect of the catalysts, it is preferable to use a compound having an amino group as part of its structure. Examples thereof include triethylamine (TEA), N,N-dimethylcyclohexylamine (DMEDA), N,N,N',N'-tetramethylethylenediamine (TMEDA), N,N,N',N'-tetramethylpropane-1,3-diamine (TMPDA), N,N,N',N'-tetramethylhexane-1,6-diamine (TMHMDA), N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA), N,N,N',N",N"-pentamethyldipropylene-triamine (PMDPTA), Examples of amine compounds include triethylenediamine (TEDA), N,N'-dimethylpiperazine (DMP), N,-methyl,N'-(2-dimethylamino)-ethylpiperazine (TMNAEP), N-methylmorpholine (NMMO), N.(N',N'-dimethylaminoethyl)-morpholine (DMAEMO), bis(2-dimethylaminoethyl)ether (BDMEE), ethylene glycol bis(3-dimethyl)-aminopropyl ether (TMEGDA), and diisopropylethylamine (DIEA). Any of these may be used alone, or two or more may be used in any combination and ratio.

[0100] <Other Components> The composition for holographic recording media of the present invention may contain other components in addition to the above-mentioned components (a) to (g), provided that the other components do not go against the gist of the present invention.

[0101] Other components include solvents, plasticizers, dispersants, leveling agents, antifoaming agents, adhesion promoters, etc. for preparing the recording layer of the holographic recording medium, and chain transfer agents, polymerization terminators, compatibilizers, reaction aids, sensitizers, antioxidants, etc. for controlling the recording reaction. Any one of these components may be used alone, or two or more may be used in any combination and ratio.

[0102] <Composition ratio of each component in the composition for holographic recording media> The content of each component in the composition for holographic recording media of the present invention may be any content as long as it does not deviate from the spirit of the present invention, but it is preferable that the content of each component is within the following range.

[0103] The total content of component (a) and component (b) in the composition for holographic recording media of the present invention is usually 0.1% by mass or more, preferably 10% by mass or more, and more preferably 35% by mass or more. It is also usually 99.9% by mass or less, preferably 99% by mass or less, and more preferably 98% by mass or less. By setting this content to be equal to or greater than the above-mentioned lower limit, it becomes easy to form a recording layer, and by setting it to be equal to or less than the above-mentioned upper limit, it is possible to ensure the content of other essential components.

[0104] The ratio of the number of isocyanate-reactive functional groups (hydroxyl groups) in component (b) to the number of isocyanate groups in component (a) is preferably 0.1 or more, more preferably 0.5 or more, and is usually 10.0 or less, preferably 2.0 or less. When this ratio is within the above range, there are fewer unreacted functional groups, and storage stability is improved.

[0105] The content of component (c) in the composition for holographic recording media of the present invention is usually 0.1% by mass or more, preferably 1% by mass or more, and more preferably 2% by mass or more. It is also usually 80% by mass or less, preferably 50% by mass or less, and even more preferably 30% by mass or less. When the amount of component (c) is at least the lower limit, sufficient diffraction efficiency can be obtained, and when the amount is at most the upper limit, compatibility of the recording layer can be maintained.

[0106] The content of component (d) in the composition for holographic recording media of the present invention is typically 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass or more, relative to the content of component (c). It is also typically 20% by mass or less, preferably 18% by mass or less, and more preferably 16% by mass or less. By ensuring that the proportion of component (d) is at least the above-mentioned lower limit, sufficient recording sensitivity can be obtained. On the other hand, by ensuring that the proportion is at most the above-mentioned upper limit, a decrease in sensitivity due to bimolecular termination reactions caused by excessive radical generation can be suppressed.

[0107] The content of component (e) in the composition for holographic recording media of the present invention is preferably an amount such that the molar ratio of component (e) to component (d) (component (e) / component (d)) is usually 0.1 or more, particularly 0.2 or more, and especially 0.3 or more, and usually 10 or less, particularly 8 or less, and especially 6 or less. When component (e) / component (d) is at least the above-mentioned lower limit, the effect of improving Δn by containing component (e) can be effectively obtained, and when it is at most the above-mentioned upper limit, a radical polymerization reaction can proceed during exposure for the purpose of recording, thereby obtaining the refractive index modulation degree necessary for forming a diffraction grating and achieving sufficient recording sensitivity.

[0108] The content of component (f) in the composition for holographic recording media of the present invention is typically 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass or more. It is also typically 15% by mass or less, preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less. When the amount of component (f) is at least the above-mentioned lower limit, component (f) can effectively exert its effect as a fixing monomer for iminyl radicals and acyl radicals, which cause colorants and luminescent materials. On the other hand, when the amount of component (f) is at most the above-mentioned upper limit, the holographic characteristic Δn can be maintained.

[0109] In the composition for holographic recording media of the present invention, the ratio (molar percentage) of component (f) to component (c) is 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and particularly preferably 30 mol% or more. When the ratio of component (f) to component (c) is at or above the above-mentioned lower limit, component (f) can effectively function as a fixing monomer for iminyl radicals and acyl radicals, which cause coloration and luminescence. On the other hand, the ratio (molar percentage) of component (f) to component (c) is 150 mol% or less, preferably 120 mol% or less, more preferably 100 mol% or less, even more preferably 90 mol% or less, and 70 mol% or less, particularly preferably 50 mol% or less, 45 mol% or less, 40 mol% or less, or 35 mol% or less. When the ratio of component (f) to component (c) is at or below the above-mentioned upper limit, the holographic characteristic Δn can be maintained.

[0110] In the composition for holographic recording media of the present invention, the content (mol percentage) of component (f) relative to component (d) is 100 mol% or more, preferably 120 mol% or more, more preferably 140 mol% or more, even more preferably 160 mol% or more, and particularly preferably 180 mol% or more, 200 mol% or more, or 250 mol% or more. When the content ratio of component (f) relative to component (d) is equal to or greater than the above-mentioned lower limit, component (f) can effectively exert its effect as a fixing monomer for iminyl radicals and acyl radicals, which cause the colored bodies and light-emitting bodies. Meanwhile, the content (mol percentage) of component (f) relative to component (d) is 3000 mol% or less, preferably 2800 mol% or less, more preferably 2600 mol% or less, even more preferably 2400 mol% or less, and particularly preferably 2000 mol% or less, or 1500 mol% or less. If the content ratio of component (f) to component (d) is equal to or less than the upper limit, the hologram characteristic Δn can be maintained.

[0111] The composition for holographic recording media of the present invention preferably contains component (f) in a ratio (mol percentage) relative to component (e) of 100 mol% or more, particularly 200 mol% or more, and especially 300 mol% or more. If the ratio of component (f) relative to component (e) is equal to or greater than the above-mentioned lower limit, substantial effects due to the incorporation of component (f) can be expected. On the other hand, the composition for holographic recording media of the present invention preferably contains component (f) in a ratio (mol percentage) relative to component (e) of 10,000 mol% or less, particularly 5,000 mol% or less, especially 4,500 mol% or less. If the ratio of component (f) relative to component (e) is equal to or less than the above-mentioned upper limit, the holographic characteristic Δn can be maintained.

[0112] When the composition for holographic recording media of the present invention contains component (g), the content of component (g) is preferably determined in consideration of the reaction rate of components (a) and (b), and is usually 5% by mass or less, preferably 4% by mass or less, and more preferably 1% by mass or less. On the other hand, component (g) is preferably used in an amount of 0.001% by mass or more.

[0113] The total amount of components other than components (a) to (g) in the composition for holographic recording media of the present invention may be 30% by mass or less, preferably 15% by mass or less, and more preferably 5% by mass or less.

[0114] <Method for producing composition for holographic recording media> When producing the composition for holographic recording media of the present invention, components (a) to (g) may be mixed in any combination and in any order, and other components may also be combined and mixed at that time.

[0115] The composition for holographic recording media of the present invention can be produced, for example, by the following method. In the following description, the step of filtering solutions A and B is essential, but apart from that, the method for producing the composition for holographic recording media of the present invention is not limited to the following method.

[0116] All components except for components (b), (f), and (g) are mixed to form liquid A. A mixture of components (b), (f), and (g) is formed into liquid B. It is preferable to dehydrate and degas each liquid. If dehydration and degassing are not performed or are insufficient, bubbles may form during medium production, making it impossible to obtain a uniform recording layer. Heating and decompression may be performed during this dehydration and degassing process as long as they do not damage the components.

[0117] Since component (e) is a minor component, in order to enhance uniform dispersion in the composition and to ensure chemical bonding with component (a), a masterbatch is prepared by mixing a portion of component (a), for example, 10 to 90% by mass, with a portion of component (g), for example, 10 to 90% by mass, and component (e), and this masterbatch is then mixed with liquid A, which is a mixture of all components other than components (b), (e), (f), and (g) (the remainder of the masterbatch for component (a)), and liquid B, which is a mixture of components (b), (f), and (g) (the remainder of the masterbatch for component (g)). Component (f) may be mixed with either liquid A or liquid B, but it is preferable to mix it with liquid B as described above. In the present invention, the liquid mixture of the present invention is preferably used as this masterbatch.

[0118] As described above, the composition for holographic recording media of the present invention can be produced from a composition solution set for holographic recording media containing solution A and solution B. In the composition solution set for holographic recording media containing solution A and solution B, solution A contains at least components (a), (c), (d), and (e), solution B contains at least components (b) and (g), and either solution A or solution B, or both solution A and solution B, contain component (f).

[0119] Liquid A and Liquid B are mixed immediately before molding. Conventional mixing techniques can also be used. When mixing Liquid A and Liquid B, degassing may be performed as needed to remove residual gas. Liquid A and Liquid B must each undergo a filtration process to remove foreign matter and impurities. If foreign matter or impurities are mixed into the cured product for a hologram recording medium, not only will scattered light be recorded during the hologram recording process, but the foreign matter will also be visible in the field of view when the product is used as a light guide plate for AR glasses. In this case, using the liquid mixture of the present invention as a masterbatch for component (e) is preferable because filtering the blended Liquid A does not reduce the amount of active component (e) in the masterbatch. Furthermore, as component (a)', an isocyanate-functional prepolymer obtained by the reaction of excess component (a) with component (b) can also be used. Furthermore, as component (b)', an isocyanate-reactive prepolymer obtained by the reaction of excess component (b) with component (a) can also be used.

[0120] [Cured Product for Holographic Recording Media] The cured product for holographic recording media of the present invention can be obtained by curing the composition for holographic recording media of the present invention.

[0121] The method for producing the cured product for a holographic recording medium of the present invention is not particularly limited, and in producing the composition for a holographic recording medium of the present invention, the above-mentioned liquids A and B and a master batch of component (e) can be mixed and cured to produce a cured product for a holographic recording medium. At this time, heating at 30 to 100°C for about 1 to 72 hours may be performed to promote the curing reaction.

[0122] The cured product for a holographic recording medium of the present invention can also be produced according to the method for forming a recording layer in the method for producing a holographic recording medium of the present invention described below.

[0123] The composition for holographic recording media of the present invention can be applied to various optical materials and optical parts.

[0124] Examples of optical materials include optical overcoats, hard coating agents, adhesives for optical components, resins for optical fibers, and acrylic resin modifiers.

[0125] Examples of optical components include lenses, filters, diffraction gratings, prisms, light guides, display cover glass, photosensors, photoswitches, LEDs, light-emitting elements, optical waveguides, light splitters, optical fiber adhesives, display element substrates, color filter substrates, touch panel substrates, polarizing plates, display backlights, light guide plates, anti-reflection films, viewing angle expansion films, optical recording, photolithography, and optical relief printing. They can also be used as layers of these. Examples include display protective films.

[0126] The composition for holographic recording media of the present invention is particularly suitable for use in diffraction gratings, light guide plates, and plastic lenses, including imaging lenses for cameras (such as vehicle-mounted cameras, digital cameras, PC cameras, mobile phone cameras, and surveillance cameras), eyeglass lenses, light beam focusing lenses, and light diffusing lenses.

[0127] Lenses using the composition for holographic recording media of the present invention can be subjected to physical or chemical treatments such as surface polishing, antistatic treatment, hard coating treatment, antireflective coating treatment, dyeing treatment, etc., in order to achieve improvements such as antireflection, imparting high hardness, improving abrasion resistance, improving chemical resistance, imparting antifogging properties, or imparting fashionability, as required.

[0128] [Laminate for holographic recording media] A laminate for holographic recording media can be produced by laminating the cured product for holographic recording media of the present invention as a recording layer on a support. The support may be provided on one side or both sides of the recording layer made of the cured product for holographic recording media. Details of the recording layer and the support will be described later. The method for forming a recording layer made of the cured product for holographic recording media on the support is the same as in the method for producing a holographic recording media of the present invention.

[0129] [Holographic Recording Medium] The holographic recording medium of the present invention can be obtained by subjecting the cured product for a holographic recording medium of the present invention to interference exposure.

[0130] Preferred embodiments of the holographic recording medium of the present invention will be described below.

[0131] The holographic recording medium of the present invention comprises a recording layer and, if necessary, a support or other layers. Typically, a holographic recording medium has a support, and the recording layer and other layers are laminated on this support to form the holographic recording medium. However, if the recording layer or other layers have the strength and durability required for the medium, the holographic recording medium does not need to have a support. Examples of other layers include a protective layer, a reflective layer, an anti-reflection layer (anti-reflection film), etc. The recording layer of the holographic recording medium of the present invention is preferably formed from the composition for holographic recording media of the present invention.

[0132] <Recording Layer> The recording layer of the holographic recording medium of the present invention is a layer formed from the composition for a holographic recording medium of the present invention, and is the layer in which information is recorded. Information is usually recorded as a hologram. As will be described in detail in the recording method section below, a portion of the polymerizable monomer contained in the recording layer undergoes a chemical change, such as polymerization, upon holographic recording or the like. Therefore, in the holographic recording medium after recording, a portion of the polymerizable monomer is consumed and exists as a reacted compound, such as a polymer.

[0133] The thickness of the recording layer is not particularly limited and may be appropriately determined taking into consideration the recording method, etc., but is generally in the range of usually 1 μm or more, preferably 10 μm or more, and usually 3000 μm or less, preferably 2000 μm or less. By setting the thickness of the recording layer to be equal to or greater than the above-mentioned lower limit, the selectivity of each hologram is increased during multiplexed recording in the holographic recording medium, thereby increasing the degree of multiplexed recording. Furthermore, by setting the thickness of the recording layer to be equal to or less than the above-mentioned upper limit, it is possible to uniformly mold the entire recording layer, thereby enabling multiplexed recording with uniform diffraction efficiency of each hologram and a high S / N ratio. Furthermore, it is preferable that the shrinkage rate of the recording layer due to exposure during recording and reproduction of information is 0.5% or less.

[0134] <Support> The support is not particularly limited in detail, and any support can be used as long as it has the strength and durability required for the medium. The shape of the support is also not limited, but it is usually formed into a flat plate or film shape. The material constituting the support is also not limited, and it may be transparent or opaque.

[0135] Examples of transparent materials for the support include organic materials such as acrylic, polyethylene terephthalate, polyethylene naphthoate, polycarbonate, polyethylene, polypropylene, amorphous polyolefin, polystyrene, cellulose acetate, etc., and inorganic materials such as glass, silicon, quartz, etc. Among these, polycarbonate, acrylic, polyester, amorphous polyolefin, glass, etc. are preferred, and polycarbonate, acrylic, amorphous polyolefin, and glass are particularly more preferred.

[0136] On the other hand, examples of opaque support materials include metals such as aluminum; and the above-mentioned transparent supports coated with metals such as gold, silver, and aluminum, or dielectrics such as magnesium fluoride and zirconium oxide.

[0137] The thickness of the support is not particularly limited, but is preferably in the range of 0.05 mm or more and 1 mm or less. If the thickness of the support is equal to or greater than the lower limit, the mechanical strength of the hologram recording medium can be obtained and warping of the substrate can be prevented. If the thickness of the support is equal to or less than the upper limit, the amount of light transmission can be maintained and an increase in costs can be suppressed.

[0138] The surface of the support may also be subjected to a surface treatment. This surface treatment is usually performed to improve adhesion between the support and the recording layer. Examples of surface treatments include subjecting the support to a corona discharge treatment or forming an undercoat layer on the support in advance. Examples of compositions for the undercoat layer include halogenated phenols, partially hydrolyzed vinyl chloride-vinyl acetate copolymers, polyurethane resins, etc.

[0139] Furthermore, surface treatments may be performed for purposes other than improving adhesion. Examples include reflective coating treatments that form a reflective coating layer made of a metal such as gold, silver, or aluminum; and dielectric coating treatments that form a dielectric layer made of magnesium fluoride, zirconium oxide, or the like. These layers may be formed as a single layer or as two or more layers. These surface treatments may also be performed 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 a function of suppressing the gas and moisture permeability.

[0140] Furthermore, the support may be provided on only one of the upper and lower sides of the recording layer of the holographic recording medium of the present invention, or on both sides. However, when supports are provided 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.). Furthermore, in the case of a holographic recording medium having supports on one or both sides of the recording layer, transmission or reflection holograms can be recorded. Furthermore, when a support having reflective properties is used on one side of the recording layer, reflection holograms can be recorded. Furthermore, a pattern for data addressing may be provided on the support. In this case, there are no limitations on the patterning method, and for example, unevenness may be formed on the support itself, a pattern may be formed on the reflective layer described below, or a combination of these methods may be used.

[0141] <Protective Layer> The protective layer is a layer for preventing the effects of oxygen and moisture on the recording layer, such as a decrease in sensitivity and deterioration in storage stability. There are no restrictions on the specific configuration of the protective layer, and any known protective layer can be used. For example, a layer made of a water-soluble polymer, organic / inorganic material, etc. can be formed as the protective layer. There are no particular restrictions on the position where the protective layer is formed, and it may be formed, for example, on the surface of the recording layer, between the recording layer and the support, or on the outer surface side of the support. The protective layer may also be formed between the support and another layer.

[0142] <Reflective Layer> The reflective layer is formed when the holographic recording medium is configured to be a reflective type. In the case of a reflective type holographic recording medium, the reflective layer may be formed between the support and the recording layer, or may be formed on the outer surface of the support, but it is usually preferable that the reflective layer is formed between the support and the recording layer. Any known reflective layer can be used, and for example, a thin metal film or the like can be used.

[0143] <Anti-reflection film> In both transmission and reflection holographic recording media, an anti-reflection film may be provided on the side where the object light and readout light enter and exit, or between the recording layer and the support. The anti-reflection film improves the light utilization efficiency and suppresses the occurrence of ghost images. Any known anti-reflection film can be used.

[0144] <Method of Manufacturing Holographic Recording Media> The method of manufacturing the holographic recording medium of the present invention is not limited. For example, the holographic recording medium can be manufactured by applying the composition for holographic recording media of the present invention onto a support without using a solvent to form a recording layer. Any method can be used to apply the composition for holographic recording media. Specific examples include spraying, spin coating, wire bar coating, dipping, air knife coating, roll coating, blade coating, and doctor roll coating. Furthermore, when forming a recording layer with a particularly large thickness, a method of molding the composition for holographic recording media of the present invention into a mold or a method of applying the composition onto a release film and punching out a mold can also be used. Alternatively, the holographic recording medium of the present invention can be manufactured by mixing the composition for holographic recording media of the present invention with a solvent or additives to prepare a coating liquid, which is then applied to a support and dried to form a recording layer. In this case, any coating method can be used, and for example, the same methods as those described above can be used.

[0145] There are no limitations on the solvent used in the coating solution, but it is generally preferable to use one that has sufficient solubility for the components used, provides good coating properties, and does not attack supports such as resin substrates. Examples of solvents include ketone-based solvents such as acetone and methyl ethyl ketone; aromatic solvents such as toluene and xylene; alcohol-based solvents such as methanol and ethanol; ketone alcohol-based solvents such as diacetone alcohol; ether-based solvents such as tetrahydrofuran; halogen-based solvents such as dichloromethane and chloroform; cellosolve-based solvents such as methyl cellosolve and ethyl cellosolve; propylene glycol-based solvents such as propylene glycol monomethyl ether and propylene glycol monoethyl ether; ester-based solvents such as ethyl acetate and methyl 3-methoxypropionate; perfluoroalkyl alcohol-based solvents such as tetrafluoropropanol; highly polar solvents such as dimethylformamide and dimethyl sulfoxide; chain hydrocarbon-based solvents such as n-hexane; cyclic hydrocarbon-based solvents such as cyclohexane and cyclooctane; or mixed solvents thereof. The solvents may be used alone, or two or more may be used in any combination and ratio. There is no limitation on the amount of solvent used, but in terms of coating efficiency and ease of handling, it is preferable to prepare a coating solution with a solids concentration of about 1 to 1000% by mass.

[0146] Furthermore, when the resin matrix composed of components (a) and (b) of the composition for holographic recording media of the present invention is thermoplastic, the composition for holographic recording media of the present invention can be molded to form a recording layer by, for example, injection molding, sheet molding, hot pressing, etc. Furthermore, when the resin matrix composed of components (a) and (b) is photo- or thermosetting with a small amount of volatile components, the composition for holographic recording media of the present invention can be molded to form a recording layer by, for example, reaction injection molding or liquid injection molding. In this case, if the molded article has sufficient thickness, rigidity, strength, etc., the molded article can be used as a holographic recording medium as is.

[0147] Examples of methods for producing a holographic recording medium include a method in which a thermally melted composition for a holographic recording medium is applied to a support, and then cooled and solidified to form a recording layer; a method in which a liquid composition for a holographic recording medium is applied to a support, and then thermally polymerized to harden the composition to form a recording layer; and a method in which a liquid composition for a holographic recording medium is applied to a support, and then photopolymerized to harden the composition to form a recording layer.

[0148] The holographic recording medium thus produced can be in the form of a free-standing slab or disc, and can be used in three-dimensional image display devices, diffractive optical elements, large-capacity memories, etc. In particular, the holographic recording medium of the present invention, which uses the composition for a holographic recording medium of the present invention, has a high Δn, can reduce color unevenness, and can improve brightness, and is therefore useful as a light guide plate for AR glass.

[0149] The holographic recording medium of the present invention can be used for recording information on a recording medium containing a polymerizable monomer, and can be used for reading information from the recording medium by irradiating the recording medium with light.

[0150] For example, when recording information as a volume hologram, an object beam and a reference beam are irradiated onto the recording layer, causing the object beam and the reference beam to interfere with each other in the recording layer. This causes the polymerizable monomer in the recording layer to polymerize and change in concentration, resulting in interference fringes that cause a refractive index difference in the recording layer. The interference fringes recorded in the recording layer are then recorded as a hologram in the recording layer.

[0151] On the other hand, when reproducing a volume hologram recorded in the recording layer, a predetermined reproduction light (usually a reference light) is irradiated onto the recording layer. The irradiated reproduction light is diffracted in accordance with the interference fringes. This diffracted light contains the same information as that in the recording layer, so the information recorded in the recording layer can be reproduced by reading the diffracted light with an appropriate detection means.

[0152] The wavelength ranges of the object light, the reproduction light, and the reference light are arbitrary depending on the application, and may be in the visible light range or the ultraviolet range. Among these lights, preferred examples include ruby, glass, Nd-YAG, and Nd-YVO ４ solid-state lasers such as GaAs, InGaAs, and GaN diode lasers; helium-neon, argon, krypton, excimer, and CO ２ and lasers with excellent monochromaticity and directivity, such as dye lasers.

[0153] Furthermore, there are no limitations on the irradiation doses of the object beam, the reproduction beam, and the reference beam, and the irradiation doses may be any within the range in which recording and reproduction are possible. However, if the irradiation dose is extremely low, the chemical change of the polymerizable monomer may be incomplete, and the heat resistance and mechanical properties of the recording layer may not be fully exhibited. Conversely, if the irradiation dose is extremely high, the components of the recording layer (components of the composition for holographic recording media of the present invention) may be deteriorated. Therefore, the object beam, the reproduction beam, and the reference beam are usually set to 0.1 J / cm depending on the composition of the composition for holographic recording media of the present invention used to form the recording layer, the type and amount of the photopolymerization initiator, etc. ２ Above, 20J / cm ２ Irradiate within the following range:

[0154] In addition, hologram recording methods include polarization collinear hologram recording and reference beam incident angle multiplexing hologram recording, and when the hologram recording medium of the present invention is used as a recording medium, any of these recording methods can provide good recording quality.

[0155] <Application to AR Glass Light Guide Plate> In the holographic recording medium of the present invention, the initiator is consumed by flood exposure in the portion where light is guided by total reflection. On the other hand, a volume hologram is recorded in the portion where light is diffracted, in the same manner as in the large-capacity memory application described above. This can be used as an optical element, and is particularly suitable for use in an AR glass light guide plate (AR light guide plate). The wavelength range of the flood exposure is arbitrary, and may be either the visible light range or the ultraviolet range. Among these light sources, examples of suitable light sources include ruby, glass, Nd-YAG, and Nd-YVO. ４and LED light sources such as GaAs, InGaAs, and GaN. There is no limit to the irradiation dose for the one-time exposure, and the irradiation dose can be any as long as it is within a range that consumes a sufficient amount of the initiator in the relevant area. However, if the irradiation dose is extremely low, the initiator will not be completely consumed, reducing the stability of the final product. Conversely, if the irradiation dose is extremely high, there is a possibility that coloration and deterioration will occur due to photodegradation of the organic material. Therefore, a dose of 10 J / cm is usually selected according to the composition of the composition for holographic recording media, the type and amount of the photopolymerization initiator, etc. ２ Above, 100J / cm ２ Irradiate within the following range:

[0156] For a volume hologram recorded in the recording layer, a predetermined reproduction light is irradiated onto the recording layer. The irradiated reproduction light is diffracted in accordance with the interference fringes. In this case, even if the wavelength of the reproduction light does not match the wavelength of the recording light, diffraction will occur as long as the interference fringes and the Bragg condition are met. Therefore, if corresponding interference fringes are recorded according to the wavelength and incident angle of the reproduction light to be diffracted, diffraction can be caused for reproduction light over a wide wavelength range, thereby expanding the display color gamut of AR glasses.

[0157] By recording corresponding interference fringes according to the wavelength and diffraction angle of the reconstructed light, it is possible to guide the reconstructed light incident from outside the hologram recording medium into the hologram recording medium, to reflect, demultiplex, enlarge or reduce the reconstructed light that has been guided inside the hologram recording medium, or to emit the reconstructed light that has been guided inside the hologram recording medium to the outside of the hologram recording medium, thereby widening the viewing angle of the AR glasses.

[0158] The wavelength ranges of the object light and the reproduction light are arbitrary depending on the respective applications, and may be either the visible light range or the ultraviolet range. Among these light sources, the aforementioned laser and the like are preferred, but the reproduction light is not limited to lasers and the like, and display devices such as liquid crystal displays (LCDs) and organic electroluminescence displays (OLEDs) are also preferred.

[0159] Furthermore, there are no limitations on the irradiation doses of the object beam, the reproduction beam, and the reference beam, and the irradiation doses may be any within the range in which recording and reproduction are possible. However, if the irradiation dose is extremely low, the chemical change of the polymerizable monomer may be incomplete, and the heat resistance and mechanical properties of the recording layer may not be fully exhibited. Conversely, if the irradiation dose is extremely high, the components of the recording layer (components of the composition for holographic recording media of the present invention) may be deteriorated. Therefore, the object beam, the reproduction beam, and the reference beam are usually set to 0.1 J / cm depending on the composition of the composition for holographic recording media of the present invention used to form the recording layer, the type and amount of the photopolymerization initiator, etc. ２ Above, 20J / cm ２ Irradiate within the following range:

[0160] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention.

[0161] [Raw Materials Used] The raw materials for the compositions used in the Examples and Comparative Examples are as follows.

[0162] Component (a): Duranate, a compound having an isocyanate group but not containing an aromatic ring or a methacrylate group ＴＭ TSS-100: Hexamethylene diisocyanate-based polyisocyanate (isocyanate group content: 17.8% by mass) (manufactured by Asahi Kasei Corporation) Takenate ＴＭ 600: 1,3-bis(isocyanatomethyl)cyclohexane (isocyanate group content: 43.2% by mass) (manufactured by Mitsui Chemicals, Inc.)

[0163] Component (b): Polycaprolactone polyol Capa 2047A: Polycaprolactone diol (molecular weight 400) (manufactured by Ingevity) Capa 2065: Polycaprolactone diol (molecular weight 650) (manufactured by Ingevity) PLACCEL 305: Polycaprolactone triol (molecular weight 550) (manufactured by Daicel Corporation)

[0164] Component (c): Acrylate monomer c-1: 2-[[[3-(2-benzothiazolylthio)-2,2-bis[[[2-(4-dibenzothienyl)phenyl]thio]methyl]propoxy]carbonyl]amino]ethyl acrylate (molecular weight 975, refractive index at a wavelength of 587.6 nm 1.6661, molar absorption coefficient at a wavelength of 405 nm 1.23 × 10 －２ L.mol －１ ・cm －１ c-1 was synthesized in the same manner as described in a known document (WO 2022 / 202538, paragraphs 0352 to 0361).

[0165] c-2: 2-[[(2,4,6-tri-9-phenanthrenylphenoxy)carbonyl]amino]ethyl acrylate (molecular weight 764, refractive index at a wavelength of 587.6 nm 1.6894, molar absorption coefficient at a wavelength of 405 nm 9.34 × 10 ―３ L.mol －１ ・cm －１ c-2 was synthesized in the same manner as described in a known document (WO 2024 / 085208, paragraphs 0393 to 0396).

[0166] Component (d): Oxime ester photopolymerization initiator d-1: 1-[6-(cyclohexylcarbonyl)-9-ethyl-9H-carbazol-3-yl]-1,2-heptadione 2-(O-acetyloxime) (molecular weight 489)

[0167] d-2: 1-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-1-(O-acetyloxime) methyl glutarate (molecular weight 505)

[0168] d-3: methyl 1-(9-ethyl-9H-carbazol-3-yl)-1-(O-acetyloxime)glutarate (molecular weight 394)

[0169] d-4: 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl)-1-(O-acetyloxime) methyl glutarate (molecular weight 513)

[0170] Component (e): a compound having a nitroxyl radical group and an isocyanate-reactive functional group; 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (TEMPOL): manufactured by Tokyo Chemical Industry Co., Ltd.

[0171] Component (f1): Compound having an isocyanate group and a methacrylate group Karenz MOI: 2-methacryloyloxyethyl isocyanate (manufactured by Resonac Co., Ltd.) Karenz MOI-EG: 2-(2-methacryloyloxyethyloxy)ethyl isocyanate (manufactured by Resonac Co., Ltd.)

[0172] Component (f2): Compound having a hydroxyl group and a methacrylate group, which are isocyanate-reactive functional groups. HEMA: Hydroxyethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.). AM-OH: 1-(acryloyloxy)-3-(methacryloyloxy)-2-propanol (manufactured by Tokyo Chemical Industry Co., Ltd.). MM-OH: Glycerol dimethacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.). Blemmer GLM: Glycerin monomethacrylate (Blemmer GLM manufactured by NOF Corporation). Blemmer PE200: Polyethylene glycol monomethacrylate (molecular weight approximately 284) (Blemmer PE200 manufactured by NOF Corporation). FM1D: Caprolactone adduct of hydroxyethyl methacrylate (molecular weight 244) (Placcel FM1D manufactured by Daicel Corporation). FM2D: Caprolactone adduct of hydroxyethyl methacrylate (molecular weight 358). (Daicel Corporation, PLACCEL FM2D) FM3: Caprolactone adduct of hydroxyethyl methacrylate (molecular weight 473) (Daicel Corporation, PLACCEL FM3) H1689: 3-hydroxy-1-methacryloyloxyadamantane (Tokyo Chemical Industry Co., Ltd., H1689)

[0173] Component (f'): a compound having only one of an isocyanate group or an isocyanate-reactive functional group and a methacrylate group, or a compound having neither; HTMP: hydroxytetramethylpiperidine (manufactured by Tokyo Chemical Industry Co., Ltd.); HPMP: hydroxypentamethylpiperidine (manufactured by Tokyo Chemical Industry Co., Ltd.); 16HDDA: 1,6-hexanediol diacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.); 16HDDM: 1,6-hexanediol dimethacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.); HEAm: N-(2-hydroxyethyl)acrylamide (manufactured by Tokyo Chemical Industry Co., Ltd.); HBA: hydroxybutyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.); AE200: hydroxyl-terminated polyalkylene glycol monoacrylate (Blenmer AE200 manufactured by NOF Corporation); Karenz AOI: 2-acryloyloxyethyl isocyanate (manufactured by Resonac Corporation). M1526: 1-adamantyl methacrylate (M1526 manufactured by Tokyo Chemical Industry Co., Ltd.) A2859: 3-hydroxy-1-adamantyl acrylate (A2859 manufactured by Tokyo Chemical Industry Co., Ltd.) A0720: 2-hydroxyadamantane (A0720 manufactured by Tokyo Chemical Industry Co., Ltd.)

[0174] Component (g): Curing catalyst U-600: octylic acid solution of tris(2-ethylhexanoate)bismuth (active ingredient amount: 56% by mass) (U-600, manufactured by Nitto Kasei Kogyo Co., Ltd.)

[0175] [Preparation of Composition for Holographic Recording Media and Preparation of Evaluation Samples] <Examples 1-1 to 1-3, 2-1, 2-2 and Comparative Examples 1-1 to 1-8, 2-1> 2.10 g of TSS100, 0.37 g of Takenate 600, 0.76 g of c-1, 25 mg of d-1, and 9.1 mg of TEMPOL were mixed and stirred until uniform to prepare Liquid A. Separately, 2.28 g of Capa 2047A, 0.25 g of PLACCEL 305, and 0.4 mg of U-600 were mixed and stirred until uniform to prepare Liquid B. However, when preparing Liquid B, component (f) or component (f') was mixed into Liquid B so that the blending ratio relative to the acrylate monomer of component (c) was the ratio (mol %) shown in Tables 1 and 2. A blank was also prepared without using either component (f) or component (f').

[0176] Examples 3-1 to 3-11 and Comparative Example 3-1: 1.87 g of TSS100, 0.33 g of Takenate 600, 0.66 g of c-2, 30 mg of d-1, and 11.1 mg of TEMPOL were mixed and stirred until uniform to form a solution called Solution A. Separately, 1.82 g of Capa 2065, 0.98 g of PLACCEL 305, and 0.3 mg of U-600 were mixed and stirred until uniform to form a solution called Solution B. However, when preparing Solution B, component (f) was mixed into Solution B so that the blending ratio relative to the acrylate monomer of component (c) was the ratio (mol%) shown in Table 3. A blank was also prepared without component (f).

[0177] Examples 4-1 to 4-4 and Comparative Examples 4-1 to 4-4 2.01 g of TSS100, 0.35 g of Takenate 600, 0.66 g of c-2, 30 mg of d-1, and 11.1 mg of TEMPOL were mixed and stirred until uniform to form a solution called Solution A. Separately, 1.98 g of Capa 2047A, 0.66 g of PLACCEL 305, and 0.2 mg of U-600 were mixed and stirred until uniform to form a solution called Solution B. However, when preparing Solution B, component (f) or component (f') was mixed into Solution B so that the blending ratio relative to the acrylate monomer of component (c) was the ratio (mol %) shown in Table 5. A blank was also prepared without component (f) or component (f').

[0178] Examples 5-1 to 5-6 and Comparative Example 5-1: 1.98 g of TSS100, 0.35 g of Takenate 600, 0.56 g of c-2, 40 mg of d-1, and 14.6 mg of TEMPOL were mixed and stirred until uniform to form a solution called Solution A. Separately, 2 g of Capa 2047A, 0.67 g of PLACCEL 305, and 0.4 mg of U-600 were mixed and stirred until uniform to form a solution called Solution B. However, when preparing Solution B, component (f) was mixed into Solution B so that the blending ratio relative to the acrylate monomer of component (c) was the ratio (mol %) shown in Table 7. A blank was also prepared without component (f).

[0179] Examples 6-1 to 6-3 and Comparative Examples 6-1 to 6-3 Solutions A and B were prepared in the same manner as in Example 4-3, except that component (d) was blended in the type and proportion (mass%) shown in Table 8. However, in Example 6-2, the blending amount of component (f) was the amount shown in Table 8, and in Example 6-3, the component (f) shown in Table 8 was used. In addition, a blank was prepared without using component (f).

[0180] Solutions A and B were each degassed under reduced pressure at room temperature for 2 hours and then filtered through a hydrophobic PTFE filter (Millex-FG, SLFGL25BS, manufactured by Merck) with a pore size of 0.2 μm. Solutions A and B were then mixed by stirring and further degassed under vacuum for several minutes. The vacuum-degassed mixture was then poured onto a glass slide with 0.5 mm thick spacer sheets placed on two opposing edges. A glass slide was then placed over the glass slide, the edges secured with clips, and the mixture was heated at 80°C for 24 hours to prepare a sample for evaluation of a composition for holographic recording media. This evaluation sample had a 0.5 mm thick recording layer formed between the glass slides as covers.

[0181] [Evaluation of Samples for Evaluating Composition for Holographic Recording Media] <Measurement and Evaluation of Light Loss (A450) and Color Difference (ΔE00)> The samples for evaluating compositions for holographic recording media were adjusted to 15°C or 22°C and subjected to one-shot exposure (80 mW / cm) using an LED light source (M405L2, manufactured by Thorlab). ２ Then, the absorption spectrum was measured at 300 to 700 nm using a UV-visible spectrophotometer V-670 (manufactured by JASCO Corporation). The absorbance at 450 nm (cm －１ ) was defined as A450. A smaller value of A450 is preferable. Furthermore, color difference ΔE00 was calculated according to JIS Z8781-6:2017. A smaller value of ΔE00 is preferable.

[0182] <Measurement and Evaluation of Color Change (PL)> As shown in Figure 1, a semiconductor laser with a wavelength of 450 nm and a power of 40 mW was incident at a 70° angle on a sample S of a holographic recording medium that had been subjected to a one-time exposure, from a semiconductor laser light source LD. Light other than the transmitted light was collected by an integrating sphere IS, and the fluorescence intensity was measured using a 450 nm bandpass filter BPF as a detector. The ratio of the fluorescence intensity to the light source intensity was defined as PL (%). A smaller PL value is preferable. PD1 and PD2 represent photodetectors.

[0183] <Evaluation of hologram recording and hologram characteristics (Δn)> Using the evaluation samples of the compositions for hologram recording media prepared in the examples and comparative examples, hologram recording and evaluation of the hologram recording performance of the hologram recording media were carried out according to the procedures described below. Hologram recording was carried out using a semiconductor laser with a wavelength of 405 nm and an exposure power density per beam of 10 mW / cm. ２ Using the exposure apparatus shown in Figures 2 and 3, a two-beam plane wave hologram was recorded, as will be explained in detail below.

[0184] (Hologram Recording Device) Figure 2 is a schematic diagram of the device used for transmission hologram recording, and Figure 3 is a schematic diagram of the device used for reflection hologram recording. In Figures 2 and 3, S is a sample hologram recording medium, and M1, M2, and M3 all represent mirrors. CS is an exposure time control shutter, and BS is a beam shutter. PBS is a polarizing beam splitter, LED is a post-exposure light source (an LED manufactured by THORLAB with a central wavelength of 405 nm), LD is a recording light laser light source that emits light with a wavelength of 405 nm (a single-mode laser manufactured by TOPTICA Photonics that can obtain light with a wavelength around 405 nm), and PD1 and PD2 are photodetectors.

[0185] <Transmission Hologram Recording Exposure> In transmission hologram recording exposure, light with a wavelength of 405 nm generated from an LD was split by a PBS, and these were considered as object light (M1 side) and reference light (M2 side). The two beams were irradiated so that they intersected on the recording surface at an angle of 59.3°. At this time, the bisector of the angle between the two beams (hereinafter referred to as the optical axis) was perpendicular to the recording surface of the recording layer of the hologram recording medium, and further, the vibration plane of the electric field vectors of the two beams obtained by splitting was perpendicular to the plane containing the two intersecting beams. The above case was set as a sample rotation angle of 0°, and 181 multiplexed recording exposures were performed at the same location while changing the sample rotation angle from -18° to +18° in 0.2° increments. At this time, in all Examples and Comparative Examples, the total recording energy was set to 2 J / cm so that the amounts of polymerizable compound and photopolymerization initiator consumed for recording were equal. ２ The recording exposure was carried out equally so that

[0186] <Reflection Hologram Recording Exposure> In reflection hologram recording exposure, light with a wavelength of 405 nm generated from an LD was split by a PBS, and these were considered as object light (M1-M3 side) and reference light (M2 side). The two beams were irradiated so that they intersected on the recording surface at an angle of 127°. The sample rotation angle of 0° was the same as in the transmission hologram recording exposure device, and 161 multiplexed recording exposures were performed at the same location while changing the orientation of the hologram recording medium from -24° to +29°. In all examples and comparative examples, the total recording energy was set to 2 J / cm so that the amounts of polymerizable monomer and photopolymerization initiator consumed in recording were equal. ２ The recording exposure was carried out equally so that

[0187] <Post-exposure> After the multiplex recording exposure, the rotation angle is returned to 0°, and a signal growth time of 120 seconds is waited in the dark. The post-exposure light source LED is then irradiated with 4 J / cm ２ The recording was fixed by irradiation.

[0188] 2 and 3, the beam shutter BS on the object beam side was closed, and the reference beam on the mirror M2 side was irradiated to reconstruct the recorded hologram. The light intensity detected by PD1 was expressed as the diffracted light I ｄｉ , the light intensity detected by PD2 is the transmitted light I ｔｉ As a result, the diffraction efficiency η of each light diffracted from each of the multiplexed recorded interference patterns can be calculated from the formula (1). ｉ The cumulative transmission Δn is calculated from equations (2) and (3). Ｔ and cumulative reflection Δn Ｒ were calculated respectively.

[0189]

[0190] Using multiple samples, evaluations were performed multiple times under different irradiation energy conditions, such as increasing or decreasing the irradiation energy at the beginning of recording and increasing or decreasing the total irradiation energy, to find the conditions under which the polymerizable monomer is almost completely consumed (Δn reaches almost equilibrium during multiplex recording), and the Δn was maximized. The obtained maximum value was then used as the Δn of the medium. A larger Δn value is preferable. Furthermore, it is preferable that the rate of change in Δn is increased compared to when component (f) or component (f') is not included, or, if decreased, the decrease is less than 10%.

[0191] <Accelerated Test> The sample subjected to one-shot exposure or hologram recording was subjected to an accelerated test in dry air at 70° C. for 336 hours in accordance with JIS C 60068-2-2: 2010. After the accelerated test, A450, ΔE00, PL, and Δn were measured again by the above-mentioned methods.

[0192] The evaluation results are shown in Tables 1 to 8. In the tables below, "_T0" indicates the hologram before the accelerated test, and "_T336" indicates the hologram after the accelerated test. Furthermore, "T" indicates a transmission hologram, and "R" indicates a reflection hologram.

[0193]

[0194]

[0195]

[0196]

[0197]

[0198]

[0199]

[0200]

[0201] <Discussion> Table 1 shows that in the examples containing component (f2): a compound having a hydroxyl group and a methacrylate group, which are isocyanate-reactive functional groups, A450, PL, and ΔE00 all decreased compared to the blank (Comparative Example 1-1), and the decrease in Δn was less than 10%. These results demonstrate that the addition of component (f1) can suppress light loss, color difference, and changes in color while maintaining the hologram characteristic Δn, thereby achieving desirable properties for an AR glass light guide plate.

[0202] Table 2 shows that the examples containing component (f1): a compound having an isocyanate group and a methacrylate group, exhibited the same effects as those of component (f2). Table 3 shows that the effects of adding component (f) were similarly exhibited even when component (c) was c-2 and component (b) was composed of Capa 2065 and PLACCEL 305. It was also shown that the decreases in A450, PL, and ΔE00 increased as the amount of component (f) added increased. Table 4 shows that the examples containing component (f) did not have an adverse effect on the hologram characteristic Δn after accelerated testing.

[0203] Table 5 shows that the effect of incorporating component (f) is similarly exhibited even when component (c) is c-2 and component (b) is composed of Capa 2047A and PLACCEL 305. Table 6 shows that in the Examples incorporating component (f), there is no adverse effect on the hologram characteristic Δn after the accelerated test. On the other hand, in Comparative Example 4-2 incorporating component (f'), it was found that the hologram characteristic Δn after the accelerated test decreased to 92%. These results demonstrate that it is essential for component (f) to have an isocyanate group or an isocyanate-reactive functional group.

[0204] Tables 7 and 8 demonstrate that the effects of adding component (f) are similarly observed even when the amount of component (d): oxime ester photoinitiator is increased. Furthermore, it was shown that the decreases in A450, PL, and ΔE00 increase with increasing amounts of component (f). The oxime ester photoinitiator generates iminyl radicals and acyl radicals upon irradiation with light. These radicals are thought to form complexes with dimers or polymerizable monomers, resulting in colored or luminescent materials. In the composition for holographic recording media of the present invention, the compound having an isocyanate group and a methacrylate group (compound (f)) or the methacrylate group of a compound having an isocyanate-reactive functional group and a methacrylate group captures these radicals, thereby suppressing the formation of colored or luminescent materials. This is thought to prevent undesirable phenomena, such as light loss and changes in the color of displayed images, that are caused by colored or luminescent materials. When component (f) does not have an isocyanate group or an isocyanate-reactive functional group, but does have a methacrylate group, the polymer exhibiting holographic refractive index modulation bonds to the nitroxy radical group of component (e) via the methacrylate group and is immobilized in the matrix. It has been reported that the bond dissociation temperature (Tc) of an NO-C bond via a methacrylate group is 50°C, which is lower in heat resistance than the Tc of an NO-C bond via an acrylate group (115°C) (A. Gaudel-Siri, et al., ChemPhysChem 2006, 7, 430-438). Therefore, it is believed that the hologram characteristic Δn after the accelerated test in Comparative Example 4-2 decreased. Based on the above considerations, it is believed that the essential requirement for component (f) to exhibit its effects is that it is a compound having an isocyanate group and a methacrylate group, or a compound having an isocyanate-reactive functional group and a methacrylate group.

[0205] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible within the scope of the invention. This application is based on Japanese Patent Application No. 2024-124907, filed on July 31, 2024, and is incorporated by reference in its entirety.

[0206] LD Semiconductor laser light source S Hologram recording medium PD1, PD2, PD3 Photodetector IS Integrating sphere BPF Bandpass filter M1, M2, M3 Mirror CS Shutter L2 Laser light source for reproduction light PBS Polarizing beam splitter 1 LED unit

Claims

1. A composition for a holographic recording medium containing the following components (a) to (f): Component (a): an isocyanate compound not containing an aromatic ring or a methacrylate group; Component (b): a polycaprolactone polyol; Component (c): an acrylate monomer; Component (d): an oxime ester photopolymerization initiator; Component (e): a compound having a nitroxyl radical group and an isocyanate-reactive functional group; and Component (f): a compound having an isocyanate group and a methacrylate group, or a compound having an isocyanate-reactive functional group and a methacrylate group.

2. The composition for holographic recording media according to claim 1, wherein in component (f), the isocyanate-reactive functional group is a hydroxyl group, an amino group, or a mercapto group.

3. The composition for holographic recording media according to claim 1, wherein the component (f) is a compound having an isocyanate group and a methacrylate group, or a compound having a hydroxyl group and a methacrylate group.

4. The composition for holographic recording media according to claim 3, wherein the component (f) is a compound having a hydroxyl group and a methacrylate group.

5. A composition for holographic recording media according to claim 1 or 2, wherein the content of said component (f) relative to said component (c) is 10 mol % or more and 100 mol % or less.

6. The composition for holographic recording media according to claim 1 or 2, wherein in component (c), the acrylate monomer has a refractive index of 1.65 or more.

7. The composition for a holographic recording medium according to claim 1 or 2, wherein the component (d) is a ketoxime ester photopolymerization initiator.

8. The composition for holographic recording media according to claim 1 or 2, further comprising the following component (g): a catalyst that promotes the reaction between an isocyanate group and an isocyanate-reactive functional group.

9. A cured product for a holographic recording medium obtained by curing the composition for a holographic recording medium according to claim 1.

10. A laminate for a holographic recording medium, comprising a recording layer made of the cured product for a holographic recording medium according to claim 9 and a support.

11. A holographic recording medium obtained by exposing the cured product for a holographic recording medium according to claim 9 or the laminate for a holographic recording medium according to claim 10.

12. An optical material comprising the cured product for a holographic recording medium according to claim 9.

13. An optical part comprising the cured product for a holographic recording medium according to claim 9.

14. A large-capacity memory including the holographic recording medium according to claim 11.

15. An optical element obtained by holographically recording on the holographic recording medium according to claim 11.

16. An AR light guide plate comprising the optical element according to claim 15.

17. AR glasses comprising the optical element according to claim 15.

18. A composition solution set for a holographic recording medium comprising Solution A and Solution B, wherein Solution A contains at least the following components (a), (c), (d), and (e), Solution B contains at least the following components (b) and (g), and either Solution A or Solution B, or both Solution A and Solution B, contain Component (f): Component (a): an isocyanate compound not containing an aromatic ring or a methacrylate group, Component (b): a polycaprolactone polyol, Component (c): an acrylate monomer, Component (d): an oxime ester photopolymerization initiator, Component (e): a compound having a nitroxyl radical group and an isocyanate-reactive functional group, Component (f): a compound having an isocyanate group and a methacrylate group, or a compound having an isocyanate-reactive functional group and a methacrylate group, Component (g): a catalyst that promotes the reaction between an isocyanate group and an isocyanate-reactive functional group.

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