JP2007101935A - Composition for hologram recording medium, hologram recording medium, hologram recording method, and hologram reproduction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for a hologram high density recording medium having high sensitivity for high speed recording, dry processing, facilitating manufacture and handling, consuming silver halide by a small amount, and preventing print-out; and to provide a hologram recording medium, a hologram recording method, and a hologram reproduction method therefor. <P>SOLUTION: The composition for the hologram recording medium includes at least (A) a binder having a reactive group, (B) a crosslinking agent having a functional group reacted with the reactive group of the binder having the reactive group, (C) a polimerization compound having ethylene double coupling in a molecule, (D) silver halide, and (E) a reducing agent. The hologram recording medium, the hologram recording method and the hologram reproduction method are provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is capable of high-sensitivity and high-speed recording, is capable of dry processing, is easy to manufacture and handle, uses a small amount of silver halide, prevents print-out, and records at high density. The present invention relates to a hologram recording medium composition that can be used, a hologram recording medium using the hologram recording medium composition, an efficient hologram recording method using the hologram recording medium, and a hologram reproducing method.

  An optical recording medium is one of recording media capable of writing a large amount of information such as high-density image data. As this optical recording medium, for example, a rewritable optical recording medium such as a magneto-optical disk and a phase change optical disk and a write-once optical recording medium such as a CD-R have already been put into practical use. The demand for larger capacity is increasing. However, all conventionally proposed optical recording media are two-dimensional recording, and there is a limit to increasing the recording capacity. Therefore, recently, a hologram type optical recording medium capable of recording information three-dimensionally has attracted attention.

In general, the hologram type optical recording medium is formed by superimposing information light given a two-dimensional intensity distribution and information light and reference light having a substantially constant intensity inside a photosensitive recording layer. Information is recorded by generating a distribution of optical characteristics inside the recording layer using an interference pattern. On the other hand, when reading (reproducing) written information, the recording layer is irradiated with only the reference light in the same arrangement as during recording, and the reproduction has an intensity distribution corresponding to the optical characteristic distribution formed inside the recording layer. Light is emitted from the recording layer as light.
In this hologram type optical recording medium, since the optical characteristic distribution is three-dimensionally formed in the recording layer, an area where information is written by one information light, an area where information is written by other information light, and Can be partially overlapped, that is, multiple recording can be performed. When digital volume holography is used, the signal-to-noise ratio (S / N ratio) of one spot is extremely high, so that the original information can be faithfully reproduced even if the S / N ratio is somewhat lowered by overwriting. As a result, the number of times of multiple recording reaches several hundreds, and the recording capacity of the optical recording medium can be remarkably increased (see Patent Document 1).

  As such a hologram type optical recording medium, for example, as shown in FIG. 1, a servo pit pattern 3 is provided on the surface of the lower substrate 1, and a reflective film 2 made of aluminum or the like is provided on the surface of the servo pit pattern. One having a recording layer 4 on the reflective film 2 and an upper substrate 5 on the recording layer 4 has been proposed (see Patent Document 2).

However, the optical recording medium 20 having the configuration shown in FIG. 1 has a problem that the servo zone and the recording zone are separated in the plane, and the recording density is halved accordingly.
Therefore, in Patent Document 3, circularly polarized light is used as information light and reference light, a cholesteric liquid crystal layer or dichroic mirror as a filter layer is provided between the recording layer and the reflective film, and the recording layer and the servo layer are arranged in the thickness direction. It is piled up. This technique doubles the recording density. In addition, when a single-layer cholesteric liquid crystal layer having the same rotation direction as the circular polarization of information light in a spiral structure is used as the filter layer, it is excellent in productivity and enables mass production of an optical recording medium at a low cost. The filter effect at 0 ° is good. However, in this proposal, when the incident angle changes, the selective reflection wavelength shifts. When the incident light is tilted by 10 ° or more, the information light and the reference light pass through the filter layer and reach the reflection film and are reflected, and noise is generated. Arise. This means that it cannot be used for the incident light of the lens optical system in a normal optical recording medium of ± 10 ° or more that is narrowed by the lens.
Further, the filter using the cholesteric liquid crystal layer is a technique suitable for mass production because the production cost can be kept low. However, this filter composed of a cholesteric liquid crystal layer can sufficiently reflect when the writing light or the reading light (350 to 600 nm) is only circularly polarized light, but the reflectivity is changed when the recording system design is changed to linearly polarized light or ordinary light. Falls to a minimum of 20%, and there is a problem that the amount of leaked light increases.
On the other hand, when a film capable of supporting the normal lens optical system is designed using the dichroic mirror, multilayer deposition of 50 layers or more is required, resulting in an extremely high cost optical recording medium.
Therefore, even if the incident angle changes, the selective reflection wavelength does not shift, and the hologram light that can prevent irregular reflection from the reflection film of the optical recording medium by the information light and the reference light and prevent the generation of noise. Efficient mass production of optical recording media at low cost has not yet been realized, and the immediate provision of such optical recording media is desired.

In addition, as a material of the optical recording medium, a radical polymerization monomer and a binder polymer, a radical photopolymerization initiator, a sensitizing dye as main components, and a material using a difference in refractive index between the radical polymerization monomer and the binder polymer are known. In addition, since the production is performed by solvent coating, it is difficult to ensure a sufficient film thickness of the hologram recording layer.
From the viewpoint of ensuring a sufficient thickness, a photopolymer containing an NCO-terminated prepolymer and a polymer matrix precursor such as a polyol and further containing a photopolymerization initiator has been proposed (see Patent Document 4). .
However, since a high-power laser is used for hologram recording, the recording apparatus becomes expensive. From the viewpoint of improving the recording speed and efficiency, it is desirable that exposure can be performed with a low-power laser. There is a problem that takes a long time, and a highly sensitive material is demanded.
From the viewpoint of increasing the sensitivity, there has been a proposal focusing on the selection and combination of a binder, a polymerizable monomer, a sensitizing dye, and a radical initiator (see Patent Document 5). In this proposal, by using a specific photopolymerization start containing a cationic dye, radicals are generated efficiently and high sensitivity is attempted.
In addition, as a photosensitive material for photoresists with high sensitivity, a proposal has been made that microcapsules containing silver halide, a reducing agent, a polymerizable compound, and the like are contained in a photosensitive layer (see Non-Patent Document 1). ). In this case, after exposing the photosensitive layer to form a latent image on the silver halide, the latent image forming portion reacts with a reducing agent and silver halide to generate a polymerization initiator, thereby polymerizing the polymerizable compound. By doing so, an image is formed. Thereafter, the image forming material is transferred from the photosensitive material to the image receiving material by pressurization while being superimposed on the image receiving material. Moreover, in patent document 6, a polymeric compound is polymerized on an image by developing the silver halide exposed with the developing solution, and a polymer image is formed. In this case also, during the development, the polymerization of the polymerizable compound is initiated by the oxidant radical of the reducing agent obtained by reducing the silver halide.
However, in these cases, the pressing process and the wet process are performed for the development and the fixing process of the image as described above, and thus, it is not suitable for the image recording on the hologram recording medium.
Patent Document 7 proposes a composition for a hologram recording medium that is highly sensitive and can be dry-processed. However, in this case, since recording is performed by density modulation formed by reduced silver, unlike a photopolymer material that forms refractive index modulation, it is difficult to form a thick film volume hologram that can increase the capacity. However, since a large amount of silver halide is used, there is a problem that light fog is likely to occur.
Therefore, high-sensitivity and high-speed recording is possible, dry processing is possible, manufacturing and handling are easy, and only a small amount of silver halide is used, preventing printout and high-density recording. Holographic recording medium composition, holographic recording medium using the holographic recording medium composition, low-cost and efficient holographic recording method using the holographic recording medium, holographic reproducing method, and holographic recording Holograms recorded by the method have not yet been provided, and the present situation is that further improvement and development are desired.

JP 2002-123949 A Japanese Patent Laid-Open No. 11-311936 JP 2004-265472 A JP-T-2004-537620 JP 2004-287138 A JP 7-28246 A JP 2001-305938 A Aztec Co., Ltd. Known Technology No. 5 (issued March 22, 1991)

  An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention is capable of high-sensitivity and high-speed recording, can be dry-processed, is easy to manufacture and handle, requires a small amount of silver halide, prevents printouts, Composition for hologram recording medium capable of density recording, hologram recording medium using the composition for hologram recording medium, and low-cost and efficient hologram recording method, hologram reproducing method using the hologram recording medium, Another object is to provide a hologram recorded by the hologram recording method.

Means for solving the problems are as follows. That is,
<1> (A) a binder having a reactive group, (B) a crosslinking agent having a functional group capable of reacting with the reactive group of the binder having the reactive group, and (C) an ethylenic double bond in the molecule. A hologram recording medium composition comprising at least a polymerizable compound having (D) a silver halide and (E) a reducing agent.
In the composition for hologram recording medium according to <1>, silver halide forms a photosensitive nucleus by exposure, and a series of reactions of a reducing agent is generated, whereby active radicals are generated, and polymerization of a polymerizable monomer is performed. Be started. A hologram image is formed by polymerizing the polymerizable monomer. Therefore, high-sensitivity and high-speed recording is possible, dry processing is possible, manufacturing and handling are easy, and only a small amount of silver halide is used, preventing printout and high-density recording. A composition for a holographic recording medium can be obtained, and an efficient and high-density holographic recording becomes possible.
<2> (E) The hologram recording medium composition according to <1>, wherein the reducing agent generates radicals by an oxidation reaction.
<3> (E) The hologram recording medium composition according to any one of <1> to <2>, wherein the reducing agent is a hydrazine compound.
<4> The hologram recording medium composition according to any one of <1> to <3>, including a base precursor.
<5> The composition for a hologram recording medium according to any one of <1> to <4>, comprising an antifoggant precursor.

<6> (A) The reactive group of the binder having a reactive group is selected from hydroxyl group, mercapto group, carboxyl group, amino group, epoxy group, oxetane group, isocyanate group, carbodiimide group, oxazine group, and metal alkoxide. The composition for a hologram recording medium according to any one of <1> to <5>, wherein the composition is at least one reactive group.
<7> (C) The composition for a hologram recording medium according to any one of <1> to <6>, wherein the content of the polymerizable compound having an ethylenic double bond in the molecule is 3 to 20% by mass. It is a thing.

<8> An optical recording medium comprising at least a substrate and a hologram recording layer comprising the hologram recording medium composition according to any one of <1> to <7>.
<9> The hologram recording medium according to <8>, wherein the hologram recording medium includes at least a wavelength selective reflection layer between a substrate and the hologram recording layer.
<10> The hologram recording medium according to any one of <8> to <9>, wherein the substrate has a servo pit pattern.
<11> The hologram recording medium according to <10>, wherein the substrate has a reflective surface formed on a servo pit pattern.
<12> The hologram recording medium according to any one of <9> to <11>, wherein the wavelength selective reflection layer is a layer formed of a dichroic mirror.
<13> The hologram recording medium according to any one of <9> to <12>, wherein the wavelength selective reflection layer is a layer made of cholesteric liquid crystal.
<14> The hologram recording medium according to any one of <11> to <13>, wherein a gap layer for smoothing the substrate surface is provided between the wavelength selective reflection layer and the reflection surface.

<15> The hologram recording medium according to any one of <8> to <14> is irradiated with information light and reference light as a coaxial light beam, and information is obtained by an interference pattern due to interference between the information light and the reference light. The hologram recording method is characterized by recording on a hologram recording layer.
In the hologram recording method of the present invention described in <15>, the hologram recording medium of the present invention is used to irradiate information light and reference light as a coaxial light beam, and interference due to interference between the information light and the reference light. By recording information on the hologram recording layer by a pattern, high-speed recording and unprecedented high-density recording can be realized.
<16> The hologram recording method according to <15>, wherein the laser beam having a wavelength of 300 to 1,200 nm and coherent light other than the laser beam are irradiated.
<17> The hologram recording method according to any one of <15> to <16>, wherein after the information is recorded on the hologram recording layer, the hologram recording layer is thermally developed.
<18> The hologram recording method according to <17>, wherein the heat development is performed by any one selected from laser light irradiation, infrared light irradiation, and contact with a heat roller.

<19> A hologram reproducing method, wherein information is reproduced by irradiating the interference pattern recorded on the hologram recording layer with reference light by the hologram recording method according to any one of <15> to <18>. is there.
In the hologram reproducing method of the present invention described in <19>, the interference recorded on the hologram recording layer by the hologram recording method on the hologram recording medium of the present invention using the composition for a hologram recording medium of the present invention. The pattern can be read efficiently and accurately to reproduce high-density recorded information.

  According to the present invention, conventional problems can be solved, high-sensitivity and high-speed recording is possible, dry processing is possible, manufacturing and handling are easy, and the use of silver halide is small, and printing is possible. Composition for hologram recording medium capable of high-density recording by preventing out-out, hologram recording medium using the composition for hologram recording medium, and low-cost and efficient hologram using the hologram recording medium A recording method, a hologram reproducing method, and a hologram recorded by the hologram recording method can be provided.

(Composition for hologram recording medium)
The volume hologram recording medium composition of the present invention has, as essential components, (A) a binder having a reactive group, and (B) a functional group capable of reacting with the reactive group of the binder having the reactive group. It contains at least a cross-linking agent, (C) a polymerizable compound having an ethylenic double bond in the molecule, (D) silver halide, and (E) a reducing agent, and, if necessary, additives and other components. Comprising.
<(A) Binder having reactive group>
The binder is used for the purpose of enhancing the effects of improving coating properties, film strength, and hologram recording characteristics.
The binder is preferably a compound that is liquid at room temperature or has a melting point of 100 ° C., and more preferably a compound that is liquid at room temperature or has a melting point of 50 ° C. or less. The hologram recording medium of the present invention is produced by sandwiching a recording composition that is liquid at room temperature or liquid at a temperature of 100 ° C. or less at a predetermined thickness between two substrates. It is preferable that the photopolymerization initiator described later can be prevented from being deteriorated by heat.
The reactive group of the binder having the reactive group is at least one selected from a hydroxyl group, a mercapto group, a carboxyl group, an amino group, an epoxy group, an oxetane group, an isocyanate group, a carbodiimide group, an oxazine group, and a metal alkoxide. It is preferably a reactive group of a species, and among these, a hydroxyl group, a mercapto group, an epoxy group, and an isocyanate group are particularly preferable.
By using a binder having such a reactive group, the crosslinking reaction between the binder and the crosslinking agent is promoted, and after the hologram recording medium is formed, the composition for the hologram recording medium can be prevented from flowing in the medium, and the hologram The recorded information after recording can be fixed.

  In addition, the hologram recording provides a refractive index difference between the holographic exposure part and the non-exposure part by diffusion polymerization of the monomer, so that a binder matrix formed from the binder and the cross-linking agent, and an ethylenic double bond in the molecule described later. It is preferable that there is a difference in refractive index from the polymerizable monomer having. Therefore, it is preferable that at least one of the binder and the cross-linking agent having a functional group capable of reacting with the reactive group of the binder is a compound having either a siloxane bond or a carbon-fluorine bond in the molecule. When a compound having a refractive index greater than about 1.50 is used as the polymerizable monomer having an ethylenic double bond, the difference in refractive index can be increased.

The binder is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, an unsaturated acid such as (meth) acrylic acid or itaconic acid, an alkyl (meth) acrylate, Copolymers with phenyl (meth) acrylate, benzyl (meth) acrylate, styrene, α-methylstyrene, etc .; polymers of alkyl methacrylate and alkyl acrylate represented by polymethyl methacrylate; (meth) acrylic acid Copolymers of alkyl and acrylonitrile, vinyl chloride, vinylidene chloride, styrene, etc .; Copolymers of acrylonitrile and vinyl chloride or vinylidene chloride; Cellulose modified products having a carboxyl group in the side chain; Polyethylene oxide, polypropylene oxide, polybutylene Polyalkylene oxides such as oxides; Rupyrrolidone; phenol, o-, m-, p-cresol, and / or novolak resin obtained by condensation reaction of xylenol with aldehyde, acetone, etc .; polyether of epichlorohydrin and bisphenol A; soluble nylon; Vinylidene chloride; chlorinated polyolefin; copolymer of vinyl chloride and vinyl acetate; polymer of vinyl acetate; copolymer of acrylonitrile and styrene; copolymer of acrylonitrile, butadiene and styrene; polyvinyl alkyl ether; Ketone; Polystyrene; Polyurethane; Polyethylene terephthalate isophthalate; Acetylcellulose; Acetylpropoxycellulose; Acetylbutoxycellulose; Nitrocellulose; Celluloid; Polyvinyl butyral; Epoxy tree Fats; melamine resins; formalin resins, polyurethane resins composed of polyhydric alcohols and polyisocyanates; polyurethane / urea resins composed of polyhydric alcohols, water, and polyisocyanates; organosiloxane polymers, and the like. In this specification, when referring to both or one of “acrylic and methacrylic”, it may be expressed as “(meth) acrylic”.
As content in the hologram recording layer of the said binder, 10-98 mass% is preferable in the total solid of a hologram recording layer, and 35-95 mass% is more preferable. When the content is less than 10% by mass, the recorded program image may be deteriorated with time, and when it is more than 98% by mass, the diffraction efficiency of the recorded hologram image is low and effective. Recording may not be possible.

<(B) Crosslinking agent having functional group capable of reacting with reactive group of binder having reactive group>
The crosslinking agent is not particularly limited as long as it can react with the reactive group possessed by the binder, and can be appropriately selected from known ones according to the purpose. In the case of having a group, a crosslinking agent having an isocyanate group, a carbodiimide group, a metal alkoxide, or the like is preferably exemplified. When the binder has a mercapto group, a crosslinking agent having an isocyanate group, a carbodiimide group, an epoxy group, or the like is used. When the binder has a carboxyl group, a crosslinking agent having an oxetane group, a carbodiimide group, an oxazine group, or a metal alkoxide is preferably used. When the binder has an amino group, an isocyanate group, an epoxy Group or acid anhydride Crosslinkers which are suitably mentioned, when the binder has an epoxy group, a mercapto group, an amino group, a crosslinking agent having a carboxyl group or a sulfonic acid group are preferably exemplified.
In addition, when the binder has an oxetane group, a crosslinking agent having a carboxyl group or a sulfonic acid group is preferably exemplified. When the binder has an isocyanate group, a hydroxyl group, a mercapto group, an amino group, or the like. When the binder has a carbodiimide group, a crosslinking agent having a hydroxyl group, a mercapto group, a carboxyl group or a sulfonic acid group is preferably exemplified, and the binder has an oxazine group. When it has, the crosslinking agent which has a carboxyl group or a sulfonic acid group etc. is mentioned suitably.
The cross-linking agent may have a functional group capable of reacting with a binder having a reactive group from the beginning, or the functional group is expressed by applying another energy such as heat or light. It may be a crosslinking agent such as a precursor.

In addition, these may be used individually by 1 type and may use 2 or more types together.
As content in the hologram recording layer of the said crosslinking agent, 0.1-70 mass% is preferable in the total solid of a hologram recording layer, and 0.5-50 mass% is more preferable. When the content is less than 0.1% by mass, the recorded hologram image may be significantly deteriorated over time, and even if the content exceeds 70% by mass, the crosslinking effect may not be improved. .
The crosslinking agent is preferably added so that the ratio of the reactive group of the binder to the reactive group of the crosslinking agent is 1: 0.5 to 1: 2, and is preferably 1: 1. More preferably.

<(C) Polymerizable compound having an ethylenic double bond in the molecule>
The polymerizable compound (hereinafter may be referred to as a polymerizable monomer) is not particularly limited as long as it is a compound having an ethylenic double bond, and can be appropriately selected from known compounds according to the purpose. However, in consideration of adhesion to the substrate and compatibility with the binder when the hologram recording medium is used, a compound having an acyloxy group or an acylamide group in the molecule is preferable, and further, a steric structure for radical polymerization is used. A compound having a (meth) acryloyl group is more preferable from the viewpoint of hindrance. The (meth) acryloyl group in the present invention represents an acryloyl group or a methacryloyl group.

Examples of the compound having the (meth) acryloyl group include, as a compound having one (meth) acryloyl group, (meth) acrylate of phenol, nonylphenol and 2-ethylhexanol, (meth) acrylamide, and alkylene of these alcohols. Examples thereof include (meth) acrylates and (meth) acrylamides of oxide adducts.
Examples of the compound having two (meth) acryloyl groups include di (meth) acrylates of bisphenol A, isocyanuric acid and fluorene, (meth) acrylamide, and di (meth) acrylates of alkylene oxide adducts of these alcohols, ( And (meth) acrylamide, di (meth) acrylate of polyalkylene glycol such as ethylene glycol and propylene glycol, (meth) acrylamide, and the like.
Examples of the compound having three (meth) acryloyl groups include tri (meth) acrylate, tri (meth) acrylamide of pentaerythritol, trimethylolpropane and isocyanuric acid, and tri (meth) of alkylene oxide adducts of these alcohols. Examples thereof include acrylate and tri (meth) acrylamide.
Examples of the compound having four or more (meth) acryloyl groups include pentaerythritol, poly (meth) acrylate of dipentaerythritol, poly (meth) acrylamide, and the like.
Also known are conventionally known acrylic or acrylamide monomers / oligomers such as urethane acrylates with urethane bonds as the main chain, polyester acrylates with ester bonds as the main chain, and epoxy (meth) acrylates obtained by adding acrylic acid to epoxy compounds. In the invention, it can be selected and used as appropriate.

  The compound having a plurality of (meth) acryloyl groups may have (meth) acrylate alone or (meth) acrylamide alone, or a compound having (meth) acrylate and (meth) acrylamide. It may be.

Specific examples of the polymerizable monomer include acryloylmorpholine, phenoxyethyl acrylate, isobornyl acrylate, 2-hydroxypropyl acrylate, 2-ethylhexyl acrylate, 1,6-hexanediol diacrylate, and tripropylene glycol diacrylate. Acrylate, neopentyl glycol PO-modified diacrylate, 1,9-nonanediol diacrylate, hydroxypivalate neopentyl glycol diacrylate, EO-modified bisphenol A diacrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, Pentaerythritol hexaacrylate, EO-modified glycerol triacrylate, trimethylol Lopantriacrylate, EO-modified trimethylolpropane triacrylate, 2-naphth-1-oxyethyl acrylate, 2-carbazoyl-9-ylethyl acrylate, (trimethylsilyloxy) dimethylsilylpropyl acrylate, vinyl-1-naphthoate, N-vinyl Preferred examples include carbazole, 2,4,6-tribromophenyl acrylate, pentabromophenyl acrylate, phenylthioethyl acrylate, tetrahydrofurfuryl acrylate, and styrene.
These polymerizable monomers may be used individually by 1 type, and may use 2 or more types together.

  In addition, a polymerizable monomer having an ethylenic double bond obtained by diffusion polymerization with respect to a binder matrix formed from a crosslinking agent having a functional group capable of reacting with the reactive group of the binder having the reactive group described above. In order to make the refractive index difference from the polymer more prominent, it is preferable to use a higher or lower refractive index than the binder and / or crosslinking agent as the refractive index of the polymerizable monomer. In particular, when a compound having a refractive index of about 1.47 is used as the binder compound and / or the crosslinking agent, a polymerizable monomer having a high refractive index is preferably a compound having a refractive index of 1.52 or more. This is preferable because a polymer of

These polymerizable monomers may be used individually by 1 type, and may use 2 or more types together.
The content of these polymerizable monomers in the hologram recording layer is preferably 2 to 80% by mass, more preferably 2 to 70% by mass, and particularly preferably 3 to 20% by mass in the total solid content of the hologram recording layer. . If the content is less than 2% by mass, sufficient diffraction efficiency may not be obtained, and if it exceeds 80% by mass, the resolution of hologram recording may be reduced and the recording density may not be improved. .

<(D) Silver halide>
The silver halide is not particularly limited as long as it has the ability to generate a photosensitive nucleus by photoexcitation, react with a reducing agent to generate an active radical, and initiate polymerization of the polymerizable monomer, and is appropriately selected from known ones For example, those having photosensitivity to laser light having a wavelength of 300 to 1,200 nm and other coherent light are preferable.
Examples of the silver halide include silver chloride, silver bromide, silver iodide, or silver chlorobromide, silver chloroiodide, silver iodobromide, silver chloroiodobromide, and the like. . The shape of the silver halide grains is preferably a cube or a tetrahedron, but is not limited to a regular crystal form, and may be an irregular crystal form or a composite form thereof. Examples of the irregular crystal forms include potato, spherical, plate, and flat plate crystal forms. In the tabular grains, the grain diameter generally has a value of 5 times or more the grain thickness.

  There is no restriction | limiting in particular as a grain size of a silver halide, According to the objective, it can be set as an appropriate size, For example, 0.01 micrometer or less fine grain can also be utilized. On the other hand, large particles of about 10 μm can also be used. With respect to grain size distribution, monodisperse grains are preferred over polydisperse emulsions. The monodispersed emulsion is described in U.S. Pat. Nos. 3,574,628 and 3,655,394 and British Patent No. 1413748. The crystal structure of the silver halide grains may be uniform, may have a different halogen composition inside or outside, or may have a layered structure. Further, silver halides having different compositions may be joined by epitaxial joining. Further, it may be bonded to a compound other than silver halide. The compound other than the silver halide is not particularly limited and can be appropriately selected from known compounds according to the purpose. Examples thereof include rhodium silver and lead oxide, but are not limited thereto. .

The silver halide grains may contain salts of other elements. Specific examples of the other elements include copper, thallium, lead, bismuth, cadmium, zinc, chalcogen (eg, sulfur, selenium, tellurium), gold and Group VIII noble metals (eg, rhodium, iridium, iron, platinum, Palladium). These element salts can be added during the formation of silver halide grains or after the formation of grains and can be contained in the grains. Specific methods include U.S. Pat. Nos. 1,195,432, 1,951,933, 2,448,060, 2,628,167, 2,950,972, 3,488,709, 3,737,313, 3,770,331, and 4,269,927 and Research Disclosure. (RD), Vol. 134, No. There is a description in 13452 (June 1975). When the silver halide emulsion is prepared, an iridium compound aqueous solution is added to the emulsion, whereby iridium ions can be introduced into the silver halide grains. Examples of water-soluble iridium compounds include hexachloroiridium (III) and hexachloroiridium (IV). Similarly, rhodium ions may be introduced into the silver halide grains by adding an aqueous solution of a rhodium compound to the emulsion. Specific examples of the water-soluble rhodium compound include rhodium ammonium chloride, rhodium trichloride, and rhodium chloride.
The iridium compound or rhodium compound may be used by dissolving in an aqueous solution of a halide for forming silver halide grains. Further, an aqueous solution of an iridium compound or a rhodium compound may be added before the particles are formed or may be added while the particles are being formed. Furthermore, you may add between particle | grain formation and a chemical sensitization process. It is particularly preferred to add while the particles are being formed. The iridium ion or rhodium ion is preferably used in an amount of 10 ⁻⁸ to 10 ⁻³ mol, more preferably 10 ⁻⁷ to 10 ⁻⁵ mol, per mol of silver halide. In addition, when using a rhodium compound and an iridium compound together, it is preferable that the former use is a preceding stage rather than the latter use.

  Two or more types of silver halide grains having different halogen compositions, crystal habits, and grain sizes can be used in combination. Silver halide is preferably used as an emulsion. Examples of the silver halide emulsion include Research Disclosure (RD), No. 17643 (December 1978), pages 22-23, “I. Emulsion preparation and types”, and 18716 (November 1979), page 648. The silver halide emulsion is usually chemically sensitized after physical ripening, but chemical sensitization may not be performed. It is preferable to use silver halide grains having a relatively low fog value. Additives used in such processes are described in Research Disclosure, No. 17643 and No. 18716. For chemical sensitizers, see “No. 17643 (page 23) and no. 18716 (page 648, right column), respectively. In addition, known additives other than those described above are also described in the above two research disclosure magazines. For example, for a sensitivity increasing agent, No. 18716 (page 648, right column), for antifoggants and stabilizers, see 17643 (pages 24-25) and No. 18716 (from page 649, right column).

The silver halide emulsion is usually used after spectral sensitization. As the sensitizing dye used in the light-sensitive material, a silver halide sensitizing dye known in photographic technology and the like can be used. Examples of sensitizing dyes include cyanine dyes, merocyanine dyes, composite merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes. In addition to a sensitizing dye, a dye having no spectral sensitizing action or a compound that does not substantially absorb visible light and exhibits supersensitization (supersensitizer) may be added to the emulsion. Good.
As content of the said silver halide, 0.001-5.0 mass% is preferable in the total solid of a hologram recording layer, and 0.01-0.1 mass% is more preferable. When the content is less than 0.001% by mass, high sensitivity of the hologram recording layer may not be obtained, and when it is more than 5.0% by mass, stain is generated by exposure after hologram recording. There is.

-Organic metal salt-
An organic metal salt can be added to the composition for a hologram medium of the present invention together with silver halide. As such an organic metal salt, it is particularly preferable to use an organic silver salt. Organic compounds used to form the organic silver salt include triazoles, tetrazoles, imidazoles, indazoles, thiazoles, thiadiazoles, azaindenes, aliphatics having a mercapto group as a substituent, aromatic or Heterocyclic compounds can be mentioned. Moreover, the silver salt of carboxylic acid and acetylene silver can also be used as an organic silver salt. These organic silver salts may be used alone or in combination of two or more. The organic silver salt is preferably used in an amount of 10 ⁻⁵ to 10 mol, more preferably 10 ⁻⁴ to 1 mol, per mol of silver halide. Further, instead of the organic silver salt, an organic compound constituting the organic silver salt may be added to the composition for a hologram recording medium and partially reacted with silver halide in the sensitive composition to be converted into an organic silver salt.

<(E) Reducing agent>
As the reducing agent, hydrazine is preferably used. The hydrazine has a function of generating active radicals by reducing silver halide and initiating polymerization of the polymerizable monomer. When hydrazine is used as the reducing agent, the image forming mechanism is as follows. By exposing the composition for a hologram recording medium of the present invention, the silver halide is photoexcited to generate a photosensitive nucleus, which is reduced by reacting with the reducing agent. The reducing agent itself is oxidized to form an oxidant, and the decomposition reaction proceeds in the hologram recording layer to generate active radicals, whereby the polymerization of the polymerizable monomer is started. A holographic image is formed by forming a polymer around the photosensitive nucleus of silver halide. Thus, the photosensitivity of silver halide triggers, causing a series of reactions of the reducing agent, and a hologram image is formed by polymerization of the polymerizable monomer, so that the use of silver halide can be reduced, The remaining silver halide in the unexposed portion is small and the printout phenomenon can be prevented.

  Moreover, you may add reducing agents other than the said hydrazine. The reducing agent is not particularly limited and may be appropriately selected depending on the purpose. Hydroquinones, catechols, p-aminophenols, p-phenylenediamines, 3-pyrazolidones, 3-aminopyrazoles 4-amino-5-pyrazolones, 5-aminouracils, 4,5-dihydroxy-6-aminopyrimidines, reductones, aminoreductones, o- or p-sulfonamidophenols, o- or p-sulfone Amidonaphthols, 2,4-disulfonamidophenols, 2,4-disulfonamidonaphthols, o- or p-acylaminophenols, 2-sulfonamidoindanones, 4-sulfonamido-5-pyrazolones, 3-sulfonamidoindoles, sulfonamidopyrazolobenzimidazo Le ethers, sulfonamides pyrazolotriazoles, alpha-sulfonamides ketones, and the like.

  The above reducing agents are disclosed in JP-A Nos. 61-183640, 61-188535, 61-228441, 62-70836, 62-86354, 62-86355, 62-206540, JP-A-62-264041, JP-A-62-109437, JP-A-63-254442, JP-A-1-267536, JP-A-2-141756, JP-A-2-141757, JP-A-2-207254, JP-A-2-262626, No. 2-269352 (including those described as developers or hydrazine derivatives). As for the reducing agent, T.W. “The Theory of the Photographic Process” by James, 4th edition, pages 291-334 (1977), Research Disclosure, Vol. 170, No. 17029, pages 9 to 15, (June 1978), and the same journal, Vol. 176, No. 17643, pages 22 to 31 (December 1978). Further, like the light-sensitive material described in JP-A-62-210446, a reducing agent precursor that releases the reducing agent under heating conditions or in contact with a base may be used instead of the reducing agent.

  Among these reducing agents, those having basicity to form a salt with an acid can also be used in the form of a salt with a suitable acid. These reducing agents may be used alone, but as described in each of the above publications, two or more reducing agents may be used in combination. When two or more reducing agents are used in combination, the interaction of the reducing agents is firstly to promote reduction of silver halide (and / or organic silver salt) by so-called super-addition, and secondly Initiating polymerization of a polymerizable compound via an oxidation-reduction reaction with another reducing agent in the presence of an oxidized form of the first reducing agent formed by reduction of silver halide (and / or organic silver salt) (Or suppress polymerization). However, in actual use, since the above reactions can occur simultaneously, it is difficult to specify which action is performed. The reducing agent is preferably used in an amount of 0.1 to 10 mol, more preferably 0.25 to 2.5 mol, per mol of silver halide.

  On the other hand, when a reducing agent other than hydrazine is used in combination, the oxidant of the reducing agent does not generate radicals (or is difficult to generate), and the reducing agent itself or the oxidant has a polymerization inhibiting function, Polymerization can be promoted by including a radical generator) together with a reducing agent. Examples of the reducing agent having the above function include 1-phenyl-3-pyrazolidones and hydroquinones. In this case, it is necessary to add a thermal polymerization initiator or a photopolymerization initiator as described below to the photosensitive material.

上記一般式（１）中、Ｒ^１は、置換もしくは非置換のアルキル基、シクロアルキル基、アリール基、アルケニル基、アルキニル基、ヘテロ環基のいずれかを表す。これらの中でも、置換もしくは非置換のアリール基、アラルキル基、ヘテロ環基が好ましい。
前記Ｒ^２は、水素原子、置換もしくは非置換のアルキル基、シクロアルキル基、アラルキル基、アリール基、アルケニル基、アルキニル基、ヘテロ環基、アルコキシ基、アリールオキシ基、アルキルチオ基、カルバモイル基、アルコキシカルボニル基、アミノ基のいずれかを表す。これらの中でも、水素原子、置換もしくは非置換のアルキル基、アラルキル基、アリール基、アルケニル基、アルキニル基、ヘテロ環基が好ましい。
前記置換基としては、ハロゲン原子、アルコキシ基、アリールオキシ基、アシル基、アシルアミノ基、アミノ基、アルキルスルホニル基、アリールスルホニル基、アルキルチオ基、アリールチオ基、カルバモイル基、スルファモイル基、シアノ基、アルコキシカルボニル基、ヒドロキシ基、などが挙げられる。 Examples of the reducing agent further include compounds represented by the following general formula (1).

In the general formula (1), R ¹ represents any ^one of a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, alkenyl group, alkynyl group, and heterocyclic group. Among these, a substituted or unsubstituted aryl group, aralkyl group, and heterocyclic group are preferable.
R ² represents a hydrogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, an alkenyl group, an alkynyl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, a carbamoyl group, an alkoxy group. It represents either a carbonyl group or an amino group. Among these, a hydrogen atom, a substituted or unsubstituted alkyl group, an aralkyl group, an aryl group, an alkenyl group, an alkynyl group, and a heterocyclic group are preferable.
Examples of the substituent include a halogen atom, alkoxy group, aryloxy group, acyl group, acylamino group, amino group, alkylsulfonyl group, arylsulfonyl group, alkylthio group, arylthio group, carbamoyl group, sulfamoyl group, cyano group, alkoxycarbonyl Group, hydroxy group, and the like.

上記一般式（２）中、Ｒ^３は、置換もしくは非置換の芳香環、芳香族、ヘテロ環から誘導される一価の基のいずれかを表す。
前記Ｒ^４及びＲ^５は、置換もしくは非置換のアリール基を表す。
前記Ｒ^６は、水素原子、置換もしくは非置換のアルキル基、アリール基、アルコキシカルボニル基、カルバモイル基のいずれかを表す。
前記置換基としては、ハロゲン原子、アルコキシ基、アリールオキシ基、アシル基、アシルアミノ基、アミノ基、アルキルスルホニル基、アリールスルホニル基、アルキルチオ基、アリールチオ基、カルバモイル基、スルファモイル基、シアノ基、アルコキシカルボニル基、ヒドロキシ基、などが挙げられる。 Examples of the reducing agent further include compounds represented by the following general formula (2).

In the general formula (2), R ³ represents any one of a monovalent group derived from a substituted or unsubstituted aromatic ring, aromatic, or heterocyclic ring.
R ⁴ and R ⁵ represent a substituted or unsubstituted aryl group.
R ⁶ represents any one of a hydrogen atom, a substituted or unsubstituted alkyl group, an aryl group, an alkoxycarbonyl group, and a carbamoyl group.
Examples of the substituent include a halogen atom, alkoxy group, aryloxy group, acyl group, acylamino group, amino group, alkylsulfonyl group, arylsulfonyl group, alkylthio group, arylthio group, carbamoyl group, sulfamoyl group, cyano group, alkoxycarbonyl Group, hydroxy group, and the like.

Specific examples of the reducing agent represented by the general formula (1) or (2) include the following compounds, but the present invention is not limited thereto.

  Of these compounds, those having a basic group that forms a salt with an acid can also be used in the form of an appropriate acid and salt, and also have an active site (NH group or OH group) that exhibits reducibility. ) Can be used in a form protected with a suitable protecting group (for example, formyl group, acetyl group, trifluoroacetyl group, etc.).

-Base or Base Precursor Here, a base or a base precursor may be added to the composition for a hologram medium in order to promote the oxidation or reduction reaction between the silver halide having a photosensitive nucleus and a reducing agent.
Examples of the base or base precursor include inorganic and organic bases and base precursors thereof (decarboxylation type, decomposition type, reaction type, complex salt formation type, etc.).
Examples of the inorganic base include alkali metal or alkaline earth metal hydroxides described in JP-A-62-209448 (for example, potassium hydroxide, sodium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide). , Etc.), phosphates (for example, dipotassium hydrogen phosphate, disodium hydrogen phosphate, ammonium hydrogen phosphate sodium / sodium phosphate, calcium hydrogen phosphate, etc.) ), Carbonates (for example, potassium carbonate, sodium carbonate, sodium bicarbonate, magnesium carbonate, etc.), borates (for example, potassium borate, sodium borate, sodium metaborate, etc.), Organic acid salts (eg potassium acetate, sodium acetate, potassium oxalate, sodium oxalate) , Acetylides of alkali metals or alkaline earth metals described in JP-A-63-25208 (for example, the following structure) And compounds represented by formulas (I-1) to (I-3)) and other metal hydroxides (for example, aluminum hydroxide, zinc hydroxide, etc.). .

また、前記有機の塩基としては、更に、グアニジン類（例えば、水溶性のモノグアニジン（例えば、グアニジン、ジメチルグアニジン、テトラメチルグアニジン、２−アミノイミダゾリン、２−アミノ−１，４，５−テトラヒドロピリミジン、などが挙げられる）、特開昭６３−７０８４５号公報記載の水不溶性のモノあるいはビスグアニジン、（例えば、下記構造式（Ｉ−８）〜（Ｉ−９）で表される化合物などが挙げられる）、ビスあるいはトリスあるいはテトラグアニジン（例えば、特開昭６４−６８７４６号公報記載の下記構造式（Ｉ−１０）〜（Ｉ−１４）で表される化合物などが挙げられる）、４級アンモニウムの水酸化物（例えば、テトラメチルアンモニウムハイドロオキサイド、テトラエチルアンモニウムハイドロオキサイド、テトラブチルアンモニウムハイドロオキサイド、トリメチルベンジルアンモニウムハイドロオキサイド、トリオクチルメチルアンモニウムハイドロオキサイド、メチルピリジニウムハイドロオキサイド、などが挙げられる）、などが挙げられる。

前記塩基としては、ｐｋａ７以上の塩基が好ましい。 Examples of the organic base include ammonia, aliphatic or aromatic amines (for example, primary amines (for example, methylamine, ethylamine, butylamine, n-hexylamine, cyclohexylamine, 2-ethylhexylamine, allylamine). , Ethylenediamine, 1,4-diaminobutane, hexamethylenediamine, aniline, anisidine, p-toluidine, α-naphthylamine, m-phenylenediamine, 1,8-diaminonaphthalene, benzylamine, phenethylamine, ethanolamine, thallium, etc. Secondary amines (eg, dimethylamine, diethylamine, dibutylamine, diallylamine, N-methylaniline, N-methylbenzylamine, N-methylethanolamine, diethanolamine, etc.) Tertiary amines (for example, N-methylmorpholine, N-hydroxyethylmorpholine, N-methylpiperidine, N-hydroxyethylpiperidine, N, N′-dimethylpiperazine described in JP-A-62-170954, N, N′-dihydroxyethylpiperazine, diazabicyclo [2,2,2] octane, N, N-dimethylethanolamine, N, N-dimethylpropanolamine, N-methyldiethanolamine, N-methyldipropanolamine, triethanolamine N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetrahydroxyethylethylenediamine, N, N, N ′, N′-tetramethyltrimethylenediamine, N-methylpyrrolidine , Etc.), polyamines (for example, diethyleneto Amines, triethylenetetramine, polyethyleneimine, polyallylamine, polyvinylbenzylamine, poly- (N, N-diethylaminoethyl methacrylate), poly- (N, N-dimethylvinylbenzylamine, etc.), hydroxylamines ( For example, hydroxylamine, N-hydroxy-N-methylaniline, etc.), heterocyclic amines (for example, pyridine, lutidine, imidazole, aminopyridine, N, N-dimethylaminopyridine, indole, quinoline, isoquinoline, Poly-4-vinylpyridine, poly-2-vinylpyridine, etc.), amidines (eg, monoamidine, (eg, acetamidine, imidazotan, 2-methylimidazole, 1,4,5,6-tetrahydro) Limidine, 2-methyl-1,4,5,6-tetrahydropyrimidine, 2-phenyl-1,4,5,6-tetrahydropyrimidine, iminopiperidine, diazabicyclononene, diazabicycloundecene (DBU), etc. ), Bis, tris, or tetraamidine (for example, compounds represented by the following structural formulas (I-4) to (I-7) described in JP-A-63-316760).

Examples of the organic base further include guanidines (for example, water-soluble monoguanidine (for example, guanidine, dimethylguanidine, tetramethylguanidine, 2-aminoimidazoline, 2-amino-1,4,5-tetrahydropyrimidine). And the like, and water-insoluble mono- or bisguanidines described in JP-A-63-70845 (for example, compounds represented by the following structural formulas (I-8) to (I-9)). Bis, tris or tetraguanidine (for example, compounds represented by the following structural formulas (I-10) to (I-14) described in JP-A No. 64-68746), quaternary ammonium (E.g., tetramethylammonium hydroxide, tetraethylammonium hydroxide) , Tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide, trioctylmethylammonium hydroxide, methylpyridinium hydroxide, and the like), and the like.

The base is preferably a pka7 or higher base.

また、前記塩基プレカーサとしては、更に、スルホニル酢酸と塩基の塩（例えば、フェニルスルホニル酢酸グアニジン、４−クロロフェニルスルホニル酢酸グアニジン、４−メタンスルホニルフェニルスルホニル酢酸グアニジン、メチルスルホニル酢酸グアニジン、フェニルスルホニル酢酸モルホリン、４−メタンスルホニルフェニルスルホニル酢酸２−メチル−１，４，５，６−テトラヒドロピリミジン、４−クロロフェニルスルホニル酢酸２−メチルイミダゾリン、フェニルスルホニル酢酸ジアザビシクロウンデセン、４−クロロフェニルスルホニル酢酸２−フェニル−１，４，５，６−テトラヒドロピリミジン、フェニルスルホニル酢酸トリシクロへキシルグアニジン、１−フェニルフェニルスルホニル酢酸グアニジン、ペンタクロロフェニルスルホニル酢酸グアニジン、１−ナフタレンスルホニル酢酸トリシクロへキシルグアニジン、特開昭６３−３１６７６０号公報記載のビスグアニジンの塩（例えば、下記構造式（ＩＩ−５）〜（ＩＩ−６）で表される化合物などが挙げられる）、特開昭６４−６８７４６号公報記載のビスあるいはトリスあるいはテトラグアニジン塩（例えば、下記構造式（ＩＩ−７）〜（ＩＩ−１１）で表される化合物などが挙げられる）、プロピオール酸と塩基の基（例えば、特開昭５９−１８０５３７Ａ号、同６１−３１３４３１号公報記載の、下記構造式（ＩＩ−１２）〜（ＩＩ−１５）で表される化合物などが挙げられる）、特開６３−３１６７６０号公報記載の下記構造式（ＩＩ−１６）〜（ＩＩ−１７）で表される化合物、などが挙げられる。

Examples of the base precursor include salts of organic acids and bases that are decarboxylated by heating, compounds that release amines by reactions such as intramolecular nucleophilic substitution reaction, Rossen rearrangement, Beckmann rearrangement, etc. And those that generate a base by electrolysis or the like are preferred.
Examples of the base precursor include organic acid and base salts that are decarboxylated by heating, for example, trichloroacetic acid and base salts (for example, guanidine trichloroacetic acid, piperidine trichloroacetic acid, morpholine trichloroacetic acid, p-toluidine trichloroacetic acid, 2-picoline). Trichloroacetic acid, 2-phenyl-1,4,5,6-tetrahydropyrimidine trichloroacetic acid, salts of bisamidine described in JP-A-63-3316760 (for example, structural formulas (II-1) to (II-2) below) And bisguanidine salts described in JP-A No. 64-68746 (for example, compounds represented by the following structural formulas (II-3) to (II-4)). Preferably).

The base precursor further includes a sulfonylacetic acid and base salt (for example, phenylsulfonylacetic acid guanidine, 4-chlorophenylsulfonylacetic acid guanidine, 4-methanesulfonylphenylsulfonylacetic acid guanidine, methylsulfonylacetic acid guanidine, phenylsulfonylacetic acid morpholine, 4-Methanesulfonylphenylsulfonylacetic acid 2-methyl-1,4,5,6-tetrahydropyrimidine, 4-chlorophenylsulfonylacetic acid 2-methylimidazoline, phenylsulfonylacetic acid diazabicycloundecene, 4-chlorophenylsulfonylacetic acid 2-phenyl- 1,4,5,6-tetrahydropyrimidine, phenylsulfonylacetic acid tricyclohexylguanidine, 1-phenylphenylsulfonylacetic acid guanidine, pentachloro Guanidinium sulfonylsulfonyl acetate, 1-naphthalenesulfonylacetic acid tricyclohexylguanidine, and salts of bisguanidine described in JP-A-63-316760 (for example, represented by the following structural formulas (II-5) to (II-6)) Bis, tris or tetraguanidine salts described in JP-A No. 64-68746 (for example, compounds represented by the following structural formulas (II-7) to (II-11)). ), Propiolic acid and base groups (for example, compounds represented by the following structural formulas (II-12) to (II-15) described in JP-A Nos. 59-180537A and 61-313431) And compounds represented by the following structural formulas (II-16) to (II-17) described in JP-A-63-316760, and the like. It is.

Further, as the salt of propiolic acid and base, decomposition is promoted by a decomposition accelerator such as metallic silver, silver compound, metallic copper and copper compound as described in JP-A-63-51937. be able to.
Examples of the decomposition accelerator include metallic silver, metallic copper, Ag ₂ O, Cu ₂ O, CuO, Ag ₂ S, Cu ₂ S, CuS, AgCl, CuCl, CuCl, CuCl ₂ , CuCl ₂ .2H ₂ O, AgBr. , CuBr, compounds represented by the following structural formulas (II-18) to (II-19), represented by the following structural formulas (II-20) to (II-22) described in JP-A No. 64-68746 And the like.

The base precursor preferably releases a base at 50 to 200 ° C, and more preferably releases a base at 80 to 160 ° C.
As content of the said base or a base precursor, 5-40 mass% is preferable with respect to the said polymeric compound, and 10-30 mass% is more preferable.
In the present invention, in order to accelerate development, a base or a base precursor is contained in the capsule wall as described in Japanese Patent Application No. 62-31482, or Japanese Patent Application Nos. 62-188580 and 63-92686. Base precursors can also be incorporated into capsules as described in the publication. As a method of incorporating the base precursor into the capsule, as described in JP-A No. 64-32251 and Japanese Patent Application No. 63-92686, it is dissolved in a polymerizable compound in the capsule or in the form of a solid dispersion. As described in Japanese Patent Application No. 63-218964 and Japanese Patent Application No. 1-160148, the base precursor is introduced in the form of emulsification in the polymerizable compound in a dispersed state in water. May be.

-Antifoggant precursor-
In addition, an antifoggant precursor may be added to the composition for hologram medium in order to further enhance the printout prevention effect.
In this case, after the hologram recording, heating, ultraviolet exposure, etc. are performed, and the antifoggant is generated from the antifoggant precursor by thermal decomposition or photolysis, thereby inactivating the silver halide remaining in the hologram recording layer. In addition, the fixing effect can be ensured and the printout prevention effect can be further ensured.
Examples of the antifoggant precursor include polyhalogen compounds, disulfide compounds, nitrogen-containing heterocyclic compounds, and the like.

Examples of the polyhalogen compound include Japanese Patent Publication No. 54-165, U.S. Pat. Nos. 3,874,946, 4,756,999, European Patent 605,981A, 631,176A1 specification etc. are mentioned. Specific examples include compounds represented by the following structural formulas.

Examples of the polyhalogen compound further include compounds represented by the following structural formulas described in JP-A-11-43483.

Examples of the polyhalogen compound further include compounds represented by the following structural formulas described in JP-A-10-171063.

Examples of the polyhalogen compound further include compounds represented by the following structural formulas described in JP-A-10-197989.

Examples of the disulfide compound include compounds represented by the following structural formulas described in JP-A-11-43483.

Examples of the nitrogen-containing heterocyclic compound include compounds represented by the following structural formulas described in JP-A-11-338100.

  The content of the antifoggant precursor is preferably 0.01 to 5 mol, more preferably 0.1 to 1 mol, per mol of the silver halide.

-Thermal polymerization initiator-
The thermal polymerization initiator is described in pages 6 to 18 of “Addition polymerization / ring-opening polymerization” (1983, Kyoritsu Shuppan) edited by the Society of Polymer Science and Polymer Experiments Editorial Committee and JP-A 61-243449. There is a description. Examples of the thermal polymerization initiator include azo compounds (eg, azobis (isobutyronitrile), 1,1′-azobis (1-cyclohexanecarbonitrile), dimethyl-2,2′-azobisisobutyrate, 2 , 2'-azobis (2-methylbutyronitrile), azobisdimethylvaleronitrile), peroxides (eg, benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, t-butyl hydroperoxide) , Cumene hydroperoxide, hydrogen peroxide, potassium persulfate, ammonium persulfate) and sodium p-toluenesulfinate. As for the photopolymerization initiator, Oster et al. “Chemical Review” Vol. 68 (1968), pages 125 to 151, Kosar “Light-Sensitive System” (John Wiley & Sons, 1965) and pages 158 to 193. There are descriptions in JP-A-61-75342 and JP-A-2-207254. Examples of photopolymerization initiators include carbonyl compounds (eg, α-alkoxyphenyl ketones, polycyclic quinones, benzophenone derivatives, xanthones, thioxanthones, benzoins, commercially available photopolymerization initiators (specific examples, Ciba-Geigy). “Irgacure 651”, “Irgacure 907”), halogen-containing compounds (eg, chlorosulfonyl and chloromethyl polynuclear aromatic compounds, chlorosulfonyl and chloromethyl heterocyclic compounds, chlorosulfonyl and chloromethylbenzophenones, Fluorenones), haloalkanes, α-halo-α-phenylacetophenones, redox couples of photoreducing dyes and reducing agents, organic sulfur compounds, peroxides, optical semiconductors (eg, titanium dioxide, zinc oxide), Metal compounds (eg, iron (I) salts, metal carbo Le, metal complexes, uranyl salt), a halogen halide, azo and diazo compounds.

-Photopolymerization initiator-
Specific examples of the photopolymerization initiator include 2-dimethoxy-2-phenylacetophenone, 2-methyl- {4- (methylthio) phenyl} -2-morpholino-1-propanone, benzoin butyl ether, benzoin isopropyl ether, benzophenone, Michler's ketone 4,4′-diethylaminobenzophenone, chloromethylbenzophenone, chlorosulfonylbenzophenone, 9,10-anthraquinone, 2-methyl-9,10-anthraquinone, chlorosulfonylanthraquinone, chloromethylanthraquinone, 9,10-phenone Nanthrenequinone, xanthone, chloroxanthone, thioxanthone, chlorothioxanthone, 2,4-diethylthioxanthone, chlorosulfonylthioxanthone, chloromethylbenzothiazole, chloros Sulfonylbenzoxazole, chloromethylquinoline, fluorene and carbon tetrabromide.
As addition amount of these heat | fever or photoinitiators, it is preferable to use 0.001-0.5g per 1g of polymeric compounds, and it is more preferable to use 0.01-0.2g.

<Additives and other ingredients>
For the purpose of improving the storage stability of the hologram recording layer, a photopolymer polymerization inhibitor or an antioxidant may be added. Examples of the polymerization inhibitor and antioxidant include hydroquinone, p-benzoquinone, hydroquinone monomethyl ether, 2,6-ditertiary-butyl-p-cresol, 2,2′-methylenebis (4-methyl-6-tertiary-butylphenol). ), Trifel phosphite, trisnonylphenyl phosphite, phenothiazine, N-isopropyl-N′-phenyl-p-phenylenediamine, and the like.
The addition amount of the additive is preferably within 3% by mass with respect to the total amount of the polymerizable monomer used in the composition for hologram recording medium. When the addition amount exceeds 3% by mass, the polymerization is slowed down, or when it is remarkable, the polymerization may be stopped.
Besides these, for the purpose of accelerating the reaction between the binder and the crosslinking agent, a reaction accelerator, a thermal expansion agent for the purpose of preventing thermal shrinkage after recording, and preventing thermal polymerization during the preparation of the recording composition. For this purpose, a thermal polymerization inhibitor, a plasticizer for adjusting the liquid viscosity at the time of preparing the recording composition, a hot-melt compound, or the like may be selected and used as needed.

(Hologram recording medium)
The hologram recording medium of the present invention comprises at least a substrate and a hologram recording layer comprising the hologram recording medium composition described above, and if necessary, between the substrate and the hologram recording layer. And a wavelength selective reflection layer, and a gap layer and other layers.

[Hologram recording layer]
The hologram recording layer is formed by depositing the composition for a hologram recording medium of the present invention between two substrates including a first substrate and a second substrate. The hologram recording layer is capable of recording information using holography. As a material whose optical characteristics such as an extinction coefficient and a refractive index change according to the intensity of the hologram recording layer when irradiated with an electromagnetic wave of a predetermined wavelength, By using the composition for a hologram recording medium of the invention, high-density recording and accurate reproduction thereof are possible.
For example, by attaching a gasket for holding the hologram recording medium composition of the present invention to the substrate, and depositing the hologram recording medium composition of the present invention between two substrates by holding the gasket. It can be carried out.
As the substrate, glass is generally used as described later. In addition to glass, other materials that are transparent to irradiation light used for data recording, such as polycarbonate, poly (methyl methacrylate), and cyclic olefin ring-opening. A plastic such as a polymer can also be used. Further, a spacer for forming a hologram recording medium layer with a desired thickness may be disposed between two substrates to deposit the composition for a hologram recording medium.
The hologram recording medium composition may be deposited by placing the hologram recording medium composition with a dispenser in a deposition space formed by a gasket, or by punching out a previously formed film shape, vacuum bonding, etc. You may stick together.
When the binder component of the hologram recording medium composition of the present invention is a three-dimensional polymer matrix precursor, after depositing the hologram recording medium composition of the present invention between two substrates in this way, Alternatively, a three-dimensional polymer matrix can be formed by heating and aging for a predetermined time.
That is, before hologram exposure, (A) a binder having a reactive group and (B) a crosslinking agent having a functional group capable of reacting with the reactive group of the binder having the reactive group are crosslinked by heat or the like. By forming a binder matrix, it becomes possible to ensure planarity, and (C) a hologram of a polymer formed by diffusion polymerization of a polymerizable compound having an ethylenic double bond in the molecule Movement within the recording layer can be prevented.
The crosslinking reaction for forming the binder matrix in the hologram recording method of the present invention may cause the binder having the reactive group and the crosslinking agent having a functional group to react with each other without causing any practical problems. Only a part of the range may be reacted. Furthermore, after recording information on the hologram recording medium, it has a binder and a functional group having a remaining reactive group by light and heat applied as necessary for the purpose of fixing the recorded hologram information. It is preferable to polymerize a crosslinking agent and a polymerizable compound having an ethylenic double bond in the molecule. In this case, it is preferable that the light used for exposure is exposed to the entire hologram recording medium.
When the binder component of the hologram recording medium composition of the present invention is a polymer, the hologram recording medium composition is coated on the second substrate using a suitable solvent and dried. It can be. A hologram recording medium can be obtained by superimposing another first substrate thereon.

  The thickness of the hologram recording layer is preferably 1 to 5,000 μm, and more preferably 100 to 1,000 μm. If the thickness is less than 1 μm, it may be difficult to obtain a high recording capacity by multiplex recording, and if it exceeds 5,000 μm, the S / N ratio may deteriorate due to scattering of the hologram recording medium. is there. The preferable numerical range is advantageous in that a sufficient S / N ratio can be obtained even when multiple recording such as 10 to several hundred multiplexing is performed, and the more preferable numerical range is advantageous in that it is remarkable. It is.

[substrate]
The shape, structure, size and the like of the first and second substrates are not particularly limited and can be appropriately selected according to the purpose. Examples of the shape include a disk shape and a card shape. It is necessary to select a material that can ensure the mechanical strength of the hologram recording medium. In addition, when light used for recording and reproduction enters through the substrate, it is necessary to be sufficiently transparent in the wavelength region of the light used.
The second substrate preferably has a servo pit pattern, and a reflective surface is preferably formed on the servo pit pattern.
As the substrate material, glass, ceramics, resin, and the like are usually used, but resin is particularly preferable from the viewpoint of moldability and cost.
Examples of the resin include polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitrile-styrene copolymer, polyethylene resin, polypropylene resin, silicone resin, fluorine resin, ABS resin, and urethane resin. Among these, acrylic resins such as polycarbonate resin and polymethyl methacrylate are particularly preferable from the viewpoints of moldability, optical characteristics, and cost.
The substrate may be appropriately synthesized or a commercially available product may be used.

  In the second substrate, address-servo areas as a plurality of positioning areas extending linearly in the radial direction are provided at predetermined angular intervals, and a sector-shaped section between adjacent address-servo areas becomes a data area. Yes. In the address-servo area, information for performing focus servo and tracking servo by the sampled servo method and address information are recorded in advance by embossed pits (servo pits) (preformat). In addition, focus servo can be performed using a reflective surface. As information for performing the tracking servo, for example, a wobble pit can be used. When the hologram recording medium is card-shaped, there is no need for the servo pit pattern.

  There is no restriction | limiting in particular as thickness of the said 1st, 2nd board | substrate, According to the objective, it can select suitably, 0.1-5 mm is preferable and 0.3-2 mm is more preferable. If the thickness of the substrate is less than 0.1 mm, distortion of the shape during storage of the disk may not be suppressed. If the thickness exceeds 5 mm, the weight of the entire disk increases and an excessive load is applied to the drive motor. Sometimes.

<Reflection surface>
The reflective surface is formed on the servo pit pattern surface of the second substrate.
As the material of the reflecting surface, it is preferable to use a material having a high reflectance with respect to recording light and reference light. When the wavelength of light to be used is 400 to 780 nm, for example, Al, Al alloy, Ag, Ag alloy, etc. are preferably used. When the wavelength of light to be used is 650 nm or more, it is preferable to use Al, Al alloy, Ag, Ag alloy, Au, Cu alloy, TiN, or the like.
Note that a hologram recording medium such as a DVD (Digital Video Disc) that can reflect and erase light as well as a write-once or erase is used as the reflecting surface, and to which area the hologram is recorded, and when it is rewritten. It is also possible to additionally write and rewrite directory information, such as whether or not there is an error and how the alternation process was performed, without affecting the hologram.

The formation of the reflecting surface is not particularly limited and can be appropriately selected depending on the purpose. Various vapor deposition methods such as vacuum deposition, sputtering, plasma CVD, photo CVD, ion plating An electron beam evaporation method or the like is used. Among these, the sputtering method is excellent in terms of mass productivity and film quality.
The thickness of the reflecting surface is preferably 50 nm or more, and more preferably 100 nm or more so that sufficient reflectance can be realized.

[Wavelength selective reflection layer]
The wavelength selective reflection layer prevents the occurrence of noise by preventing irregular reflection from the reflection film of the optical recording medium by information light and reference light without causing a shift in the selective reflection wavelength even when the incident angle changes. There is. By laminating the wavelength selective reflection layer on the optical recording medium, optical recording with high resolution and excellent diffraction efficiency can be obtained.
The function of the filter for optical recording media is preferably to transmit light of the first wavelength and reflect light of the second wavelength different from the light of the first wavelength, and the light of the first wavelength is 350 It is preferable that the second wavelength is 600 to 900 nm. For that purpose, it is preferable that the optical recording medium has a structure in which an optical recording layer, a wavelength selective reflection layer, and a servo pit pattern are laminated in this order as viewed from the optical system side.
The wavelength selective reflection layer has a light transmittance at 655 nm of 50% or higher, preferably 80% or higher, and a light reflectance at 532 nm of 30% or higher at an incident angle of ± 40 °. % Or more is preferable.
The wavelength selective reflection layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a dielectric vapor deposition layer (a layer composed of a dichroic mirror), a single layer or two or more cholesteric liquid crystal layers, It is formed by a laminate of other layers as necessary. Moreover, you may have a color material content layer. Japanese Patent Application No. 2004-352084 can be referred to for the color material-containing layer.
The wavelength selective reflection layer may be laminated together with the direct optical recording layer on the support by coating or the like, or laminated on a substrate such as a film to produce a filter for an optical recording medium. The recording medium filter may be laminated on the support.

-Dielectric deposition layer-
The dielectric vapor deposition layer is formed by laminating a plurality of dielectric thin films having different refractive indexes. In order to obtain a wavelength selective reflection film, a dielectric thin film having a high refractive index and a dielectric thin film having a low refractive index are used. Although it is preferable to laminate a plurality of layers alternately, it is not limited to two or more types, and may be more types. Moreover, when providing a color material content layer, it forms under a dielectric material vapor deposition layer.
The number of stacked layers is preferably 2 to 50 layers, more preferably 4 to 20 layers, and particularly preferably 6 to 15 layers. If the number of stacked layers exceeds 50, production efficiency may be reduced due to multilayer deposition, and the object and effects of the present invention may not be achieved.

  The order of lamination of the dielectric thin films is not particularly limited and can be appropriately selected according to the purpose. For example, when the refractive index of an adjacent film is high, a film having a lower refractive index is first laminated. To do. Conversely, when the refractive index of the adjacent layer is low, a film having a higher refractive index is first laminated. The threshold value for determining whether the refractive index is high or low is preferably 1.8. Note that whether the refractive index is high or low is not absolute. Among high-refractive-index materials, there may be a material with a relatively high refractive index and a material with a relatively low refractive index, which are used alternately. May be.

The material for the high refractive index dielectric thin film is not particularly limited and may be appropriately selected depending on the intended purpose. For example, Sb ₂ O ₃ , Sb ₂ S ₃ , Bi ₂ O ₃ , CeO ₂ , CeF _{3, HfO 2, La 2 O} 3, Nd 2 O 3, Pr 6 O 11, Sc 2 O 3, SiO, Ta 2 O 5, TiO 2, TlCl, Y 2 O 3, ZnSe, ZnS, ZrO 2 , etc. Can be mentioned. Among these, Bi ₂ O ₃ , CeO ₂ , CeF ₃ , HfO ₂ , SiO, Ta ₂ O ₅ , TiO ₂ , Y ₂ O ₃ , ZnSe, ZnS, ZrO ₂ are preferable, and among these, SiO, Ta ₂ O ₅ , TiO ₂ , Y ₂ O ₃ , ZnSe, ZnS, and ZrO ₂ are more preferable.

The material for the low refractive index dielectric thin film is not particularly limited and may be appropriately selected depending on the intended purpose. For example, Al ₂ O ₃ , BiF ₃ , CaF ₂ , LaF ₃ , PbCl ₂ , PbF ₂ , LiF, MgF ₂ , MgO, NdF ₃ , SiO ₂ , Si ₂ O ₃ , NaF, ThO ₂ , ThF _{4 and the} like. Among these, Al ₂ O ₃ , BiF ₃ , CaF ₂ , MgF ₂ , MgO, SiO ₂ , Si ₂ O ₃ are preferable, and among these, Al ₂ O ₃ , CaF ₂ , MgF ₂ , MgO, SiO ₂ , Si ₂ O ₃ is more preferable.
In the dielectric thin film material, the atomic ratio is not particularly limited and can be appropriately selected according to the purpose. The atomic ratio can be adjusted by changing the atmospheric gas concentration during film formation. .

The method for forming the dielectric thin film is not particularly limited and may be appropriately selected depending on the purpose. For example, a physical vapor deposition method such as ion plating, vacuum deposition using an ion beam, sputtering, or the like. (PVD method), chemical vapor deposition method (CVD method) and the like. Among these, vacuum deposition and sputtering are preferable, and sputtering is more preferable.
As the sputtering, a DC sputtering method having a high film formation rate is preferable. In the DC sputtering method, it is preferable to use a material having high conductivity.
In addition, as a method for forming a multilayer film by sputtering, for example, (1) a one-chamber method in which a plurality of targets are alternately or sequentially formed in one chamber, and (2) continuous film formation in a plurality of chambers. There is a multi-chamber method. Among these, the multi-chamber method is particularly preferable from the viewpoint of preventing productivity and material contamination.
The thickness of the dielectric thin film is preferably λ / 16 to λ, more preferably λ / 8 to 3λ / 4, and more preferably λ / 6 to 3λ / 8 in the order of the optical wavelength.

<Cholesteric liquid crystal layer>
The cholesteric liquid crystal layer contains at least a nematic liquid crystal compound and a photoreactive chiral compound, and contains a polymerizable monomer and, if necessary, other components.

The cholesteric liquid crystal layer in the wavelength selective reflection layer uses a photoreactive chiral compound and continuously changes the helical pitch in the thickness direction of the liquid crystal layer, so that the vertical incidence is 0 ° and λ ₀ is in the range of ± 20 °. ~λ ₀ / cos20 ° (However, lambda ₀ represents a wavelength of the irradiated light) is preferably light reflectance at not less than 40%, a normal incidence is in the range of ± 40 ° and ₀ ° λ 0 ~λ 0 It is particularly preferable that the light reflectance at / cos 40 ° (where λ ₀ represents the irradiation light wavelength) is 40% or more.
Wherein λ ₀ ~λ ₀ / cos20 °, especially λ ₀ ~λ ₀ / cos40 ° (However, lambda ₀ represents a wavelength of the irradiated light) as long as the light reflectance of 40% or more in the range of the angle of the irradiation light reflected The dependency can be eliminated, and a lens optical system used in a normal hologram recording medium can be employed.

Specifically, a photoreactive chiral compound having photosensitivity as the chiral compound and capable of greatly changing the helical pitch of the liquid crystal by light is used, and the content and UV irradiation time of the photoreactive chiral compound are adjusted. By adjusting the wavelength selective reflection layer for hologram recording medium, the spiral pitch is continuously changed in the thickness direction of the liquid crystal layer. FIG. 2 shows that the reflection characteristic for vertically incident light from the front (0 °) is 40% or more. On the other hand, when it becomes the incident light from the oblique direction, it gradually shifts to the short wavelength side, and when tilted by 40 ° within the liquid crystal layer, the reflection characteristic as shown in FIG. 3 is shown.
Similarly, when the helical pitch is continuously changed in the thickness direction of the liquid crystal layer by adjusting the content of the photoreactive chiral compound and the UV irradiation time, the hologram recording having reflection characteristics as shown in FIG. A wavelength selective reflection layer for a medium is obtained. FIG. 4 shows that the reflection characteristic for vertically incident light from the front (0 °) is 40% or more. On the other hand, when it becomes the incident light from the oblique direction, it gradually shifts to the short wavelength side, and when tilted by 20 ° in the liquid crystal layer, the reflection characteristic as shown in FIG. 5 is shown.
The reflection region of λ ₀ ~1.3λ ₀ shown in FIG. 2, 1.3λ ₀ = 692nm next when lambda ₀ = 532 nm, the servo light in the case of 655nm would reflect servo light. The range of λ _{0 to} 1.3λ ₀ shown here is suitable for ± 40 ° incident light in the wavelength selective reflection layer. However, when actually using such a large oblique light, the servo within an incident angle of ± 20 ° is used. If the light is masked and used, servo control can be performed without any problem. If the spiral pitch of the cholesteric liquid crystal layer in the wavelength selective reflection layer to be used is sufficiently large, it is easy to design all the incident angles within ± 20 ° in the wavelength selective reflection layer. Since the cholesteric liquid crystal layer of λ _{0 to} 1.1λ ₀ shown in FIG.
Therefore, from the results shown in FIGS. 2 to 5, even if the incident wavelength is inclined by 0 ° to 20 ° (preferably 0 ° to 40 °) in the wavelength selective reflection layer for the hologram recording medium of the present invention, it is 40% or more. Therefore, it is possible to produce a wavelength selective reflection layer for a hologram recording medium that does not interfere with signal reading.

The cholesteric liquid crystal layer preferably has a circularly polarized light separation function. The cholesteric liquid crystal layer having the function of separating circularly polarized light has only a circularly polarized light component in which the rotation direction (clockwise or counterclockwise) of the liquid crystal is coincident with the circular polarization direction and the wavelength is the helical pitch of the liquid crystal. Has a selective reflection characteristic of reflecting the light. Using the selective reflection characteristics of the cholesteric liquid crystal layer, only circularly polarized light having a specific wavelength is transmitted and separated from natural light in a certain wavelength band, and the rest is reflected.
Therefore, the cholesteric liquid crystal layer preferably transmits light having a first wavelength and reflects circularly polarized light having a second wavelength different from the light having the first wavelength. It is preferable that the wavelength is 600 nm and the light having the second wavelength is 600 to 900 nm.

The selective reflection wavelength bandwidth of the cholesteric liquid crystal layer is preferably 100 nm or more, and more preferably 150 to 300 nm. When the selective reflection wavelength bandwidth is less than 100 nm, reflection suitability for incident light within ± 20 ° may be insufficient.
The selective reflection wavelength band of the cholesteric liquid crystal layer is preferably continuous. Here, the "continuous", there is no gap between the wavelength λ ₀ ~λ ₀ / cos20 ° (preferably _{λ 0 ~λ 0 / cos40 °)} , substantially the reflectance of the range 40% That means that.

-Nematic liquid crystal compounds-
The nematic liquid crystal compound is characterized in that the liquid crystal phase is fixed below the liquid crystal transition temperature, the liquid crystal compound having a refractive index anisotropy Δn of 0.10 to 0.40, a polymer liquid crystal compound, and polymerization The liquid crystal compound can be appropriately selected according to the purpose. While it is in the liquid crystal state at the time of melting, it can be used as a solid phase by, for example, aligning by using an alignment substrate subjected to alignment treatment such as rubbing, and then cooling and fixing as it is.

  There is no restriction | limiting in particular as said nematic liquid crystal compound, According to the objective, it can select suitably, For example, the following compound etc. can be mentioned.

  In the above formula, n represents an integer of 1 to 1,000. In addition, in each of the exemplified compounds, those in which the side chain linking group is changed to the following structure can also be cited as suitable.

  Among the above exemplified compounds, the nematic liquid crystal compound is preferably a nematic liquid crystal compound having a polymerizable group in the molecule from the viewpoint of ensuring sufficient curability, and among these, a UV polymerizable liquid crystal is preferable. . Commercially available products can be used as the UV polymerizable liquid crystal, for example, trade name PALIOCOLOR LC242 manufactured by BASF; trade name E7 manufactured by Merck; trade name LC-Slicon-CC3767 manufactured by Wacker-Chem; Takasago Examples include trade names L35, L42, L55, L59, L63, L79, and L83 manufactured by Perfume Co., Ltd.

  As content of the said nematic liquid crystal compound, 30-99 mass% is preferable with respect to the total solid content mass of the said cholesteric liquid crystal layer, and 50-99 mass% is more preferable. When the content is less than 30% by mass, the alignment of the nematic liquid crystal compound may be insufficient.

-Photoreactive chiral compounds-
The photoreactive chiral compound means a chiral compound that has photosensitivity and can greatly change the helical pitch of liquid crystal by light.
The photoreactive chiral compound preferably has a chiral site and a photoreactive group, and the chiral site is at least one selected from an isosorbide compound, an isomannide compound, and a binaphthol compound.
The photoreactive group is preferably a group that causes isomerization of a carbon-carbon double bond from trans to cis upon irradiation with light.

There is no restriction | limiting in particular as said isosorbide compound, According to the objective, it can select suitably, For example, Unexamined-Japanese-Patent No. 2002-80851, Unexamined-Japanese-Patent No. 2002-179681, Unexamined-Japanese-Patent No. 2002-179682, Unexamined-Japanese-Patent No. JP 2002-338575 A, JP 2002-338668 A, JP 2003-306490 A, JP 2003-306491 A, JP 2003-313187 A, JP 2003-313292 A, JP 2003-200392 A. No. 3131189, etc.
There is no restriction | limiting in particular as said isomannide compound, According to the objective, it can select suitably, For example, Unexamined-Japanese-Patent No. 2002-80478, Unexamined-Japanese-Patent No. 2003-313188, etc. illustrate.
There is no restriction | limiting in particular as said binaphthol compound, According to the objective, it can select suitably, For example, Unexamined-Japanese-Patent No. 2002-302487, Unexamined-Japanese-Patent No. 2002-179670, Unexamined-Japanese-Patent No. 2002-179669, etc. Illustrated.

Specific examples of the photoreactive chiral agent include the following.

  As content of the said chiral compound, 1-30 mass% is preferable with respect to the total solid content mass of the said cholesteric liquid crystal layer, and 1-20 mass% is more preferable. When the content is less than 1% by mass, the helical pitch becomes too long and may deviate from the selection wavelength that can be adopted as the system. When the content exceeds 30% by mass, the orientation of the cholesteric liquid crystal layer becomes insufficient. There is.

-Polymerizable monomer-
In the cholesteric liquid crystal layer, for example, a polymerizable monomer can be used in combination for the purpose of improving the degree of curing such as film strength. When the polymerizable monomer is used in combination, after changing the twisting force of the liquid crystal by light irradiation (patterning) (for example, after forming a selective reflection wavelength distribution), the helical structure (selective reflectivity) is fixed, The strength of the cholesteric liquid crystal layer after fixation can be further improved. However, when the liquid crystal compound has a polymerizable group in the same molecule, it is not necessarily added.
The polymerizable monomer is not particularly limited and may be appropriately selected from known ones according to the purpose. Examples thereof include monomers having an ethylenically unsaturated bond, and specifically, pentaerythritol. Examples thereof include polyfunctional monomers such as tetraacrylate and dipentaerythritol hexaacrylate.
Specific examples of the monomer having an ethylenically unsaturated bond include the following compounds. These may be used alone or in combination of two or more.

  As addition amount of the said polymerizable monomer, 0-50 mass% is preferable with respect to the total solid content mass of the said cholesteric liquid crystal layer, and 1-20 mass% is more preferable. When the addition amount exceeds 50% by mass, the orientation of the cholesteric liquid crystal layer may be inhibited.

-Other ingredients-
The other components are not particularly limited and may be appropriately selected depending on the purpose. For example, photopolymerization initiator, sensitizer, binder resin, polymerization inhibitor, solvent, surfactant, thickener , Dyes, pigments, ultraviolet absorbers, gelling agents, and the like.

There is no restriction | limiting in particular as said photoinitiator, According to the objective, it can select suitably according to the objective, For example, p-methoxyphenyl-2,4-bis (trichloromethyl) -s-triazine, 2- (p-butoxystyryl) -5-trichloromethyl 1,3,4-oxadiazole, 9-phenylacridine, 9,10-dimethylbenzphenazine, benzophenone / Michler's ketone, hexaarylbiimidazole / mercaptobenzimidazole, benzyl Examples thereof include dimethyl ketal and thioxanthone / amine. These may be used alone or in combination of two or more.
As the photopolymerization initiator, commercially available products can be used. Examples of the commercially available products include trade names of Irgacure 907, Irgacure 369, Irgacure 784, and Irgacure 814 manufactured by Ciba Specialty Chemicals; And Lucylin TPO.

  The addition amount of the photopolymerization initiator is preferably 0.1 to 20% by mass, and more preferably 0.5 to 5% by mass with respect to the total solid mass of the cholesteric liquid crystal layer. When the addition amount is less than 0.1% by mass, it may take a long time because the curing efficiency at the time of light irradiation is low, and when it exceeds 20% by mass, the light transmittance from the ultraviolet region to the visible light region is increased. May be inferior.

There is no restriction | limiting in particular as said binder resin, According to the objective, it can select suitably according to the objective, For example, Polyvinyl alcohol; Polystyrene compounds, such as a polystyrene and poly-alpha-methylstyrene; Methylcellulose, ethylcellulose, acetyl Cellulose resins such as cellulose; acidic cellulose derivatives having a carboxyl group in the side chain; acetal resins such as polyvinyl formal and polyvinyl butyral; methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer Examples thereof include a polymer, a maleic acid copolymer, a partially esterified maleic acid copolymer; a homopolymer of acrylic acid alkyl ester or a homopolymer of alkyl methacrylate, and other polymers having a hydroxyl group. These may be used alone or in combination of two or more.
Examples of the alkyl group in the homopolymer of acrylic acid alkyl ester or the homopolymer of methacrylic acid alkyl ester include, for example, methyl group, ethyl group, normal-propyl group, normal-butyl group, iso-butyl group, and normal-hexyl group. Cyclohexyl group, 2-ethylhexyl group, and the like.
Examples of the other polymer having a hydroxyl group include benzyl (meth) acrylate / (homopolymer of methacrylic acid) acrylic acid copolymer, benzyl (meth) acrylate / (meth) acrylic acid / multiple monomers of other monomers. Polymer, and the like.

  As content of the said binder resin, 0-80 mass% is preferable with respect to the total solid mass of the said cholesteric liquid crystal layer, and 0-50 mass% is more preferable. When the content exceeds 80% by mass, the orientation of the cholesteric liquid crystal layer may be insufficient.

There is no restriction | limiting in particular as said polymerization inhibitor, According to the objective, it can select suitably, For example, hydroquinone, hydroquinone monomethyl ether, phenothiazine, benzoquinone, or these derivatives etc. are mentioned.
As addition amount of the said polymerization inhibitor, 0-10 mass% is preferable with respect to solid content of the said polymerizable monomer, and 100 ppm-1 mass% is more preferable.

  The solvent is not particularly limited and may be appropriately selected from known solvents according to the purpose. For example, 3-methoxypropionic acid methyl ester, 3-methoxypropionic acid ethyl ester, 3-methoxypropionic acid propyl Esters, alkoxypropionic acid esters such as 3-ethoxypropionic acid methyl ester, 3-ethoxypropionic acid ethyl ester, 3-ethoxypropionic acid propyl ester; 2-methoxypropyl acetate, 2-ethoxypropyl acetate, 3-methoxybutyl acetate Esters of alkoxy alcohols such as: Lactic acid esters such as methyl lactate and ethyl lactate; Ketones such as methyl ethyl ketone, cyclohexanone and methylcyclohexanone; γ-butyrolactone, N-methylpyrrolidone, di Sulfoxide, chloroform, tetrahydrofuran, and the like. These may be used individually by 1 type and may use 2 or more types together.

<Base material>
As the base material in the case of forming the wavelength selective reflection layer by laminating on the base material, the shape, structure, size and the like are not particularly limited and can be appropriately selected according to the purpose. Examples of the shape include a flat plate shape and a sheet shape. The structure may be a single layer structure or a laminated structure, and the size may be the wavelength for the hologram recording medium. It can be appropriately selected according to the size of the selective reflection layer.

There is no restriction | limiting in particular as a material of the said base material, Both an inorganic material and an organic material can be used suitably.
Examples of the inorganic material include glass, quartz, silicon, and the like.
Examples of the organic material include acetate resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and acrylic resins. , Polynorbornene resins, cellulose resins, polyarylate resins, polystyrene resins, polyvinyl alcohol resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyacrylic resins, and the like. These may be used alone or in combination of two or more.

The base material may be appropriately synthesized, or a commercially available product may be used.
There is no restriction | limiting in particular as thickness of the said base material, According to the objective, it can select suitably, 10-500 micrometers is preferable and 50-300 micrometers is more preferable. When the thickness of the base material is less than 10 μm, the adhesion may be lowered due to the bending of the substrate. On the other hand, if it exceeds 500 μm, the focal positions of the information light and the reference light must be greatly shifted, and the optical system size becomes large.

As a method for forming the wavelength selective reflection layer, for example, a cholesteric liquid crystal layer coating solution prepared using the solvent is applied onto the substrate, dried, and irradiated with, for example, ultraviolet rays, thereby forming a cholesteric liquid crystal layer. Can be formed.
The most suitable method for mass production is to prepare the base material in a roll form, and apply a coating solution for the cholesteric liquid crystal layer on the base material such as bar coat, die coat, blade coat, curtain coat, etc. A type in which coating is performed with a long continuous coater is preferable.

Examples of the coating method include spin coating, casting, roll coating, flow coating, printing, dip coating, casting film formation, bar coating, and gravure printing.
There is no restriction | limiting in particular as conditions for the said ultraviolet irradiation, According to the objective, it can select suitably, For example, 160-380 nm is preferable and, as for irradiation ultraviolet rays, 250-380 nm is more preferable. For example, the irradiation time is preferably 0.1 to 600 seconds, and more preferably 0.3 to 300 seconds. By adjusting the conditions of ultraviolet irradiation, the helical pitch in the cholesteric liquid crystal layer can be continuously changed along the thickness direction of the liquid crystal layer.

  In order to adjust the conditions of the ultraviolet irradiation, an ultraviolet absorber may be added to the cholesteric liquid crystal layer. There is no restriction | limiting in particular as this ultraviolet absorber, According to the objective, it can select suitably, For example, a benzophenone type ultraviolet absorber, a benzotriazole type ultraviolet absorber, a salicylic acid type ultraviolet absorber, a cyanoacrylate type ultraviolet absorber Preferable examples include oxalic acid anilide-based ultraviolet absorbers. Specific examples of these ultraviolet absorbers include JP-A Nos. 47-10537, 58-111942, 58-212844, 59-19945, 59-46646, 59. No. -109055, No. 63-53544, No. 36-10466, No. 42-26187, No. 48-30492, No. 48-31255, No. 48-41572, No. 48. -54965, 50-10726, U.S. Pat. Nos. 2,719,086, 3,707,375, 3,754,919, 4, No. 220,711 and the like.

  The thickness of the cholesteric liquid crystal layer is, for example, preferably 1 to 10 μm, and more preferably 2 to 7 μm. When the thickness is less than 1 μm, the selective reflectance is not sufficient, and when it exceeds 10 μm, the uniform alignment of the liquid crystal layer may be disturbed.

  The cholesteric liquid crystal layer is disposed on the second substrate by applying a coating solution for the cholesteric liquid crystal layer on the base material, aligning, solidifying, processing the whole base material into a disk shape (for example, punching processing), and the like. Is preferred. Moreover, when using for the wavelength selective reflection layer of a hologram recording medium, it can also provide directly on a 2nd board | substrate not via a base material. Specifically, (1) a method of applying directly to the second substrate by means such as spin coating, and (2) once forming a cholesteric liquid crystal layer on the substrate, then laminating on the second substrate and only the substrate And a method of attaching the obtained cholesteric liquid crystal layer to the second substrate.

[First gap layer]
The first gap layer is provided between the wavelength selective reflection layer and the reflection surface as necessary, and is formed for the purpose of smoothing the surface of the second substrate. It is also effective for adjusting the size of the hologram generated in the recording layer. That is, since it is necessary for the recording layer to form an interference region for recording reference light and information light to a certain size, it is effective to provide a gap between the recording layer and the servo pit pattern.
The first gap layer can be formed, for example, by applying a material such as an ultraviolet curable resin on the servo pit pattern by spin coating or the like and curing it. Moreover, when using what was apply | coated and formed on the transparent base material as a wavelength selection reflection layer, this transparent base material will work | function also as a 1st gap layer.
There is no restriction | limiting in particular as thickness of the said 1st gap layer, According to the objective, it can select suitably, 1-200 micrometers is preferable.

[Second gap layer]
The second gap layer is provided between the recording layer and the wavelength selective reflection layer as necessary.
The material of the second gap layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, triacetyl cellulose (TAC), polycarbonate (PC), polyethylene terephthalate (PET), polystyrene (PS) ), Transparent resin films such as polysulfone (PSF), polyvinyl alcohol (PVA), polymethyl methacrylate-polymethyl methacrylate (PMMA), etc. And norbornene-based resin films. Among these, those having high isotropic properties are preferred, and TAC, PC, trade name ARTON, and trade name ZEONOR are particularly preferred.
There is no restriction | limiting in particular as thickness of the said 2nd gap layer, According to the objective, it can select suitably, 1-200 micrometers is preferable.

Here, the hologram recording medium of the present invention will be described in more detail with reference to the drawings.
<First embodiment>
FIG. 6 is a schematic cross-sectional view showing the configuration of the hologram recording medium in the first embodiment of the present invention. In the hologram recording medium 21 according to the first embodiment, a servo pit pattern 3 is formed on a polycarbonate resin substrate or a glass substrate 1, and the servo pit pattern 3 is coated with aluminum, gold, platinum or the like to be a reflective surface. 2 is provided. In FIG. 6, the servo pit pattern 3 is formed on the entire surface of the second substrate 1, but it may be formed periodically as shown in FIG. The height of the servo pit pattern 3 is normally 1750 mm (175 nm), which is sufficiently smaller than the thicknesses of the substrate and other layers.

The first gap layer 8 is formed by applying a material such as an ultraviolet curable resin on the reflective surface 2 of the second substrate 1 by spin coating or the like. The first gap layer 8 is effective for protecting the reflection surface 2 and adjusting the size of the hologram generated in the recording layer 4. That is, in the hologram recording layer 4, it is necessary to form an interference area of the recording reference light and the information light with a certain size. Therefore, it is effective to provide a gap between the recording layer 4 and the servo pit pattern 3.
A wavelength selective reflection layer 6 is provided on the first gap layer 8, and the hologram recording medium 21 is sandwiched between the wavelength selective reflection layer 6 and the first substrate 5 (polycarbonate resin substrate or glass substrate) so that the hologram recording medium 21 is sandwiched. Composed.

In FIG. 6, the wavelength selective reflection layer 6 transmits only red light and does not transmit light of other colors. Therefore, since the information light, the recording and reproduction reference light are green or blue light, the light does not pass through the wavelength selective reflection layer 6 and does not reach the reflection surface 2 but becomes return light and is emitted from the incident / exit surface A. It will be.
The wavelength selective reflection layer 6 is composed of a single cholesteric liquid crystal layer whose spiral pitch is continuously changed in the thickness direction of the liquid crystal layer. The wavelength selective reflection layer 6 composed of the cholesteric liquid crystal layer may be directly formed on the first gap layer 8 by coating, or a film in which a cholesteric liquid crystal layer is formed on a substrate is punched into a hologram recording medium shape. May be. By a single cholesteric liquid crystal layer whose spiral pitch is continuously changed in the thickness direction of the liquid crystal layer, λ _{0 to} λ ₀ / cos 20 °, particularly λ _{0 to} λ ₀ / cos 40 ° (where λ ₀ is the wavelength of the irradiation light) In this case, the light reflectance is 40% or more, and the selective reflection wavelength does not shift even if the incident angle changes.

  The hologram recording medium 21 in the present embodiment may be disk-shaped or card-shaped. In the case of a card shape, there is no need for the servo pit pattern. In the hologram recording medium 21, the second substrate 1 is 0.6 mm, the first gap layer 8 is 100 μm, the wavelength selective reflection layer 6 is 2 to 3 μm, the recording layer 4 is 0.6 mm, and the first substrate 5 is 0 mm. The total thickness is about 1.9 mm.

Next, the optical operation around the hologram recording medium 21 will be described with reference to FIG. First, servo light (red light) emitted from the servo laser is reflected almost 100% by the dichroic mirror 13 and passes through the objective lens 12. Servo light is irradiated onto the hologram recording medium 21 by the objective lens 12 so as to be focused on the reflecting surface 2. That is, the dichroic mirror 13 transmits light having a wavelength of green or blue, and reflects light having a wavelength of red by almost 100%. The servo light incident from the light incident / exit surface A of the hologram recording medium 21 passes through the first substrate 5, the hologram recording layer 4, the wavelength selective reflection layer 6, and the first gap layer 8, and is reflected by the reflection surface 2. Then, the light passes through the first gap layer 8, the wavelength selective reflection layer 6, the hologram recording layer 4, and the first substrate 5 and is emitted from the incident / exit surface A again. The returned return light passes through the objective lens 12, is reflected almost 100% by the dichroic mirror 13, and servo information is detected by a servo information detector (not shown). The detected servo information is used for focus servo, tracking servo, slide servo, and the like. Since the hologram material constituting the hologram recording layer 4 is not sensitive to red light, even if the servo light passes through the hologram recording layer 4 or the servo light is irregularly reflected on the reflecting surface 2, The hologram recording layer 4 is not affected. Further, since the return light from the reflection surface 2 of the servo light is reflected almost 100% by the dichroic mirror 13, the servo light is detected by the CMOS sensor or CCD 14 for detecting the reproduced image. In addition, there is no noise with respect to the reproduction light.
The reflection region of λ ₀ ~1.3λ ₀ shown in FIG. 2, 1.3λ ₀ = 692nm next when lambda ₀ = 532 nm, the servo light in the case of 655nm would reflect servo light. The range of λ _{0 to} 1.3λ ₀ shown here is suitable for ± 40 ° incident light in the wavelength selective reflection layer. However, when actually using such a large oblique light, the servo within an incident angle of ± 20 ° is used. If the light is masked and used, servo control can be performed without any problem. If the spiral pitch of the cholesteric liquid crystal layer in the wavelength selective reflection layer to be used is sufficiently large, it is easy to design all the incident angles within ± 20 ° in the wavelength selective reflection layer. Since the cholesteric liquid crystal layer of λ _{0 to} 1.1λ ₀ shown in FIG.

  The information light and the recording reference light generated from the recording / reproducing laser pass through the polarizing plate 16 to become linearly polarized light, pass through the half mirror 17 and pass through the quarter-wave plate 15 at a time. Become polarized. The hologram recording medium 21 passes through the dichroic mirror 13 and is irradiated by the objective lens 12 so as to generate an interference pattern in the information light and recording reference light hologram recording layer 4. The information light and the recording reference light enter from the incident / exit surface A and interfere with each other in the hologram recording layer 4 to generate an interference pattern there. Thereafter, the information light and the recording reference light pass through the hologram recording layer 4 and enter the wavelength selective reflection layer 6, but are reflected to the bottom surface of the wavelength selective reflection layer 6 to become return light. That is, the information light and the recording reference light do not reach the reflecting surface 2. This is because the wavelength selective reflection layer 6 is formed of a single cholesteric liquid crystal layer whose spiral pitch continuously changes in the thickness direction of the liquid crystal layer, and has a property of transmitting only red light. Alternatively, if the light passing through the wavelength selective reflection layer is suppressed to 20% or less of the incident light intensity, even if the leaked light reaches the bottom surface and becomes return light, it is reflected again by the wavelength selective reflection layer. Therefore, the light intensity mixed in the reproduction light is 20% × 20% = 4% or less, which is not a problem.

<Second Embodiment>
FIG. 7 is a schematic cross-sectional view showing the configuration of the hologram recording medium in the second embodiment of the present invention. In the hologram recording medium 22 according to the second embodiment, a servo pit pattern 3 is formed on a polycarbonate resin or glass substrate 1, and the surface of the servo pit pattern 3 is coated with aluminum, gold, platinum or the like to form a reflection surface 2. Is provided. The height of the servo pit pattern 3 is the same as that of the first embodiment in that it is normally 1750 mm (175 nm).

  The difference in structure between the second embodiment and the first embodiment is that, in the hologram recording medium 22 according to the second embodiment, the second gap layer 7 is provided between the wavelength selective reflection layer 6 and the hologram recording layer 4. It is provided.

  A wavelength selective reflection layer 6 composed of a single cholesteric liquid crystal layer whose helical pitch continuously changes in the thickness direction of the liquid crystal layer is formed on the first gap layer 8 after the first gap layer 8 is formed. The thing similar to said 1st embodiment can be used.

  The second gap layer 7 has a point where information light and reproduction light are focused. If this area is filled with a photopolymer, excessive consumption of monomers due to overexposure occurs, resulting in a decrease in multiple recording capability. Therefore, it is effective to provide a non-reactive and transparent second gap layer.

  In the hologram recording medium 22, the second substrate 1 is 1.0 mm, the first gap layer 8 is 100 μm, the wavelength selective reflection layer 6 is 3 to 5 μm, the second gap layer 7 is 70 μm, and the recording layer 4 is 0.6 mm. The first substrate 5 has a thickness of 0.4 mm, and the total thickness is about 2.2 mm.

  When recording or reproducing information, the hologram recording medium 22 having such a structure is irradiated with red servo light, green information light, and recording and reproduction reference light. The servo light enters from the incident / exit surface A, passes through the hologram recording layer 4, the second gap layer 7, the wavelength selective reflection layer 6, and the first gap layer 8, is reflected by the reflection surface 2, and returns as light. Become. The return light again passes through the first gap layer 8, the wavelength selective reflection layer 6, the second gap layer 7, the hologram recording layer 4, and the first substrate 5 in this order, and is emitted from the incident / exit surface A. The emitted return light is used for focus servo, tracking servo, and the like. Since the hologram material constituting the hologram recording layer 4 is not sensitive to red light, even if the servo light passes through the hologram recording layer 4 or the servo light is irregularly reflected on the reflecting surface 2, The recording layer 4 is not affected. Green information light or the like enters from the incident / exit surface A, passes through the hologram recording layer 4 and the second gap layer 7, and is reflected by the wavelength selective reflection layer 6 to become return light. The return light again passes through the second gap layer 7, the hologram recording layer 4, and the first substrate 5 in this order, and is emitted from the incident / exit surface A. Also during reproduction, not only the reproduction reference light but also the reproduction light generated by irradiating the hologram recording layer 4 with the reproduction reference light is emitted from the incident / exit surface A without reaching the reflecting surface 2. The optical operation in the vicinity of the hologram recording medium 22 (the objective lens 12, the wavelength selective reflection layer 6, the CMOS sensor or the CCD 14 as a detector in FIG. 8) is the same as that in the first embodiment (FIG. 8) and will be described. Omitted.

(Method for manufacturing hologram recording medium)
As a method for producing the hologram recording medium of the present invention, the hologram recording layer is formed by depositing the composition for a hologram recording medium of the present invention between a first substrate and a second substrate. At least a process, a wavelength selective reflection layer forming process, a reflecting surface forming process, and further other processes as necessary.
<Hologram recording layer forming step>
The hologram recording layer forming step is a step of forming the hologram recording layer by depositing the composition for a hologram recording medium of the present invention between a first substrate and a second substrate. The method for depositing the hologram recording layer between the first substrate and the second substrate is as described in the description of the hologram recording layer.

<Wavelength selective reflection layer forming step>
The wavelength selective reflection layer forming step is a step of bonding the wavelength selective reflection layer processed into the same shape as the hologram recording medium to the second substrate, and the method of forming the wavelength selective reflection layer is as described above. .
<Reflective surface formation process>
The reflection surface forming step is a step of forming a reflection surface on the servo pit pattern surface of the substrate, and the method of forming the reflection surface is as described above.

There is no restriction | limiting in particular as a shape of the said hologram recording medium, According to the objective, it can select suitably, A disk shape, a card | curd shape, etc. are mentioned.
There is no restriction | limiting in particular as said process, According to the objective, it can select suitably, For example, the cutting process by a press cutter, the punching process by a punch cutter, etc. are mentioned.
In the bonding, for example, an adhesive, a pressure-sensitive adhesive, or the like is used to attach a filter to the substrate so that bubbles do not enter.
The adhesive is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include various adhesives such as a UV curable type, an emulsion type, a one-component curable type, and a two-component curable type, Known adhesives can be used in any combination.
There is no restriction | limiting in particular as said adhesive, According to the objective, it can select suitably, For example, a rubber adhesive, an acrylic adhesive, a silicone adhesive, a urethane adhesive, a vinyl alkyl ether adhesive , Polyvinyl alcohol pressure sensitive adhesive, polyvinyl pyrrolidone pressure sensitive adhesive, polyacrylamide pressure sensitive adhesive, cellulose pressure sensitive adhesive, and the like.
The application thickness of the adhesive or the pressure-sensitive adhesive is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of optical properties and thinning, 0.1 to 10 μm is preferable in the case of an adhesive, 0.1-5 micrometers is more preferable. Moreover, in the case of an adhesive, 1-50 micrometers is preferable and 2-30 micrometers is more preferable.

  In some cases, the wavelength selective reflection layer can be formed directly on the substrate. For example, a method of forming a cholesteric liquid crystal layer by applying a coating solution for a cholesteric liquid crystal layer containing at least a nematic liquid crystal compound and a photoreactive chiral compound on a substrate can be mentioned.

  Depending on the method for producing the hologram recording medium of the present invention, since a compound capable of reacting with a polymerizable group in the monomer by external stimulation is contained, the monomer does not move or polymerize over time, and the hologram image has a high height. It is possible to efficiently manufacture a hologram recording medium capable of density recording and accurate reproduction.

(Hologram recording method and hologram reproducing method)
The hologram recording method of the present invention irradiates the hologram recording medium of the present invention with information light and reference light as a coaxial light beam, and records information on a recording layer by an interference pattern due to interference between the information light and the reference light. Further, it is preferable to perform heat development on the hologram recording layer after the recording. This heat development inactivates the remaining silver halide and prevents printout.
Further, the light used for the hologram recording is preferably coherent light such as laser light having a wavelength of 300 to 1,200 nm.
In the hologram reproducing method of the present invention, information is reproduced by irradiating the interference pattern recorded on the hologram recording layer by the hologram recording method of the present invention with reference light.

  In the hologram recording method and the hologram reproducing method of the present invention, as described above, a photosensitive hologram recording layer is formed by combining information light having a two-dimensional intensity distribution and the information light and reference light having a substantially constant intensity. Information is recorded by superimposing them inside and generating a distribution of optical characteristics inside the hologram recording layer by using an interference pattern formed by them. On the other hand, when reading (reproducing) written information, the hologram recording layer is irradiated with only the reference light in the same arrangement as in recording, and an intensity distribution corresponding to the optical characteristic distribution formed inside the hologram recording layer is obtained. The reproduced light is emitted from the hologram recording layer.

<Recording and reproduction of hologram image>
As a method and a hologram recording / reproducing apparatus for recording a hologram on the hologram recording medium of the present invention and a hologram recording / reproducing apparatus, any of those proposed can be used for recording and reproducing a hologram on the hologram recording medium of the present invention. Can be used in a timely manner. Examples of such hologram recording and hologram reproducing method and hologram recording / reproducing apparatus include, for example, US Pat. Nos. 5,719,691, 5,838,467, 6,163,391, and 6,414. 296, U.S. Publication No. 2002-136143, JP-A-9-305978, JP-A-10-124872, JP-A-11-219540, JP-A-2000-98862, JP-A-2000-2988837, JP-A-2001-23169, 2002-83431, 2002-123949, 2002-123948, 2003-43904, 2004-171611, World Patents 99/57719, 02/05270, 02/75727, etc. What has been described can be mentioned. As a light source as a laser used in the above-described hologram recording and hologram reproducing method and hologram recording / reproducing apparatus, the photopolymerization initiator in the recording medium is activated to enable holographic recording, and the recorded hologram is read. Any laser light source that can be used can be used without particular limitation. Examples of such a light source include a blue region semiconductor laser, an argon laser, a He—Cd laser, a frequency doubled YAG laser, a He—Ne laser, a Kr laser, and a near infrared region semiconductor laser.

<Heat development>
By performing thermal development on the hologram recording layer after the hologram recording, in the region where a latent image is formed by exposure to silver halide, the reaction with the reducing agent is accelerated and active radicals are generated. The polymerization reaction can be efficiently advanced, and the sensitivity can be dramatically improved. At the same time, the remaining silver halide that has not been consumed by the reduction can be inactivated and fixed, and the printout prevention effect can be enhanced.
Examples of the thermal development method include a method in which the hologram recording layer is brought into close contact with a heated object (for example, a metal plate, a block, a roller, etc.), a method in which the hologram recording layer is immersed in a heated liquid, and infrared irradiation. This method can be performed using a method, a method of irradiating laser light, or the like. Among these, in order to sequentially develop only the recorded portion, a method of irradiating a laser beam is preferable.

<Fixing of hologram image>
The composition for hologram recording medium used in the present invention can be fixed. Fixing refers to photolysis of the photoinitiator in the composition for a hologram recording medium by irradiating the hologram recording layer on which hologram recording has been completed, thereby losing its polymerization initiation ability. In order not to damage the hologram image by this fixing, it is necessary to perform light irradiation using incoherent light under a mild condition with respect to the hologram recording layer.
As a light irradiation method in the previous period, irradiation may be performed on the entire surface, irradiation may be performed in a line shape, or irradiation may be performed in a dot shape.
The light source used for fixing is preferably irradiated with incoherent light, and examples thereof include a fluorescent lamp, a high-pressure mercury lamp, a xenon lamp, and a light emitting diode. The energy intensity at the time of light irradiation is preferably less than 1 J / cm ² , and more preferably less than 300 mJ / cm ² . If the energy intensity exceeds 1 J / cm ² , the hologram image may be damaged.

Here, the hologram recording method and hologram reproducing method of the present invention are specifically performed using, for example, the hologram recording / reproducing apparatus of the present invention described below.
A hologram recording / reproducing apparatus used in the hologram recording method and hologram reproducing method of the present invention will be described with reference to FIG.
FIG. 9 is an overall configuration diagram of a hologram recording / reproducing apparatus according to an embodiment of the present invention. The hologram recording / reproducing apparatus includes a hologram recording apparatus and a hologram reproducing apparatus.
The hologram recording / reproducing apparatus 100 controls a spindle 81 to which the hologram recording medium 20 is attached, a spindle motor 82 for rotating the spindle 81, and the spindle motor 82 so as to keep the rotation speed of the hologram recording medium 20 at a predetermined value. A spindle servo circuit 83.
The hologram recording / reproducing apparatus 100 records information by irradiating the hologram recording medium 20 with information light and a recording reference light, and irradiates the hologram recording medium 20 with a reproduction reference light for reproduction. A pickup 31 for detecting light and reproducing information recorded on the hologram recording medium 20 is provided, and a drive device 84 that enables the pickup 31 to move in the radial direction of the hologram recording medium 20.

  The hologram recording / reproducing apparatus 100 uses a detection circuit 85 for detecting a focus error signal FE, a tracking error signal TE, and a reproduction signal RF from an output signal of the pickup 31, and a focus error signal FE detected by the detection circuit 85. Based on this, the actuator in the pickup 31 is driven to move the objective lens (not shown) in the thickness direction of the hologram recording medium 20 to perform focus servo, and the tracking error signal detected by the detection circuit 85. A tracking servo circuit 87 that drives the actuator in the pickup 31 based on TE to move the objective lens in the radial direction of the hologram recording medium 20 to perform tracking servo, a tracking error signal TE, and a controller to be described later And a slide servo circuit 88 for performing a slide servo for moving the pickup 31 in the radial direction of the hologram recording medium 20 by controlling the drive unit 84 based on the command.

The hologram recording / reproducing apparatus 100 further decodes output data of a later-described CMOS or CCD array in the pickup 31 to reproduce data recorded in the data area of the hologram recording medium 20 or reproduce from the detection circuit 85. A signal processing circuit 89 that reproduces a basic clock and discriminates an address from the signal RF, a controller 90 that controls the entire hologram recording / reproducing apparatus 100, and an operation unit 91 that gives various instructions to the controller 90 It has.
The controller 90 inputs the basic clock and address information output from the signal processing circuit 89, and controls the pickup 31, spindle servo circuit 83, slide servo circuit 88, and the like. The spindle servo circuit 83 receives the basic clock output from the signal processing circuit 89. The controller 90 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and the CPU executes a program stored in the ROM using the RAM as a work area. The function of the controller 90 is realized.

  Since the hologram recording / reproducing apparatus used in the hologram recording method and the hologram reproducing method of the present invention uses the hologram recording medium of the present invention, the selective reflection wavelength does not shift even if the incident angle changes. It is possible to prevent irregular reflection from the reflecting surface of the hologram recording medium by information light and reference light, to prevent generation of noise, and to realize high density recording that has never been achieved.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

＜ハロゲン化銀分散液（１）の調製＞
ポリプロピレンオキサイドトリオール（分子量１，０００）６０．２ｇに対し、前記で得られたハロゲン化銀粒子０．２０ｇ、下記構造式（３）で表される化合物（ＦＦ−１）１．０ｍｇを添加し、ボールミルで８時間再分散を行い、ハロゲン化銀分散液（１）を得た。

Example 1
<Preparation of silver halide emulsion (silver halide grains)>
24 g of lime-treated inert gelatin was added to distilled water, dissolved at 40 ° C. over 1 hour, 3 g of NaCl was added, and IN sulfuric acid was added to adjust to pH 3.2.
In the above prepared solution, the solution I (AgNO ₃ 120 g, distilled water 550 g) and the solution II (KBr 85 g, distilled water 550 g) were used at 60 ° C. using the control double jet method, while maintaining pAg = 8.5. It was added over 15 minutes until the liquid disappeared. After completion of the addition, the pH was adjusted to 6.0 with IN NaOH, and 4.8 mg of the compound (ATR-1) represented by the following structural formula (1) and the compound represented by the following structural formula (2) (S -1) 450 mg was added, and 100 g of an aqueous solution containing 4.1 g of KI was added at an equal flow rate over 20 to 30 minutes after the addition.
To the emulsion thus prepared, 1.1 g of poly (isobutylene-co-maleic acid monosodium) was added and precipitated, washed with water and desalted.
Thus, a monodispersed silver halide emulsion having an average grain size of 0.08 μm and a variation coefficient of 22% was prepared.
The silver halide emulsion obtained above was dried by heating at 40 ° C. under reduced pressure to take out silver halide grains.

<Preparation of silver halide dispersion (1)>
0.26 g of the silver halide grains obtained above and 1.0 mg of the compound (FF-1) represented by the following structural formula (3) were added to 60.2 g of polypropylene oxide triol (molecular weight 1,000). Then, re-dispersion was performed for 8 hours with a ball mill to obtain a silver halide dispersion (1).

<Preparation of composition for hologram recording medium>
The following compositions were mixed under a stream of dry air to prepare a composition for a hologram recording medium.
------------------------------------
-31.0 parts by mass of biscyclohexylmethane diisocyanate-60.4 parts by mass of the silver halide dispersion (1) synthesized above-2.5 parts by mass of tetramethylene glycol-3.1 parts by mass of 4-chlorophenoxyethyl acrylate -0.81 mass part of reducing agent (RD-1) represented by following Structural formula (4)-0.5 mass part of base precursor (BG-1) represented by following Structural formula (5)-The following structural formula Compound (FF-2) represented by (6) 0.5 parts by mass / dibutyl dilaurate tin 1.01 parts by mass ---------------------- ---------------
In Example 1, the content of silver halide in the hologram recording layer is 0.064% by mass, and the content of the polymerizable monomer (4-chlorophenoxyethyl acrylate) is 3.1% by mass.

<Production of hologram recording medium>
As the first and second substrates, general polycarbonate resin substrates used for DVD + RW having a diameter of 120 mm and a plate thickness of 0.6 mm were used. A servo pit pattern is formed over the entire surface of the second substrate, the track pitch is 0.74 μm, the groove depth is 175 nm, and the groove width is 300 nm.
First, a reflective surface was formed on the servo pit pattern surface of the second substrate. Aluminum (Al) was used as the reflective surface material. The film was formed by forming a 200 nm-thick Al reflecting surface by DC magnetron sputtering.

Next, SD-640 (manufactured by Dainippon Ink Co., Ltd.) was applied as a protective layer on the Al reflecting surface by spin coating so as to have a thickness of 50 μm. On this protective layer, TiO ₂ and SiO ₂ were alternately deposited to a total of 11 layers to form a wavelength selective reflection layer having a thickness of λ / 4.

  Next, the hologram recording medium composition is placed on the second substrate using a dispenser to form a hologram recording layer, and a 12 cm diameter, 0.6 mm thick polycarbonate resin layer is formed on the hologram recording layer. The hologram recording layer was sandwiched between the first substrate and the second substrate while pressing one substrate, and the end of the second substrate and the first substrate were bonded together with an adhesive. Note that a cylindrical flange portion is provided at the end of the second substrate so that the hologram recording layer has a thickness of 500 μm, and the first substrate is bonded to the flange portion to thereby form a hologram recording layer. The thickness is determined. The bonded first substrate and second substrate were allowed to cool at 40 ° C. for 24 hours to produce a hologram recording medium. FIG. 6 is a schematic cross-sectional view showing a form similar to this example. In this example, a hologram recording medium was manufactured without providing the wavelength selective reflection layer and the second gap layer shown in FIG. Yes.

<Hologram recording on the hologram recording layer and evaluation>
Using the collinear hologram recording / reproduction tester SHOT-1000 manufactured by Pulstec Industrial Co., Ltd., the hologram recording medium produced as described above was subjected to a series of multiplexing with a recording spot size of 200 μm in diameter at the focal position of the recording hologram. A hologram was written, and the sensitivity (recording energy) and multiplex number were measured and evaluated. The results are shown in Table 2.

(Measurement of sensitivity)
The irradiation light energy (mJ / cm ² ) at the time of recording was changed, and the change in the error probability (BER: Bit Error Rate) of the reproduction signal was measured. Usually, the luminance of the reproduction signal increases with the increase of irradiation light energy, and the BER of the reproduction signal tends to gradually decrease. Here, the recording light sensitivity of the hologram recording medium is defined as the lowest irradiation light energy at which a substantially good reproduced image (BER <10 ⁻³ ) can be obtained. The results are shown in Table 2.

(Evaluation of the number of times that multiple recording is possible)
As an evaluation method of the number of times of possible multiplex recording of the obtained hologram recording medium, ISOM'04, Th-J-06, pp. 184-185, Oct. In 2004, the recording spot was shifted in a spiral shape and evaluated. Here, the number of recorded holograms was 13 × 13 = 169 holograms, and the recording pitch was 28.5 μm. The multiplicity when recording the last 169th hologram is 49.
Since the multiplicity increases as the number of recording holograms increases, the BER increases as the number of recordings increases if the multiplexing characteristics of the hologram recording medium are insufficient. Here, the number of recording holograms with BER> 10−3 is defined as the multiplex characteristic M of the hologram recording medium. The results are shown in Table 2.

(Evaluation of transmission visual density)
The sample after recording was allowed to stand under a 500 lux fluorescent lamp for 24 hours, and then the part where the second substrate and the end of the first substrate were bonded was cut, and the second substrate, protective layer, Then, after peeling off the wavelength selective reflection layer, the transmission visual density of the hologram recording layer was measured using a reflection densitometer RD-904 manufactured by Macbeth. The results are shown in Table 2.

(Example 2)
<Production of hologram recording medium>
In the same manner as in Example 1, the hologram recording medium composition was prepared, and the hologram recording medium of Example 2 was produced.

<Hologram recording on the hologram recording layer>
For the obtained hologram recording medium of Example 2, hologram recording was performed in the same manner as in Example 1.
<Heat development>
The hologram recording layer on which the hologram recording was performed was thermally developed by heating at 120 ° C. for 15 seconds with a heat developing apparatus equipped with a heat roller. With respect to the hologram recording layer subjected to the heat development, the sensitivity, the number of multiplex recordings and the transmission visual density were measured. The results are shown in Table 2.

(Example 3)
<Production of hologram recording medium>
In Example 1, 60.4 parts by mass of the silver halide dispersion (1) in the hologram recording medium composition was changed to 6.1 parts by mass of the silver halide dispersion (1) and polypropylene oxide triol (molecular weight 1, 000) The composition for a hologram recording medium was prepared in the same manner as in Example 1 except that the silver halide content was 0.006% by mass, instead of 54.3 parts by mass. A hologram recording medium was produced.
The obtained hologram recording medium of Example 3 was subjected to hologram recording in the same manner as in Example 1. Then, the hologram recording layer was thermally developed in the same manner as in Example 2. For the hologram recording medium of Example 3, the sensitivity, the number of multiplex recordings and the transmission visual density were measured. The results are shown in Table 2.

Example 4
<Preparation of halogenated dispersion (2)>
For 60.2 g of polypropylene oxide triol (molecular weight 1,000), 0.94 g of silver halide grains obtained by adjusting the silver halide emulsion, compound (FF-1) represented by the structural formula (3) 4.5 mg was added and redispersed for 8 hours with a ball mill to obtain a silver halide dispersion (2).
<Production of hologram recording medium>
In Example 1, 60.4 parts by mass of the silver halide dispersion (1) in the composition for a hologram recording medium was replaced with 61.14 parts by mass of the silver halide dispersion (2) obtained above. Except for this, the hologram recording medium composition of Example 4 was prepared in the same manner as in Example 1, except that the composition for a hologram recording medium was adjusted.
In Example 4, the content of silver halide in the hologram recording layer is 0.3% by mass.
The obtained hologram recording medium of Example 4 was subjected to hologram recording in the same manner as in Example 1. Then, the hologram recording layer was thermally developed in the same manner as in Example 2. For the hologram recording medium of Example 4, the sensitivity, the number of multiplex recordings and the transmission visual density were measured. The results are shown in Table 2.

(Example 5)
<Production of hologram recording medium>
In Example 1, 0.81 part by mass of the reducing agent (RD-1) represented by the structural formula (4) in the hologram recording medium composition is used as the reducing agent represented by the following structural formula (7). (RD-2) A holographic recording medium composition of Example 5 was prepared in the same manner as in Example 1 except that the composition was changed to 1.22 parts by mass.
The obtained hologram recording medium of Example 5 was subjected to hologram recording in the same manner as in Example 1. Then, the hologram recording layer was thermally developed in the same manner as in Example 2. For the hologram recording medium of Example 5, the sensitivity, the number of multiplex recordings and the transmission visual density were measured. The results are shown in Table 2.

(Example 6)
<Production of hologram recording medium>
In Example 1, 0.81 part by mass of the reducing agent (RD-1) represented by the structural formula (4) in the hologram recording medium composition is used as the reducing agent represented by the structural formula (4). (RD-1) Hologram recording in the same manner as in Example 1 except that 0.30 part by mass and 0.81 part by mass of the reducing agent (RD-3) represented by the following structural formula (8) are used. The medium composition was adjusted to produce a hologram recording medium of Example 6.
The obtained hologram recording medium of Example 6 was subjected to hologram recording in the same manner as in Example 1, and then thermally developed on the hologram recording layer in the same manner as in Example 2. For the hologram recording medium of Example 6, the sensitivity, the number of multiplex recordings, and the transmission visual density were measured. The results are shown in Table 2.

(Example 7)
<Production of hologram recording medium>
In Example 1, the same composition as Example 1 except that 0.08 parts by mass of a reducing agent (RD-4) represented by the following structural formula (9) was further added to the composition for hologram recording medium. Then, the composition for a hologram recording medium was prepared, and the hologram recording medium of Example 7 was produced.
The obtained hologram recording medium of Example 7 was subjected to hologram recording in the same manner as in Example 1, and then thermally developed on the hologram recording layer in the same manner as in Example 2. For the hologram recording medium of Example 7, the sensitivity, the number of multiplex recordings, and the transmission visual density were measured. The results are shown in Table 2.

(Example 8)
In Example 1, a hologram recording medium was produced using the same composition for a hologram recording medium as in Example 1 except that a wavelength selective reflection layer was provided on the second substrate. The wavelength selective reflection layer was produced as follows.
<Production of hologram recording medium>
-Fabrication of wavelength selective reflection layer-
First, a base film was prepared by coating polyvinyl alcohol (manufactured by Kuraray Co., Ltd., trade name MP203) with a thickness of 1 μm on a polycarbonate film (Mitsubishi Gas Chemical Co., Ltd., trade name Iupilon) having a thickness of 100 μm. This base film was passed through a rubbing apparatus to rub the surface of the polyvinyl alcohol film to give liquid crystal alignment ability.

  Next, a coating solution for a cholesteric liquid crystal layer having a composition shown in Table 1 below was prepared by a conventional method.

＊ＵＶ重合性液晶：ＢＡＳＦ社製、商品名ＰＡＬＩＯＣＯＬＯＲ ＬＣ２４２
＊光反応型カイラル剤：下記式で表される光学活性イソソルビド誘導体

＊光重合開始剤：チバスペシャルティケミカルズ社製、商品名イルガキュア３６９
＊増感剤：ジエチルチオキサントン
＊溶剤：メチルエチルケトン（ＭＥＫ）

* UV polymerizable liquid crystal: manufactured by BASF, trade name PALIOCOLOR LC242
* Photoreactive chiral agent: optically active isosorbide derivative represented by the following formula

* Photopolymerization initiator: Product name Irgacure 369, manufactured by Ciba Specialty Chemicals
* Sensitizer: Diethylthioxanthone * Solvent: Methyl ethyl ketone (MEK)

Next, the cholesteric liquid crystal layer coating solution was applied onto the base film with a bar coater, dried, and then subjected to orientation aging at 110 ° C. for 20 seconds. Then, light irradiation was performed for 1 minute with an ultrahigh pressure mercury lamp through a bandpass filter having a light source center wavelength at 365 nm at 110 ° C. Subsequently, it was kept in a dark place for 5 minutes while being maintained at 110 ° C. Thereafter, the bandpass filter is removed, and the entire surface is further exposed with an irradiation energy of 500 mJ / cm ² with an ultrahigh pressure mercury lamp similar to the above while blowing nitrogen gas, and polymerized and cured to form a cured cholesteric liquid crystal layer having a thickness of 5 μm. did.
Thus, the wavelength selective reflection layer of Example 4 was produced.

About the obtained wavelength selective reflection layer, the light reflection characteristic was measured using a spectroscopic reflection measuring instrument (manufactured by Hamamatsu Photonics Co., Ltd., L-5562 as a light source, and photomultichannel analyzer by Hamamatsu Photonics Co., Ltd., PMA-11). .
As a result, it was confirmed that the filter can reflect 40% or more of 532 nm light, which is a selected wavelength, with respect to light having an incident angle within ± 20 ° as shown in FIGS. The selective reflection wavelength bandwidth was as wide as 180 nm.

In the same manner as in Example 1, a reflective surface was formed of aluminum on the servo pit pattern surface of the second substrate made of polycarbonate resin having a diameter of 120 mm and a plate thickness of 0.6 mm.
Next, the wavelength selective reflection layer produced above was punched into a predetermined disk size so that it could be placed on the substrate, and the base film surface was attached to the second substrate with the servo pit pattern side. The bonding was performed using an ultraviolet curable resin or a pressure-sensitive adhesive so as not to contain bubbles.

Next, using the composition for a hologram recording medium prepared in Example 1, the hologram recording is performed between the second substrate having the wavelength selective reflection layer and the first substrate by the same production method as in Example 1. A layer was formed. Thus, the hologram recording medium of Example 5 was produced. FIG. 6 is a schematic sectional view showing a form similar to the present embodiment.
The obtained hologram recording medium of Example 8 was subjected to hologram recording in the same manner as in Example 1, and then thermally developed on the hologram recording layer in the same manner as in Example 2. For the hologram recording medium of Example 8, the sensitivity, the number of multiplex recordings, and the transmission visual density were measured. The results are shown in Table 2.

Example 9
-Production of hologram recording medium-
In Example 8, the hologram recording medium of Example 9 was produced in the same manner as Example 8 except that the second gap layer was provided between the reflective surface and the wavelength selective reflection layer. In addition, as a 2nd gap layer, the 100-micrometer-thick polycarbonate film was used and it adhere | attached with the ultraviolet curable resin. FIG. 7 is a schematic sectional view showing a form similar to the present embodiment.
The obtained hologram recording medium of Example 9 was subjected to hologram recording in the same manner as in Example 1, and then thermally developed on the hologram recording layer in the same manner as in Example 2. For the hologram recording medium of Example 9, the sensitivity, the number of multiplex recordings, and the transmission visual density were measured. The results are shown in Table 2.

(Example 10)
Using the same hologram recording medium as in Example 1, hologram recording was performed in the same manner as in Example 1. The hologram recording layer on which the hologram recording was performed was subjected to heat development using a 500 W infrared laser (870 nm) instead of heating the heat roller in Example 2. The heat development was performed by irradiating an area having a diameter of 200 μm of the hologram recording layer on which the hologram recording was performed with infrared laser irradiation for 3 seconds. For the hologram recording medium of Example 10, the sensitivity, the number of multiplex recordings and the transmission visual density were measured. The results are shown in Table 2.

(Example 11)
Using the same hologram recording medium as in Example 1, hologram recording was performed in the same manner as in Example 1. The hologram recording layer on which the hologram recording was performed was subjected to heat development using a 500 W infrared lamp instead of heating the heat roller in Example 2. The heat development was performed by irradiating the entire hologram recording layer on which the hologram recording was performed with an infrared lamp for 30 seconds and heating it. For the hologram recording medium of Example 11, the sensitivity, the number of multiplex recordings and the transmission visual density were measured. The results are shown in Table 2.

(Example 12)
<Production of hologram recording medium>
A hologram recording medium was obtained in the same manner as in Example 1 except that 3.1 parts by mass of 4-chlorophenoxyethyl acrylate in the composition for hologram recording medium in Example 1 was replaced with 41.5 parts by mass. The holographic recording medium of Example 12 was prepared by adjusting the composition for use.
In Example 12, the content of silver halide in the hologram recording layer is 0.046% by mass, and the content of polymerizable monomer (4-chlorophenoxyethyl acrylate) is 30% by mass.
The obtained hologram recording medium of Example 12 was subjected to hologram recording in the same manner as in Example 1. Then, the hologram recording layer was thermally developed in the same manner as in Example 2. For the hologram recording medium of Example 12, the sensitivity, the number of multiplex recordings, and the transmission visual density were measured. The results are shown in Table 2.

(Comparative Example 1)
<Production of hologram recording medium>
In Example 1, the hologram recording medium composition was prepared in the same manner as in Example 1 except that the composition for hologram recording medium was changed to the following composition and silver halide was not used. Was made.
[Preparation of composition for hologram recording medium]
The following compositions were mixed under a stream of dry air to prepare a composition for a hologram recording medium.
------------------------------------
-Biscyclohexylmethane diisocyanate 31.0 parts by mass-Polypropylene oxide triol (molecular weight 1,000) 60.2 parts by mass-Tetramethylene glycol 2.5 parts by mass-4-Chlorophenoxyethyl acrylate 3.1 parts by mass-Start photopolymerization Agent [Ciba Special Chemical Co., Ltd., Irgacure 784] 0.69 parts by mass Dibutyl dilaurate tin 1.01 parts by mass ---------------------- ---------------
Using the hologram recording medium composition, a hologram recording medium of Comparative Example 1 was produced in the same manner as Example 1.
The obtained hologram recording medium of Comparative Example 1 was subjected to hologram recording in the same manner as in Example 1, and the sensitivity, the number of multiplex recordings and the transmission visual density were measured. The results are shown in Table 2.

表２の結果から、ハロゲン化銀を含み、該ハロゲン化銀の感光性を利用して還元剤を酸化させてラジカルを発生させ、重合性ポリマーをポリマー化させてホログラム画像を記録することが可能なホログラム記録媒体用組成物を用いた実施例１〜１２のホログラム記録媒体では、高感度で高速記録が可能であり、乾式処理が可能で製造及び取扱いが容易であって、かつ、ハロゲン化銀の使用が少量で済み、プリントアウトを防止して、高密度記録が可能であり、ホログラム画像を低コストで効率的に記録できることが判った。また、ハロゲン化銀の含有量が０．０１〜０．１質量％の範囲であり、かつ、分子内にエチレン性二重結合を有する重合性化合物の含有量が３〜２０質量％であり、更に、ホログラム記録後に熱現像により残存ハロゲン化銀を熱不活性化させた実施例２及び５〜１１では、感度及びプリントアウト防止効果に特に優れ、高密度記録情報の記録及び再生が可能であることが判った。
これに対して、ハロゲン化銀を使用しなかった比較例１では、感度が低く、ホログラム記録に時間がかかり、ホログラム記録が非効率的であった。

From the results in Table 2, it is possible to record a hologram image by containing silver halide and oxidizing the reducing agent using the photosensitivity of the silver halide to generate radicals and polymerizing the polymerizable polymer. In the hologram recording media of Examples 1 to 12 using a simple hologram recording medium composition, high-sensitivity and high-speed recording is possible, dry processing is possible, manufacturing and handling are easy, and silver halide is used. It has been found that a small amount of toner can be used, a printout is prevented, high-density recording is possible, and a hologram image can be recorded efficiently at low cost. Further, the content of silver halide is in the range of 0.01 to 0.1% by mass, and the content of the polymerizable compound having an ethylenic double bond in the molecule is 3 to 20% by mass, Furthermore, in Examples 2 and 5 to 11, in which the remaining silver halide was thermally inactivated by thermal development after hologram recording, the sensitivity and the printout prevention effect were particularly excellent, and recording and reproduction of high-density recording information was possible. I found out.
On the other hand, in Comparative Example 1 in which no silver halide was used, sensitivity was low, hologram recording took time, and hologram recording was inefficient.

The composition for a hologram recording medium of the present invention is capable of high-sensitivity and high-speed recording, can be dry-processed, is easy to manufacture and handle, requires a small amount of silver halide, and can be printed out. Therefore, it is suitable for volume hologram recording media, enabling efficient hologram recording, and reading the hologram image accurately for high-density recording. Information can be reproduced.
The hologram recording medium of the present invention can prevent the occurrence of noise without causing a shift in the selective reflection wavelength even when the incident angle is changed, has a large refractive index contrast, and enables high-density image recording. The hologram image can be accurately read and high-density recording information can be reproduced, and it is widely used as various volume hologram recording media.

FIG. 1 is a schematic cross-sectional view showing the structure of a conventional hologram recording medium. FIG. 2 is a graph showing reflection characteristics with respect to incident light from the front surface (0 °) of the wavelength selective reflection layer for a hologram recording medium of the present invention. FIG. 3 is a graph showing reflection characteristics with respect to incident light from a 40 ° inclination direction in the wavelength selective reflection layer for a hologram recording medium of the present invention. FIG. 4 is a graph showing reflection characteristics with respect to incident light from the front (0 °) of the wavelength selective reflection layer for another hologram recording medium of the present invention. FIG. 5 is a graph showing reflection characteristics with respect to incident light from a 20 ° inclination direction in the wavelength selective reflection layer for another hologram recording medium of the present invention. FIG. 6 is a schematic sectional view showing an example of a hologram recording medium according to the first embodiment of the present invention. FIG. 7 is a schematic sectional view showing an example of a hologram recording medium according to the second embodiment of the present invention. FIG. 8 is an explanatory view showing an example of an optical system around the hologram recording medium according to the present invention. FIG. 9 is a block diagram showing an example of the overall configuration of the optical recording / reproducing apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 2nd board | substrate 2 Reflecting surface 3 Servo pit pattern 4 Recording layer 5 1st board | substrate 6 Wavelength selective reflection layer 7 2nd gap layer 8 1st gap layer 12 Objective lens 13 Dichroic mirror 14 Detector 15 1/4 wavelength plate 16 Polarization Plate 17 Half mirror 20 Hologram recording medium 21 Hologram recording medium 22 Hologram recording medium 31 Pickup 81 Spindle 82 Spindle motor 83 Spindle servo circuit 84 Drive device 85 Detection circuit 86 Focus servo circuit 87 Tracking servo circuit 88 Slide servo circuit 89 Signal processing circuit 90 Controller 91 Operation unit 100 Hologram recording / reproducing device A Input / output surface FE Focus error signal TE Tracking error signal RF reproduction signal

Claims (19)

  (A) a binder having a reactive group, (B) a crosslinking agent having a functional group capable of reacting with the reactive group of the binder having the reactive group, and (C) a polymerizable having an ethylenic double bond in the molecule. A composition for a hologram recording medium, comprising at least a compound, (D) silver halide, and (E) a reducing agent.   The composition for a holographic recording medium according to claim 1, wherein the reducing agent (E) generates radicals by an oxidation reaction.   (E) The composition for hologram recording media according to claim 1, wherein the reducing agent is a hydrazine compound.   The composition for a holographic recording medium according to any one of claims 1 to 3, comprising a base precursor.   The composition for a hologram recording medium according to any one of claims 1 to 4, comprising an antifoggant precursor.   (A) the reactive group of the binder having a reactive group is at least selected from hydroxyl group, mercapto group, carboxyl group, amino group, epoxy group, oxetane group, isocyanate group, carbodiimide group, oxazine group, and metal alkoxide The composition for a hologram recording medium according to any one of claims 1 to 5, which is one kind of reactive group.   (C) Content of the polymeric compound which has an ethylenic double bond in a molecule | numerator is 3-20 mass%, The composition for hologram recording media in any one of Claim 1 to 6.   A hologram recording medium comprising at least a substrate and a hologram recording layer containing the composition for a hologram recording medium according to claim 1.   The hologram recording medium according to claim 8, further comprising at least a wavelength selective reflection layer between a substrate and the hologram recording layer.   The hologram recording medium according to claim 8, wherein the substrate has a servo pit pattern.   The hologram recording medium according to claim 10, wherein the substrate has a reflective surface formed on a servo pit pattern.   The hologram recording medium according to claim 9, wherein the wavelength selective reflection layer is a layer made of a dichroic mirror.   The hologram recording medium according to claim 9, wherein the wavelength selective reflection layer is a layer made of cholesteric liquid crystal.   The hologram recording medium according to claim 11, wherein a gap layer for smoothing the substrate surface is provided between the wavelength selective reflection layer and the reflection surface.   15. The hologram recording medium according to claim 8 is irradiated with information light and reference light as a coaxial light beam, and information is recorded on the hologram recording layer by an interference pattern due to interference between the information light and the reference light. And a hologram recording method.   The hologram recording method according to claim 15, wherein coherent light having a wavelength of 300 to 1,200 nm is irradiated.   The hologram recording method according to claim 15, wherein after the information is recorded on the hologram recording layer, the hologram recording layer is thermally developed.   The hologram recording method according to claim 17, wherein the heat development is performed by any one selected from laser light irradiation, infrared light irradiation, and contact with a heat roller. 19. A hologram reproducing method, wherein information is reproduced by irradiating the interference pattern recorded in the hologram recording layer with reference light by the hologram recording method according to claim 15.

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