JP4686380B2 - Hologram recording material, hologram recording method, and optical recording medium - Google Patents

Description

  The present invention relates to a hologram recording material and a hologram recording method applicable to a high-density optical recording medium, a three-dimensional display, a holographic optical element, and the like.

  General principles relating to the production of holograms are described in several literatures and technical books, for example, chapter 2 of “Holographic Display” (Junpei Uchinai, Sangyo Tosho [Non-Patent Document 1]). According to these, the photosensitive hologram recording material is placed at a position where one of the two light fluxes of the coherent laser light is irradiated onto the recording object and the total reflection light from the recording object can be received. The hologram recording material is directly irradiated with the other coherent light in addition to the reflected light from the object without hitting the object. Reflected light from the object is referred to as object light, and light directly applied to the recording material is referred to as reference light, and interference fringes between the reference light and object light are recorded as image information. Next, when the processed recording material is irradiated with the same light (reproduction illumination light) as the reference light, it is diffracted by the hologram so as to reproduce the wavefront of the reflected light that first reaches the recording material from the object during recording. As a result, an object image substantially the same as the real image of the object can be observed three-dimensionally.

A hologram formed by causing the reference light and the object light to enter the hologram recording material from the same direction is called a transmission hologram. The interference fringes are formed at intervals of about 1000 to 3000 per 1 mm in a form perpendicular or nearly perpendicular to the recording material film surface direction.
On the other hand, holograms formed by being incident on opposite sides of the hologram recording material are generally called reflection holograms. The interference fringes are formed at intervals of about 3000 to 7000 per 1 mm in a shape parallel or nearly parallel to the recording material film surface direction.
The transmission hologram can be created by a known method as disclosed in, for example, JP-A-6-43634 [Patent Document 1]. The reflection hologram can be created by a known method disclosed in, for example, JP-A-2-3082 [Patent Document 2] and JP-A-3-50588 [Patent Document 3].

On the other hand, a hologram whose film thickness is sufficiently thick with respect to the interference fringe interval (usually a thickness of about 5 times the interference fringe interval or about 1 μm or more) is called a volume hologram.
On the other hand, a hologram whose film thickness is about 5 times or less of the interference fringe interval or about 1 μm or less is called a planar type or a surface type.

  Further, a hologram that records interference fringes by absorption of a dye or silver is called an amplitude hologram, and a hologram that is recorded by surface relief or refractive index modulation is called a phase hologram. Amplitude holograms are not preferred in terms of light utilization efficiency because light diffraction efficiency or reflection efficiency is significantly reduced due to light absorption, and phase holograms are usually preferred.

In a volume phase hologram, the phase of light can be modulated without absorbing light by forming many interference fringes with different refractive indexes in the hologram recording material instead of optical absorption.
In particular, reflective volume phase holograms, also called Lippmann holograms, are capable of full color, white reproduction and high resolution with high diffraction efficiency due to wavelength selective reflection by black diffraction, and high resolution full color 3D display. Can be provided.
Recently, taking advantage of the wavelength selective reflection, a hologram optical element represented by a head-up display (HUD) mounted on an automobile, a pickup lens for an optical disk, a head-mounted display, a color filter for liquid crystal, a reflective liquid crystal reflector, and the like. (HOE) has been widely put into practical use.
In addition, for example, practical use or application is being studied for lenses, diffraction gratings, interference filters, optical fiber couplers, facsimile light polarizers, architectural window glass, and the like.

By the way, in the recent trend of advanced information society, networks such as the Internet and high-definition TVs are rapidly spreading. In addition, HDTV (High Definition Television) will soon be broadcast, and there is an increasing demand for a high-density recording medium for recording image information of 100 GB or more inexpensively and easily for consumer use.
In addition, in the trend of increasing computer capacity, there is a need for ultra-high-density recording media that can record large volumes of information of about 1 TB or more at high speed and low cost for business use such as computer backup and broadcast backup. It has been.
Under such circumstances, a compact, inexpensive optical recording medium that is replaceable and randomly accessible has attracted more attention than a magnetic tape medium that cannot be randomly accessed and a hard disk that is not replaceable and easily failed. However, an existing two-dimensional optical recording medium such as a DVD-R has a recording capacity that is sufficiently large to meet future demands, even if the recording / reproducing wavelength is shortened, even if the recording / reproducing wavelength is shortened. The situation cannot be expected.

  Therefore, a three-dimensional optical recording medium that performs recording in the film thickness direction has attracted attention as the ultimate ultra-high density recording medium. As a promising method, there are a method using a two-photon absorption material and a method using holography (interference). Therefore, a volume phase hologram recording material has recently attracted attention as a three-dimensional optical recording medium (holographic memory). It became so.

In a holographic memory using a volume phase hologram recording material, two-dimensional digital information (referred to as signal light) using a spatial light modulation element (SLM) such as DMD or LCD instead of object light reflected from a three-dimensional object. Will be recorded a lot. At the time of recording, multiplex recording such as angle multiplexing, phase multiplexing, wavelength multiplexing, and shift multiplexing is performed, so that the capacity can be increased to 1 TB. For reading, usually CCD or CMOS
Etc., and the parallel writing and reading out of them can achieve a high transfer rate as high as 1 Gbps.

However, the requirements for hologram recording materials used for holographic memories are more severe than those for three-dimensional displays and HOE applications as described below.
(1) High sensitivity (2) High resolution (3) High hologram diffraction efficiency (4) Recording process is dry and quick (5) Multiple recording is possible (Wide dynamic range)
(6) Shrinkage after recording is small (7) Hologram storage stability is good

  In particular, (1) high sensitivity, (3) high diffraction efficiency, (4) dry processing, (6) low shrinkage after recording, and (7) good storage stability. These are physical properties that are contradictory in chemical terms, and it is extremely difficult to achieve both.

  Here, as a known volume phase hologram recording material, a dichromate gelatin method, a bleached silver halide salt method, a photopolymer method, and the like are known as a write-once method, and a photorefractive method and a photochromic polymer as a rewritable method. Methods are known.

However, in these known volume phase hologram recording materials, particularly in the application to high-sensitivity optical recording media, materials that satisfy all of the required requirements are still desired and improvements are desired.
Specifically, for example, the dichromated gelatin method has the advantages of high diffraction efficiency and low noise characteristics, but has extremely poor storage stability, requires wet processing and has low sensitivity, and is suitable for holographic memory applications. Not suitable.
The bleached silver halide method has the advantage of high sensitivity, but it requires wet processing, is complicated in bleaching processing, has problems of large scattering and poor light resistance, and is used for holographic memory applications. After all it is not generally suitable.
Although the photorefractive material has the advantage that it can be rewritten, it has a problem that a high electric field needs to be applied at the time of recording and the record storage stability is poor.
Although the photochromic polymer system represented by azobenzene polymer material has the advantage that it can be rewritten, it has a problem that the sensitivity is very low and the storage stability is poor. For example, WO9744365A1 [Patent Document 4] presents a rewritable hologram recording material using refractive index anisotropy and orientation control of an azobenzene polymer (photochromic polymer). Although the yield is low and the system is accompanied by a change in orientation, the sensitivity is extremely low, and there is a problem in that the record storability is poor due to the contradiction of being rewritable, which is far from practical use.

Under such circumstances, the dry-processed photopolymer method disclosed in Patent Documents 1 to 3 described above has a binder, a radical polymerizable monomer, and a photopolymerization initiator as a basic composition, and a binder or We have devised a difference in refractive index by using a compound having an aromatic ring or chlorine or bromine on one of the radically polymerizable monomers, and as a result, in the bright part of the interference fringes formed during hologram exposure The monomer can form a refractive index difference by polymerization while the binder gathers in the dark part. Therefore, it can be said that it is a relatively practical method that can achieve both high diffraction efficiency and dry processing.
However, compared with the bleached silver halide method, the sensitivity is about 1/1000, the heat fixing treatment is required for nearly 2 hours in order to increase the diffraction efficiency, and radical polymerization, so that the polymerization inhibition by oxygen is inhibited. In addition, there is a problem that the diffraction wavelength and angle at the time of reproduction change due to the shrinkage of the recording material after exposure and fixing, the lack of storage stability due to the soft film, etc. Therefore, it cannot withstand use as a holographic memory application.

Here, in general, cationic polymerization, particularly cationic polymerization accompanied by ring opening of an epoxy compound or the like with respect to radical polymerization has little shrinkage after polymerization and is not subjected to polymerization inhibition by oxygen, and gives a rigid film. Therefore, some point out that cationic polymerization is more suitable for holographic memory applications.
For example, in JP-A-5-107999 [Patent Document 5] and JP-A-8-16078 [Patent Document 6], a cationically polymerizable compound (monomer or oligomer) is used instead of a binder, and further a sensitizing dye, radical A hologram recording material in which a polymerization initiator, a cationic polymerization initiator, and a radical polymerizable compound are combined is disclosed.
In addition, JP-T-2001-523842 [Patent Document 7], JP-T 11-512847 [Patent Document 8] and the like do not use radical polymerization, and sensitizing dyes, cationic polymerization initiators, cationic polymerizable compounds, and the like. A hologram recording material using only a binder is disclosed.
However, although these known cationic polymerization methods show an improvement in shrinkage rate compared to radical polymerization methods, the contradiction is that the sensitivity is lowered, and in practical use, it becomes a big problem in terms of transfer speed. Conceivable. In addition, the diffraction efficiency is lowered, which is considered to be a problem in terms of S / N ratio and multiple recording. Further, if the polymerization rate of the photopolymer is low, loss of recording may occur due to movement of residual monomers during storage.

Therefore, in order to apply hologram recording materials to holographic memory, such problems have been drastically solved, especially high diffraction efficiency, low shrinkage, multiple recording characteristics (high recording density), and good storage stability. Development of a new photopolymer hologram recording material that can be made has been strongly desired.
JP-A-6-43634 JP-A-2-3082 Japanese Patent Laid-Open No. 3-50588 WO 97/44365 pamphlet Japanese Patent Laid-Open No. 5-107999 JP-A-8-16078 Special table 2001-523842 Japanese National Patent Publication No. 11-512847 "Holographic Display", Junpei Uchiuchi, Industrial Books

  Therefore, an object of the present invention is to provide high sensitivity and high diffraction efficiency, good storage stability, low shrinkage, dry processing, multiple recording characteristics (high recording performance) that can be applied to high-density optical recording media, three-dimensional displays, holographic optical elements, and the like. It is to provide a hologram recording material and a hologram recording method capable of achieving both (recording density).

As a result of intensive studies by the inventors, the object of the present invention has been achieved by the following means.
Note that the present invention relates to the following (1) to (10) and those having the citation relationship with the following (1) to (10). Is also described.
(1) A cationically polymerizable photopolymer hologram recording material comprising at least a cationically polymerizable monomer represented by the following general formula (1-1), an acid generator, and a binder.

In General Formula (1-1), R _{1 to} R ₆ each independently represent a hydrogen atom or an alkyl group, and L ₁ represents a divalent linking group.
(2) The cationically polymerizable photo described in (1), wherein the cationically polymerizable monomer represented by the general formula (1-1) is represented by the general formula (1-2) or (1-3) Polymer hologram recording material.

In General Formula (1-2), L ₂ represents an alkylene group or an arylene group, and in General Formula (1-3), L ₃ represents an alkylene group or an arylene group.
(3) The cation polymerization photopolymer hologram recording material according to (2), wherein L ₂ is an alkylene group having 2 to 8 carbon atoms in the general formula (1-2).
(4) The cation-polymerized photopolymer hologram recording material according to (3), wherein L ₂ is a butylene group in the general formula (1-2).
(5) The cation polymerization photopolymer hologram recording material according to (2), wherein in general formula (1-3), L ₃ is an alkylene group having 1 to 8 carbon atoms.
(6) In (1) or (2), in addition to the cationically polymerizable monomer represented by the general formulas (1-1) to (1-3), the cation represented by the general formula (2-1) The cationic polymerization photopolymer hologram recording material according to any one of (1) to (5), wherein a polymerizable monomer is used in combination.

In general formula (2-1), L ₄ represents a mere bond or a divalent linking group, n1 is 0 when L ₄ is a mere bond, and 1 when L ₄ is a divalent linking group. Represents.
(7) In the general formula (2-1), L ₄ is a mere bond or a linking group comprising an alkylene group, an arylene group, and an ether group, The cationic polymerization photopolymer hologram recording according to (6) material.
(8) In (6), the cationic polymerizable monomer represented by the general formula (2-1) is represented by the general formula (1-1) to (1-3). The cationic polymerization hologram recording material according to (6) or (7), which is contained in a mass ratio of 5 to 100%.
(9) The cationically-polymerized photopolymer according to any one of (1) to (8), wherein the binder is any one of a copolymerized polymer containing acylated cellulose, polymethyl methacrylate or polymethyl methacrylate in (1) Hologram recording material.
(10) The cationic polymerization photopolymer hologram recording material according to (9), wherein the acylated cellulose in (9) is cellulose acetate butyrate.
(11) A cationically polymerizable photopolymer hologram comprising at least a cationically polymerizable monomer represented by any one of the following general formulas (3-1) to (3-5), an acid generator, and a binder Recording material.

In General Formula (3-1), L ₅ represents an alkylene group, and in General Formula (3-2), L ₆ represents a divalent linking group. In general formulas (3-3) and (3-4), R _{7 to} R ₁₅ each independently represent a hydrogen atom or an alkyl group. In General Formula (3-5), L ₇ represents an alkylene group.
(12) The cationically-polymerized photopolymer hologram recording material according to (11), wherein in general formula (3-1), L ₅ is a methylene group.
(13) A cation polymerization photopolymer hologram recording material, wherein in general formula (3-2), L ₆ is an alkylene group having 2 to 8 carbon atoms.
(14) A cationic polymerization photopolymer hologram recording material, wherein, in the general formula (3-3), R ₇ and R ₉ are methyl groups, and R ₈ , R ₁₀ and R ₁₁ are hydrogen atoms.
(15) A cationic polymerization photopolymer hologram recording material, wherein in general formula (3-4), R ₁₂ , R ₁₄ and R ₁₅ are methyl groups, and R ₁₃ is a hydrogen atom.
(16) A cation polymerization photopolymer hologram recording material, wherein in formula (3-5), L ₇ is a butylene group.
(17) In (11), in addition to the cationic polymerizable monomer represented by the general formulas (3-1) to (3-5), a cationic polymerizable monomer represented by the general formula (2-2) The cationic polymerization photopolymer hologram recording material according to (11), which is used in combination.

In General Formula (2-2), L ₈ represents a simple bond or a divalent linking group, and n2 is 0 when L ₈ is a mere bond, and 1 when L ₈ is a divalent linking group. Represents.
(18) The cationic polymerization photopolymer hologram recording material according to (17), wherein in the general formula (2-2), L ₈ represents a simple bond or an alkylene group having 2 to 8 carbon atoms.
(19) In (18), the cationic polymerizable monomer represented by the general formula (2-2) is represented by the general formula (3-1) to (3-5). The cationic polymerization hologram recording material according to (17) or (18), which is contained in a mass ratio of 5 to 100%.
(20) The description (11) to (19), wherein the binder in (11) is any one of a poly (styrene-acrylonitrile) copolymer, a poly (styrene-methyl methacrylate) copolymer, and polystyrene. Cationic polymerization photopolymer hologram recording material.
(21) The cationically-polymerized photopolymer hologram recording material according to (20), wherein the binder in (20) is a poly (styrene-acrylonitrile) copolymer.
(22) The cationic polymerization photopolymer hologram recording material according to any one of (1) to (21), wherein the mass ratio of the cationic polymerizable monomer to the binder is 5 to 100% in (1) or (11) .
(23) The cation-polymerized photopolymer hologram recording material according to (22), wherein, in (22), the mass ratio of the cation-polymerizable monomer to the binder is 10 to 30%.
(24) In (1) or (11), the acid generator is any of a diaryliodonium salt, a sulfonium salt, a diazonium salt, a metal arene complex, a trihalomethyl-substituted triazine, a sulfonate ester, or an imide sulfonate. The cationic polymerization photopolymer hologram recording material according to any one of (1) to (23).
(25) The cationic polymerization photopolymer hologram recording material according to (24), wherein the acid generator in (24) is a diaryliodonium salt or a sulfonium salt.
(26) In (1) or (11), in addition to the cationic polymerizable monomer, the acid generator, and the binder, the composition further has a sensitizing dye having absorption at the hologram recording wavelength, and the sensitizing dye has the general formula ( The cationically-polymerized photopolymer hologram recording material according to any one of (1) to (25), which is represented by any one of (4-1) to (4-6).

In general formulas (4-1) to (4-5), R ₂₁ , R ₂₂ , R ₂₄ , R ₂₅ , R ₂₆ , R ₂₇ , and R ₃₄ are each independently a hydrogen atom, an alkyl group, an alkenyl group, or a cycloalkyl group. R ₂₄ and R ₂₅ may be linked to each other to form a ring, and R ₂₃ , R ₃₂ , and R ₃₃ are each independently an alkyl group, an alkenyl group, a cycloalkyl group, or an aryl group. Represents.
In general formula (4-4), R ₂₈ and R ₂₉ each independently represents an alkyl group, an alkenyl group, a cycloalkyl group, or an aryl group. R ₂₈ and R ₂₉ may be connected to each other to form a ring.
In general formulas (4-5) and (4-6), R ₃₀ , R ₃₁ , R ₃₅ , and R ₃₆ each independently represent a substituent, and a30, a31, a35, and a36 each independently represent 0 to 4 Represents an integer.
When a30 and a31 are 2 or more, the plurality of R ₃₀ and R ₃₁ may be the same or different, and may be connected to each other to form a ring. When a35 and a36 are 2 or more, the plurality of R ₃₅ and R ₃₆ may be the same or different, and may be connected to each other to form a ring. The a35, a36 when the one or more _{together, R 35} and _{R 36} may combine with each other to form a ring. CI represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge.

(27) The cationic polymerization photopolymer hologram recording material according to (26), wherein in general formula (4-4), R ₂₈ is an alkyl group substituted with an electron withdrawing group.
(28) In (27), the electron-withdrawing group substituted for the alkyl group is a cyano group, an alkoxycarbonyl group, a carbamoyl group, a halogen atom, an alkoxy group, an aryloxy group, an acyloxy group, an alkylsulfonyl group, or an arylsulfonyl group. The cationic polymerization photopolymer hologram recording material according to (27), which is any one of the following.
(29) The cationic polymerization photopolymer hologram recording material according to (26), wherein in the general formula (4-5), R ₃₀ and R ₃₁ are chlorine atoms.
(30) The cationic polymerization photopolymer hologram according to any one of (1) to (29), further comprising an alcohol represented by the general formula (5) in (1), (11), and (26) Recording material.

In General Formula (5), R ₄₁ represents an alkyl group or an aryl group, and R _{42 to} R ₄₅ each independently represent a hydrogen atom or a methyl group. n1 represents an integer of 1 to 10.
(31) The cationic polymerization photopolymer hologram recording material according to (30), wherein in formula (5), R ₄₁ is an alkyl group having 1 to 12 carbon atoms.
(32) In (26), in addition to the cationic polymerizable monomer, acid generator, binder, and sensitizing dye, before addition of acid, the hologram recording wavelength has no absorption and is generated from the acid generator during hologram recording. (26) to (31), comprising a “sensitizing dye supplying dye precursor” which can be colored by adding an acid to form a sensitizing dye having absorption at a hologram recording wavelength. Cationic polymerization photopolymer hologram recording material.
(33) The cationic polymerization photopolymer hologram recording material according to (32), wherein the “sensitizing dye supplying dye precursor” in (32) is a cyanine-based dye precursor.
(34) The “sensitizing dye supplying dye precursor” in (32) is a cyanine-based dye precursor represented by the following general formula (6-1) or (6-2) ( 32) The cationic polymerization photopolymer hologram recording material described in 32).

In general formulas (6-1) and (6-2), X ₁ and X ₂ each independently represent any of —S—, —O—, —NR ₈₃ —, —CR ₈₄ R ₈₅ —, and R _{83 to} R ₈₅ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a heterocyclic group, and R ₈₄ and R ₈₅ may be linked to each other to form a ring. . R ₇₅ represents any of an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and a heterocyclic group, R _{71 to} R ₇₄ each independently represent a hydrogen atom or a substituent, and L ₁₁ and L ₁₂ are each independently Represents a single bond or a double bond. a71~a74 each independently represent 1 or _2, when _{L 11} is a single bond a71, a72 represents 2, and when _{L 1} is a double bond a71, a72 represents _{1, L 12} is a single A73 and a74 represent 2 when bonded, a73 and a74 represent 1 when L ₁₂ is a double bond, and when a71 to a74 are 2, a plurality of R _{71 to} R ₇₄ may be the same or different good. R ₇₁ and R ₇₂ , R ₇₃ and R ₇₄ may be linked to form a ring. _{R 76,} R 77, R ₇₈ represents a hydrogen atom or a substituent, n3 denotes an integer of 0 to 3.
In General Formula (6-2), Z ₁ represents an atomic group forming a 5- or 6-membered ring, R ₇₉ and R ₈₀ each independently represent a hydrogen atom or a substituent, and R ₈₁ and R ₈₂ each independently Represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, or an acyl group, and R ₈₁ and R ₈₂ may be linked to each other to form a ring. n1 represents the integer of 1-4.
(35) The hologram recording method according to any one of (1) to (34), wherein multiplex recording is performed 10 times or more using the hologram recording material according to (1) to (34).
(36) An optical recording medium comprising the cationic polymerization photopolymer hologram recording material according to (1) to (35).
(37) An optical recording medium, wherein the cationic polymerization photopolymer hologram recording material according to any one of (1) to (34) is stored in a light shielding cartridge during storage.
(38) A three-dimensional display hologram using the cationic polymerization photopolymer hologram recording material according to any one of (1) to (34).
(39) A holographic optical element using the cationic polymerization photopolymer hologram recording material according to any one of (1) to (34).

  By using the cationic polymerization photopolymer hologram recording material of the present invention, it is possible to provide a hologram recording material having excellent diffraction efficiency, shrinkage rate, multiple recording characteristics, and storage stability.

The hologram recording method and hologram recording material of the present invention will be described in detail below.
In addition, although this invention is related to the said (1)-(10) and what has a citation relationship with said (1)-(10), another matter is also demonstrated as reference.
The hologram recording method of the present invention uses a photopolymer obtained by cationic polymerization. The refractive index of the cationic polymerizable monomer and the binder are different, and the composition ratio between the cationic polymerizable monomer and its polymerization reaction product and the binder becomes non-uniform in the bright and dark interference areas due to photopolymerization and mass transfer during hologram exposure. Thus, hologram recording by refractive index modulation is possible.

The cationic polymerization photopolymer hologram recording material of the present invention is preferably not subjected to wet processing.
The cationic polymerization photopolymer hologram recording material of the present invention is preferably a system that cannot be rewritten. Here, the non-rewritable method is a method of recording by irreversible reaction, and indicates a method in which once recorded data can be stored without being rewritten even if it is overwritten and recorded. Therefore, it is suitable for storing important data that requires long-term storage. However, of course, it is possible to newly record in an area that has not been recorded yet. In that sense, it is generally called “write-once type” or “write-once type”.

The light used for hologram recording of the present invention is preferably any of ultraviolet light, visible light, and infrared light having a wavelength of 200 to 2000 nm, more preferably ultraviolet light or visible light having a wavelength of 300 to 700 nm, and still more preferably. It is visible light of 400 to 700 nm.
Furthermore, the light used for the hologram recording of the present invention is preferably a coherent laser beam (having the same phase and wavelength). The laser used may be any of a solid laser, a semiconductor laser, a gas laser, and a liquid laser. Preferred laser beams include, for example, a 532 nm YAG laser double wave, a 355 nm YAG laser triple wave, and a wavelength around 400 to 415 nm. Semiconductor lasers such as GaN and InGaN, semiconductor lasers such as AlGaInP near 650 to 660 nm, 488 or 515 nm Ar ion laser, 632 or 633 nm He—Ne laser, 647 nm Kr ion laser, 694 nm ruby laser and 636, 634, 538, 534, and 442 nm He—Cd laser.
It is also preferable to use a nanosecond or picosecond order pulse laser.
When the hologram recording material of the present invention is used for an optical recording medium, it is preferable to use a semiconductor laser such as a 532 nm YAG laser double wave, a GaN or InGaN laser near 400 to 415 nm, or an AlGaInP near 650 to 660 nm.
The wavelength of light used for hologram reproduction is preferably the same or longer than the wavelength of light used for hologram exposure (recording), and more preferably the same.

In the cationic polymerization photopolymer hologram recording material of the present invention, after the hologram exposure, a fixing step may be performed by light, heat, or both.
In the case of light fixing, the entire area of the hologram recording material is irradiated with ultraviolet light or visible light (non-interference exposure). Preferred examples of the light source used include a visible light laser, an ultraviolet light laser, a carbon arc, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp, a tungsten lamp, an LED, and an organic EL.
In the case of thermal fixing, the fixing step is preferably performed at 40 ° C to 160 ° C, more preferably 60 ° C to 130 ° C.
When both photofixing and heat fixing are performed, light and heat may be applied simultaneously, or light and heat may be added separately.

  The refractive index modulation amount at the time of interference fringe recording is preferably 0.00001 to 0.5, and more preferably 0.0001 to 0.3. In addition, it is preferable that the refractive index modulation amount is smaller as the film thickness of the hologram recording material is larger, and it is preferable that the refractive index modulation amount is larger as the film thickness of the hologram recording material is thinner.

The (relative) diffraction efficiency η of the hologram recording material is given by the following equation.
η = Idiff / Io (Formula 1)
Here, Io is the intensity of transmitted light that is not diffracted, and Idiff is the intensity of light that is diffracted (transmitted) or reflected (reflected). The diffraction efficiency takes any value from 0 to 100%, preferably 30% or more, more preferably 60% or more, and most preferably 80% or more.

The sensitivity of the hologram recording material is generally the exposure amount per unit area (mJ / cm ² ).
It can be said that the smaller this value, the higher the sensitivity. However, the exposure amount at which time is taken as sensitivity varies depending on documents and patents. When the exposure amount starts recording (refractive index modulation), the exposure amount gives the maximum diffraction efficiency (refractive index modulation). In some cases, the exposure amount giving a diffraction efficiency half that of the maximum diffraction efficiency may be an exposure amount at which the gradient of the diffraction efficiency is maximized with respect to the exposure amount E.
Further, from the Kugelnick's theoretical formula, the refractive index modulation amount Δn for giving a certain diffraction efficiency is inversely proportional to the film thickness d. That is, the sensitivity for giving a certain diffraction efficiency varies depending on the film thickness, and the smaller the refractive index modulation amount Δn is, the thicker the film thickness d is. Therefore, unless conditions such as film thickness are matched, the sensitivity cannot be generally compared.
In the present invention, the sensitivity is defined as “exposure amount giving half the maximum diffraction efficiency (mJ / cm ² )”. The sensitivity of the hologram recording material of the present invention, for example, when the film thickness is about 10 to 200 [mu] m, is preferably 2J / cm ² or less, more preferably 1 J / cm ² or less, 500 mJ / cm ² or less More preferably, it is most preferably 200 mJ / cm ² or less.

  When the cationic polymerization photopolymer hologram recording material of the present invention is used as an optical recording medium in a holographic memory, a large amount of two-dimensional digital information (referred to as signal light) is recorded using a spatial light modulation element (SLM) such as DMD or LCD. It is preferable to continue. In order to increase the recording density, it is preferable to use multiplex recording. The multiplex recording method includes multiplex recording such as angle multiplex, phase multiplex, wavelength multiplex, and shift multiplex. It is preferable to use shift multiple recording. Also, a CCD or CMOS is preferably used for reading the reproduced two-dimensional data.

  When the cation polymerization photopolymer hologram recording material of the present invention is used in a holographic memory as an optical recording medium, it is essential to perform multiplex recording in order to improve the capacity (recording density). At that time, it is more preferable to perform multiplex recording 10 times or more, more preferably to perform multiplex recording 50 times or more, and most preferably to perform multiplex recording 100 times or more.

  When the cationic polymerization photopolymer hologram recording material of the present invention is used for an optical recording medium, it is preferable that the hologram recording material during storage is stored in a light shielding cartridge. In addition, a light shielding filter capable of cutting a part of the wavelength range of ultraviolet light, visible light, and infrared light other than the recording light and reproduction light wavelengths may be provided on the front surface, back surface, or both surfaces of the hologram recording material. preferable.

  When the cationic polymerization photopolymer hologram recording material of the present invention is used for an optical recording medium, the optical recording medium may be disk-shaped, card-shaped, tape-shaped, or any shape.

  Hereinafter, each component of the cationic polymerization photopolymer hologram recording material of the present invention will be described in detail.

The cationic polymerization photopolymer hologram recording material of the present invention has at least an acid generator (polymerization initiator), a cationic polymerizable monomer, and a binder, preferably further has a sensitizing dye, and the refractive index of the cationic polymerizable monomer and the binder. The photopolymerization and mass transfer caused by the light absorption by the sensitizing dye during hologram exposure caused the composition ratio of the cationic polymerizable monomer and its polymerization reaction product and binder to be non-uniform in the interference bright part and interference dark part. Occurring is characterized in that hologram recording by refractive index modulation is possible.
However, the sensitizing dye and the acid generator may serve both functions. That is, recording may be performed by directly exciting an acid generator (polymerization initiator).

  First, the sensitizing dye that absorbs light and generates an excited state in the hologram exposure of the present invention will be described in detail.

  The sensitizing dye of the present invention preferably generates an excited state by absorbing any of ultraviolet light, visible light, and infrared light having a wavelength of 200 to 2000 nm, more preferably ultraviolet light having a wavelength of 300 to 700 nm. It absorbs light or visible light to generate an excited state, and more preferably absorbs visible light of 400 to 700 nm to generate an excited state.

  The sensitizing dye of the present invention is particularly preferably represented by any one of the general formulas (4-1) to (4-6).

In the general formulas (4-1) to (4-5), R ₂₁ , R ₂₂ , R ₂₄ , R ₂₅ , R ₂₆ , R ₂₇ and R ₃₄ are each independently a hydrogen atom or an alkyl group (preferably the number of carbon atoms 1-20 (hereinafter referred to as C number), for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, n-octyl, n-octadecyl, benzyl, 2-methoxyethyl, 2-butoxyethyl, 2- (2′-methoxyethoxy) ethyl, 3-sulfopropyl, 4-sulfobutyl, carboxymethyl, 5-carboxypentyl, 2-chloroethyl, 2-cyanoethyl, 2- (methylsulfonyl) ethyl, 2- (phenylsulfonyl) Ethyl, methoxycarbonylmethyl, 2- (acetyloxy) methyl), alkenyl groups (preferably C 2-20, eg, , Allyl, 2-butenyl, 1,3-butadienyl), a cycloalkyl group (preferably having 3 to 20 carbon atoms, such as cyclopentyl, cyclohexyl), an aryl group (preferably having 6 to 20 carbon atoms, such as phenyl, 2- Chlorophenyl, 4-methoxyphenyl, 3-methylphenyl, 1-naphthyl, 2-naphthyl).
R ₂₄ and R ₂₅ may combine with each other to form a ring, and the ring to be formed is preferably a benzene ring or a naphthalene ring.
R ₂₁ and R ₂₂ preferably represent a hydrogen atom, an alkyl group, or an aryl group, more preferably an alkyl group, and most preferably an ethyl group.
R ₂₄ preferably represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, more preferably represents a hydrogen atom or a methyl group.
R ₂₅ preferably represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group, more preferably a hydrogen atom or a phenyl group.
R ₂₆ and R ₂₇ preferably represent a hydrogen atom, an alkyl group, or an aryl group, more preferably a methyl group or a phenyl group, and most preferably a phenyl group.
R ₃₄ preferably represents a hydrogen atom or an alkyl group, more preferably a hydrogen atom or an ethyl group.

In general formulas (4-1) to (4-3) (4-5), R ₂₃ , R ₃₂ and R ₃₃ are each independently an alkyl group, an alkenyl group, a cycloalkyl group or an aryl group (more preferred substituents). Represents the same as the examples given for R ₂₁ ), preferably an alkyl group.

In general formula (4-4), R ₂₈ and R ₂₉ each independently represent an alkyl group, an alkenyl group, a cycloalkyl group, or an aryl group (the examples of the preferred substituents are the same as those described in R ₂₁ ), Preferably it represents an alkyl group.
In particular, R ₂₈ is preferably an alkyl group substituted with an electron withdrawing group. Here, the electron withdrawing group is a substituent having a negative Hammet's σm value, and the electron withdrawing group is preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, a halogen atom, an alkoxy group, an aryloxy group. Group, acyloxy group, alkylsulfonyl group and arylsulfonyl group, more preferably cyano group, alkoxycarbonyl group, halogen atom and alkoxy group.
R ₂₈ is preferably an alkyl group in which these electron-withdrawing groups are substituted at the α-position or β-position. Preferred specific examples include 2-methoxyethyl, 2-butoxyethyl, 2- (2 '-Methoxyethoxy) ethyl, 2-chloroethyl, 2-cyanoethyl, 2- (methylsulfonyl) ethyl, 2- (phenylsulfonyl) ethyl, methoxycarbonylmethyl, 2- (acetyloxy) methyl and the like, more preferred specific examples Examples include 2-methoxyethyl, 2-chloroethyl, 2-cyanoethyl, methoxycarbonylmethyl and the like.
R ₂₈ and R ₂₉ may be connected to each other to form a ring, and preferred examples of the ring formed include a pyrrolidine ring, a piperidine ring, a morpholine ring, and a piperazine ring.

In general formulas (4-5) and (4-6), R ₃₀ , R ₃₁ , R ₃₅ , and R ₃₆ each independently represent a substituent. Preferred examples of the substituent include an alkyl group (preferably a C number). 1 to 20, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, benzyl, 2-butoxyethyl, 2- (2′-methoxyethoxy) ethyl, 3-sulfopropyl, 4-sulfobutyl , Carboxymethyl, 5-carboxypentyl), alkenyl group (preferably C 2-20, for example, vinyl, allyl, 2-butenyl, 1,3-butadienyl), cycloalkyl group (preferably C 3-20, For example, cyclopentyl, cyclohexyl), aryl group (preferably having 6 to 20 carbon atoms, such as phenyl, 2-chlorophenyl, 4-methoxypheny , 3-methylphenyl, 1-naphthyl), heterocyclic group (preferably C 1-20, eg pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrrolyl, pyrazolyl, pyrrolidino, piperidino, morpholino), alkynyl group (preferably C 2-20, for example, ethynyl, 2-propynyl, 1,3-butadiynyl, 2-phenylethynyl), halogen atom (for example, F, Cl, Br, I), amino group (preferably C 0- 20, for example, amino, dimethylamino, diethylamino, dibutylamino, anilino), cyano group, nitro group, hydroxyl group, mercapto group, carboxyl group, sulfo group, phosphonic acid group, acyl group (preferably having 1 to 20 carbon atoms, For example, acetyl, benzoyl, salicyloyl, pivaloyl), alkoxy group (preferably Preferably, it has 1 to 20 carbon atoms, such as methoxy, butoxy, cyclohexyloxy), an aryloxy group (preferably 6 to 26 carbon atoms, such as phenoxy, 1-naphthoxy), an alkylthio group (preferably 1 to 20 carbon atoms). , For example, methylthio, ethylthio), an arylthio group (preferably having 6 to 20 carbon atoms, such as phenylthio, 4-chlorophenylthio), an alkylsulfonyl group (preferably having 1 to 20 carbon atoms, such as methanesulfonyl, butanesulfonyl), Arylsulfonyl group (preferably C 6-20, such as benzenesulfonyl, paratoluenesulfonyl), sulfamoyl group (preferably C 0-20, such as sulfamoyl, N-methylsulfamoyl, N-phenylsulfamoyl) ), A carbamoyl group (preferably C 1-2) , For example, carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-phenylcarbamoyl), acylamino group (preferably having 1 to 20 carbon atoms such as acetylamino, benzoylamino), imino group (preferably having 2 C atoms) -20, such as phthalimino), acyloxy group (preferably C1-20, such as acetyloxy, benzoyloxy), alkoxycarbonyl group (preferably C2-20, such as methoxycarbonyl, phenoxycarbonyl), carbamoylamino group (Preferably having 1 to 20 carbon atoms, such as carbamoylamino, N-methylcarbamoylamino, N-phenylcarbamoylamino).
R ₃₀ and R ₃₁ are more preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, a halogen atom, a cyano group, an alkoxy group, a sulfamoyl group, a carbamoyl group, and an alkoxycarbonyl group, and more preferably a halogen atom. And most preferably a chlorine atom.
R ₃₂ and R ₃₃ are more preferably alkyl groups, alkenyl groups, aryl groups, heterocyclic groups, halogen atoms, cyano groups, nitro groups, alkoxy groups, sulfamoyl groups, carbamoyl groups, and alkoxycarbonyl groups.
a30, a31, a35, and a36 each independently represent an integer of 0 to 4. When a30 and a31 are 2 or more, a plurality of R ₃₀ and R ₃₁ may be the same or different, and may be connected to each other to form a ring. The ring formed is preferably a benzene ring, a pyridine ring, or the like. Can be mentioned. a30 and a31 are preferably integers of 0 to 2, and preferably 0 or 1.
When a35 and a36 are 2 or more, a plurality of R ₃₅ and R ₃₆ may be the same or different, and may be connected to each other to form a ring. The ring to be formed is preferably a benzene ring, a pyridine ring or the like. Can be mentioned. The a35, when a36 is 1 or more together, R ₃₅ and R ₃₆ may combine with each other to form a ring, preferably benzene ring, as the ring formed. a35 and a36 are preferably 0 or 1.
CI represents an ion that neutralizes the charge. Whether a compound is a cation, an anion, or has a net ionic charge depends on its substituent. Typical cations are ammonium ions and alkali metal ions, while anions can be either inorganic ions or organic ions.
Examples of the cation include sodium ion, potassium ion, triethylammonium ion, diethyl (i-propyl) ammonium ion, pyridinium ion, and 1-ethylpyridinium ion. Examples of the anion include halogen anion (for example, Chlorine ion, bromine ion, fluorine ion, iodine ion), substituted aryl sulfonate ion (eg, paratoluene sulfonate ion), substituted alkyl sulfonate ion (eg, methane sulfonate ion, trifluoromethane sulfonate ion), alkyl sulfate ion (For example, methyl sulfate ion), sulfate ion, perchlorate ion, acetate ion, PF ₆ ⁻ , SbF ₆ ⁻ , BF ₄ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , and the like. y represents a number necessary for neutralizing the electric charge.

  Although the specific example of the sensitizing dye of this invention represented by general formula (4-1)-(4-6) below is shown, this invention is not limited to this.

In addition to the sensitizing dyes represented by the general formulas (4-1) to (4-6), examples of the sensitizing dye of the present invention include cyanine dyes, squarylium cyanine dyes, styryl dyes, pyrylium dyes, and merocyanines. Dye, benzylidene dye, oxonol dye, azurenium dye, coumarin dye, ketocoumarin dye, styryl coumarin dye, pyran dye, xanthene dye, thioxanthene dye, phenothiazine dye, phenoxazine dye, phenazine dye, phthalocyanine dye, azaporphyrin dye, porphyrin dye , Condensed ring aromatic dyes, perylene dyes, azomethine dyes, anthraquinone dyes, metal complex dyes, metallocene dyes, etc., more preferably cyanine dyes, squarylium cyanine dyes, pyrylium dyes, merocyanine dyes, oxonol colors , Coumarin dyes, ketocoumarin dyes, styrylcoumarin dyes, pyran dyes, xanthene dyes, thioxanthene dyes, condensed aromatic dyes, metal complex dyes, metallocene dyes and the like are also preferred. More preferred are cyanine dyes, merocyanine dyes, oxonol dyes, metal complex dyes and metallocene dyes. As the metal complex dye, a Ru complex dye is particularly preferable, and as the metallocene dye, ferrocenes are particularly preferable.
In addition, "Dye Handbook" (Shin Okawara et al., Kodansha 1986), "Chemistry of Functional Dye" (Shin Okawara et al. CMC 1981), "Special Functional Materials" (Chemical Icmori Taro Saburo et al. CMC 1986) The dyes and dyes described in 1) can also be used as the sensitizing dye of the present invention. The sensitizing dye of the present invention is not limited to these, and any dye and dye that absorbs visible light can be used. These sensitizing dyes can be selected in accordance with the wavelength of the laser serving as a light source according to the purpose of use, and two or more kinds of sensitizing dyes may be used in combination depending on the application.

  Specific examples of the sensitizing dye of the present invention are given below, but the present invention is not limited thereto.

  In addition, since cationic polymerization photopolymer hologram recording material is used in a thick film and most of the recording light needs to pass through the film, adding a sensitizing dye by reducing the molar extinction coefficient of the sensitizing dye at the hologram exposure wavelength Increasing the amount as much as possible is preferable for increasing sensitivity. The molar extinction coefficient of the sensitizing dye at the hologram exposure wavelength is preferably 1 or more and 10,000 or less, more preferably 1 or more and 5000 or less, further preferably 5 or more and 2500 or less, and more preferably 10 or more and 1000 or less. Most preferred.

  The recording wavelength light transmittance of the hologram recording material is preferably 10 to 99%, more preferably 20 to 95%, further preferably 30 to 90%, and 40 to 85%. It is most preferable in terms of diffraction efficiency, sensitivity, and recording density (multiplicity). Therefore, it is preferable to adjust the molar extinction coefficient and the added molar concentration at the recording wavelength of the sensitizing dye in accordance with the film thickness of the hologram recording material so as to be like that.

  Further, λmax of the sensitizing dye is preferably shorter than the hologram recording wavelength, and more preferably in the range from the same as the hologram recording wavelength to a wavelength shorter than 100 nm.

Furthermore, the molar extinction coefficient at the recording wavelength of the sensitizing dye is preferably 1/5 or less of the molar extinction coefficient of λmax, and more preferably 1/10 or less.
In particular, when the sensitizing dye is an organic dye such as a cyanine dye or a merocyanine dye, it is preferably 1/20 or less, more preferably 1/50 or less, and 1/100 or less. Is most preferred.

  In the case of a YAG laser double wave with a hologram recording wavelength of 532 nm, as a sensitizing dye, a trimethine cyanine dye having a benzoxazole ring, a merocyanine dye having a Babiturtool acidic nucleus, a benzylidene dye having a pyrazolidinedioic acid nucleus, Ru complex dyes and ferrocenes are particularly preferred. In the case of a laser of 400 to 415 nm GaN, InGaN or the like, monomethine cyanine dyes, merocyanine dyes, Ru complex dyes, and ferrocenes having a benzoxazole ring are particularly preferred.

  Other preferred examples of the sensitizing dye of the present invention are described in JP-A No. 2005-99751. The sensitizing dye of the present invention is a commercial product, or can be synthesized by a known method.

  Next, the cationic polymerizable monomer and binder used in the cationic polymerization photopolymer hologram recording material of the present invention will be described.

In interference fringe recording by polymerization reaction, it is preferable that the refractive index of the cationic polymerizable monomer and the binder are different. In order to increase the refractive index modulation, the refractive index difference between the cationic polymerizable monomer and the binder in the bulk is preferably large, and the refractive index difference is preferably 0.01 or more, and preferably 0.05 or more. More preferably, it is more preferably 0.1 or more.
For this purpose, either the cationically polymerizable monomer or the binder contains at least one aryl group, aromatic heterocyclic group, chlorine atom, bromine atom, iodine atom or sulfur atom, and the other one contains them. It is preferably not included. It does not matter whether the cationically polymerizable monomer has a higher refractive index or the binder has a higher refractive index.

The cationically polymerizable monomer of the present invention is an oligomer or polymerized by causing addition polymerization with an acid (Bronsted acid or Lewis acid) generated by irradiating light to a sensitizing dye and an acid generator (polymerization initiator). Is a possible compound.
Examples of preferable cationic polymerizable monomers will be described below in the case of A) refractive index: cationic polymerizable monomer> binder and B) refractive index: binder> cation polymerizable monomer.

  A) Refractive index: Cationic polymerizable monomer> Preferred examples of cationic polymerizable monomer in the case of binder

In this case, the cationically polymerizable monomer of the present invention is preferably represented by the general formula (1-1).
In General Formula (1-1), R _{1 to} R ₆ each independently represent a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.
In general formula (1-1), L ₁ represents a divalent linking group, which may be any linking group, but is preferably an alkylene group (preferably having 1 to 20 carbon atoms (hereinafter referred to as C number), such as methylene. , Ethylene, propylene, butylene, pentylene, hexylene, octylene), arylene groups (preferably having 6 to 26 carbon atoms such as phenylene and naphthylene), alkenylene groups (preferably having 2 to 20 carbon atoms such as ethenylene and propenylene), alkynylene groups (Preferably C 2-20, such as ethynylene, propynylene), amide group, ester group, sulfoamide group, sulfonic acid ester group, ureido group, sulfonyl group, sulfinyl group, thioether group, ether group, carbonyl group, heterylene group ( Preferably C number 1 to 26, for example 6-chloro-1,3,5-triazi R-2,4-diyl group, pyrimidine-2,4-diyl group, quinoxaline-2,3-diyl group) and a combination of one or more carbon atoms, 0-100 or less, preferably 1 or more Or a linking group having 20 or less carbon atoms, more preferably a linking group having 2 to 20 carbon atoms constituted by combining one or more alkylene groups, arylene groups, ester groups, ether groups, and thioether groups,

The cationically polymerizable monomer represented by the general formula (1-1) is preferably represented by the general formula (1-2) or (1-3).
In the general formula (1-2), L ₂ is an alkylene group (preferably having a C number of 1 to 20, for example, ethylene, propylene, butylene, hexylene, octylene) or an arylene group (preferably having a C number of 6 to 20, for example, 1, 2 -Phenylene, 1,3-phenylene, 1,4-phenylene, 1,4-naphthylene), preferably an alkylene group, more preferably an alkylene group having 2 to 8 carbon atoms, and most preferably a butylene group. Represents.
In the general formula (1-3), L ₃ represents an alkylene group or an arylene group (preferred examples are the same as the examples shown in L ₂ ), preferably an alkylene group, and most preferably a C 1-8. Represents an alkylene group.

  Specific examples of the cationic polymerizable monomer of the present invention represented by the general formulas (1-1) to (1-3) are shown below, but the present invention is not limited thereto.

  In the cationic polymerization photopolymer hologram recording material of the present invention, in addition to the cationic polymerizable monomer represented by the general formulas (1-1) to (1-3), a cation represented by the general formula (2-1) It is also preferable to use a polymerizable monomer in combination.

In general formula (2-1), L ₄ represents a simple bond or a divalent linking group (preferred examples include those listed in L ₁ ), and preferably a simple bond, an alkylene group, and an arylene. A linking group comprising a group or an alkylene group and an arylene group and an ether group, more preferably a mere bond or a linking group comprising an alkylene group, an arylene group and an ether group.
n1 represents 0 when L ₄ is a simple bond, and 1 when L ₄ is a divalent linking group.

  When using the cationically polymerizable monomer represented by the general formula (2-1), the mass ratio of the cationically polymerizable monomer represented by the general formulas (1-1) to (1-3) is as follows. It is preferable that 5-95% is contained.

  Specific examples of the cationic polymerizable monomer represented by the general formula (2-1) are shown below, but the present invention is not limited thereto.

A) Preferred examples of binders in the case of refractive index: polymerizable compound> binder.

In this case, the binder preferably has a low refractive index, and is preferably a binder containing no aryl group, aromatic heterocyclic group, chlorine atom, bromine atom, iodine atom, or sulfur atom.
Specific examples of preferred low refractive index binders include acrylate and alpha-alkyl acrylate esters and acidic polymers and interpolymers (eg, polymethyl methacrylate and polyethyl methacrylate, methyl methacrylate and other (meth) acrylic acid alkyl esters). Copolymers), polyvinyl esters (eg, polyvinyl acetate, polyacetic acid / vinyl acrylate, polyacetic acid / vinyl methacrylate and hydrolyzable polyvinyl acetate), ethylene / vinyl acetate copolymers, saturated and unsaturated polyurethanes, Butadiene and isoprene polymers and copolymers and polyglycol high molecular weight poly (ethylene oxide) having an average molecular weight of approximately 4,000 to 1,000,000, epoxides (e.g. epoxies having acrylate or methacrylate groups) Product), polyamide (for example, N-methoxymethyl polyhexamethylene adipamide), cellulose ester (for example, cellulose acetate, cellulose acetate succinate and cellulose acetate butyrate), cellulose ether (for example, methyl cellulose, ethyl cellulose, ethyl benzyl cellulose) ), Polycarbonate, polyvinyl acetal (for example, polyvinyl butyral and polyvinyl formal), polyvinyl alcohol, polyvinyl pyrrolidone, and the like.

  A fluorine atom-containing polymer is also preferable as the low refractive index binder. Preferably, fluoroolefin is an essential component, and one or more selected from alkyl vinyl ether, alicyclic vinyl ether, hydroxy vinyl ether, olefin, haloolefin, unsaturated carboxylic acid and ester thereof, and carboxylic acid vinyl ester It is a polymer soluble in an organic solvent having the unsaturated monomer as a copolymerization component. Preferably, the weight average molecular weight is 5,000 to 200,000, and the fluorine atom content is 5 to 70% by mass.

  Specific examples of the fluorine atom-containing polymer include, for example, an organic solvent-soluble “Lumiflon” series having a hydroxyl group (for example, Lumiflon LF200, weight average molecular weight: about 50,000, manufactured by Asahi Glass Co., Ltd.). In addition, organic solvent-soluble fluorine atom-containing polymers are also marketed by Daikin Industries, Ltd., Central Glass Co., Ltd., and Penwort Co., Ltd., and these can also be used.

Also, preferred examples include silicon compounds such as poly (dimethylsiloxane) and silicon oils that do not contain aromatics.
In addition, an epoxy oligomer compound containing no aromatic can also be used as a low refractive index reactive binder.

  More preferably, the binder of the present invention in which the refractive index is polymerizable compound> binder includes acylated cellulose, polymethyl methacrylate, or a copolymer containing polymethyl methacrylate, and more preferably acylated cellulose. Most preferred is cellulose acetate butyrate.

B) Refractive index: Cationic polymerizable monomer <Preferred example of cationic polymerizable monomer in the case of binder

  In this case, the cationically polymerizable monomer of the present invention is preferably represented by any one of the general formulas (3-1) to (3-5).

In General Formula (3-1), L ₅ represents an alkylene group (preferred examples are the same as the examples given for L ₂ ), and more preferably represents a methylene group.
In general formula (3-2), L ₆ represents a divalent linking group (preferred examples are the same as the examples given in L ₁ , more preferably an alkylene group, an arylene group, or an alkylene group, an arylene group, and an ether group. And more preferably an alkylene group, and still more preferably an alkylene group having 2 to 8 carbon atoms.

In general formulas (3-3) and (3-4), R _{7 to} R ₁₅ each independently represent a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group.
In general formula (3-3), it is more preferable that R ₇ and R ₉ are methyl groups, and R ₈ , R ₁₀ , and R ₁₁ are hydrogen atoms.
In the general formula _{(3-4), R 12, R} 14, R 15 is a methyl _group, more preferably _{R 13} is a hydrogen atom.

In General Formula (3-5), L ₇ represents an alkylene group, preferably an alkylene group having 2 to 8 carbon atoms, and more preferably a butylene group.

  Specific examples of the cationically polymerizable monomer of the present invention represented by general formulas (3-1) to (3-5) are shown below, but the present invention is not limited thereto.

  In the cationic polymerization photopolymer hologram recording material of the present invention, in addition to the cationic polymerizable monomer represented by the general formulas (3-1) to (3-5), a cation represented by the general formula (2-2) It is also preferable to use a polymerizable monomer in combination.

In general formula (2-2), L ₈ represents a simple bond or a divalent linking group (preferred examples are the same as the examples given in L ₁ ), and n2 is 0 when L ₈ is a simple bond. , L ₈ represents a divalent linking group.
L ₈ is preferably a simple bond or an alkylene group having 2 to 8 carbon atoms.

  When using the cationically polymerizable monomer represented by the general formula (2-2), the cation polymerizable monomer represented by the general formulas (3-1) to (3-5) is used in a mass ratio. It is preferable that 5-95% is contained.

  Specific examples of the cationic polymerizable monomer represented by the general formula (2-2) are shown below, but the present invention is not limited thereto.

B) Refractive index: A preferred example of a binder in the case of binder> polymerizable compound.

In this case, the binder preferably has a high refractive index, and is preferably a binder containing at least one aryl group, aromatic heterocyclic group, chlorine atom, bromine atom, iodine atom, or sulfur atom. More preferably, the binder contains.
Specific examples of preferable high refractive index binders include polystyrene polymers and copolymers such as acrylonitrile, maleic anhydride, acrylic acid, methacrylic acid and esters thereof, and vinylidene chloride copolymers (eg, vinylidene chloride / acrylonitrile copolymer). Polymer, vinylidene chloride / methacrylate copolymer, vinylidene chloride / vinyl acetate copolymer), polyvinyl chloride and copolymers (eg, polyvinyl chloride / acetate, vinyl chloride / acrylonitrile copolymer), polyvinyl benzal synthetic rubber (For example, butadiene / acrylonitrile copolymer, acrylonitrile / butadiene / styrene copolymer, methacrylate / acrylonitrile / butadiene / styrene copolymer, 2-chlorobutadiene-1,3 polymer, chlorinated rubber, On / butadiene / styrene, styrene / isoprene / styrene block copolymer), copolyesters (e.g., formula _HO (CH 2) polymethylene glycol nOH (n in the formula is an integer of 2 to 10) and, ( 1) manufactured from reaction products of hexahydroterephthalic acid, sebacic acid and terephthalic acid, (2) terephthalic acid, isophthalic acid and sebacic acid, (3) terephthalic acid and sebacic acid, (4) terephthalic acid and isophthalic acid And (5) mixtures of the glycols and (i) terephthalic acid, isophthalic acid and sebacic acid and (ii) copolyesters made from terephthalic acid, isophthalic acid, sebacic acid and adipic acid), poly N-vinylcarbazole And its copolymer, polycarbonate comprising carbonate and bisphenol And the like.

Preferable examples include poly (methylphenylsiloxane), silicon compounds such as 1,3,5-trimethyl-1,1,3,5,5-pentaphenyltrisiloxane, silicon oil containing a large amount of aromatics, and the like. .
In addition, an epoxy oligomer compound containing a large amount of aromatics can also be used as a high refractive index reactive binder.

  More preferably, the refractive index is any of a poly (styrene-acrylonitrile) copolymer, a poly (styrene-methyl methacrylate) copolymer, and polystyrene, most preferably as a binder of the present invention when the polymerizable compound <the binder. Is a poly (styrene-acrylonitrile) copolymer. The copolymerization ratio (mass ratio) may be any number, but is most preferably 75:25.

  In the cationic polymerization photopolymer hologram recording material of the present invention, the mass ratio of the cationic polymerizable monomer to the binder is preferably 5 to 100%, more preferably 10 to 30%.

  The cationically polymerizable monomer of the present invention is a commercial product or can be synthesized by a known method.

  The acid generator (polymerization initiator) used for interference fringe recording by the cationic polymerization reaction of the present invention is preferably a diaryliodonium salt, a sulfonium salt, a diazonium salt, a metal arene complex, a trihalomethyl-substituted triazine, a sulfonic acid ester or an imide sulfonate. More preferred are diaryliodonium salts and sulfonium salts.

  Specific preferred examples of the acid generator of the present invention include the examples described in JP-A No. 2005-99753.

  Specific examples of preferred acid generators in the present invention are listed below, but the present invention is not limited thereto.

  The acid generator of the present invention is a commercially available product or can be synthesized by a known method.

The cationic polymerization photopolymer hologram recording material of the present invention preferably further contains an alcohol represented by the general formula (5) for the purpose of improving sensitivity and diffraction efficiency.
In the general formula (5), R ₄₁ represents an alkyl group or an aryl group (preferred examples are the same as the examples given for R ₂₁ ), more preferably an alkyl group, and still more preferably 1 to 12 carbon atoms. Represents an alkyl group, most preferably a hexyl group.
R _{42 to} R ₄₅ each independently represent a hydrogen atom or a methyl group, preferably a hydrogen atom.
n1 represents an integer of 1 to 10, preferably an integer of 1 to 4, and more preferably 2.

  Although the preferable specific example of the alcohol of this invention represented by General formula (5) below is shown, this invention is not limited to this.

  The alcohol of the present invention is a commercially available product or can be synthesized by a known method.

In the cation polymerization photopolymer hologram recording material of the present invention, in addition to the cation polymerizable monomer, acid generator, binder, sensitizing dye, alcohol, etc., before the addition of acid, the hologram recording wavelength has no absorption, and the hologram It is also possible to include a “sensitizing dye-providing dye precursor” that is colored by addition of an acid generated from an acid generator during recording and can be a sensitizing dye having absorption at the hologram recording wavelength. It is preferable for the purpose of compensating for the sensitivity and the diffraction efficiency decrease due to decomposition.
The “sensitizing dye supplying dye precursor” is preferably a cyanine-based dye precursor, and the cyanine-based dye precursor is more preferably represented by the general formula (6-1) or (6-2).

In general formulas (6-1) and (6-2), X ₁ and X ₂ are each independently -S-, -O-,
—NR ₈₃ — or —CR ₈₄ R ₈₅ —, wherein R _{83 to} R ₈₅ each independently represents any of a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and a heterocyclic group. (The above preferred examples are the same as the examples given for R ₂₁ ), and more preferably an alkyl group. R ₈₃ and R ₈₄ may be connected to each other to form a ring, and the ring formed is preferably a cyclohexane ring or a cyclopentane ring.
In the general formula (6-1), R ₇₅ is an alkyl group, alkenyl group, cycloalkyl group, aryl group or heterocyclic group (preferred examples are the same as those listed for R _30), preferably Represents an alkyl group.
In General Formula (6-1), R _{71 to} R ₇₄ each independently represent a hydrogen atom or a substituent (preferred examples are the same as the examples given for R ₃₀ ), preferably a hydrogen atom, an alkyl group, an alkenyl group, Represents an aryl group.
In General Formula (6-1), L ₁₁ and L ₁₂ each independently represent a single bond or a double bond. a71~a74 each independently represent 1 or _2, when _{L 11} is a single bond a71, a72 represents 2, and when _{L 1} is a double bond a71, a72 represents _{1, L 12} is a single A73 and a74 represent 2 when bonded, a73 and a74 represent 1 when L ₁₂ is a double bond, and when a71 to a74 are 2, a plurality of R _{71 to} R ₇₄ may be the same or different good. R ₇₁ and R ₇₂ , R ₇₃ and R ₇₄ may be linked to form a ring, and the ring formed is preferably a benzene ring, a naphthalene ring, or a pyridine ring.
In general formula (6-1), R ₇₆ , R ₇₇ and R ₇₈ represent a hydrogen atom or a substituent (preferred examples are the same as the examples given for R ₃₀ ), preferably a hydrogen atom, an alkyl group, an alkenyl group, An aryl group, a heterocyclic ring, or a halogen atom is represented, more preferably a hydrogen atom or an alkyl group.
In General Formula (6-1), n3 represents an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

In general formula (6-2), Z ₁ represents an atomic group forming a 5- or 6-membered ring, and the 5- or 6-membered ring formed is preferably a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, or a quinoline ring. , Pyrrolidine ring, piperidine ring, morpholine ring, pyrrole ring, imidazole ring, benzimidazole ring, imidazoline ring, triazole ring, benzotriazole ring, indolenine ring, thiazole ring, benzothiazole ring, thiazoline ring, oxazole ring, benzoxazole ring Oxazoline ring, more preferably pyridine ring, quinoline ring, imidazole ring, benzimidazole ring, imidazoline ring, indolenine ring, thiazole ring, benzothiazole ring, thiazoline ring, oxazole ring, benzoxazole ring, oxazoline ring, Represents and even better Preferably, it represents a thiazole ring, a benzothiazole ring, a thiazoline ring, an oxazole ring, a benzoxazole ring, or an oxazoline ring.
In general formula (6-2), R ₇₉ and R ₈₀ each independently represent a hydrogen atom or a substituent, and preferred examples are the same as those given for R ₃₀ , preferably a hydrogen atom, an alkyl group, An alkenyl group, an aryl group, a heterocycle, and a halogen atom are represented, more preferably a hydrogen atom or an alkyl group, and most preferably a hydrogen atom.
In the general formula _{(6-2), R 81, R} 82 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, an acyl group (preferred examples for _{R 30} The same as the examples given), more preferably an alkyl group or an alkyl group substituted by an alkoxycarbonyl group (preferably, for example, ethoxycarbonylmethyl, hexyloxycarbonylmethyl, octyloxycarbonylmethyl, octyloxycarbonylpropyl). R ₈₁ and R ₈₂ may combine with each other to form a ring, and preferred examples of the ring formed include a pyrrolidine ring, a piperidine ring, and a morpholine ring.
In general formula (6-2), n1 represents the integer of 1-4, Preferably 1 or 2 is represented, More preferably, 1 is represented.

  Specific examples of the cyanine-based dye precursor as the “sensitizing dye supplying dye precursor” in the present invention are shown below, but the present invention is not limited thereto.

  The cyanine-based dye precursor of the present invention can be synthesized by a known method.

  In addition to the sensitizing dye, acid generator, cation polymerizable monomer, binder, alcohol, sensitizing dye supplying dye precursor, etc., the hologram recording material of the present invention further has an electron donating property as required. Additives such as a compound, an electron accepting compound, a crosslinking agent, a plasticizer, and a solvent can be used.

The electron-donating compound has the ability to reduce the radical cation of the sensitizing dye, and the electron-accepting compound has the ability to oxidize the radical anion of the sensitizing dye, together with the function of regenerating the sensitizing dye color former. . Specifically, for example, an example described in JP-A-2005-99751 can be given as a preferable example.
In particular, the electron donating compound is useful for high sensitivity because it can quickly regenerate the radical cation of the sensitizing dye after electron transfer to the acid generator. As the electron donating compound, those having an oxidation potential lower than that of the sensitizing dye are preferable. Preferred specific examples of the electron donating compound are listed below, but the present invention is not limited thereto.

  Especially as an electron-donating compound, a phenothiazine type compound (for example, 10-methylphenothiazine, 10- (4′-methoxyphenyl) phenothiazine), a triphenylamine type compound (for example, triphenylamine, tri (4′-methoxyphenyl) amine) , TPD compounds (for example, TPD) are preferable, and phenothiazine compounds are more preferable.

  Preferable examples of the crosslinking agent, plasticizer, solvent and the like include the examples described in JP-A-2005-99753.

  The plasticizer is used to change the adhesiveness, flexibility, hardness, and other mechanical properties of the hologram recording material. Examples of the plasticizer include triethylene glycol dicaprylate, triethylene glycol bis (2-ethylhexanoate), tetraethylene glycol diheptanoate, diethyl sebacate, dibutyl suberate, tris (2-ethylhexyl) phosphate, Examples include tricresyl phosphate, dibutyl phthalate, alcohols, and phenols.

The hologram recording material of the present invention may be prepared by a usual method.
For example, as a method for forming a hologram recording material of the present invention, the above binder and each component may be dissolved in a solvent and applied using a spin coater or a bar coater.
In that case, preferably as a solvent, for example, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, acetone, cyclohexanone, ester solvents such as ethyl acetate, butyl acetate, ethylene glycol diacetate, ethyl lactate, cellosolve acetate, cyclohexane, toluene, Hydrocarbon solvents such as xylene, ether solvents such as tetrahydrofuran, dioxane, diethyl ether, cellosolv solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, dimethyl cellosolve, methanol, ethanol, n-propanol, 2-propanol, n- Alcohol solvents such as butanol and diacetone alcohol, fluorine solvents such as 2,2,3,3-tetrafluoropropanol, dichloromethane, chloroform , 1,2-halogenated hydrocarbon solvents such as dichloroethane, N, amide solvents such as N- dimethylformamide, acetonitrile, and nitrile-based solvents such as propionitrile.

The hologram recording material of the present invention can be applied directly on the substrate by using a spin coater, roll coater, bar coater or the like, or cast as a film and then laminated on the substrate by a usual method. It can be a hologram recording material.
Here, “substrate” means any natural or synthetic support, preferably one that can exist in the form of a flexible or rigid film, sheet or plate.
Preferred examples of the substrate include polyethylene terephthalate, resin-primed polyethylene terephthalate, polyethylene terephthalate subjected to flame or electrostatic discharge treatment, cellulose acetate, polycarbonate, polymethyl methacrylate, polyester, polyvinyl alcohol, and glass.
The solvent used can be removed by evaporation during drying. Heating or reduced pressure may be used for evaporation removal.

The hologram recording material of the present invention may be formed by melting a binder containing each component at a temperature equal to or higher than the glass transition temperature of the binder or a melting point, and melt-extrusion or injection molding. At that time, a reactive cross-linking binder may be used as the binder, and the film may be cured by cross-linking after extrusion or molding to increase the film strength. In that case, radical polymerization reaction, cationic polymerization reaction, condensation polymerization reaction, addition polymerization reaction, etc. can be used for the crosslinking reaction. In addition, methods described in JP-A Nos. 2000-250382 and 2000-172154 can also be preferably used.
In addition, a method in which each component is dissolved in a monomer solution forming a binder and then the monomer is thermally polymerized or photopolymerized to form a polymer, which is preferably used as a binder. As a polymerization method at that time, a radical polymerization reaction, a cationic polymerization reaction, a condensation polymerization reaction, an addition polymerization reaction, or the like can be used.

  Furthermore, a protective layer for blocking oxygen may be formed on the hologram recording material. The protective layer is made of a plastic film or plate such as polyolefin such as polypropylene or polyethylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate or cellophane film by electrostatic adhesion or lamination using an extruder. Alternatively, the polymer solution may be applied. Further, a glass plate may be bonded. Further, an adhesive or a liquid substance may be present between the protective layer and the photosensitive film and / or between the base material and the photosensitive film in order to improve airtightness.

When the hologram recording material of the present invention is used for holographic optical memory applications, it is more preferable that the hologram recording material does not shrink before and after hologram recording from the viewpoint of improving the S / N ratio during signal reproduction.
Therefore, for example, an expansion agent described in JP-A-2000-86914 is used for the hologram recording material of the present invention, or a shrink-resistant binder described in JP-A-2000-250382, 2000-172154, and JP-A-11-344917 is used. It is also preferable to use it.
In addition, it is also preferable to adjust the interference fringe interval by using a diffusing element described in JP-A-3-46687, 5-204288, JP-A-9-506441 and the like.

  As described above, the hologram recording material of the present invention can solve the above-mentioned problems drastically, and can particularly achieve both high diffraction efficiency and low shrinkage, dry processing, multiple recording characteristics (high recording density), and good storage stability. It provides a completely new recording method, and is particularly preferably used for an optical recording medium (holographic optical memory).

  When the hologram recording material of the present invention is used as an optical recording medium, the medium configuration described in Japanese Patent Application Laid-Open No. 2004-265472 may be used, and recording and reproduction are performed using the system described in Japanese Patent Application Laid-Open No. 2004-335044. It is also preferable. It is also preferable to perform recording / reproduction using a system described in JP-A Nos. 2004-177958 and 2004-272268.

  In addition to the optical recording medium, the hologram recording material of the present invention includes a three-dimensional display hologram, a holographic optical element (HOE, for example, a head-up display (HUD) mounted on an automobile, a pickup lens for an optical disk, a head mount. Displays, color filters for liquid crystals, reflective liquid crystal reflectors, lenses, diffraction gratings, interference filters, optical fiber couplers, optical polarizers for facsimiles, architectural window glass), covers for books, magazines, displays such as POPs, It can be preferably used for credit cards, banknotes, packaging and the like for security purposes for preventing gifts and counterfeiting.

[Example]
In the following, specific examples of the present invention have been described based on experimental results. Of course, the present invention is not limited to these examples. In addition, the sample using LE-1-9 as a cation polymerizable monomer is a reference example.

[Hologram recording using the cationic polymerization photopolymer hologram recording material of the present invention]

  Under red light, the sensitizing dye, cationic polymerizable monomer, binder, alcohol, and sensitizing dye supplying dye precursor shown in Table 1 were dissolved in 3 to 4 times the mass of methylene chloride, stirred, and further acidified. The generator was dissolved in 15% by mass of acetonitrile in methylene chloride, added, and stirred to prepare compositions for hologram recording material 101-124. Binder CAB represents cellulose acetate butyrate (CAB + 531-1 manufactured by Eastman Kodak Company), and binder PS-AN represents a poly (styrene-25% wt acrylonitrile) copolymer (Mw165000, manufactured by ACROS).

  The composition for hologram recording material 101 to 124 is applied to a glass substrate with a blade so that the thickness is about 80 μm (overcoat if necessary) to form a photosensitive layer, and then dried at 40 ° C. for 3 minutes. The solvent was distilled off. Further, hologram recording materials 101 to 124 were produced by covering the photosensitive layer with a TAC film with a hard coat layer.

  Further, according to Example 2 of JP-T-11-512847, sensitizing dye S-57 1.33 mg, iodonium salt I-13 0.133 g, cation polymerizable monomer M-1 2.0 g, polysiloxane binder B- 1 0.667 g (Dow 710 manufactured by Dow Chemical Co., Ltd.) was dissolved in 0.397 g of methylene chloride. Thereafter, a known cationic polymerization photopolymer hologram recording material was prepared in the same manner as the sample of the present invention. The film thickness was also adjusted to 80 μm.

The hologram recording material was exposed and recorded using a YAG laser double wave (532 nm, output 2 W) as a light source by the two-beam optical system for transmission hologram recording shown in FIG. The angle between the object beam and the reference beam is 30 degrees. The beam has a diameter of 0.6 cm and an intensity of 8 mW / cm ² , and the holographic exposure time varies from 0.1 to 800 seconds (irradiation energy ranges from 0.8 to 6400 mJ / cm ² ). And exposed. While exposing the hologram, a He—Ne laser beam of 632 nm was passed through the center of the exposure region at a black angle, and the ratio of the diffracted light to the incident light (absolute diffraction efficiency) was measured in real time. In addition, since there is no absorption of a sensitizing dye at 632 nm, the He—Ne laser does not expose the hologram recording material.

  Table 2 shows the evaluation results of the maximum diffraction efficiency and the shrinkage rate in the hologram recording materials 101 to 124 and Comparative Example 1. The shrinkage rate was obtained from the change rate of the maximum diffraction wavelength in the reflection hologram.

From Table 2, the cationic polymerization photopolymer recording material of the present invention has a higher diffraction efficiency than the comparative example 1 described in JP-A-11-512847, which is advantageous for holographic memory applications and 3D display hologram applications. .
Further, the shrinkage rate is small, and it can be seen that it is advantageous in terms of multiple recording and S / N in holographic memory applications.

  Next, using the cationic polymerization hologram recording material according to the present invention, the multiple holograms are repeated 10 times at the same place by changing the angle of the reference light by 1 degree with the light amount of 1/10 of the exposure amount giving the maximum diffraction efficiency. After recording, it was confirmed that it was possible to reproduce each object light while maintaining the diffraction efficiency by changing the angle of the reproduction light by 1 degree and irradiating. On the other hand, when the same thing was done in Comparative Example 1, it was found that the diffraction efficiency during reproduction was considerably lowered. This is presumably because the film of the binder of Comparative Example 1 is liquid and the film is too soft and it is difficult to hold the record during multiple recording.

  From the above, since the hologram recording material of the present invention has good multiplex recording characteristics, more multiplex recording is possible and high density (capacity) recording is considered possible.

Furthermore, the hologram recording materials 101 to 124 and the comparative hologram recording material 1 of the present invention were stored in the dark for 5 days under the condition of 80 ° C. dry after the hologram recording, and then the diffraction efficiency was measured again. Table 3 below shows the residual ratios of diffraction efficiency after storage at 80 ° C. for 5 days with respect to fresh diffraction efficiency.

  From Table 3, it is considered that Comparative Example 1 has poor record storage, because the binder is liquid and soft and the thermal stability of the cationic polymerizable monomer and its polymer is poor. It can be seen that the cationic polymerization hologram recording material of the invention is very excellent in storage stability and is advantageous in holographic memory applications and 3D display hologram applications.

In samples 101 to 124, sensitizing dyes were SS-1, SS-5, SS-13, SS-16, SS-19 to SS-21, SS31 to SS-41, SS-47, SS. -48, S-1 to S-3, S-8, S-10, S-11, S-50, S-58, S-75, S-79, S-86, the same effect can be obtained. Obtained.
Further, in Samples 101 to 124, the acid generator is changed to I-2 to I-14, I-21 to I-25, PI-2 to PI-17, and PI-28 to PI-45. The effect was obtained.
Moreover, even if it changed alcohol into AA-1, AA-2, AA-5, AA-6, AA-11, and AA-12 in the samples 101-124, the same effect was acquired.
Further, in the samples 101 to 110, even when the cationic polymerizable monomer is changed to HE-2 to HE-8 or HE-12, or even when OX-1, OX-2, or OX-4 is further added. The effect was obtained.
In Samples 114 to 120, the same effect was obtained even when OX-5 to OX-7 were used instead of the cationic polymerizable monomer OX-4.

It is the schematic explaining the two-beam optical system for hologram exposure.

Explanation of symbols

10 YAG laser 12 Laser beam 14 Mirror 20 Beam splitter 22 Beam segment 24 Mirror 26 Spatial filter 28 Sample 30 Hologram recording material 32 He-Ne laser beam 34 He-Ne laser 36 Detector 38 Rotating stage 40 Beam expander

Claims (18)

A cationically polymerizable photopolymer hologram recording material comprising at least a cationically polymerizable monomer represented by the following general formula (1-1), an acid generator, and a binder.

In General Formula (1-1), R _{1 to} R ₆ each independently represent a hydrogen atom or an alkyl group, and L ₁ represents a divalent linking group. The cationically polymerizable photopolymer hologram recording according to claim 1, wherein the cationically polymerizable monomer represented by the general formula (1-1) is represented by the general formula (1-2) or (1-3). material.

In General Formula (1-2), L ₂ represents an alkylene group or an arylene group, and in General Formula (1-3), L ₃ represents an alkylene group or an arylene group. In addition to the cationic polymerizable monomer represented by the general formulas (1-1) to (1-3), the cationic polymerizable monomer represented by the general formula (2-1) is used in combination. The cationic polymerization photopolymer hologram recording material according to claim 1 or 2.

In general formula (2-1), L ₄ represents a mere bond or a divalent linking group, n1 is 0 when L ₄ is a mere bond, and 1 when L ₄ is a divalent linking group. Represents. 4. The cationic polymerization photopolymer hologram recording material according to claim 1 , wherein the binder is any of a copolymerized polymer including acylated cellulose, polymethyl methacrylate, or polymethyl methacrylate . 5. Boiled claim 1, cationically polymerizable photopolymer hologram recording material according to any one of claims 1 to 4, wherein the weight ratio of the cationically polymerizable monomer to binder is from 5 to 100%. At claim 5, cationically polymerizable photopolymer hologram recording material according to claim 5, wherein the weight ratio of the cationically polymerizable monomer to binder is 10 to 30%. Similar Claim 1, an acid generator is a diaryliodonium salt, a sulfonium salt, claim diazonium salts, metal arene complex, trihalomethyl-substituted triazine, characterized in that either a sulfonate ester or imide sulfonates 1-6 The cationic polymerization photopolymer hologram recording material according to any one of the above. Cationic polymerization photopolymer hologram recording material according to claim 7, wherein the acid generator in claim 7 is a diaryl iodonium salt or sulfonium salt. Boiled claim 1, cationically polymerizable monomer, an acid generating agent, in addition to the binder, a sensitizing dye having absorption in the wavelength of hologram recording, said sensitizing dye is Formula (4-1) to (4 The cationic polymerization photopolymer hologram recording material according to any one of claims 1 to 8, which is represented by any one of (-6).

In general formulas (4-1) to (4-5), R ₂₁ , R ₂₂ , R ₂₄ , R ₂₅ , R ₂₆ , R ₂₇ , and R ₃₄ are each independently a hydrogen atom, an alkyl group, an alkenyl group, a cyclo Represents an alkyl group or an aryl group, and R ₂₄ and R ₂₅ may combine with each other to form a ring, and R ₂₃ , R ₃₂ , and R ₃₃ each independently represent an alkyl group, an alkenyl group, a cycloalkyl group, an aryl Represents a group.
In general formula (4-4), R ₂₈ and R ₂₉ each independently represents an alkyl group, an alkenyl group, a cycloalkyl group, or an aryl group. R ₂₈ and R ₂₉ may be connected to each other to form a ring.
In general formulas (4-5) and (4-6), R ₃₀ , R ₃₁ , R ₃₅ , and R ₃₆ each independently represent a substituent, and a30, a31, a35, and a36 each independently represent 0 to 4 Represents an integer. When a30 and a31 are 2 or more, the plurality of R ₃₀ and R ₃₁ may be the same or different, and may be connected to each other to form a ring. When a35 and a36 are 2 or more, the plurality of R ₃₅ and R ₃₆ may be the same or different, and may be connected to each other to form a ring. The a35, a36 when the one or more _{together, R 35} and _{R 36} may combine with each other to form a ring. CI represents an ion for neutralizing the charge, and y represents a number necessary for neutralizing the charge. The cationic polymerization photopolymer hologram recording material according to claim 9, wherein in the general formula (4-4), R ₂₈ is an alkyl group substituted with an electron withdrawing group. Boiled claim 1, 9, cationic polymerization photopolymer hologram recording material according to any one of claims 1 to 10, further comprising an alcohol represented by general formula (5).

In General Formula (5), R ₄₁ represents an alkyl group or an aryl group, and R _{42 to} R ₄₅ each independently represent a hydrogen atom or a methyl group. n3 represents an integer of 1 to 10. In claim 9 , in addition to the cation polymerizable monomer, acid generator, binder, and sensitizing dye, the acid generated from the acid generator at the time of hologram recording does not have absorption at the hologram recording wavelength before the acid is added. colored by adding, in any one of claims 9-11, characterized in that it comprises a "sensitizing dye supply dye precursor" which may be a sensitizing dye having absorption in the wavelength of hologram recording The cationic polymerization photopolymer hologram recording material as described. Claim 12, wherein the at claim 12 "sensitizing dye supply dye precursor" is a cyanine-based dye precursor represented by the following general formula (6-1) or (6-2) Cationic polymerization photopolymer hologram recording material.

In general formulas (6-1) and (6-2), X ₁ and X ₂ each independently represent any of —S—, —O—, —NR ₈₃ —, —CR ₈₄ R ₈₅ —, and R _{83 to} R ₈₅ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a heterocyclic group, and R ₈₄ and R ₈₅ may be linked to each other to form a ring. . R ₇₅ represents any of an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and a heterocyclic group, R _{71 to} R ₇₄ each independently represent a hydrogen atom or a substituent, and L ₁₁ and L ₁₂ are each independently Represents a single bond or a double bond. a71~a74 each independently represent 1 or _2, when _{L 11} is a single bond a71, a72 represents 2, and when _{L 1} is a double bond a71, a72 represents _{1, L 12} is a single A73 and a74 represent 2 when bonded, a73 and a74 represent 1 when L ₁₂ is a double bond, and when a71 to a74 are 2, a plurality of R _{71 to} R ₇₄ may be the same or different good. R ₇₁ and R ₇₂ , R ₇₃ and R ₇₄ may be linked to form a ring. _{R 76,} R 77, R ₇₈ represents a hydrogen atom or a substituent, n3 denotes an integer of 0 to 3.
In General Formula (6-2), Z ₁ represents an atomic group forming a 5- or 6-membered ring, R ₇₉ and R ₈₀ each independently represent a hydrogen atom or a substituent, and R ₈₁ and R ₈₂ each independently Represents a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, or an acyl group, and R ₈₁ and R ₈₂ may be linked to each other to form a ring. n4 represents an integer of 1 to 4. By using a hologram recording material according to any one of claims 1 to 13, wherein the sulfo program recording method that performs 10 times more multiple recording. An optical recording medium comprising the cationic polymerization photopolymer hologram recording material according to any one of claims 1 to 13 . An optical recording medium, wherein the cationic polymerization photopolymer hologram recording material according to any one of claims 1 to 13 is stored in a light-shielding cartridge at the time of storage. A three-dimensional display hologram using the cationic polymerization photopolymer hologram recording material according to any one of claims 1 to 13 . A holographic optical element using the cationic polymerization photopolymer hologram recording material according to any one of claims 1 to 13 .

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