Composition, polymer, hologram recording medium, optical material, and optical component

Abstract

Provided is a composition suitable for forming a cured film having high solvent resistance and a high refractive index. The composition comprises a polymerizable compound (A) and a polymerizable compound (B), wherein the content of the polymerizable compound (B) with respect to 100 parts by mass of the polymerizable compound (A) is 0.0001 parts by mass to 10 parts by mass. The polymerizable compound (A) has a structure represented by formula (1) and has a refractive index of 1.60 or more. The polymerizable compound (B) is represented by formula (2). (In formula (1), R1 is a hydrogen atom or a methyl group. L1 is a (n1+1)-valent linking group. n1 is 1 or 2. In formula (2), R2 is a hydrogen atom or a methyl group. L2 is a (n2+1)-valent linking group. n2 is 1 or 2.)

Description

Composition, polymer, holographic recording medium, optical material, and optical component

[0001] The present invention relates to a composition having a high refractive index, high transparency, ease of polymerization, and excellent chemical stability. The present invention also relates to a holographic recording medium, an optical material, and an optical component using the composition or a polymer thereof.

[0002] Glass has traditionally been widely used as an optical material. For example, when manufacturing optical lenses using a material with a high refractive index, even lenses with the same focal length can be made thinner, offering the advantages of reduced weight and increased freedom in designing the optical path. High refractive index optical lenses are also effective in reducing the size, increasing the resolution, and widening the angle of view of optical imaging devices.

[0003] In recent years, highly transparent plastics have been attracting attention as an alternative optical material to glass. Compared to glass, plastic materials have advantages such as being easier to reduce in weight, improving in mechanical strength, and being easier to process and mold. With the development of peripheral technologies, there is an increasing demand for improved performance in plastic optical materials, and they are required to be easy to polymerize, have good curing properties, have a high refractive index after polymerization, be chemically stable, and be easy to mold.

[0004] Many resins have been developed to increase the refractive index. Introducing aromatic rings is an effective way to increase the refractive index. Patent Documents 1 and 2 describe that compounds with high refractive indexes can be obtained by using high-refractive-index aromatic acrylate compounds substituted with multiple aromatic rings. However, these compounds have the problem of reduced polymerizability of the acrylate compound due to steric hindrance caused by the multiple aromatic rings.

[0005] Patent Documents 3 to 6 describe high refractive index acrylate compounds in which polymerizability and solubility are improved by introducing a linking group between the moiety that exhibits a high refractive index and the polymerizable group. In particular, compounds having a urethane structure in the linking group are known to have significantly improved polymerizability, and are attracting attention as high refractive index materials and as hologram materials that can provide high diffraction efficiency.

[0006] However, even with these linking group-introduced polymerizable compounds, the polymerizability is not sufficiently high due to an increase in molecular weight to increase the refractive index and steric hindrance, and the adhesion to the substrate tends to decrease due to the hydrophobicity of the aromatic ring group, which is the high refractive index group. Therefore, when a cured film is formed on a substrate, the coating film has a problem of low chemical stability, particularly low solvent resistance.

[0007] One known method for improving the solvent resistance of cured films is to form three-dimensional crosslinked films by adding polyfunctional polymerizable compounds. However, when high refractive index polyfunctional polymerizable compounds are used, there is still concern about insufficient polymerizability due to steric hindrance, and when highly reactive low molecular weight compounds are used as crosslinking agents, a decrease in the refractive index of the cured film becomes a problem.

[0008] International Publication No. 2009 / 151061, Japanese Patent No. 5664707, Japanese Patent No. 7371699, International Publication No. 2022 / 202538, International Publication No. 2024 / 063135, International Publication No. 2024 / 085208

[0009] An object of the present invention is to provide a composition suitable for forming a cured film having high solvent resistance and a high refractive index, and a high refractive index polymer useful as a high refractive index cured film formed using the composition, an optical material, or an optical component.

[0010] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by further using a specific compound in a polymerizable composition containing a urethane (meth)acrylate compound. This has resulted in a composition that solves the problems of the present invention, and the cured film and polymer obtained by polymerizing this composition have improved solvent resistance while maintaining a high refractive index. Furthermore, the present inventors have found that the composition of the present invention is useful for holographic recording media, leading to the completion of the present invention.

[0011] That is, the gist of the present invention lies in the following.

[0012] [1] A composition comprising the following polymerizable compound (A) and the following polymerizable compound (B), wherein the content of the polymerizable compound (B) relative to 100 parts by mass of the polymerizable compound (A) is 0.0001 parts by mass or more and 10 parts by mass or less. Polymerizable compound (A): A compound having a structure represented by the following formula (1) and having a refractive index of 1.60 or more. Polymerizable compound (B): A compound represented by the following formula (2):

[0013]

[0014] (In formula (1), R １ represents a hydrogen atom or a methyl group, L １ is (n １ represents a (+1)valent linking group. １ represents 1 or 2. １ If there are multiple R １ may be the same or different. ２ represents a hydrogen atom or a methyl group, L ２ are each independently, (n ２ represents a (+1)valent linking group. ２ Each independently represents 1 or 2. ２ If there are multiple R ２ may be the same or different.)

[0015] [2] L in the formula (1) １ and L in the formula (2) ２ [3] The composition according to [1] or [2], wherein the polymerizable compound (B) is a compound represented by any one of the following formulas (3) to (5):

[0016]

[0017] (In formulas (3) to (5), R ２ is R in the formula (2). ２ is synonymous with

[0018] [4] The composition according to any one of [1] to [3], wherein the polymerizable compound (A) is a compound represented by the following formula (6-1) or formula (6-2):

[0019]

[0020] (In formula (6-1), R １ , L １ , n １ is R in the formula (1). １ , L １ , n １ It is synonymous with X. １ represents a (r+1)-valent linking group, and Ar represents an aromatic ring group which may have a substituent. Y represents a monovalent organic group. p represents 0 or 1, q represents an integer of 0 to 10, and r represents an integer of 1 to 5. When q and / or r are integers of 2 or greater, multiple Ars and Ys may be the same or different.

[0021]

[0022] (In formula (6-2), R １ , L １ , n １ is R in the formula (1). １ , L １ , n １ It is synonymous with X. ２ represents a divalent linking group, and Ar represents an aromatic ring group which may have a substituent. Y represents a monovalent organic group. p represents 0 or 1, and q represents an integer of 0 to 10. Z represents a single bond, a divalent organic group having 1 to 20 carbon atoms, a carbonyl group, a sulfonyl group, a divalent oxygen atom, or a divalent sulfur atom. When q is an integer of 2 or more, multiple Ys may be the same or different.

[0023] [5] The composition according to any one of [1] to [4], further comprising a polymerization initiator. [6] A holographic recording medium comprising the composition according to any one of [1] to [5]. [7] A polymer obtained by polymerizing the composition according to any one of [1] to [5].

[0024] [8] An optical material comprising the polymer according to [7]. [9] An optical component comprising the polymer according to [7].

[0025]

[10] A large-capacity memory including the holographic recording medium according to [6].

[11] An optical element obtained by holographically recording in the holographic recording medium according to [6].

[0026]

[12] An AR light guide plate including the optical element according to

[11] .

[13] AR glasses including the optical element according to

[11] .

[0027] The composition of the present invention can provide a cured film having a high refractive index and excellent solvent resistance, which is useful as an optical material. The composition of the present invention is particularly useful as a reactive composition for use in hard coat layers of optical lenses and optical members, and in holographic recording media.

[0028] FIG. 1 is a schematic diagram showing an outline of the configuration of an apparatus used for holographic recording.

[0029] Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof. In the present invention, "(meth)acrylate" is a general term for acrylate and methacrylate. "(meth)acryloyl group" is a general term for acryloyl group and methacryloyl group. The same applies to "(meth)acrylic". In the present invention, "aromatic ring" is a general term for "aromatic hydrocarbon ring" and "aromatic heterocyclic ring". Similarly, "aromatic ring group" is a general term for "aromatic hydrocarbon group" and "aromatic heterocyclic group". In addition, in the present invention, "optionally having a substituent" means that the group may have one or more substituents.

[0030] 1. Composition of the Present Invention The composition of the present invention is a composition containing the following polymerizable compound (A) and the following polymerizable compound (B), characterized in that the content of the polymerizable compound (B) relative to 100 parts by mass of the polymerizable compound (A) is 0.0001 parts by mass or more and 10 parts by mass or less. Polymerizable compound (A): A compound having a structure represented by the following formula (1) and having a refractive index of 1.60 or more. Polymerizable compound (B): A compound represented by the following formula (2):

[0031]

[0032] (In formula (1), R １ represents a hydrogen atom or a methyl group, L １ is (n １ represents a (+1)valent linking group. １ represents 1 or 2.１ If there are multiple R １ may be the same or different. ２ represents a hydrogen atom or a methyl group, L ２ are each independently, (n ２ represents a (+1)valent linking group. ２ Each independently represents 1 or 2. ２ If there are multiple R ２ may be the same or different.)

[0033] 1-1. Polymerizable Compound (A) The polymerizable compound (A) is a compound having a structure represented by the above formula (1) and a refractive index of 1.60 or more.

[0034] 1-1-1. Structure of polymerizable compound (A) In the formula (1), R １ represents a hydrogen atom or a methyl group. １ For example, from the viewpoint of the polymerizability of the polymerizable compound (A), R １ On the other hand, from the viewpoint of improving the stability of the polymer of the polymerizable compound (A), R １ is preferably a methyl group. １ If there are multiple R １ may be the same or different, but from the viewpoint of ease of synthesis, it is preferable that they are all the same.

[0035] In the formula (1), L １ is (n １ From the viewpoint of ease of synthesis and availability, the linking group is preferably an aliphatic hydrocarbon group which may have a substituent, or a linking group having an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. １ is more preferably an aliphatic hydrocarbon group which may have a substituent.

[0036] The number of carbon atoms in the aliphatic hydrocarbon group, which may have a substituent (not including the number of carbon atoms in the substituent), is preferably 1 to 8. When the aliphatic hydrocarbon group has 8 or less carbon atoms, the refractive index of the polymerizable compound (A), the composition of the present invention containing the polymerizable compound (A), and the polymer thereof tends not to decrease. The aliphatic hydrocarbon group may be either a cyclic aliphatic hydrocarbon group or a chain aliphatic hydrocarbon group, or a combination of these structures. From the viewpoint of alleviating steric hindrance around the (meth)acryloyl group (hereinafter sometimes referred to as a "polymerizable (meth)acryloyl group") which is the polymerizable group and improving polymerization performance, a chain aliphatic hydrocarbon group is preferred, and an alkylene group having 1 to 4 carbon atoms is more preferred.

[0037] The aliphatic hydrocarbon group which may have a substituent is, for example, n １ When n is 1, that is, when it is a divalent linking group, examples of the divalent linking group include divalent linking groups in which one hydrogen atom has been removed from any position of the alkyl moiety of an alkyl group that may have a substituent, such as an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms and having an alkoxy group as a substituent, or a cycloalkyl group having 3 to 7 carbon atoms. Among these, from the viewpoint of solubility, divalent linking groups in which one hydrogen atom has been removed from any position of the alkyl moiety of an alkyl group having 1 to 8 carbon atoms or an alkyl group having 1 to 8 carbon atoms and having an alkoxy group as a substituent are preferred, and from the viewpoint of ease of synthesis, an alkylene group having 1 to 8 carbon atoms is more preferred. １ When is 2, that is, L １ When is a trivalent linking group, examples thereof include trivalent linking groups in which two hydrogen atoms have been taken from any position of the alkyl moiety of an alkyl group which may have a substituent, such as an alkyl group having 3 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms and having an alkyl group as a substituent, or an alkyl group having 3 to 10 carbon atoms and having an alkoxy group as a substituent. Among these, from the viewpoint of heat resistance, a trivalent linking group in which two hydrogen atoms have been taken from any position of the alkyl moiety of an alkyl group having 3 to 10 carbon atoms and having an alkyl group as a substituent is preferred, and a trivalent linking group in which two hydrogen atoms have been taken from any position of the alkyl moiety of an alkyl group having 3 to 10 carbon atoms and having an alkyl group as a substituent with a tetrasubstituted carbon is more preferred.

[0038] The linking group having an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent may be cyclic or chain-like, but is preferably chain-like from the viewpoint of alleviating steric hindrance around the polymerizable (meth)acryloyl group and improving polymerization performance.

[0039] The chain linking group having an oxygen atom, a sulfur atom or a nitrogen atom which may have a substituent includes n １ is 1, that is, L １ When is a divalent linking group, -CH ２ CH ２ OCH ２ CH ２ -, -CH ２ CH ２ OCH ２ CH ２ OCH ２ CH ２ -, -CH ２ CH ２ SCH ２ CH ２ -, -CH ２ CH ２ (CO)-, -CH ２ CH ２ CH ２ (CO)-, -CH ２ CH ２ CH ２ CH ２ (CO)-, -CH ２ CH ２ CH ２ CH ２ CH ２ (CO)-, -CH ２ CH ２ OCH ２ CH ２ (CO)-, -CH ２ CH ２ NH(CO)-, -CH ２ CH ２ CH ２ NH(CO)-, -CH ２ CH ２ CH ２ CH ２ NH(CO)-, -CH ２ CH ２ OCH ２ CH ２NH(CO)- and the like. １ may be a combination of two or more of these groups. １ When is 2, that is, L １ is a trivalent linking group, -(CH ２ ) ２ C(CH ３ ) -, -(CH ２ ) ２ C(CH ３ )(CO)-,-(CH ２ ) ２ C(CH ２ CH ３ )(CO)-,-(CH ２ ) ３ C(CO)-,-(CH ２ ) ２ C(CH ３ )NH(CO)-, and linking groups in which any hydrogen atom in the chain linking group is substituted with a bond to the polymerizable (meth)acryloyl group. In this case, the linking group may be bonded to the polymerizable (meth)acryloyl group via a branched structure.

[0040] L in formula (1) １ and L in formula (2) described below. ２ may be different or the same and can be selected arbitrarily. From the viewpoint of ease of synthesis and improvement of affinity between the polymerizable compound (A) and the polymerizable compound (B), L １ and L ２ Furthermore, from the viewpoint of availability, it is preferable that L １ and L ２ But -CH ２ CH ２ OCH ２ CH ２ - or -CH ２ CH ２ OCH ２ CH ２ OCH ２ CH ２ It is more preferable that it is -.

[0041] In the formula (1), n １represents 1 or 2. Since a high refractive index tends to be achieved, the polymerizable compound (A) preferably has a smaller number of polymerizable groups, and is more preferably a monofunctional compound having 1 polymerizable group. １ is preferably 1. １ If = 2, multiple R １ may be the same or different.

[0042] 1-1-2. Refractive index of polymerizable compound (A) Generally, the overall density is increased by a polymerization reaction, and therefore the refractive index of the resulting polymer tends to be higher than that of its precursor, the compound before polymerization (referred to as a monomer). By sufficiently progressing the polymerization reaction using a monomer with a high refractive index, the refractive index of the resulting polymer can be increased, and therefore it is considered important to improve the refractive index of the polymer by designing the molecular structure of the monomer.

[0043] The refractive index of the polymerizable compound (A) is 1.60 or more. When the refractive index is 1.60 or more, a polymer that is sufficiently useful as a high refractive index material can be obtained. From the viewpoint of achieving a high refractive index of the polymer, the refractive index of the polymerizable compound (A) is preferably 1.62 or more, more preferably 1.65 or more, and even more preferably 1.68 or more. On the other hand, although there is no upper limit to the refractive index of the polymerizable compound (A), in the ultra-high refractive index region, the effect of adding the polymerizable compound (B) tends to decrease, so the refractive index of the polymerizable compound (A) is preferably 1.90 or less, more preferably 1.85 or less, and even more preferably 1.80 or less.

[0044] The refractive index shows a large value when evaluated with irradiation light of a short wavelength, but a sample that shows a relatively large refractive index at a short wavelength also shows a relatively large refractive index at a long wavelength, and this relationship is not reversed. Therefore, by evaluating and comparing the refractive index at a constant wavelength, it is possible to compare the intrinsic refractive index of the material. In the present invention, the value at an irradiation light wavelength of 587.6 nm was used as the standard. A specific method for measuring the refractive index of the polymerizable compound (A) is as shown in the Examples section below.

[0045] 1-1-3. Suitable Compounds for Polymerizable Compound (A) From the viewpoint of achieving both high solubility and a high refractive index, the polymerizable compound (A) is preferably a compound represented by the following formula (6-1) or formula (6-2), and more preferably a compound represented by the following formula (6-1). Furthermore, from the viewpoint of coloring due to exposure during hologram recording, it is preferable that the polymerizable compound (A) does not contain a sulfur atom in one molecule. Among these, X in the following formula (6-1) is particularly preferable. １ and X in the following formula (6-2): ２ It is more preferable that the alkyl group does not contain sulfur atoms.

[0046]

[0047] (In formula (6-1), R １ , L １ , n １ is R in the formula (1). １ , L １ , n １ It is synonymous with X. １ represents a (r+1)-valent linking group, and Ar represents an aromatic ring group which may have a substituent. Y represents a monovalent organic group. p represents 0 or 1, q represents an integer of 0 to 10, and r represents an integer of 1 to 5. When q and / or r are integers of 2 or greater, multiple Ars and Ys may be the same or different.

[0048]

[0049] (In formula (6-2), R １ , L １ , n １ is R in the formula (1). １ , L １ , n １ It is synonymous with X. ２ represents a divalent linking group, and Ar represents an aromatic ring group which may have a substituent. Y represents a monovalent organic group. p represents 0 or 1, and q represents an integer of 0 to 10. Z represents a single bond, a divalent organic group having 1 to 20 carbon atoms, a carbonyl group, a sulfonyl group, a divalent oxygen atom, or a divalent sulfur atom. When q is an integer of 2 or more, multiple Ys may be the same or different.

[0050] Ar in formula (6-1) and formula (6-2) represents an aromatic ring group which may have a substituent. The total number of carbon, nitrogen, oxygen, and sulfur atoms constituting the aromatic ring of the aromatic ring group of Ar is preferably 5 to 20. When the total number of carbon, nitrogen, oxygen, and sulfur atoms is 5 or more, a high refractive index of the polymerizable compound (A) can be expected. On the other hand, when the total number of carbon, nitrogen, oxygen, and sulfur atoms is 20 or less, synthesis of the polymerizable compound (A) is facilitated. From the above viewpoints, the total number of carbon, nitrogen, oxygen, and sulfur atoms constituting Ar is preferably 6 to 18, more preferably 10 to 14. The aromatic ring group is broadly classified into an aromatic hydrocarbon group and an aromatic heterocyclic group. The aromatic ring of these aromatic ring groups may have a monocyclic structure or a fused ring structure. Furthermore, the aromatic ring may have a structure in which two or more aromatic rings are connected via a direct bond.

[0051] 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.

[0052] 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.

[0053] The aromatic hydrocarbon ring constituting Ar is preferably a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a biphenylene ring, or a fluorene ring from the viewpoint of ease of synthesis and availability. From the viewpoint of suppressing the fluorescence of the polymerizable compound (A), the aromatic hydrocarbon ring constituting Ar is more preferably a benzene ring, a naphthalene ring, a phenanthrene ring, a biphenylene ring, or a fluorene ring.

[0054] As the aromatic heterocycle constituting Ar, a sulfur-containing aromatic heterocycle is preferred because it tends to be able to increase the refractive index even when the cured film is immersed in a solvent. The sulfur-containing aromatic heterocycle has at least a sulfur atom as a heteroatom constituting the aromatic heterocycle. In addition to the sulfur atom, the heteroatom may have an oxygen atom, a nitrogen atom, or both an oxygen atom and a nitrogen atom. From the viewpoints of avoiding coloration and ensuring solubility, the number of heteroatoms constituting the sulfur-containing aromatic heterocycle is preferably 1 to 3, more preferably 1 to 2. Examples of sulfur-containing aromatic heterocycles include aromatic heterocycles containing one sulfur atom, such as a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, a thiopyran ring, a naphthothiophene ring, a dinaphthothiophene ring, and a dibenzothiopyran ring; aromatic heterocycles containing two or more sulfur atoms, such as a thianthrene ring; and aromatic heterocycles containing two or more heteroatoms, such as a thiazole ring, an isothiazole ring, a benzothiazole ring, a naphthothiazole ring, a phenothiazine ring, a thiazoloimidazole ring, a thiazolopyridine ring, a thiazolopyridazine ring, a thiazolopyrimidine ring, a dioxazolopyrazine ring, a thiazolopyrazine ring, a thiazolooxazole ring, a dibenzobenzothiophene ring, a thienoxazole ring, a thienothiadiazole ring, and a thiazolothiadiazole ring.

[0055] The sulfur-containing aromatic heterocycle may be a single ring or a fused ring. From the viewpoint of increasing the refractive index, a fused ring is preferred. The number of rings constituting the fused ring is preferably 2 to 8, more preferably 2 to 6, and particularly preferably 2 to 5, from the viewpoint of facilitating raw material availability and synthesis. In particular, from the viewpoints of increasing the refractive index and reducing coloration, the sulfur-containing aromatic heterocycle is preferably a benzothiazole ring, a dibenzothiophene ring, a benzothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, or a thianthrene ring.

[0056] The aromatic heterocycle constituting Ar may be a nitrogen-containing aromatic heterocycle from the viewpoint of ease of synthesis. The nitrogen-containing aromatic heterocycle has at least a nitrogen atom as a heteroatom constituting the aromatic heterocycle. In addition to the nitrogen atom, the heteroatom may have an oxygen atom, a sulfur atom, or both an oxygen atom and a sulfur atom. From the viewpoint of avoiding coloration, the number of heteroatoms constituting the nitrogen-containing aromatic heterocycle is preferably 1 to 3, more preferably 1 to 2. Examples of the nitrogen-containing aromatic heterocycle include aromatic heterocycles containing one nitrogen atom, such as a pyrrole ring, an indole ring, a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a pyridine ring, a quinoline ring, an isoquinoline ring, an oxazole ring, a thiazole ring, a benzoxazole ring, a naphthoxazole ring, a benzothiazole ring, a naphthothiazole ring, a phenoxazine ring, a phenothiazine ring, a thienoxazole ring, a thiazolooxazole ring, an oxazolooxazole ring, a furothiazole ring, a thienothiazole ring, and a thiazolothiazole ring; an imidazole ring, a triazole ring, Examples of aromatic heterocycles containing two or more nitrogen atoms include a tetrazole ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a thiadiazole ring, a benzimidazole ring, an oxazoloimidazole ring, an oxazolopyridine ring, an oxazolopyridazine ring, an oxazolopyrimidine ring, an oxazolopyrazine ring, a quinolinoxazole ring, a dioxazolopyrazine ring, a thiazoloimidazole ring, a thienothiadiazole ring, a thiazolothiadiazole ring, a thiazolopyridine ring, a thiazolopyridazine ring, a thiazolopyrimidine ring, a thiazolopyrazine ring, and a quinolinothiazole ring.

[0057] The nitrogen-containing aromatic heterocycle may be a single ring or a fused ring. From the viewpoint of increasing the refractive index, a fused ring is preferred. The number of rings constituting the fused ring is preferably 2 to 8, more preferably 2 to 6, and particularly preferably 2 to 5, from the viewpoint of facilitating raw material availability and synthesis. In particular, from the viewpoint of increasing the refractive index and reducing coloration, the nitrogen-containing aromatic heterocycle is preferably a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a pyridine ring, a quinoline ring, an isoquinoline ring, a benzoxazole ring, a benzothiazole ring, a benzimidazole ring, or a thiadiazole ring, and more preferably a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a benzoxazole ring, a benzothiazole ring, a benzimidazole ring, or a thiadiazole ring.

[0058] The aromatic heterocycle constituting Ar may be an oxygen-containing aromatic heterocycle. The oxygen-containing aromatic heterocycle tends to improve the heat resistance and weather resistance of a polymer made from the polymerizable compound (A). The oxygen-containing aromatic heterocycle has at least an oxygen atom as a heteroatom constituting the aromatic heterocycle. In addition to the oxygen atom, the heteroatom may have a nitrogen atom, a sulfur atom, or both a nitrogen atom and a sulfur atom. From the viewpoint of ensuring heat resistance, the number of oxygen atoms constituting the oxygen-containing aromatic heterocycle is preferably 1 to 3, more preferably 1 to 2. Examples of the oxygen-containing aromatic heterocycle include aromatic heterocycles containing one oxygen atom such as a furan ring, a benzofuran ring, a dibenzofuran ring, a naphthofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, a phenoxazine ring, an oxazole ring, an isoxazole ring, a benzoxazole ring, a benzisoxazole ring, a naphthoxazole ring, a thienoxazole ring, a thiazolooxazole ring, an oxazoloimidazole ring, and a furothiazole ring; and aromatic heterocycles containing two or more oxygen atoms such as a dibenzodioxin ring, an oxazolooxazole ring, and a dioxazolopyrazine ring.

[0059] The oxygen-containing aromatic heterocycle may be a single ring or a fused ring. From the viewpoint of increasing the refractive index, a fused ring is preferred. The number of rings constituting the fused ring is preferably 2 to 8, more preferably 2 to 6, and particularly preferably 2 to 5, from the viewpoint of facilitating raw material availability and synthesis. In particular, from the viewpoint of increasing the refractive index and reducing coloration, the oxygen-containing aromatic heterocycle is preferably a dibenzofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, an oxazole ring, an isoxazole ring, a benzoxazole ring, a benzisoxazole ring, or a naphthoxazole ring, and more preferably a dibenzofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, or a benzoxazole ring.

[0060] The aromatic ring constituting Ar 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 alkynyl 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 aromatic ring thio 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, aromatic ring thio groups having 6 to 10 carbon atoms, cyano groups, acetyloxy groups, alkylcarbonyloxy groups having 2 to 9 carbon atoms, sulfamoyl groups, alkylsulfamoyl groups having 2 to 9 carbon atoms, and nitro groups.

[0061] From the viewpoint of increasing the refractive index of the polymerizable compound (A), it is preferable that the aromatic rings constituting these Ar further have a group containing an aromatic ring as a substituent. The aromatic ring contained in the substituent has the same meaning as the aromatic ring constituting Ar. The aromatic ring contained in these substituents may be directly bonded to the aromatic ring constituting Ar at any position, or may be bonded via an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent, or may be bonded via any linking group. It is more preferable that the substituent is directly bonded to the aromatic ring constituting Ar. Furthermore, by making the aromatic ring contained in this substituent a sulfur-containing aromatic heterocycle, the refractive index of the cured film when immersed in a solvent tends to be higher. The definition of the sulfur-containing aromatic heterocycle is the same as in Ar. The sulfur-containing aromatic heterocycle is more preferably a fused ring, and in particular, a benzothiazole ring, a dibenzothiophene ring, a benzothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, or a thianthrene ring is preferred.

[0062] The number of aromatic rings that Ar has as a substituent is not particularly limited, but from the viewpoints of ease of synthesis and solubility, 1 to 4 is preferred, and 1 or 2 is more preferred.

[0063] From the viewpoint of achieving both a high refractive index and high solubility in various media, the aromatic ring constituting Ar is preferably a fused aromatic ring which may have a substituent, or a monocyclic aromatic ring substituted with an aromatic ring group, and more preferably a fused aromatic heterocycle which may have a substituent, or an aromatic hydrocarbon ring which has an aromatic heterocyclic group as a substituent. The aromatic ring constituting Ar may have two or more selected from the above-mentioned aromatic hydrocarbon ring, sulfur-containing aromatic heterocycle, nitrogen-containing aromatic heterocycle, and oxygen-containing aromatic heterocycle.

[0064] In formula (6-1), when r is 2 or more, or in formula (6-2), the aromatic rings constituting the two Ars may be the same or different. When the plurality of Ars are the same aromatic ring, this is more preferable from the viewpoint of easy availability of raw materials. When the plurality of Ars are different aromatic rings, this is more preferable from the viewpoint of solubility.

[0065] X in formula (6-1) １represents a (r+1)-valent linking group. ２ represents a divalent linking group. When p=0, X １ , X ２ does not exist (direct bond). In this case, r in formula (6-1) is 1.

[0066] When p=1, X in formula (6-1) １ is a divalent to hexavalent linking group depending on the value of r.

[0067] X in formula (6-1) when p = 1 １ , X in formula (6-2) ２ does not necessarily contain a heteroatom, but from the viewpoint of ease of synthesis, it preferably contains an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. From the viewpoint of improving high solubility, p=1 is preferred.

[0068] X １ , X ２ is preferably an aliphatic hydrocarbon group having 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 in the compounds represented by formula (6-1) and formula (6-2). However, as described above, from the viewpoint of coloration due to exposure during hologram recording, X １ , X ２ It is preferable that X does not contain a sulfur atom. The number of carbon atoms in the aliphatic hydrocarbon group (not including the number of carbon atoms in the substituent) is preferably 1 to 8. When the number of carbon atoms in the aliphatic hydrocarbon group is 8 or less, the refractive index of the compounds represented by formula (6-1) and formula (6-2) is less likely to decrease, and the viscosity is reduced due to the small molecular weight, which tends to improve processability. １ , X ２ The aliphatic hydrocarbon group constituting the formula (I) may be either a cyclic aliphatic hydrocarbon group or a chain aliphatic hydrocarbon group, or a combination of these structures. From the viewpoint of reducing steric hindrance around the polymerizable (meth)acryloyl group, a chain aliphatic hydrocarbon group is preferred.

[0069] X in formula (6-1) when r = 1 １ , X in formula (6-2) ２Examples of the chain aliphatic hydrocarbon group having an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent, which constitutes the above 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, an —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 ２ NHC(S)-,-OCH ２ CH ２ SCH ２ CH ２ NHC(S)-,-OCH ２ CH ２ NHC(S)- and the like. １ , X ２ may be a combination of two or more of these groups. １ As for -(OCH ２ ) ２ C(CH ３ )NHC(O)-, and linking groups in which any hydrogen atom in the chain aliphatic hydrocarbon group is substituted with a bond to the oxygen atom on the polymerizable (meth)acryloyl group side. In this case, the linking group may be a branched structure.

[0070] X １ , X ２ is preferably a cyclic group from the viewpoint of a high refractive index, １ , X ２ The ring contained in the cyclic group constituting X may have a monocyclic structure or a condensed ring structure. １ , X ２The number of rings contained in X is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2. １ , X ２ The ring contained in X does not necessarily need to be aromatic, but it is preferably an aromatic hydrocarbon ring in order to maintain a high refractive index while keeping the size of the ring in the entire molecule small. １ , X ２ Examples of the aromatic hydrocarbon ring constituting the formula (I) include a benzene ring, an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, an acenaphthylene ring, an anthracene ring, a phenanthrene ring, and a pyrene ring.

[0071] X １ , X ２ may have a substituent. １ , X ２ Examples of the substituent that may be substituted include a halogen atom (a chlorine atom, a bromine atom, an iodine atom), a hydroxyl group, a mercapto group, 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 phenyl group, a mesityl group, a tolyl group, a naphthyl group, 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 having an alkyl group having 1 to 4 carbon atoms bonded thereto, a trifluoromethyl group, an alkylthio group having 1 to 8 carbon atoms, an aromatic ring thio group having 6 to 10 carbon atoms, and a nitro group.

[0072] When p is 1 and r is 2 or more, particularly when r is 3, X in formula (6-1) １is preferably a linking group of a pentaerythritol skeleton centered on a quaternary carbon atom. In this case, it is preferable that r -Ar-(Y)q each have a structure in which they are bonded to the quaternary carbon atom of the pentaerythritol skeleton via an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent. Here, the atom present between the quaternary carbon atom and -Ar-(Y)q is preferably an oxygen atom or a sulfur atom, more preferably a sulfur atom which imparts a high refractive index. There are no particular restrictions on the group that may be substituted on the nitrogen atom, 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.

[0073] In formula (6-2), Z represents a single bond, a divalent organic group having 1 to 20 carbon atoms, a carbonyl group, a sulfonyl group, a divalent oxygen atom, or a divalent sulfur atom. Examples of the divalent organic group having 1 to 20 carbon atoms represented by Z include L in formula (1). １ Examples of such a divalent organic group include those described above. From the viewpoint of easy availability of raw materials and ease of synthesis, the divalent organic group having 1 to 20 carbon atoms for Z is preferably a divalent organic group having 1 to 10 carbon atoms. Among the divalent organic groups having 1 to 20 carbon atoms, carbonyl groups, sulfonyl groups, oxygen atoms, and sulfur atoms for Z, from the viewpoint of achieving a high refractive index, easy availability of raw materials, and compound stability, a single bond, a divalent organic group having 1 to 10 carbon atoms, a sulfonyl group, and a sulfur atom are preferred, and a divalent organic group having 1 to 10 carbon atoms and a sulfonyl group are more preferred.

[0074] In addition, in the formula (6-2), -(X) ２ ) p-X ２ , p may be the same or different, but are preferably the same from the viewpoint of ease of synthesis, and are preferably different from the viewpoint of solubility. For the same reason, the structure on the left side and the structure on the right side via -Z- in formula (6-2) are preferably the same from the viewpoint of ease of synthesis, and are preferably different from the viewpoint of solubility.

[0075] In formula (6-1) and formula (6-2), Y represents a monovalent organic group. Examples of the organic group include those previously described as the substituents that the aromatic ring constituting Ar may have. Among the aforementioned substituents, Y is preferably an aromatic hydrocarbon ring or an aromatic heterocycle from the viewpoint of achieving a high refractive index, and more preferably a fused aromatic hydrocarbon ring or a fused aromatic heterocycle.

[0076] Furthermore, q, which represents the number of substituents on Y, is an integer of 0 to 10, but from the viewpoints of ease of synthesis and achieving both refractive index and solubility, it is preferably an integer of 0 to 8, more preferably 1 to 6, and even more preferably 1 to 5. Here, when q is 2 or more, the multiple Ys present may be the same or different.

[0077] In formula (6-1), r represents an integer of 1 to 5. From the viewpoint of ease of synthesis, r is preferably 1 to 4, and more preferably 1 to 3. When r is 2 or more, the plurality of Ar, Y, and q may be the same or different.

[0078] 1-1-4. Molecular Weight From the viewpoint of keeping the viscosity low and maintaining good processability, the polymerizable compound (A) preferably has a molecular weight of 2,000 or less, more preferably 1,500 or less, and even more preferably 1,200 or less. From the viewpoint of reducing the shrinkage rate during polymerization, the polymerizable compound (A) preferably has a molecular weight of 500 or more, more preferably 600 or more, and even more preferably 650 or more.

[0079] 1-1-5. Exemplary Compounds Specific examples of the polymerizable compound (A) are shown below. The polymerizable compound (A) of the present invention is not limited to these examples as long as it does not depart from the gist of the invention.

[0080]

[0081] 1-2. Polymerizable Compound (B) The polymerizable compound (B) is a compound represented by the formula (2).

[0082] 1-2-1. Structure of polymerizable compound (B) R in the formula (2) ２ represents a hydrogen atom or a methyl group. ２ For example, from the viewpoint of the polymerizability of the polymerizable compound (B), R ２On the other hand, from the viewpoint of improving the stability of the polymer of the polymerizable compound (B), R ２ is preferably a methyl group. ２ may be the same or different, but from the viewpoint of ease of synthesis, it is preferable that they are all the same.

[0083] In the formula (2), L ２ are each independently, (n ２ Two L in formula (2) represent a linking group having a valence of +1. ２ may be the same or different, but are preferably the same from the viewpoint of ease of synthesis, and are preferably different from the viewpoint of solubility of the polymerizable compound (B).

[0084] L in the formula (2) ２ (n ２ As the (+1)-valent linking group, from the viewpoints of ease of synthesis and availability, an aliphatic hydrocarbon group which may have a substituent, or a linking group having an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent, is preferred. ２ is more preferably an aliphatic hydrocarbon group which may have a substituent.

[0085] The number of carbon atoms in the aliphatic hydrocarbon group which may have a substituent (not including the number of carbon atoms in the substituent) is preferably 1 to 8. When the number of carbon atoms in the aliphatic hydrocarbon group is 8 or less, the refractive index of the polymerizable compound (B), the composition of the present invention containing the same, and the polymer thereof tends not to decrease. The aliphatic hydrocarbon group may be either a cyclic aliphatic hydrocarbon group or a chain aliphatic hydrocarbon group, or a combination of these structures. From the viewpoint of alleviating steric hindrance around the polymerizable (meth)acryloyl group and improving polymerization performance, a chain aliphatic hydrocarbon group is preferred.

[0086] The aliphatic hydrocarbon group which may have a substituent is, for example, n ２When n is 1, that is, when it is a divalent linking group, examples of the divalent linking group include a divalent linking group in which one hydrogen atom has been removed from any position of the alkyl moiety of an alkyl group that may have a substituent, such as an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms and having an alkoxy group as a substituent, or a cycloalkyl group having 3 to 7 carbon atoms. Among these, from the viewpoint of solubility, a divalent linking group in which one hydrogen atom has been removed from any position of the alkyl moiety of an alkyl group having 1 to 8 carbon atoms or an alkyl group having 1 to 8 carbon atoms and having an alkoxy group as a substituent is preferred, and an alkylene group having 1 to 8 carbon atoms is more preferred. ２ When is 2, that is, L ２ When is a trivalent linking group, examples thereof include trivalent linking groups in which two hydrogen atoms have been taken from any position of the alkyl moiety of an alkyl group which may have a substituent, such as an alkyl group having 3 to 10 carbon atoms, an alkyl group having 3 to 10 carbon atoms and having an alkyl group as a substituent, or an alkyl group having 3 to 10 carbon atoms and having an alkoxy group as a substituent. Among these, from the viewpoint of heat resistance, a trivalent linking group in which two hydrogen atoms have been taken from any position of the alkyl moiety of an alkyl group having 3 to 10 carbon atoms and having an alkyl group as a substituent is preferred, and a trivalent linking group in which two hydrogen atoms have been taken from any position of the alkyl moiety of an alkyl group having 3 to 10 carbon atoms and having an alkyl group as a substituent with a tetrasubstituted carbon is more preferred.

[0087] The linking group having an oxygen atom, a sulfur atom, or a nitrogen atom which may have a substituent may be cyclic or chain-like, but is preferably chain-like from the viewpoint of alleviating steric hindrance around the polymerizable (meth)acryloyl group and improving polymerization performance.

[0088] The chain linking group having an oxygen atom, a sulfur atom or a nitrogen atom which may have a substituent includes n ２ is 1, that is, L ２ When is a divalent linking group, -CH ２ CH ２ OCH ２ CH ２ -, -CH ２ CH ２ OCH ２ CH ２ OCH ２ CH２ -, -CH ２ CH ２ SCH ２ CH ２ -, -CH ２ CH ２ (CO)-, -CH ２ CH ２ CH ２ (CO)-, -CH ２ CH ２ CH ２ CH ２ (CO)-, -CH ２ CH ２ CH ２ CH ２ CH ２ (CO)-, -CH ２ CH ２ OCH ２ CH ２ (CO)-, -CH ２ CH ２ NH(CO)-, -CH ２ CH ２ CH ２ NH(CO)-, -CH ２ CH ２ CH ２ CH ２ NH(CO)-, -CH ２ CH ２ OCH ２ CH ２ NH(CO)- and the like. ２ may be a combination of two or more of these groups. ２ When is 2, that is, L ２ is a trivalent linking group, -(CH ２ ) ２ C(CH ３ ) -, -(CH ２ ) ２ C(CH ３ )(CO)-,-(CH ２ ) ２ C(CH ２ CH ３ )(CO)-,-(CH ２ ) ３ C(CO)-,-(CH ２ ) ２ C(CH ３)NH(CO)-, and linking groups in which any hydrogen atom in the chain linking group is substituted with a bond to the polymerizable (meth)acryloyl group. In this case, the linking group may be bonded to the polymerizable (meth)acryloyl group via a branched structure.

[0089] As described above, L in the above formula (1) １ and L in formula (2) ２ may be different or the same and can be selected arbitrarily. However, from the viewpoint of ease of synthesis and improvement of affinity between the polymerizable compound (A) and the polymerizable compound (B), L １ and L ２ Furthermore, from the viewpoint of availability, it is preferable that L １ and L ２ But -CH ２ CH ２ OCH ２ CH ２ - or -CH ２ CH ２ OCH ２ CH ２ OCH ２ CH ２ It is more preferable that it is -.

[0090] In the formula (2), n ２ represents 1 or 2. Since a high refractive index tends to be achieved, it is preferable that the polymerizable compound (B) has a smaller number of polymerizable groups, and n ２ is preferably 1. In addition, the two n ２ may be the same or different, but n ２ Even when R = 2, multiple R ２ may be the same or different, but are preferably the same from the viewpoint of ease of synthesis.

[0091] 1-2-2. Preferred Polymerizable Compound (B) From the viewpoint of easy availability of raw materials, the polymerizable compound (B) is preferably a compound represented by any one of the following formulas (3) to (5), more preferably a compound represented by formula (3) or formula (4), and even more preferably a compound represented by formula (3).

[0092]

[0093] (In formulas (3) to (5), R ２ is R in the formula (2). ２ is synonymous with

[0094] 1-3. Method for synthesizing polymerizable compound (A) and polymerizable compound (B) The polymerizable compound (A) and polymerizable compound (B) can be synthesized according to known methods.

[0095] A common method for synthesizing the polymerizable compound (A) is to react a high refractive index compound having a hydroxy group with an isocyanate compound having a (meth)acryloyl group to obtain a high refractive index (meth)acrylate compound having a urethane bond. The polymerizable compound (B) can be obtained by reacting an isocyanate compound having a (meth)acryloyl group with water.

[0096] 1-4. Content ratio of polymerizable compound (A) and polymerizable compound (B) The composition of the present invention is characterized in that the content of the polymerizable compound (B) per 100 parts by mass of the polymerizable compound (A) is 0.0001 parts by mass or more and 10 parts by mass or less. By adding an appropriate amount of the polymerizable compound (B) to the polymerizable compound (A), the polymerization reactivity and adhesion to the substrate can be increased while maintaining the high refractive index derived from the polymerizable compound (A), and the solvent resistance of the cured film can be improved.

[0097] Although the details of this mechanism are not clear, it is presumed as follows. Polymerizable compounds (A) with a high refractive index usually have many aromatic rings, and are low in reactivity due to insufficient mobility and steric hindrance around the polymerizable group, so that unreacted monomers tend to remain in the polymerization reaction. However, by adding an appropriate amount of polymerizable compound (B) that has a low molecular weight, high mobility, and high structural affinity with polymerizable compound (A), the reaction rate is improved, the amount of unreacted monomers is reduced, and the cured film is stabilized by the formation of a partial crosslinked structure, which is thought to improve solvent resistance. Furthermore, the addition of polymerizable compound (B) causes hydrogen bonds to form between urethane bonds and urea bonds in the cured film, shortening the distance between the main chains and improving density, thereby maintaining the refractive index. It is also thought that the affinity between the cured film and the substrate is improved, and adhesion is increased.

[0098] Since the polymerizable compound (B) tends to be highly crystalline and has low solubility in various media, when the content of the polymerizable compound (B) relative to 100 parts by mass of the polymerizable compound (A) is 10 parts by mass or less, not only can the refractive index of the polymer be improved, but also precipitation of the polymerizable compound (B) from the medium and phase separation with the polymerizable compound (A) can be suppressed. On the other hand, when the content of the polymerizable compound (B) is 0.0001 parts by mass or more, the effects of sufficiently improving the polymerizability and improving the density of the polymer can be obtained. From the viewpoint of sufficiently improving solvent resistance and obtaining a transparent cured film, the content of the polymerizable compound (B) relative to 100 parts by mass of the polymerizable compound (A) is preferably 0.001 parts by mass or more, 0.005 parts by mass or more, of which 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, 0.5 parts by mass or more, of which 0.6 parts by mass or more, even more preferably 0.8 parts by mass or more, and particularly preferably 1.0 parts by mass or more, of which 1.1 parts by mass or more. On the other hand, from the viewpoint of solubility in various media and affinity with the polymerizable compound (A), the content of the polymerizable compound (B) is preferably 13 parts by mass or less, and 10 parts by mass or less, more preferably 8.0 parts by mass or less, more preferably 5.0 parts by mass or less, even more preferably 3.0 parts by mass or less, and particularly preferably 2.0 parts by mass or less.

[0099] The total content of the polymerizable compound (A) and the polymerizable compound (B) in the composition of the present invention is preferably 1% by mass or more, more preferably 5% by mass or more, relative to the total solid content of the composition of the present invention. If the total content of the polymerizable compound (A) and the polymerizable compound (B) is less than 1% by mass, the effects of using the polymerizable compound (A) and the polymerizable compound (B) are not fully exhibited. The composition of the present invention may consist of only the polymerizable compound (A) and the polymerizable compound (B). However, in order to obtain sufficient curability, the total content of the polymerizable compound (A) and the polymerizable compound (B) is usually preferably 99% by mass or less, more preferably 95% by mass or less.

[0100] The composition of the present invention may contain a compound corresponding to each of the polymerizable compound (A) and the polymerizable compound (B) alone, or may contain two or more types in any combination and ratio.

[0101] 2. Polymerizable Composition of the Present Invention The composition of the present invention is preferably a polymerizable composition containing a polymerizable compound (A), a polymerizable compound (B), and a polymerization initiator (hereinafter, sometimes referred to as the "polymerizable composition of the present invention"). The polymerization initiator causes a polymerization reaction between the polymerizable (meth)acryloyl groups of the polymerizable compound (A) and the polymerizable compound (B), thereby producing the polymer of the present invention.

[0102] 2-1. Polymerization initiator The type of polymerization initiator is not particularly limited, and may be appropriately selected from known polymerization initiators depending on the polymerization method. The polymerization method is also not limited, and known methods such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, and partial polymerization can be used.

[0103] Examples of the polymerization initiator contained in the polymerizable composition of the present invention include a radical polymerization initiator, a redox polymerization initiator, an anionic polymerization initiator, etc. The examples of polymerization initiators described below also include those generally called polymerization catalysts.

[0104] 2-1-1. Radical Polymerization Initiator <Photopolymerization Initiator> Any known photoradical polymerization initiator can be used as the photopolymerization initiator that assists in the polymerization of the polymerizable composition of the present invention. Examples include azo compounds, azide compounds, organic peroxides, organic borates, onium salts, bisimidazole derivatives, titanocene compounds, iodonium salts, organic thiol compounds, halogenated hydrocarbon derivatives, acetophenones, benzophenones, hydroxybenzenes, thioxanthones, anthraquinones, ketals, acylphosphine oxides, sulfone compounds, carbamic acid derivatives, sulfonamides, triarylmethanols, and oxime esters. Among these, benzophenones, acylphosphine oxide compounds, and oxime ester compounds are preferred as photopolymerization initiators from the viewpoints of compatibility, availability, and the like.

[0105] Specific examples of the photopolymerization initiator include benzophenone, 2,4,6-trimethylbenzophenone, methyl orthobenzoylbenzoate, 4-phenylbenzophenone, t-butylanthraquinone, 2-ethylanthraquinone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, oligo{2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone}, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1-(4-mol), bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one, methyl benzoyl formate, 1-[4-(phenylthio)-2-(O-benzoyloxime)]-1,2-octanedione, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime)ethanone, and the like.

[0106] These photopolymerization initiators may be used either alone or as a mixture of two or more kinds in any combination and ratio.

[0107] The content of the photopolymerization initiator in the polymerizable composition of the present invention is usually 0.01 parts by mass or more, preferably 0.02 parts by mass or more, and more preferably 0.05 parts by mass or more, when the total amount of all radically polymerizable compounds in the polymerizable composition is 100 parts by mass. The upper limit is usually 10 parts by mass or less, preferably 5 parts by mass or less, and more preferably 3 parts by mass or less. If the content of the photopolymerization initiator is too high, polymerization may proceed too rapidly, which may not only increase the birefringence of the cured product but also worsen the hue. On the other hand, if the content is too low, the polymerizable composition may not polymerize sufficiently.

[0108] <Thermal Polymerization Initiator> Any known thermal radical polymerization initiator can be used as the thermal polymerization initiator that assists the polymerization of the polymerizable composition of the present invention. Examples include organic peroxides and azo compounds. Among them, organic peroxides are preferred from the viewpoint of preventing bubbles from forming in the polymer obtained by the polymerization reaction.

[0109] Specific examples of organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide; peroxyketals such as 1,1-di(t-hexylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-hexylperoxy)cyclohexane, and 1,1-di(t-butylperoxy)cyclohexane; hydroperoxides such as 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and p-menthane hydroperoxide; dicumyl peroxide, di-t-butyl peroxide, and the like. diacyl peroxides such as dilauroyl peroxide and dibenzoyl peroxide; peroxydicarbonates such as di(4-t-butylcyclohexyl)peroxydicarbonate and di(2-ethylhexyl)peroxydicarbonate; and peroxyesters such as t-butylperoxy-2-ethylhexanoate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxybenzoate, and 1,1,3,3-tetramethylbutyl-2-ethylhexanoate.

[0110] Specific examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 1,1'-azobis-1-cyclohexanecarbonitrile, dimethyl-2,2'-azobisisobutyrate, 4,4'-azobis-4-cyanovaleric acid, and 2,2'-azobis-(2-amidinopropane) dihydrochloride.

[0111] These thermal polymerization initiators may be used either alone or as a mixture of two or more kinds in any combination and ratio.

[0112] The content of the thermal polymerization initiator in the polymerizable composition of the present invention is usually 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 0.8 parts by mass or more, when the total amount of all radically polymerizable compounds in the polymerizable composition is 100 parts by mass. The upper limit is usually 10 parts by mass or less, preferably 5 parts by mass or less, and more preferably 2 parts by mass or less. If the amount of thermal polymerization initiator is too much, the polymerization may proceed too rapidly, which may impair the optical uniformity of the obtained polymer and may also deteriorate the hue. On the other hand, if the amount is too little, the thermal polymerization may not proceed sufficiently.

[0113] When a photopolymerization initiator and a thermal polymerization initiator are used in combination, the mass ratio thereof is usually 100:1 to 1:100 (photopolymerization initiator:thermal polymerization initiator, hereinafter the same in this paragraph), preferably 10:1 to 1:10. If the amount of thermal polymerization initiator is too small, polymerization may be insufficient, and if the amount is too large, coloration may occur.

[0114] 2-1-2. Redox Polymerization Initiators Redox polymerization initiators are radical initiators that utilize a redox reaction involving a combination of a peroxide and a reducing agent. They are capable of generating radicals even at low temperatures and are typically used in emulsion polymerization.

[0115] Specific examples of redox polymerization initiators include a combination of dibenzoyl peroxide as a peroxide and aromatic tertiary amines such as N,N-dimethylaniline, N,N-dimethyl-p-toluidine, and N,N-bis(2-hydroxypropyl)-p-toluidine as a reducing agent; a combination of hydroperoxide as a peroxide and metal soaps as a reducing agent; and a combination of hydroperoxide as a peroxide and thioureas as a reducing agent. Water-soluble redox polymerization initiators include a combination of a peroxide such as persulfate, hydrogen peroxide, or hydroperoxide with a water-soluble inorganic reducing agent (Fe ２＋ or NaHSO ３ etc.) or in combination with an organic reducing agent (alcohol, polyamine, etc.).

[0116] The preferred range of the content of the redox polymerization initiator in the polymerizable composition of the present invention is the same as that of the thermal polymerization initiator.

[0117] 2-1-3. Anionic Polymerization Initiator Examples of the anionic polymerization initiator used in the polymerizable composition of the present invention include alkali metals, n-butyllithium, sodium amide, sodium naphthalenide, Grignard reagents, lithium alkoxides, alkali metal benzophenone ketyl, etc. Any one of these may be used alone, or two or more may be used in any combination and in any ratio.

[0118] 2-2. Polymerizable Compounds Other than Polymerizable Compound (A) and Polymerizable Compound (B) The polymerizable composition of the present invention may contain a polymerizable compound other than the polymerizable compound (A) and the polymerizable compound (B). Examples of polymerizable compounds other than the polymerizable compound (A) and the polymerizable compound (B) include anionic polymerizable monomers and radically polymerizable monomers. These polymerizable compounds may be used alone or in any combination and ratio of two or more. Polymerizable compounds having two or more polymerizable functional groups per molecule (sometimes referred to as polyfunctional monomers) may also be used. When a polyfunctional monomer is used, a crosslinked structure is formed within the polymer, thereby improving thermal stability, weather resistance, solvent resistance, and the like.

[0119] When the polymerizable composition of the present invention contains a polymerizable compound other than the polymerizable compound (A) and the polymerizable compound (B), the content thereof is, relative to the total solid content of the composition of the present invention, preferably 0.1 mass % or more and 10 mass % or less, and more preferably 0.3 mass % or more and 5 mass % or less. If the content ratio of the other polymerizable compound is less than 0.1 mass %, the effect of imparting properties by its addition is not fully exhibited, while if it exceeds 10 mass %, problems such as impairment of optical properties and strength tend to occur.

[0120] <Anionically Polymerizable Monomer> Examples of the anionically polymerizable monomer include hydrocarbon monomers and polar monomers.

[0121] Examples of hydrocarbon monomers include styrene, α-methylstyrene, butadiene, isoprene, vinylpyridine, vinylanthracene, and derivatives thereof.

[0122] Examples of polar monomers include methacrylic acid esters (e.g., methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, etc.); acrylic acid esters (e.g., methyl acrylate, ethyl acrylate, etc.); vinyl ketones (e.g., methyl vinyl ketone, isopropyl vinyl ketone, cyclohexyl vinyl ketone, phenyl vinyl ketone, etc.); isopropenyl ketones (e.g., methyl isopropenyl ketone, phenyl isopropenyl ketone, etc.); and other polar monomers (e.g., acrylonitrile, acrylamide, nitroethylene, methylene malonic acid esters, cyanoacrylic acid esters, vinylidene cyanide, etc.).

[0123] These anionically polymerizable monomers may be used either alone or as a mixture of two or more kinds in any combination and ratio.

[0124] <Radical Polymerizable Monomer> The radical polymerizable monomer is a compound having one or more ethylenically unsaturated double bonds in one molecule, and examples thereof include (meth)acrylic acid esters, (meth)acrylamides, vinyl esters, and styrenes.

[0125] Examples of (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, (n- or i-)propyl (meth)acrylate, (n-, i-, sec- or t-)butyl (meth)acrylate, amyl (meth)acrylate, adamantyl (meth)acrylate, chloroethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, cyclohexyl (meth)acrylate, allyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, pentaerythritol mono(meth)acrylate, benzyl (meth)acrylate, methoxybenzyl (meth)acrylate, chlorobenzyl (meth)acrylate, hydroxybenzyl (meth)acrylate, Dimethyl (meth)acrylate, hydroxyphenethyl (meth)acrylate, dihydroxyphenethyl (meth)acrylate, furfuryl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, phenyl (meth)acrylate, hydroxyphenyl (meth)acrylate, chlorophenyl (meth)acrylate, sulfamoylphenyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 2-(hydroxyphenylcarbonyloxy)ethyl (meth)acrylate, phenol EO-modified (meth)acrylate, phenylphenol EO-modified (meth)acrylate, paracumylphenol EO-modified (meth)acrylate, nonylphenol EO-modified (meth)acrylate, N-acryloyloxyethyl hexahydrophthalimide, bisphenol F EO-modified diacrylate, bisphenol A EO-modified diacrylate, dibromophenyl (meth)acrylate, tribromophenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl acrylate, tricyclodecane dimethylol di(meth)acrylate, bisphenoxyethanol fluorene di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate,Dipentaerythritol hexa(meth)acrylate, etc. Here, "EO" means "ethylene oxide."

[0126] Examples of (meth)acrylamides include (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-butyl(meth)acrylamide, N-benzyl(meth)acrylamide, N-hydroxyethyl(meth)acrylamide, N-phenyl(meth)acrylamide, N-tolyl(meth)acrylamide, N-(hydroxyphenyl)(meth)acrylamide, N-(sulfamoylphenyl)(meth)acrylamide, N-(phenylsulfonyl)(meth)acrylamide, N-(tolylsulfonyl)(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-methyl-N-phenyl(meth)acrylamide, and N-hydroxyethyl-N-methyl(meth)acrylamide.

[0127] Examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl benzoate, vinyl benzoate, vinyl t-butylbenzoate, vinyl chlorobenzoate, vinyl 4-ethoxybenzoate, vinyl 4-ethylbenzoate, vinyl 4-methylbenzoate, vinyl 3-methylbenzoate, vinyl 2-methylbenzoate, vinyl 4-phenylbenzoate, and vinyl pivalate.

[0128] Examples of styrenes include styrene, p-acetylstyrene, p-benzoylstyrene, 2-butoxymethylstyrene, 4-butylstyrene, 4-sec-butylstyrene, 4-tert-butylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, dichlorostyrene, 2,4-diisopropylstyrene, dimethylstyrene, p-ethoxystyrene, 2-ethylstyrene, 2-methoxystyrene, 4-methoxystyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, p-methylstyrene, p-phenoxystyrene, p-phenylstyrene, and divinylbenzene.

[0129] These radical polymerizable monomers may be used either alone or as a mixture of two or more kinds in any combination and ratio.

[0130] Any of the anionic polymerizable monomers and radical polymerizable monomers exemplified above may be used, or two or more of them may be used in combination. For example, for high refractive index optical lenses and holographic recording media, it is preferable to use radical polymerizable monomers as other polymerizable compounds to be used in combination with the polymerizable compound (A) and the polymerizable compound (B), because they are less likely to inhibit the reaction of forming a resin matrix.

[0131] 2-3. Other Additive Components Other components may be added to the polymerizable composition of the present invention as long as the effects of the present invention are not impaired.

[0132] Examples of other components include various additives such as solvents, antioxidants, plasticizers, ultraviolet absorbers, sensitizers, chain transfer agents, antifoaming agents, polymerization inhibitors, any fillers made of organic or inorganic substances, diffusing agents, pigments, and wavelength converting materials such as fluorescent substances.

[0133] The polymerizable composition of the present invention may contain a solvent to adjust the viscosity.

[0134] Specific examples of the solvent include, depending on the physical properties of the polymerizable composition, alcohols such as ethanol, propanol, isopropanol, ethylene glycol, and propylene glycol; aliphatic hydrocarbons such as hexane, pentane, and heptane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and chloroform; chain ethers such as dimethyl ether and diethyl ether; cyclic ethers such as dioxane and tetrahydrofuran; esters such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, and ethyl butyrate; ketones such as acetone, ethyl methyl ketone, methyl isobutyl ketone, and cyclohexanone; Examples of organic solvents include cellosolves such as ethyl cellosolve and butyl cellosolve; carbitols such as methyl carbitol, ethyl carbitol and butyl carbitol; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol mono-n-butyl ether; glycol ether esters such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; N,N-dimethylformamide, N,N-dimethylacetamide, etc.), sulfoxides (amides such as dimethyl sulfoxide; nitriles such as acetonitrile and benzonitrile; and N-methylpyrrolidone.

[0135] These solvents can be used alone or as a mixed solvent. Depending on the polymerization method (emulsion polymerization, suspension polymerization, etc.), water can also be used. When a solvent (or dispersion medium) is used, the amount thereof is not particularly limited, and it may be adjusted to obtain a polymerizable composition with a suitable viscosity depending on the polymerization method, processing method, and application.

[0136] In the present invention, in order to improve the heat yellowing resistance and weather resistance of the resulting polymer, it is preferable to incorporate an antioxidant and a light stabilizer as additives into the polymerizable composition.

[0137] Specific examples of the antioxidant include phenolic antioxidants such as 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, n-octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, triethylene glycol bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]; and triphenyl phosphite, trisisodecyl phosphite, isodecyl diphenyl phosphite, 2-ethylhexyl diphenyl phosphite, Examples of phosphorus-based antioxidants include tetra(C12-C15 alkyl)-4,4'-isopropylidene diphenyl diphosphite, tris(nonylphenyl)phosphite, tristridecyl phosphite, 2,4,8,10-tetra-tert-butyl-6-[(2-ethylhexan-1-yl)oxy]-12H-dibenzo[d,g][1,3,2]dioxaphosphocin, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-dioctadecan-1-yl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, and tris(2,4-di-t-butylphenyl)phosphite. These can be used alone or in combination of two or more.

[0138] As the antioxidant, it is preferable to use a phenolic antioxidant in combination with a phosphorus-based antioxidant. A preferred combination of a phenolic antioxidant and a phosphorus-based antioxidant is a combination of at least one selected from tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane and n-octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate as the phenolic antioxidant and tris(2,4-di-t-butylphenyl)phosphite as the phosphorus-based antioxidant.

[0139] The content of the antioxidant in the polymerizable composition of the present invention is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.1 to 2 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable composition, in terms of improving the heat yellowing resistance of the resulting polymer.

[0140] As the light stabilizer, a hindered amine light stabilizer (HALS) is preferably used. Specific examples of HALS include 2,2,6,6-tetramethyl-4-piperidinyl stearate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, bis(2,2,6,6-tetramethyl-1-undecyloxypiperidin-4-yl)carbonate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, and ADK STAB L. A-68 (manufactured by ADEKA Corporation), Adekastab LA-63P (manufactured by ADEKA Corporation), butane-1,2,3,4-tetracarboxylic acid tetrakis(1,2,2,6,6-pentamethyl-4-piperidinyl), 1,2,3,4-butanetetracarboxylic acid tetrakis(2,2,6,6-tetramethyl-4-piperidinyl), TINUVIN 111FDL, TINUVIN 123, TINUVIN 144, TINUVIN 152, TINUVIN 249, TINUVIN 292, TINUVIN 5100 (all manufactured by BASF), and the like. These may be used alone or in combination of two or more.

[0141] The content of the light stabilizer in the polymerizable composition of the present invention is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.1 to 2 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable composition, from the viewpoint of improving the heat yellowing resistance and weather resistance of the resulting polymer.

[0142] The antioxidants and light stabilizers may be used either alone or in combination of two or more thereof.

[0143] 2-4. Method for Producing Polymerizable Composition The polymerizable composition of the present invention may be produced by mixing the respective components, or by premixing the components other than the polymerization initiator and adding the polymerization initiator immediately before the polymerization reaction.

[0144] 2-5. Polymerization Method of Polymerizable Composition The polymerization method of the polymerizable composition of the present invention is not particularly limited, but includes a method of polymerizing by irradiation with active energy rays and a method of polymerizing by heating.

[0145] 2-5-1. Polymerization initiation method (active energy rays) When the polymerizable composition of the present invention is subjected to photoradical polymerization, the polymerization is carried out by irradiation with active energy rays. The active energy rays used are preferably electron beams or light in the wavelength range from ultraviolet to infrared. As the light source, for example, if the active energy rays are ultraviolet rays, an ultra-high pressure mercury light source or a metal halide light source can be used; if they are visible light, a metal halide light source or a halogen light source can be used; and if they are infrared rays, a halogen light source can be used. In addition to these, light sources such as lasers and LEDs can also be used.

[0146] The amount of active energy ray irradiation is appropriately set depending on the type of light source, the thickness of the coating film, etc., but is preferably set so that the reaction rate of the total amount of polymerizable functional groups of the polymerizable compound (A), the polymerizable compound (B), and other polymerizable compounds is 80% or more, more preferably 90% or more. The reaction rate is calculated from the change in absorption peak intensity of the polymerizable functional groups before and after the reaction using infrared absorption spectroscopy. After polymerization by irradiation with active energy rays, the polymerization may be further promoted by heat treatment or annealing treatment as needed. The heating temperature in this case is preferably in the range of 80 to 200°C. The heating time is preferably in the range of 10 to 60 minutes.

[0147] 2-5-2. Polymerization initiation method (heating) When heat treatment is performed to polymerize the polymerizable composition of the present invention, the heating temperature is preferably in the range of 80 to 200° C., more preferably in the range of 100 to 150° C. If the heating temperature is lower than 80° C., a longer heating time is required, which tends to be uneconomical, while if the heating temperature is higher than 200° C., it requires higher energy costs and takes longer to heat up and cool down, which tends to be uneconomical.

[0148] 3. Polymerizable Composition Suitable for Holographic Recording Media The polymerizable composition of the present invention can be suitably used in the recording layer of a holographic recording medium. In this case, the polymerizable composition of the present invention is preferably a photoreactive composition containing, in addition to the polymerizable compound (A), the polymerizable compound (B), and a polymerization initiator, a matrix resin, a radical scavenger, and other additives. Furthermore, it is preferable to use a photopolymerization initiator as the polymerization initiator. Hereinafter, the polymerizable composition suitable as a material for a holographic recording medium will be described in detail.

[0149] 3-1. Matrix Resin The polymerizable composition of the present invention preferably contains a matrix resin. In particular, the matrix resin constituting the recording layer of the holographic recording medium is an organic substance that does not undergo significant chemical or physical changes upon irradiation with light, and is mainly composed of a polymer of an organic compound.

[0150] Since the matrix resin constitutes the polymerizable composition of the present invention together with the polymerizable compound (A) and the polymerizable compound (B), the polymerization initiator, etc., it is strongly required that the matrix resin have excellent compatibility with the polymerizable compound (A) and the polymerizable compound (B), the polymerization initiator, etc. If the matrix resin has poor compatibility with the other components, an interface will be formed between the materials, and light will be refracted or reflected at the interface, causing light to leak to unwanted areas. This can distort or break interference fringes, resulting in recording in inappropriate areas and potentially degrading information. The compatibility between the matrix resin and the other components can be evaluated based on the scattered light intensity obtained by placing a detector in a direction different from that of the transmitted light relative to the sample, as described, for example, in Japanese Patent No. 3737306.

[0151] The matrix resin may be a resin that is composed of a plurality of materials that are soluble in a solvent in the polymerizable composition and that is three-dimensionally crosslinked after being formed into a usable state, and examples of such a resin include thermoplastic resins, thermosetting resins, and photocurable resins, which will be described below.

[0152] Three-dimensionally crosslinked resins are solvent-insoluble and are cured products of the reaction between a polymerizable compound that is liquid at room temperature and a compound reactive with the polymerizable compound. The three-dimensionally crosslinked resin acts as a physical barrier, suppressing volumetric changes during recording. That is, after recording, the recording layer tends to expand in bright areas and contract in dark areas, resulting in unevenness on the surface of the holographic recording medium. To suppress this volumetric change, it is more preferable to use a polymerizable composition containing a three-dimensionally crosslinked resin matrix for the recording layer. Among these, thermosetting resins are preferred as matrix resins in terms of adhesion to the support. Resin materials that can be used as matrix resins are described in detail below.

[0153] 3-1-1. Thermoplastic Resin Specific examples of thermoplastic resin materials include chlorinated polyethylene, polymethyl methacrylate resin (PMMA), copolymers of methyl methacrylate and other alkyl acrylate esters, copolymers of vinyl chloride and acrylonitrile, polyvinyl acetate resin (PVAC), polyvinyl alcohol, polyvinyl formal, polyvinylpyrrolidone, cellulose resins such as ethyl cellulose and nitrocellulose, polystyrene resins, polycarbonate resins, etc. These may be used alone or in combination of two or more.

[0154] The solvent for these thermoplastic resins is not particularly limited as long as it dissolves them, and examples thereof include ketones such as acetone and methyl ethyl ketone, esters such as butyl acetate and propylene glycol methyl ether acetate, aromatic hydrocarbons such as toluene and xylene, ethers such as tetrahydrofuran and 1,2-dimethoxyethane, amides such as N,N-dimethylacetamide and N-methylpyrrolidone, etc. These may be used alone or in combination of two or more.

[0155] 3-1-2. Thermosetting Resins When using a thermosetting resin as the matrix resin, the curing temperature varies depending on the type of crosslinker and catalyst. Typical examples of functional group combinations that cure at room temperature include epoxy and amine, epoxy and thiol, and isocyanate and amine. Typical examples of combinations that use a catalyst include epoxy and phenol, epoxy and acid anhydride, and isocyanate and polyol.

[0156] The former is simple because it reacts immediately upon mixing, but when molding, such as in a holographic recording medium, adjustments are difficult due to the limited time available. On the other hand, the latter allows for flexible control of the curing temperature and curing time by appropriately selecting the type and amount of catalyst used, making it suitable for curing while molding, such as in a holographic recording medium. A wide variety of resin raw materials, from low molecular weight to high molecular weight, are commercially available, so they can be selected while maintaining compatibility with polymerizable reactive compounds and photoinitiators, adhesion to the substrate, etc. Each raw material is explained below, but each raw material may be used alone or in combination of two or more types.

[0157] <Epoxy> Examples of the epoxy include polyglycidyl ether compounds of polyols such as (poly)ethylene glycol, (poly)propylene glycol, (poly)tetramethylene glycol, trimethylolpropane, and glycerin; alicyclic epoxy compounds having a cyclic aliphatic group with a 4- to 7-membered ring such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate; bisphenol A type epoxy compounds, hydrogenated bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, and phenol or cresol novolac type epoxy compounds.

[0158] The epoxy preferably has two or more epoxy groups in one molecule, but the type is not particularly limited. If the number of epoxy groups is small, the hardness required for the matrix may not be obtained. There is no particular upper limit on the number of epoxy groups in one molecule, but it is usually 8 or less, and preferably 4 or less. If the number of epoxy groups is too large, it may take a long time to consume the epoxy groups, and the formation of the matrix resin may take too long.

[0159] <Amine> The amine may be one containing a primary amino group or a secondary amino group. Examples of such amines include aliphatic polyamines such as ethylenediamine, diethylenetriamine, and derivatives thereof, alicyclic polyamines such as isophoronediamine, menthanediamine, N-aminoethylpiperazine, and derivatives thereof, aromatic polyamines such as m-xylylenediamine, diaminodiphenylmethane, and derivatives thereof, polyamides such as condensates of dicarboxylic acids such as dimer acid with the above-mentioned polyamines, imidazole compounds such as 2-methylimidazole and derivatives thereof, and other compounds such as dicyandiamide and adipic dihydrazide.

[0160] <Thiol> Examples of thiols include thiol compounds such as dithiols such as 1,3-butanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,2-benzeneedithiol, 1,3-benzeneedithiol, 1,4-benzeneedithiol, 1,10-decanedithiol, 1,2-ethaneedithiol, 1,6-hexaneedithiol, and 1,9-nonanedithiol, and polythiols such as Thiokol (manufactured by Toray Fine Chemicals Co., Ltd.) and jER Cure QX40 (manufactured by Mitsubishi Chemical Corporation). Of these, commercially available fast-curing polythiols such as jER Cure QX40 are preferably used.

[0161] <Phenol> Examples of phenol include bisphenol A, novolac-type phenolic resins, and resol-type phenolic resins.

[0162] <Acid Anhydride> Examples of the acid anhydride include monofunctional acid anhydrides such as phthalic anhydride, tetrahydrophthalic anhydride and derivatives thereof, and difunctional acid anhydrides such as pyromellitic anhydride, benzophenonetetracarboxylic anhydride and derivatives thereof.

[0163] <Amount of amine, thiol, phenol, or acid anhydride used> The amount of amine, thiol, phenol, or acid anhydride used is, in terms of the ratio to the number of moles of epoxy groups, usually 0.1 equivalents or more, preferably 0.7 equivalents or more, and usually 2.0 equivalents or less, preferably 1.5 equivalents or less. If the amount of amine, thiol, phenol, or acid anhydride used is too small or too large, the number of unreacted functional groups will be large, and storage stability may be impaired.

[0164] <Polymerization Initiator for Thermosetting Resin> As a catalyst for curing a thermosetting resin, an anionic polymerization initiator or a cationic polymerization initiator can be used depending on the curing temperature and curing time.

[0165] Anionic polymerization initiators generate anions upon exposure to heat or active energy rays, and examples thereof include amines. Examples of amines include amino group-containing compounds such as dimethylbenzylamine, dimethylaminomethylphenol, and 1,8-diazabicyclo[5.4.0]undecene-7, and derivatives thereof; imidazole compounds such as imidazole, 2-methylimidazole, and 2-ethyl-4-methylimidazole, and derivatives thereof. These may be used alone or in combination depending on the curing temperature and curing time.

[0166] The cationic polymerization initiator generates cations when exposed to heat or active energy rays, and examples thereof include aromatic onium salts. Specific examples include SbF ６ -, BF ４ -, AsF ６ -, PF ６ -, CF ３ SO ３ -, B (C ６ F ５ ) ４Examples of suitable compounds include compounds comprising an anion component such as - and an aromatic cation component containing an atom such as iodine, sulfur, nitrogen, or phosphorus. Among these, diaryliodonium salts and triarylsulfonium salts are preferred. These can be used alone or in combination depending on the curing temperature and curing time.

[0167] The amount of these thermosetting resin polymerization initiators used is usually 0.001% by mass or more, preferably 0.01% by mass or more, and usually 50% by mass or less, preferably 10% by mass or less, based on the matrix resin. If the amount of these thermosetting resin polymerization initiators used is too small, the concentration of the thermosetting resin polymerization initiator will be too low, and the polymerization reaction may take too long. On the other hand, if the amount of thermosetting resin polymerization initiator used is too large, the polymerization reaction may not undergo a continuous ring-opening reaction.

[0168] <Isocyanate> The isocyanate is preferably one having two or more isocyanate groups per molecule, but the type is not particularly limited. If the number of isocyanate groups per molecule is small, the hardness required for a matrix resin may not be obtained. The upper limit of the number of isocyanate groups per molecule is not particularly limited, but is usually 8 or less, and preferably 4 or less. If the number of isocyanate groups per molecule is too large, it may take a long time to consume the isocyanate groups, and the formation of the matrix resin may take too long. The upper limit of the number of isocyanate groups per molecule is not particularly limited, but is usually about 20 or less.

[0169] Examples of isocyanates include aliphatic isocyanates such as hexamethylene diisocyanate, lysine methyl ester diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate; alicyclic isocyanates such as isophorone diisocyanate and 4,4'-methylenebis(cyclohexyl isocyanate); aromatic isocyanates such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, and naphthalene-1,5'-diisocyanate; and oligomers thereof, of which trimers to heptamers are preferred.

[0170] Other examples include reaction products of the above-mentioned isocyanates with polyhydric alcohols such as water, trimethylolethane, and trimethylolpropane, and hexamethylene diisocyanate polymers or derivatives thereof. The molecular weight of the isocyanate is preferably 100 to 50,000 in number average molecular weight, more preferably 150 to 10,000, and even more preferably 150 to 5,000. If the number average molecular weight is too small, the crosslinking density increases, which can lead to excessive hardness of the matrix resin and reduced recording speed. If the number average molecular weight is too large, the compatibility with other components decreases or the crosslinking density decreases, which can lead to excessively low hardness of the matrix resin and the loss of recorded content.

[0171] <Polyol> Examples of polyols include polypropylene polyol, polycaprolactone polyol, polyester polyol, and polycarbonate polyol.

[0172] (Polypropylene Polyol) Polypropylene polyol is obtained by reacting propylene oxide with a diol or a polyhydric alcohol. Examples of diols or polyhydric alcohols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, polyethylene glycol, and polytetramethylene glycol. Commercially available polypropylene polyols include Sannix GP-400 and GP-1000 (all manufactured by Sanyo Chemical Industries, Ltd., trade names), and Adeka Polyether G400, G700, and G1500 (all manufactured by ADEKA Corporation, trade names).

[0173] (Polycaprolactone polyol) Polycaprolactone polyol is obtained by reacting a lactone with a diol or a polyhydric alcohol. Examples of lactones include α-caprolactone, β-caprolactone, γ-caprolactone, ε-caprolactone, α-methyl-ε-caprolactone, and β-methyl-ε-caprolactone.

[0174] Examples of diols or polyhydric alcohols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, polyethylene glycol, and polytetramethylene glycol.

[0175] Commercially available polycaprolactone polyols obtained by the reaction of ε-caprolactone include PLACCEL 205, PLACCEL 205H, PLACCEL 205U, Examples of such products include PLACCEL 205UT, PLACCEL 210, PLACCEL 210N, PLACCEL 210CP, PLACCEL 220, PLACCEL 230, PLACCEL 230N, PLACCEL 240, PLACCEL 220EB, PLACCEL 220EC, PLACCEL 303, PLACCEL 305, PLACCEL 308, PLACCEL 309, PLACCEL 312, PLACCEL 320, PLACCEL 401, PLACCEL L205AL, PLACCEL L212AL, PLACCEL L220AL, PLACCEL L320AL, PLACCEL T2103, PLACCEL T2205, PLACCEL P3403, and PLACCEL 410 (all of which are trade names manufactured by Daicel Corporation).

[0176] (Polyester Polyol) Examples of polyester polyols include those obtained by polycondensing a dicarboxylic acid or an anhydride thereof with a polyol.

[0177] Examples of dicarboxylic acids include succinic acid, adipic acid, sebacic acid, azelaic acid, dimer acid, maleic anhydride, isophthalic acid, terephthalic acid, and trimellitic acid.

[0178] Examples of polyols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, polyethylene glycol, and polytetramethylene glycol.

[0179] Examples of polyester polyols include polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, etc. Commercially available polyester polyols include the ADEKA New Ace F series, ADEKA New Ace Y series, and ADEKA New Ace NS series (trade names, manufactured by ADEKA Corporation), and Kuraray Polyol N-2010, P-4011, and P-1020 (trade names, all manufactured by Kuraray Co., Ltd.).

[0180] (Polycarbonate Polyol) Examples of polycarbonate polyols include those obtained by a dealcoholization condensation reaction between glycols and dialkyl carbonates (e.g., dimethyl carbonate, diethyl carbonate, etc.), those obtained by a dephenolation condensation reaction between glycols and diphenyl carbonates, and those obtained by a glycol removal condensation reaction between glycols and carbonates (e.g., ethylene carbonate, diethyl carbonate, etc.).

[0181] Examples of glycols include aliphatic diols such as 1,6-hexanediol, diethylene glycol, propylene glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, and neopentyl glycol, and alicyclic diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol.

[0182] Examples of polycarbonate polyols include poly(hexamethylene carbonate) polyol obtained by the condensation reaction of 1,6-hexanediol and diethyl carbonate, poly(pentylene carbonate) obtained by the condensation reaction of pentanediol and diethyl carbonate, and poly(butylene carbonate) obtained by the condensation reaction of 1,4-butanediol and diethyl carbonate.

[0183] Commercially available polycarbonate polyols include Placcel CD CD205, Placcel CD CD210, and Placcel CD CD220 (all of which are trade names manufactured by Daicel Corporation), and Duranol T5651, Duranol T5652, and Duranol T5650J (all of which are trade names manufactured by Asahi Kasei Corporation).

[0184] (Molecular Weight of Polyol) The molecular weight of the polyol described above is preferably 100 to 50,000 in number average molecular weight, more preferably 150 to 10,000, and even more preferably 150 to 5,000. If the number average molecular weight is too small, the crosslinking density increases, which may cause the matrix resin to have too high hardness, resulting in a decrease in recording speed. On the other hand, if the number average molecular weight is too large, the compatibility with other components may decrease or the crosslinking density may decrease, which may cause the matrix resin to have too low hardness, resulting in the erasure of recorded content.

[0185] <Other Components> The matrix resin in the present embodiment may contain other components in addition to the above-described components, as long as it does not go against the spirit of the present invention.

[0186] Examples of such other components include compounds having a hydroxyl group, such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, trimethylolpropane, polyethylene glycol, and polytetramethylene glycol, which are used for the purpose of changing the physical properties of the matrix resin.

[0187] <Urethane Polymerization Catalyst> A suitable urethane polymerization catalyst may be contained to promote the reaction of the isocyanate and the polyol. Examples of the urethane polymerization catalyst include onium salts such as bis(4-t-butylphenyl)iodonium perfluoro-1-butanesulfonate, bis(4-t-butylphenyl)iodonium p-toluenesulfonate, bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate, (4-bromophenyl)diphenylsulfonium triflate, (4-t-butylphenyl)diphenylsulfonium trifluoromethanesulfonate, diphenyliodonium perfluoro-1-butanesulfonate, (4-fluorophenyl)diphenylsulfonium trifluoromethanesulfonate, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoromethanesulfonate, and bis(alkylphenyl)iodonium hexafluorophosphonic acid; zinc chloride, tin chloride, iron chloride, aluminum chloride, and BF ３protonic acids such as hydrochloric acid and phosphoric acid; amines such as trimethylamine, triethylamine, triethylenediamine, dimethylbenzylamine, and diazabicycloundecene; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-undecylimidazolylium trimellitate; bases such as sodium hydroxide, potassium hydroxide, and potassium carbonate; tin catalysts such as dibutyltin laurate, dioctyltin laurate, and dibutyltin octoate; bismuth catalysts such as tris(2-ethylhexanoate)bismuth and tribenzoyloxybismuth; and zirconium catalysts such as tetrakis(ethylacetoacetate)zirconium, 1,1'-isopropylidene zirconocene dichloride, and tetrakis(2,4-pentanedionato)zirconium.

[0188] Among these, bismuth catalysts and zirconium catalysts are preferred for improving storage stability.

[0189] The bismuth catalyst is not particularly limited as long as it is a catalyst containing bismuth element and is a compound that promotes the reaction between isocyanate and polyol. Examples of the bismuth catalyst include tris(2-ethylhexanoate)bismuth, tribenzoyloxybismuth, bismuth triacetate, tris(dimethyldicarbamate)bismuth, bismuth hydroxide, triphenylbismuth(V) bis(trichloroacetate), tris(4-methylphenyl)oxobismuth(V), and triphenylbis(3-chlorobenzoyloxy)bismuth(V).

[0190] Among these, trivalent bismuth compounds are preferred from the viewpoint 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 above bismuth catalysts may be used alone or in any combination and ratio of two or more.

[0191] The zirconium catalyst is not particularly limited as long as it is a catalyst containing zirconium element and is a compound that promotes the reaction of isocyanate and polyol. Examples thereof include cyclopentadienyl zirconium trichloride, decamethyl zirconocene dichloride, 1,1'-dibutyl zirconocene dichloride, 1,1'-isopropylidene zirconocene dichloride, tetrakis(2,4-pentanedionato)zirconium, tetrakis(trifluoro-2,4-pentanedionato)zirconium, tetrakis(hexafluoro-2,4-pentanedionato)zirconium, zirconium butoxide, zirconium Examples of the zirconium oxide include barium zirconium oxide, calcium zirconium oxide, zirconium bromide, zirconium chloride, zirconium fluoride, zirconium dichloride (indenyl) and zirconium carbonate.

[0192] Among these, compounds having an organic ligand are preferred in terms of compatibility with other components, and are more preferred than compounds having an alkoxide or acetylacetonate (2,4-pentanedionato) structure. Any one of the above zirconium compounds may be used alone, or two or more may be used in any combination and ratio.

[0193] The bismuth-based catalyst and the zirconium-based catalyst may be used alone or in combination.

[0194] The amount of the urethane polymerization catalyst used, in terms of the ratio to the matrix resin, is usually 0.0001% by mass or more, preferably 0.001% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less. If the amount of the urethane polymerization catalyst used is too small, curing may take too long. On the other hand, if the amount used is too large, it may be difficult to control the curing reaction.

[0195] Although the composition can be cured at room temperature by using a urethane polymerization catalyst, it may also be cured at elevated temperatures, preferably between 40°C and 90°C.

[0196] 3-1-3. Photocurable resins When using photocurable resins as the matrix resin, they must be cured using a photoinitiator for the matrix resin that is appropriate for the wavelength used. Since curing during light irradiation can cause problems with molding and adhesion, it is desirable for the curing reaction to be stable around room temperature, which is the temperature at which the resin is primarily worked. Given this, catalytic curing using a photoinitiator for the matrix resin is the preferred choice.

[0197] Generally, when a matrix resin photoinitiator is irradiated with light, it generates either a cationic or anionic active substrate. Therefore, it is considered best to select a material that undergoes curing with these active substrates and then cure it to form a matrix resin.

[0198] Examples of functional groups that react with cations such as protons include epoxy groups and oxetanyl groups. Specific examples of compounds containing these groups include polyglycidyl ether compounds of polyols such as (poly)ethylene glycol, (poly)propylene glycol, (poly)tetramethylene glycol, trimethylolpropane, and glycerin, which contain epoxy groups; alicyclic epoxy compounds having a 4- to 7-membered cyclic aliphatic group such as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1-methylhexanecarboxylate; bisphenol A epoxy compounds, hydrogenated bisphenol A epoxy compounds, bisphenol F epoxy compounds, and phenol or cresol novolac epoxy compounds. Examples of compounds containing an oxetanyl group include 2-ethyl-2-oxetanyl ether of bisphenol A and 1,6-bis(2-ethyl-2-oxetanyloxy)hexane. (Note that the term "(poly)ethylene glycol" refers to both "ethylene glycol" and its polymer, "polyethylene glycol.")

[0199] Examples of functional groups that react with anions include epoxy groups and episulfide groups. Specific examples of compounds having an episulfide group include phenyl episulfide and diepisulfide methyl ether of bisphenol A.

[0200] The amount of the matrix resin photoinitiator used when photocuring the matrix resin described above is typically 0.01% by mass or more, preferably 0.1% by mass or more, and typically 1% by mass or less, preferably 0.5% by mass or less, relative to the polymerizable compound. If the amount of matrix resin photoinitiator used is too small, curing may take too long. On the other hand, if the amount used is too large, it may be difficult to control the curing reaction.

[0201] Furthermore, particularly when used as a hologram recording material, it is important that the wavelength during curing is different from the wavelength during recording, since light is also irradiated during recording, and the wavelength difference is at least 10 nm, preferably 30 nm. The selection of a photoinitiator for the matrix resin can generally be predicted from the absorption wavelength of the initiator.

[0202] 3-2. Photopolymerization initiator The above-mentioned photoradical polymerization initiators can be used as the photopolymerization initiator. Among them, titanocene compounds, acylphosphine oxide compounds, and oxime ester compounds are preferred because they undergo polymerization reaction with light in the visible region.

[0203] 3-2-1. Titanocene Compound When a titanocene compound is used as a photopolymerization initiator, the type thereof is not particularly limited, and may be appropriately selected from the various titanocene compounds described in, for example, JP-A-59-152396 and JP-A-61-151197.

[0204] Specific examples of titanocene compounds include dicyclopentadienyl-Ti-dichloride, dicyclopentadienyl-Ti-bis-phenyl, dicyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophenyl-1-yl, dicyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophenyl-1-yl, dicyclopentadienyl-Ti-bis-2,4,6-trifluorophenyl-1-yl, and dicyclopentadienyl-Ti-bis-2,6-difluorophenyl-1-yl. , dicyclopentadienyl-Ti-bis-2,4-difluorophenyl-1-yl, dimethylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophenyl-1-yl, dimethylcyclopentadienyl-Ti-bis-2,3,5,6-tetrafluorophenyl-1-yl, dimethylcyclopentadienyl-Ti-bis-2,6-difluorophenyl-1-yl, dicyclopentadienyl-Ti-bis-2,6-difluoro-3-(pyr-1-yl)-phenyl-1-yl, and the like.

[0205] 3-2-2. Acylphosphine oxide compounds Specific examples of acylphosphine oxide compounds include monofunctional initiators that have only one photocleavage site per molecule, and bifunctional initiators that have two photocleavage sites per molecule.

[0206] Examples of the monofunctional initiator include triphenylphosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and 2,6-dichlorobenzoyldiphenylphosphine oxide.

[0207] Examples of the bifunctional initiator include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, and bis(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide.

[0208] Specific examples of oxime ester compounds include 1-[4-(phenylthio)-2-(O-benzoyloxime)]-1,2-octanedione, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime)ethanone, 4-(acetoximino)-5-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-5-oxopentanoate, and 5-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-4-(O-acetyloxime)-5-oxopentanoate. , methyl 5-(9-ethyl-9H-carbazol-3-yl)-4-(O-acetyloxime)-5-oxopentanoate, 1-(9-ethyl-9H-carbazol-3-yl)-1-(O-acetyloxime)-3-methylbutanoic acid, and the like.

[0209] 3-2-4. Amount of Photopolymerization Initiator Used Any one of the above-mentioned various photopolymerization initiators may be used alone, or two or more of them may be used in any combination and ratio.

[0210] The content of the photopolymerization initiator in the polymerizable composition of the present invention is preferably 0.5 μmol / g or more, more preferably 1 μmol / g or more, in terms of molar amount per unit weight of the polymerizable composition, and is preferably 100 μmol / g or less, more preferably 50 μmol / g or less, in terms of molar amount per unit weight of the polymerizable composition.

[0211] If the content of the photopolymerization initiator is too low, the amount of radicals generated will be small, which may slow down the photopolymerization rate and result in a decrease in the recording sensitivity of the holographic recording medium. On the other hand, if the content of the photopolymerization initiator is too high, the radicals generated by light irradiation will recombine with each other or undergo disproportionation, which may reduce their contribution to photopolymerization and also result in a decrease in the recording sensitivity of the holographic recording medium. When two or more photopolymerization initiators are used in combination, it is preferable that the total amount thereof satisfies the above range.

[0212] 3-3. Radical Scavenger In hologram recording, a radical scavenger may be added to accurately fix the interference light intensity pattern as a polymer distribution in the hologram recording medium. The radical scavenger preferably has both a functional group that captures radicals and a reactive group that is covalently fixed to the matrix resin. An example of a functional group that captures radicals is a stable nitroxyl radical group.

[0213] 3-3-1. Types of Radical Scavenger Reactive groups that can be covalently bonded to a matrix resin include hydroxyl groups, amino groups, isocyanate groups, and thiol groups. Examples of such radical scavengers include 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (TEMPOL), 3-hydroxy-9-azabicyclo[3.3.1]nonane N-oxyl, 3-hydroxy-8-azabicyclo[3.2.1]octane N-oxyl, and 5-HO-AZADO: 5-hydroxy-2-azatricyclo[3.3.1.1]octane N-oxyl. ３，７ ] decane N-oxyl.

[0214] 3-3-2. Content of Radical Scavenger Any one of the above-mentioned various radical scavengers may be used alone, or two or more may be used in any combination and ratio. The content of the radical scavenger in the polymerizable composition of the present invention is preferably 0.5 μmol / g or more, more preferably 1 μmol / g or more, in terms of molar amount per unit weight of the polymerizable composition. The content of the radical scavenger in the composition of the present invention is preferably 100 μmol / g or less, more preferably 50 μmol / g or less.

[0215] If the content of the radical scavenger is too low, the radical scavenging efficiency will be low, and the polymer with a low degree of polymerization will diffuse, tending to result in an increase in components that do not contribute to signals. On the other hand, if the content of the radical scavenger is too high, the polymer polymerization efficiency will be reduced, tending to make it impossible to record signals. When two or more radical scavengers are used in combination, it is preferable that their total amount satisfies the above range.

[0216] 3-4. Other Components Even when used as a holographic recording medium, the polymerizable composition of the present invention may contain other components in addition to the above-described components, as long as the other components do not deviate from the spirit of the present invention.

[0217] Other components include solvents, plasticizers, dispersants, leveling agents, antifoaming agents, adhesion promoters, etc. for preparing the polymerizable composition, and, particularly when used in holographic recording media, chain transfer agents, polymerization terminators, compatibilizers, reaction aids, sensitizers, etc. for controlling the recording reaction. Examples of additives that may be required for improving other properties include preservatives, stabilizers, antioxidants, UV absorbers, light stabilizers, etc. Any one of these components may be used alone, or two or more may be used in any combination and ratio.

[0218] <Sensitizer> A compound that controls the excitation of the photopolymerization initiator can be added to the polymerizable composition of the present invention. Examples of such compounds include a sensitizer and a sensitization aid.

[0219] The sensitizer can be selected from various known sensitizers, but generally, colored compounds such as dyes are used as sensitizers to absorb visible and ultraviolet laser light. When used in holographic recording media, the sensitizers vary depending on the wavelength of the laser light used for recording and the type of initiator used. In systems using green lasers, specific examples of preferred sensitizers include those described in JP-A-5-241338, JP-A-2-69, JP-B-2-55446, etc. In systems using blue lasers, specific examples of preferred sensitizers include those described in JP-A-2000-10277, JP-A-2004-198446, etc. These sensitizers may be used alone or in any combination and ratio of two or more.

[0220] When the resulting holographic recording medium is required to be colorless and transparent, it is preferable to use a cyanine dye as a sensitizer. Since cyanine dyes are generally easily decomposed by light, post-exposure, i.e., leaving the holographic recording medium under room light or sunlight for several hours to several days, decomposes the cyanine dye in the holographic recording medium, and the cyanine dye no longer absorbs in the visible range, thereby obtaining a colorless and transparent holographic recording medium.

[0221] The amount of sensitizer needs to be increased or decreased depending on the thickness of the recording layer to be formed, but it is preferable that the ratio to the aforementioned photopolymerization initiator is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less. If the amount of sensitizer used is too small, the initiation efficiency may decrease and recording may take a long time. On the other hand, if the amount of sensitizer used is too large, the absorption of light used for recording and reproduction may increase, making it difficult for light to reach the depth direction. When two or more sensitizers are used in combination, the total amount thereof should be within the above range.

[0222] <Plasticizer> The polymerizable composition of the present invention may contain a plasticizer in order to improve the reaction efficiency and adjust the physical properties of the recording layer of the holographic recording medium.

[0223] Examples of the plasticizer include phthalates such as dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, and diundecyl phthalate; adipates such as bis(2-ethylhexyl) adipate, diisononyl adipate, and di-n-butyl adipate; sebacates such as dioctyl sebacate and dibutyl sebacate; phosphates such as tricresyl phosphate; citric acid esters such as acetyl tributyl citrate; trimellitates such as trioctyl trimellitate; epoxidized soybean oil, chlorinated paraffin, alkoxylated (poly)alkylene glycol esters such as acetoxymethoxypropane; and terminally alkoxylated polyalkylene glycols such as dimethoxypolyethylene glycol.

[0224] It is also possible to use a plasticizer containing a fluorine element, such as those exemplified in Japanese Patent No. 6069294. Examples of the plasticizer containing a fluorine element include 2,2,2-trifluoroethyl butylcarbamate, bis(2,2,2-trifluoroethyl)-(2,2,4-trimethylhexane-1,6-diyl)biscarbamate, bis(2,2,2-trifluoroethyl)-[4-({[(2,2,2-trifluoroethoxy)carbonyl]amino}-methyl)octane-1,8-diyl]biscarbamate, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluorononyl butylcarbamate, and 2,2,2-trifluoroethyl phenylcarbamate.

[0225] These plasticizers are used in an amount of usually 0.01% by mass to 50% by mass, preferably 0.05% by mass to 20% by mass, based on the total solid content of the polymerizable composition. If the plasticizer content is less than this range, the effects of improving reaction efficiency and adjusting physical properties will not be exhibited, whereas if it is more than this range, the transparency of the recording layer will decrease and bleeding out of the plasticizer will become significant.

[0226] <Leveling Agent> A leveling agent can be used in the polymerizable composition of the present invention. Examples of the leveling agent include sodium polycarboxylate, ammonium polycarboxylate, amine polycarboxylate, silicon-based leveling agents, acrylic leveling agents, ester compounds, ketone compounds, and fluorine compounds. Any one of these may be used alone, or two or more may be used in any combination and ratio.

[0227] <Chain Transfer Agent> A chain transfer agent can be used in the polymerizable composition of the present invention. Examples of the chain transfer agent include phosphinates such as sodium phosphite and sodium hypophosphite, mercaptans such as mercaptoacetic acid, mercaptopropionic acid, 2-propanethiol, 2-mercaptoethanol, and thiophenol, aldehydes such as acetaldehyde and propionaldehyde, ketones such as acetone and methyl ethyl ketone, halogenated hydrocarbons such as trichloroethylene and perchloroethylene, terpenes such as terpinolene, α-terpinene, β-terpinene, and γ-terpinene, 1,4-cyclohexadiene, 1,4-cycloheptadiene, 1,4-cyclooctadiene, and 1,4-heptadiene. non-conjugated dienes such as thiadiene, 1,4-hexadiene, 2-methyl-1,4-pentadiene, 3,6-nonanedien-1-ol, and 9,12-octadecadienol; linolenic acids such as linoleic acid, γ-linolenic acid, methyl linolenate, ethyl linolenate, isopropyl linolenate, and linoleic acid anhydride; linoleic acids such as linoleic acid, methyl linoleate, ethyl linoleate, isopropyl linoleate, and linoleic acid anhydride; eicosapentaenoic acids such as eicosapentaenoic acid and ethyl eicosapentaenoate; and docosahexaenoic acids such as docosahexaenoic acid and ethyl docosahexaenoate.

[0228] The amount of these additives used is, relative to the total solid content of the polymerizable composition of the present invention, usually 0.001% by mass or more, preferably 0.01% by mass or more, and usually 30% by mass or less, preferably 10% by mass or less. When two or more additives are used in combination, the total amount thereof should satisfy the above range.

[0229] 3-5. Compositional Ratio of Each Component in the Polymerizable Composition The content of each component in the polymerizable composition is arbitrary as long as it does not deviate from the gist of the present invention.

[0230] The content of the polymerizable compounds, including the polymerizable compound (A) and the polymerizable compound (B), in the polymerizable composition of the present invention is preferably 5 μmol / g or more, more preferably 10 μmol / g or more, and even more preferably 100 μmol / g or more, based on the molar amount per unit mass of the polymerizable composition. The content of the polymerizable compounds is preferably 1000 μmol / g or less, more preferably 500 μmol / g or less, and even more preferably 300 μmol / g or less. When the content of the polymerizable compounds is equal to or greater than the lower limit, sufficient diffraction efficiency can be obtained in the holographic recording medium. When the content of the polymerizable compounds is equal to or less than the upper limit, compatibility with the resin matrix in the recording layer is maintained, and shrinkage of the recording layer due to recording tends to be kept low.

[0231] When an isocyanate and a polyol are used as the matrix resin in the polymerizable composition of the present invention, the total content thereof is usually 0.1% by mass or more, preferably 10% by mass or more, more preferably 35% by mass or more, and usually 99.9% by mass or less, preferably 99% 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.

[0232] In this case, the ratio of the number of isocyanate-reactive functional groups in the polyol to the number of isocyanate groups in the isocyanate is preferably 0.1 or more, more preferably 0.5 or more, and 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.

[0233] The content of the urethane polymerization catalyst in the polymerizable composition is preferably determined in consideration of the reaction rate of the isocyanate and the polyol, and is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 1% by mass or less. The content of the urethane polymerization catalyst is preferably 0.003% by mass or more.

[0234] The total amount of other components in the polymerizable composition other than the above components may be 30% by mass or less, preferably 15% by mass or less, and more preferably 5% by mass or less.

[0235] 3-6. Method for Producing Polymerizable Composition In the present invention, the method for producing the polymerizable composition containing polymerizable compounds including the polymerizable compound (A) and the polymerizable compound (B), a matrix resin, and a photopolymerization initiator is not particularly limited, and the order of mixing and the like can be adjusted as appropriate. Furthermore, when the polymerizable composition contains components other than those described above, the components may be mixed in any combination and in any order.

[0236] When an isocyanate and a polyol are used as the matrix resin, the polymerizable composition can be obtained, for example, by the following method, but the present invention is not limited to this. A photoreactive composition (liquid A) is obtained by mixing a polymerizable compound, a photopolymerization initiator, and all components other than the isocyanate and urethane polymerization catalyst. A mixture of the isocyanate and the urethane polymerization catalyst is obtained as liquid B. Alternatively, the photoreactive composition (liquid A) can be obtained by mixing a polymerizable compound and a photopolymerization initiator with all components other than the isocyanate.

[0237] It is preferable to dehydrate and degas each liquid. If dehydration and degassing are insufficient, bubbles may form during the production of the holographic recording medium, making it impossible to obtain a uniform recording layer. During this dehydration and degassing process, heating and decompression may be performed as long as the components are not damaged.

[0238] The preparation of the polymerizable composition by mixing liquid A and liquid B is preferably carried out immediately before molding the holographic recording medium. Conventional mixing techniques can also be used for this purpose. When mixing liquid A and liquid B, degassing may be performed as needed to remove residual gas. Furthermore, liquid A and liquid B are preferably subjected to a filtration step to remove foreign matter and impurities, either individually or after mixing, and it is more preferable to filter each liquid separately.

[0239] Also, an isocyanate-functional prepolymer obtained by reacting an isocyanate having an excess of isocyanate groups with a polyol can be used as the matrix resin. Furthermore, an isocyanate-reactive prepolymer obtained by reacting an isocyanate with a polyol having an excess of isocyanate-reactive functional groups can be used as the matrix resin.

[0240] 4. Polymer The polymer of the present invention obtained by polymerizing the composition of the present invention will be described below.

[0241] 4-1. Refractive Index Generally, because the overall density increases through a polymerization reaction, the refractive index of a polymer tends to be higher than that of its precursor compound (called a monomer) before polymerization. By using a monomer with a high refractive index and allowing the polymerization reaction to proceed sufficiently, the refractive index of the resulting polymer can be increased, so it is considered important to improve the refractive index of a polymer by designing the molecular structure of the monomer.

[0242] The refractive index shows a large value when evaluated with irradiation light of a short wavelength, but a sample that shows a relatively large refractive index at a short wavelength also shows a relatively large refractive index at a long wavelength, and this relationship is not reversed. Therefore, by evaluating and comparing the refractive index at a constant wavelength, it is possible to compare the intrinsic refractive index of the material. In the present invention, the value at an irradiation light wavelength of 587 nm was used as the standard.

[0243] The refractive index of the polymer of the present invention is preferably 1.60 or more, more preferably 1.63 or more, particularly preferably 1.65 or more, and most preferably 1.67 or more. There is no particular upper limit to the refractive index of the polymer of the present invention, but it is usually 2.0 or less.

[0244] When the polymer of the present invention is used as a recording layer material for a holographic recording medium, the refractive index of the polymer of the present invention is usually in the range of 1.65 to 1.78, preferably 1.77. If the refractive index is less than 1.65, the diffraction efficiency is low and the multiplicity is insufficient. If the refractive index is more than 1.78, the difference in refractive index with the matrix resin becomes too large, resulting in increased scattering and reduced transmittance, requiring greater energy for recording and reproduction.

[0245] When the polymer of the present invention is used as an optical material such as a lens, if the refractive index is less than 1.60, the central portion of the optical lens becomes thick, which may impair the lightweight property that is a characteristic of plastics, which is undesirable. Furthermore, in the development of precision optical components such as lenses, it is also important to combine optical materials with multiple refractive indices to achieve optical properties suitable for the component. From this perspective, monomers and polymers with a refractive index exceeding 1.65 can be said to be particularly useful materials for optical components.

[0246] 4-2. Glass Transition Temperature The glass transition temperature of the polymer of the present invention is preferably 90°C or higher, more preferably 100°C or higher, even more preferably 110°C or higher, particularly preferably 120°C or higher, and preferably 250°C or lower, more preferably 220°C or lower, and even more preferably 200°C or lower. If the glass transition temperature is below this range, the optical properties may change from the designed values ​​under the usage environment, and the practically required heat resistance may not be satisfied. If the glass transition temperature is above this range, the processability of the polymer may decrease, and a molded product with a good appearance and high dimensional accuracy may not be obtained. In addition, the polymer may become brittle, the mechanical strength may decrease, and the handleability of the molded product may deteriorate.

[0247] 5. Optical Materials and Optical Components The composition, polymerizable composition, and polymer of the present invention have properties such as a high refractive index, easy processability, and high chemical stability, and can therefore be applied to various optical materials and optical components.

[0248] Examples of optical materials include optical overcoats, hard coating agents, adhesives for optical components, resins for optical fibers, and acrylic resin modifiers.

[0249] 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.

[0250] Among these, the polymer of the present invention is particularly preferably applied to diffraction gratings, light guide plates, and plastic lenses due to its high refractive index, and is more preferably applied to diffraction gratings and light guide plates. Examples of lenses include imaging lenses for cameras (such as in-vehicle cameras, digital cameras, PC cameras, mobile phone cameras, and surveillance cameras), eyeglass lenses, light beam focusing lenses, and light diffusing lenses.

[0251] Lenses using the composition and polymer 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 improve the lenses, for example, to prevent reflection, to impart high hardness, to improve abrasion resistance, to improve chemical resistance, to impart antifogging properties, or to impart fashionability, as required.

[0252] 6. Holographic Recording Medium The holographic recording medium of the present invention using the composition 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.

[0253] 6-1. Recording Layer The recording layer of the holographic recording medium of the present invention is a layer formed from the composition of the present invention, and is the layer on which information is recorded. Information is usually recorded as a hologram. As will be described later in the section on recording method, the polymerizable compound (hereinafter referred to as polymerizable monomer) contained in the recording layer undergoes a chemical change, such as polymerization, in part upon holographic recording. Therefore, in the holographic recording medium after recording, part of the polymerizable monomer is consumed, and exists as a reacted compound, such as a polymer.

[0254] The thickness of the recording layer is not particularly limited and may be appropriately determined taking into consideration the recording method, etc., but is preferably 1 μm or more, more preferably 10 μm or more, and preferably 1 cm or less, more preferably 3 mm or less. By setting the thickness of the recording layer to the above-mentioned lower limit or more, selectivity of each hologram tends to be increased during multiplexed recording in the holographic recording medium, and the degree of multiplexed recording tends to be increased. By setting the thickness of the recording layer to the above-mentioned upper limit or less, it becomes possible to uniformly mold the entire recording layer, and multiplexed recording tends to be possible with uniform diffraction efficiency of each hologram and a high S / N ratio.

[0255] The shrinkage rate of the recording layer due to exposure during recording and reproduction of information is preferably 0.25% or less from the viewpoint of recording reproducibility.

[0256] 6-2. Support There are no particular limitations on the details of the support, and any support can be used as long as it has the strength and durability required for the holographic recording medium. There are no limitations on the shape of the support, but it is usually formed into a flat plate or film. There are also no limitations on the material that makes up the support, and it may be transparent or opaque.

[0257] Examples of transparent materials for the support include organic materials such as acrylic, polyethylene terephthalate, polyethylene naphthoate, polycarbonate, polyethylene, polypropylene, amorphous polyolefin, polystyrene, polycycloolefin, 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, polycycloolefin, and glass are particularly more preferred.

[0258] 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.

[0259] The thickness of the support is not particularly limited, but is preferably in the range of 0.05 mm to 1 mm. 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 ensured and warping of the substrate can be prevented. If the thickness of the support is equal to or less than the upper limit, advantages such as increased light transmittance and reduced weight and cost of the hologram recording medium can be obtained.

[0260] The surface of the support may be subjected to a surface treatment. This surface treatment is usually performed to improve the 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.

[0261] The surface of the support may be treated for purposes other than improving adhesion. Examples of such treatments include a reflective coating treatment for forming a reflective coating layer made of a metal such as gold, silver, or aluminum, and a dielectric coating treatment for forming 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.

[0262] These surface treatments may be performed for the purpose of controlling the gas and moisture permeability of the substrate. For example, the reliability of the holographic recording medium can be improved by providing the supports sandwiching the recording layer with a function of suppressing the gas and moisture permeability.

[0263] The support may be provided on either the upper or lower side 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.).

[0264] In the case of a holographic recording medium having a support on one or both sides of the recording layer, transmission or reflection holograms can be recorded. In addition, when a support having reflective properties is used on one side of the recording layer, reflection holograms can be recorded.

[0265] The support may be provided with a pattern for data addressing. In this case, the patterning method is not limited, but for example, unevenness may be formed on the support itself, a pattern may be formed on the reflective layer described later, or a combination of these methods may be used.

[0266] 6-3. Protective Layer The protective layer is a layer for preventing deterioration of the recording and reproduction characteristics of the recording layer. There are no restrictions on the specific configuration of the protective layer, and any known protective layer can be applied. For example, a layer made of a water-soluble polymer, organic / inorganic material, etc. can be formed as the protective layer.

[0267] The position where the protective layer is formed is not particularly limited, and 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.

[0268] 6-4. Reflective Layer The reflective layer is formed when the holographic recording medium is configured to be reflective. In the case of a reflective 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 be 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.

[0269] 6-5. Antireflection Film For both transmission and reflection holographic recording media, an antireflection film may be provided on the side where the information light, reference light, and reproduction light enter and exit, or between the recording layer and the support. The antireflection film improves the light utilization efficiency and suppresses noise generation. Any known antireflection film can be used.

[0270] 6-6. Manufacturing Method of Holographic Recording Medium There are no limitations on the manufacturing method of the holographic recording medium of the present invention. For example, the holographic recording medium can be manufactured by applying the composition of the present invention onto a support without a solvent to form a recording layer. In this case, any method can be used as the coating method. Specific examples include spraying, spin coating, wire bar coating, dipping, air knife coating, roll coating, blade coating, doctor roll coating, etc.

[0271] When forming a recording layer, particularly when forming a thick recording layer, a method of molding in a mold or a method of applying the composition to a release film and punching out a mold can be used. Alternatively, the recording layer can be produced by mixing the composition of the present invention with a solvent or additives to prepare a coating liquid, applying this to a support, and drying to form the recording layer. In this case, any method can be used as the coating method, and for example, the same methods as those described above can be used.

[0272] There are no limitations on the solvent used in the coating solution, but it is usually 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. A single solvent may be used, or two or more solvents may be used in any combination and ratio. There are also no limitations on the amount of solvent used, but from the standpoint of coating efficiency and handleability, it is preferable to prepare a coating solution with a solids concentration of about 1 to 100% by mass.

[0273] Examples of the solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and methyl amyl ketone; aromatic solvents such as toluene and xylene; alcohol-based solvents such as methanol, ethanol, propanol, n-butanol, heptanol, hexanol, diacetone alcohol, and furfuryl alcohol; ketone alcohol-based solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone; ether-based solvents such as tetrahydrofuran and dioxane; halogen-based solvents such as dichloromethane, dichloroethane, and chloroform; cellosolve-based solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, and ethyl cellosolve acetate; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol Examples of suitable solvents include propylene glycol solvents such as cholesteryl monobutyl ether acetate and dipropylene glycol dimethyl ether; ester solvents such as ethyl acetate, butyl acetate, amyl acetate, butyl acetate, ethylene glycol diacetate, diethyl oxalate, ethyl pyruvate, ethyl-2-hydroxybutyrate ethyl acetoacetate, methyl lactate, ethyl lactate, methyl 2-hydroxyisobutyrate, and methyl 3-methoxypropionate; perfluoroalkyl alcohol solvents such as tetrafluoropropanol, octafluoropentanol, and hexafluorobutanol; highly polar solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and dimethyl sulfoxide; chain hydrocarbon solvents such as n-hexane and n-octane; cyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, tert-butylcyclohexane, and cyclooctane; and mixed solvents thereof.

[0274] Examples of methods for producing a holographic recording medium include a method in which a polymerizable composition melted by heat is applied to a support, and then cooled and solidified to form a recording layer; a method in which a liquid polymerizable composition 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 polymerizable composition is applied to a support, and then photopolymerized to harden the composition to form a recording layer.

[0275] 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, and other applications. In particular, the holographic recording medium of the present invention, which uses the composition of the present invention, has high refractive index modulation and is also useful as an AR glass light guide plate or an AR glass waveguide plate. Here, AR is an abbreviation for augmented reality.

[0276] 6-7. Uses of Holographic Recording Medium <Large Capacity Memory Use> Information is written (recorded) and read (reproduced) to the holographic recording medium of the present invention by irradiation with light.

[0277] When recording information, light capable of causing a chemical change in the polymerizable monomer, that is, its polymerization and concentration change, is used as object light (also called recording light).

[0278] 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.

[0279] To reconstruct a volume hologram recorded in a recording layer, a predetermined reconstruction beam (usually a reference beam) is irradiated onto the recording layer. The irradiated reconstruction beam is diffracted in accordance with the interference fringes. This diffracted beam contains the same information as that in the recording layer, and so the information recorded in the recording layer can be reconstructed by reading the diffracted beam with an appropriate detection means.

[0280] 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 diode lasers such as GaAs, InGaAs, and GaN; gas lasers such as helium-neon, argon, krypton, excimer, and CO2; and lasers with excellent monochromaticity and directivity, such as dye-containing dye lasers.

[0281] There is no limitation on the irradiation dose of the object beam, the reproduction beam and the reference beam, and the irradiation dose is arbitrary as long as recording and reproduction are possible. If the irradiation dose is extremely small, the chemical change of the polymerizable monomer may be too incomplete, and the heat resistance and mechanical properties of the recording layer may not be fully exhibited, and conversely, if the irradiation dose is extremely large, the components of the recording layer (components of the composition 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 according to the composition of the composition 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:

[0282] Hologram recording methods include polarization collinear hologram recording, reference beam incident angle multiplexing hologram recording, etc. When the hologram recording medium of the present invention is used as a recording medium, good recording quality can be achieved with any of these recording methods.

[0283] <Application to AR Glass Light Guide Plate (Application to AR Glass Light Guide Plate)> A volume hologram can be recorded on the holographic recording medium of the present invention in the same manner as in the above-mentioned large-capacity memory application, and the resulting optical element can be used as an AR glass light guide plate (AR light guide plate).

[0284] 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.

[0285] 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.

[0286] 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. The reproduction light is not limited to the laser and the like, and display devices such as a liquid crystal display (LCD) and an organic electroluminescence display (OLED) are also preferred.

[0287] There is no limitation on the irradiation dose of the object beam, the reproduction beam and the reference beam, and the irradiation dose is arbitrary as long as recording and reproduction are possible. If the irradiation dose is extremely small, the chemical change of the polymerizable monomer may be too incomplete, and the heat resistance and mechanical properties of the recording layer may not be fully exhibited, and conversely, if the irradiation dose is extremely large, the components of the recording layer (components of the composition 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 according to the composition of the composition 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:

[0288] 6-8. Performance index of holographic recording media The performance of a holographic recording media is indexed by total Δn, which is calculated using the sum of the diffraction efficiencies across the entire multiplexed recording. In the case of a reflection hologram, the diffraction efficiency of the hologram is given by the ratio of the intensity of diffracted light to the sum of the intensity of transmitted light and the intensity of diffracted light. From the obtained diffraction efficiency, Δn is calculated using the following equation based on Coupled Wave Theory (H. Kogelnik, The Bell System Technical Journal (1969), 48, 2909-2947), and the sum across the entire multiplexed recording is taken as total Δn.

[0289]

[0290] Here, η is the diffraction efficiency, d is the thickness of the medium, λ is the wavelength of the reference light, and θ is the angle of incidence of the reference light with respect to the recording surface.

[0291] In the case of large-capacity memories, a higher total Δn means that more information can be recorded per unit volume, which is preferable. Furthermore, in the case of AR glasses applications, a higher total Δn means that the projected image of the projector can be delivered to the pupil brightly, power consumption can be reduced, and the viewing angle can be widened, which is preferable. On the other hand, holographic recording media with a high total Δn can record unintended holograms called holographic scatter, which can cause a decrease in the reproduction quality of information in large-capacity memories and is treated as image noise in AR glasses applications. For this reason, a low total Δn may be preferable.

[0292] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples as long as it does not deviate from the gist of the invention.

[0293] [Raw Materials Used] The raw materials for the compositions used in the Examples and Comparative Examples are as follows.

[0294] <Isocyanate> Duranate ＴＭ TSS-100: Hexamethylene diisocyanate polyisocyanate (NCO 17.8%) (manufactured by Asahi Kasei Corporation) Takenate 600: 1,3-Bis(isocyanatomethyl)cyclohexane (NCO 43.3%) (manufactured by Mitsui Chemicals, Inc.)

[0295] <Polyol> Capa 2047A: Polycaprolactone diol (molecular weight: approximately 400) (manufactured by Ingevity) PCL-305: Polycaprolactone triol (molecular weight: approximately 550) (manufactured by Daicel Corporation)

[0296] <Photopolymerization initiator> HLI02: methyl 5-(9-ethyl-6-cyclohexanoyl-9H-carbazol-3-yl)-4-(O-acetyloxime)-5-oxopentanoate (molecular weight 505)

[0297] <Radical Scavenger> TEMPOL: 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical (Tokyo Chemical Industry Co., Ltd.)

[0298] <Curing catalyst> Octylic acid solution of tris(2-ethylhexanoate)bismuth (active ingredient amount: 56% by mass)

[0299] [Example 1] <Synthesis of polymerizable compound (A-1)> Polymerizable compound (A-1) was produced by the method described in WO 2022 / 202538 (Example 2). The synthesis scheme is shown below.

[0300]

[0301] The NMR measurement data of the polymerizable compound (A-1) was as follows. １ H NMR (400 MHz, CDCl ３ , δ, ppm) 8.12 (Ar, 4H), 7.72 (Ar, 2H), 7.63 (Ar, 2H), 7.43 (Ar, 6H), 7.37 (Ar, 2H), 7.31 (Ar, 5H), 7.23 (Ar, 5H), 6.40 (d, 1H) , 6.10 (dd, 1H), 5.83 (d, 1H), 4.42 (brs, NH, 1H), 4.02 (dd, 2H), 3.78 (brs, 2H), 3.25 (brs, 2H), 3.12 (dd, 2H), 2.77 (brs, 4H)

[0302] The refractive index of the polymerizable compound (A-1) was measured by the following method. <Preparation of sample solution for refractive index measurement> A sample was prepared by dissolving the sample in a mixed solution of 3-phenoxybenzyl acrylate and trimethylolpropane trimethacrylate in a mass ratio of 4:1 so as to obtain the sample concentration described below. Two types of sample solutions were prepared, one with a sample concentration of 10 mass % and the other with a sample concentration of 20 mass %.

[0303] <Measurement of refractive index> The refractive index of each sample solution was measured using a Kalnew precision refractometer (manufactured by Shimadzu Corporation, product name: KPR-2000). The temperature of the sample solution was 23°C, and the measurement wavelength was the d-line (587.6 nm) of a helium lamp. Based on the measurement results, a calibration curve showing the correlation between sample concentration and refractive index was created, and from the obtained calibration curve, the refractive index when the sample concentration was 100% by mass was determined and used as the refractive index of the sample. As a result of the measurement, the refractive index of polymerizable compound (A-1) was 1.666.

[0304] <Synthesis of Polymerizable Compound (B-1)> Polymerizable compound (B-1) was produced by the following method: The synthesis scheme is shown below.

[0305]

[0306] 0.3 g of water was added to 2 g of 2-acryloyloxyethyl isocyanate and stirred at room temperature. The purified crystals were separated by filtration, washed with hexane, and dried under reduced pressure to obtain 1.6 g of polymerizable compound (B-1).

[0307] The NMR measurement data of the polymerizable compound (B-1) was as follows. １ H NMR (400 MHz, CDCl ３ , δ, ppm) 6.43 (dd, CH=CH2, 2H), 6.13 (dd, CH=CH2, 2H), 5.86 (dd, CH=CH2, 2H), 4.74 (brs, NH, 2H), 4.25 (t, 4H), 3.51 (q, 4H)

[0308] <Preparation of Cured Film> A cyclohexanone solution was prepared by adding 19.8 parts by mass of polymerizable compound (A-1), 0.2 parts by mass of polymerizable compound (B-1), 0.4 parts by mass of Perhexyl O (manufactured by NOF Corporation) as a polymerization initiator, and 79.6 parts by mass of cyclohexanone to 20 parts by mass of the total polymerizable compounds used to prepare a cured film. The dissolution of the solid matter was confirmed visually at room temperature, and the solubility was evaluated according to the following criteria. The evaluation results are shown in Table 1. ◯: No undissolved residue was observed. ×: Undissolved residue was observed.

[0309] The prepared solution was applied to a glass substrate using a spin coater and cured at 90°C for 90 seconds and then at 250°C for 2 hours. The refractive index and film thickness of the resulting cured film at a wavelength of 550 nm were calculated using a reflection spectroscopic film thickness meter "FE-3000" (manufactured by Otsuka Electronics Co., Ltd.). The results are shown in Table 1.

[0310] <Solvent Immersion Test> The obtained cured film was immersed together with the glass substrate in propylene glycol monomethyl ether for 3 minutes, and then dried under reduced pressure at room temperature for 30 minutes to remove the solvent. As described above, the refractive index and film thickness of the cured film after immersion were calculated at 550 nm. In addition, the residual film rate after immersion was calculated from the film thickness before and after immersion. The results are shown in Table 1.

[0311] [Example 2] A cured film was prepared in the same manner as in Example 1, except that the amount of polymerizable compound (A-1) was changed to 18.6 parts by mass and the amount of polymerizable compound (B-1) was changed to 1.4 parts by mass, and the respective evaluations were carried out. The results are shown in Table 1.

[0312] [Example 3] <Synthesis of polymerizable compound (A-2)> Polymerizable compound (A-2) was produced according to the method described in WO 2024 / 085208 (Example 2) and (Example 4). The synthesis scheme is shown below.

[0313]

[0314] The NMR measurement data of Compound A-2 was as follows: １ H NMR (400 MHz, CDCl ３ , δ, ppm) 8.82-8.66 (Ar, 6H), 8.33-8.25 (Ar, 1H), 8.15-8.01 (Ar, 2H), 7.99-7.85 (Ar, 6H), 7.84-7.77 (Ar, 2H), 7.74-7.55 ( Ar, 12H), 6.09-5.95 (CH=CH2, 1H), 5.69-5.53 (CH=CH2, 2H), 4.42-3.89 (NH, 1H), 3.29-2.80 (CH2, 2H), 2.79-2.13 (CH2, 2H)

[0315] Furthermore, the refractive index of the polymerizable compound (A-2) was measured in the same manner as that of the polymerizable compound (A-1) described above, and was found to be 1.689.

[0316] A cured film was prepared in the same manner as in Example 1, except that the polymerizable compound (A-1) was changed to 19.8 parts by mass of the polymerizable compound (A-2), and 0.2 parts by mass of the polymerizable compound (B-1), and each evaluation was carried out. The results are shown in Table 1.

[0317] Comparative Example 1 A cured film was prepared in the same manner as in Example 1, except that 20 parts by mass of polymerizable compound (A-1) was used and no polymerizable compound (B-1) was used in the preparation of the cured film, and the various evaluations were carried out. The results are shown in Table 1. In Comparative Example 1, the amount of film remaining after immersion was small, so that the refractive index and film thickness after immersion could not be measured.

[0318] [Comparative Example 2] When the amount of polymerizable compound (A-1) was changed to 16.1 parts by mass and the amount of polymerizable compound (B-1) was changed to 3.9 parts by mass in the preparation of a cured film, a homogeneous solution was not obtained and undissolved portions were observed. Therefore, a cured film could not be prepared and subsequent evaluation could not be performed.

[0319] Comparative Example 3 A cured film was prepared in the same manner as in Example 1, except that 20 parts by mass of polymerizable compound (A-2) was used and no polymerizable compound (B-1) was used in the preparation of the cured film, and the various evaluations were carried out. The results are shown in Table 1. In Comparative Example 3, no film remained after immersion, and therefore the refractive index and film thickness after immersion could not be measured.

[0320]

[0321] Table 1 demonstrates that the use of the composition of the present invention allows for the production of a cured film with a high refractive index and excellent solvent resistance. Comparing Example 1 and Example 3, the refractive indices before immersion were 1.708 and 1.716, respectively. This is expected to result in a difference of approximately 8% in total Δn, which represents holographic recording performance. Therefore, Example 3 has a diffraction efficiency approximately 1-10% higher at each multiplex. Therefore, for example, in terms of projector power consumption, Example 3 can save approximately 1-10%, which is believed to contribute to battery miniaturization and extended device continuous use time. Meanwhile, the change in refractive index before and after immersion was smaller in Example 1 than in Example 3, suggesting a tendency for the refractive index to be increased even when the cured film is immersed in a solvent.

[0322] Example 4 Synthesis of Polymerizable Composition (C-1): Mixture of Polymerizable Compound (A-3) and Polymerizable Compound (B-2) A mixture of polymerizable compound (A-3) and polymerizable compound (B-2) was produced as polymerizable composition (C-1) by the following method. The synthesis scheme is shown below.

[0323]

[0324] Under a nitrogen atmosphere, 18 g of compound S-1 (synthesized according to the method described in WO 2024 / 085208) and 3.27 g of ethylene carbonate were dissolved in 80 ml of N.N-dimethylformamide, and 0.40 g of potassium carbonate was added and heated to 120 ° C. The reaction was carried out at 120 ° C. for 3 hours, and after confirming the disappearance of the raw materials, the mixture was allowed to cool to room temperature. The reaction solution was added to 400 ml of water, and the precipitate was filtered and washed, and then purified by silica gel column chromatography to obtain 16.3 g of compound S-2.

[0325] The NMR measurement data of the compound S-2 was as follows: １ H NMR (400 MHz, CDCl ３ , δ, ppm) 8.83-8.69 (Ar, 6H), 8.33-8.26 (Ar, 1H), 8.18-8.08 (Ar, 2H), 8.03-7.86 (Ar, 6H), 7.82-7.7 6 (Ar, 2H), 7.76-7.56 (Ar, 12H), 3.38-3.27 (CH2, 2H), 2.89-2.70 (CH2, 2H), 0.60, 0.51 (t, OH, total 1H)

[0326] Under a nitrogen atmosphere, compound S-2 (3.41 g) was dissolved in 30 ml of dichloromethane, and 54 mg of dibutyltin diacetate was added. To this solution, 2-(2-methacryloyloxyethyloxy)ethyl isocyanate (1.37 g) was added and the mixture was allowed to react at room temperature. After two days, 2-(2-methacryloyloxyethyloxy)ethyl isocyanate (0.24 g) was added, and the mixture was allowed to react at room temperature for an additional three days. After confirming the disappearance of the raw materials, 4.5 g of diamine silica (SCAVENGER Diamine SILICA, manufactured by Fuji Silysia Chemical Co., Ltd.) and neutral silica gel (silica gel 60, manufactured by Kanto Chemical Co., Ltd.) were added to the reaction solution and stirred for one hour. After filtering off the silica gel, the filtrate was concentrated to 20 g, and this solution was added dropwise to 150 ml of methanol at -10°C. The precipitate was collected by filtration, washed, and then dried under reduced pressure to obtain 3.45 g of a polymerizable composition (C-1) (white powder).

[0327] When the polymerizable composition (C-1) was analyzed by NMR, it was found to be a mixture of the polymerizable compound (A-3) and the polymerizable compound (B-2), and as a result of quantitative analysis by gas chromatography, it was found to contain 0.61 parts by mass of the polymerizable compound (B-2) per 100 parts by mass of the polymerizable compound (A-3).

[0328] The NMR data of the polymerizable compound (A-3) was as follows: １ H NMR (400 MHz, CDCl ３ , δ, ppm) 8.83-8.68 (Ar, 6H), 8.34-8.25 (Ar, 1H), 8.18-8.06 (Ar, 2H), 8.05-7.85 (Ar, 6H), 7.79-7.56 (Ar, 14H), 6.11 (s , CH=CH2, 1H), 5.55 (s, CH=CH2, 1H), 4.33-4.08 (CH2, 2H), 3.65-3.12 (CH2, NH, 9H), 2.87-2.65 (CH2, 2H), 1.93 (CH3, 3H)

[0329] Furthermore, the refractive index of the polymerizable compound (A-3) was measured in the same manner as that of the polymerizable compound (A-1) described above, and was found to be 1.6975.

[0330] The NMR data of the polymerizable compound (B-2) was as follows: １H NMR (400 MHz, CDCl ３ , δ, ppm) 6.14-6.12 (CH=CH2, 2H), 5.61-5.57 (CH=CH2, 2H), 4.97 (NH, 2H), 4.31 (CH2, 4H) 3.71 (CH2, 4H), 3.57 (CH2, 4H) 3.37 (CH2, 4H), 1.95 (CH3, 6H)

[0331] <Preparation of TEMPOL Masterbatch> Duranate ＴＭ 0.3 g of TEMPOL was dissolved in 29.7 g of TSS-100. 0.003 g of a solution of tris(2-ethylhexanoate)bismuth in octylic acid was then dissolved therein, and the mixture was stirred at 45°C under reduced pressure and reacted for 2 hours. FT-IR showed a peak at 3450 cm originating from the hydroxyl group of TEMPOL. －１ The disappearance of the peak was observed to confirm the reaction of the hydroxyl groups of TEMPOL with the isocyanate groups.

[0332] <Production of holographic recording medium> Duranate ＴＭ 1.2041 g of polymerizable composition (C-1) and 0.0461 g of photopolymerization initiator HLI02 were dissolved in 2.1554 g of TSS-100 and 0.6665 g of Takenate 600, and 1.6376 g of TEMPOL masterbatch was added to prepare solution A. Separately, 4.1012 g of CAPA2047A and 0.4557 g of Placcel PCL-305 were mixed, and 0.00072 g of an octylic acid solution of tris(2-ethylhexanoate)bismuth was dissolved therein to prepare solution B.

[0333] After degassing each of solutions A and B at 45°C under reduced pressure for 2 hours, solutions A and B were 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 mixture, the edges secured with clips, and the mixture was heated at 80°C for 24 hours to prepare a holographic recording medium composition evaluation sample. This evaluation sample had a 0.5 mm-thick recording layer formed between the glass slides as a cover.

[0334] <Hologram Recording and Evaluation> Using the hologram recording medium prepared as an evaluation sample, hologram recording and evaluation of the hologram recording performance of the hologram recording medium were carried out according to the procedures described below.

[0335] Hologram recording was performed using a semiconductor laser with a wavelength of 405 nm and an exposure power density of 10.2 mW / cm per beam. ２ Using the exposure device shown in Figure 1, two-beam plane wave holographic recording was performed. The medium was rotated from -25° to +25°, and angle multiplexed recording was performed at the same location. The diffraction efficiency for each multiplexed recording was measured. Δn was calculated from the obtained diffraction efficiency, and the sum of the entire multiplexed recording was taken as total Δn. This will be explained in detail below.

[0336] (Hologram Recording) Figure 1 is a structural diagram showing an overview of the device used for hologram recording. In Figure 1, S is a sample of a hologram recording medium, and M1 and M2 both represent mirrors. PBS represents a polarizing beam splitter, and LD represents a laser light source for recording light that emits light with a wavelength of 405 nm (a single-mode laser manufactured by TOPTICA Photonics that can obtain light with a wavelength of around 405 nm). PD1 and PD2 represent photodetectors. LED represents a 40 LED unit (an LED manufactured by THORLAB with a central wavelength of 405 nm).

[0337] As shown in Figure 1, light with a wavelength of 405 nm was split by a polarizing beam splitter ("PBS" in the figure), and the two beams were made to intersect on the recording surface at an angle of 127°. At this time, the bisector of the angle between the two beams was set parallel to the recording surface, and further, the vibration plane of the electric field vectors of the two beams obtained by splitting was set perpendicular to the plane containing the two intersecting beams.

[0338] (Measurement of Diffraction Efficiency) The bisector of the angle between the two beams was set as the central angle of 0°, and 160 multiplex recordings were performed on the sample at angles from −25° to 0.2°, which are angles at which no stray light is incident when measuring the diffraction efficiency, and from 5.68° to 25° in 0.28° increments.

[0339] After multiplex recording, the LED unit (LED in the figure) was turned on for a certain period of time to consume the remaining initiator and monomer. This process is called post-exposure. The LED power was 30 mW / cm. ２ The cumulative energy is 18 J / cm ２ The irradiation was carried out so that

[0340] The diffraction efficiency of a hologram is given by the ratio of the diffracted light intensity to the sum of the transmitted light intensity transmitted through the hologram recording medium and the diffracted light intensity of the light diffracted by the recorded hologram. Light (wavelength 405 nm) from mirror M2 in FIG. 1 was irradiated, and the diffraction efficiency was measured from angles of -26° to 26°. From the obtained diffraction efficiency, Δn was calculated using the following formula based on Coupled Wave Theory (H. Kogelnik, The Bell System Technical Journal (1969), 48, 2909-2947), and the sum of the entire multiplexed recording was taken as total Δn.

[0341]

[0342] Here, η is the diffraction efficiency, d is the thickness of the medium, λ is the wavelength of the reference light, and θ is the angle of incidence (26.5°) of the reference light with respect to the recording surface.

[0343] Using multiple samples, evaluations were conducted multiple times under different irradiation energy conditions, such as increasing or decreasing the irradiation energy per multiplex recording and increasing or decreasing the total irradiation energy, to find the conditions under which the polymerizable monomer is almost completely consumed (total Δn reaches nearly equilibrium with multiplex recording), and total Δn reaches its maximum value. The maximum value obtained was then taken as the total Δn of the media. The evaluation results for total Δn are shown in Table 2.

[0344] A holographic recording medium was prepared and evaluated in the same manner as in Example 4, except that the polymerizable composition (C-1) was replaced with an equimolar amount of the polymerizable compound (A-1). The evaluation results are shown in Table 2.

[0345] Comparative Example 5 A holographic recording medium was prepared and evaluated in the same manner as in Example 4, except that the polymerizable composition (C-1) was replaced with an equimolar amount of the polymerizable compound (A-2). The evaluation results are shown in Table 2.

[0346] Comparative Example 6 When the polymerizable composition (C-1) was changed to a polymerizable composition (C-2) containing 15 parts by mass of the polymerizable compound (B-2) per 100 parts by mass of the polymerizable compound (A-3), Duranate ＴＭ The solution became cloudy when dissolved in TSS-100, making it impossible to prepare a holographic recording medium, and subsequent evaluation was also impossible.

[0347]

[0348] Table 2 shows that the composition of the present invention can achieve holographic performance equivalent to or better than that of the polymerizable compound (A) alone. Specifically, Example 4 (total Δn: 0.0467) corresponds to a diffraction efficiency 1 to 10% higher at each multiplex than Comparative Example 4 (total Δn: 0.0435). This means that the projector's power consumption can be reduced by 1 to 10%, contributing to battery miniaturization and extending the device's continuous operating time.

[0349] 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. 2024-105185 filed on June 28, 2024, the entire contents of which are incorporated herein by reference.

[0350] S Hologram recording medium M1, M2 Mirror LD Semiconductor laser light source for recording light PD1, PD2 Photodetector PBS Polarizing beam splitter LED Post-exposure LED

Claims

1. A composition comprising the following polymerizable compound (A) and the following polymerizable compound (B), wherein the content of the polymerizable compound (B) relative to 100 parts by mass of the polymerizable compound (A) is 0.0001 parts by mass or more and 10 parts by mass or less. Polymerizable compound (A): A compound having a structure represented by the following formula (1) and having a refractive index of 1.60 or more. Polymerizable compound (B): A compound represented by the following formula (2): (In formula (1), R １ represents a hydrogen atom or a methyl group, L １ is (n １ represents a linking group having a valence of n+1. １ represents 1 or 2. １ If there are multiple R １ may be the same or different. ２ represents a hydrogen atom or a methyl group, L ２ are each independently (n ２ represents a linking group having a valence of n+1. ２ Each independently represents 1 or 2. ２ If there are multiple R ２ may be the same or different.) 2. L in the formula (1) １ and L in the formula (2) ２ The composition of claim 1 , wherein:

3. The composition according to claim 1 or 2, wherein the polymerizable compound (B) is a compound represented by any one of the following formulas (3) to (5): (In formulas (3) to (5), R ２ is R in the formula (2). ２ is synonymous with 4. The composition according to claim 1 or 2, wherein the polymerizable compound (A) is a compound represented by the following formula (6-1) or formula (6-2): (In formula (6-1), R １ , L １ , n １ is R in the formula (1). １ , L １ , n １ It is synonymous with X. １ represents a (r+1)-valent linking group, and Ar represents an aromatic ring group which may have a substituent. Y represents a monovalent organic group. p represents 0 or 1, q represents an integer of 0 to 10, and r represents an integer of 1 to 5. When q and / or r are integers of 2 or greater, multiple Ars and Ys may be the same or different. (In formula (6-2), R １ , L １ , n １ is R in the formula (1). １ , L １ , n １ It is synonymous with X. ２ represents a divalent linking group, and Ar represents an aromatic ring group which may have a substituent. Y represents a monovalent organic group. p represents 0 or 1, and q represents an integer of 0 to 10. Z represents a single bond, a divalent organic group having 1 to 20 carbon atoms, a carbonyl group, a sulfonyl group, a divalent oxygen atom, or a divalent sulfur atom. When q is an integer of 2 or more, multiple Ys may be the same or different.

5. The composition according to claim 1 or 2, further comprising a polymerization initiator.

6. A holographic recording medium comprising the composition according to claim 1 or 2.

7. A polymer obtained by polymerizing the composition according to claim 1 or 2.

8. An optical material comprising the polymer according to claim 7.

9. An optical component comprising the polymer of claim 7.

10. A large-capacity memory including the holographic recording medium according to claim 6.

11. An optical element obtained by holographically recording on the holographic recording medium according to claim 6.

12. An AR light guide plate comprising the optical element according to claim 11.

13. AR glasses comprising the optical element according to claim 11.

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