JP2000109719A - Photoresponsive dicarboxylic acid monomer, its production, photoresponsive polyester and optical recording medium using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject new compound useful as an optical recording material without deteriorating the optical recording properties, having a wide utilizable wavelength region, scarcely causing a loss due to the photoabsorption and capable of providing an optical recording medium excellent in memory properties, degree of modulation, or the like. SOLUTION: This photoresponsive dicarboxylic acid monomer is represented by formula I [X is a lower alkyloxy, benzyloxy, phenyloxy, a lower aliphatic acid residue or the like; Y is H or a lower alkyl; (m) is 1-3; (n) is 2-18], e.g. a compound represented by formula II. The monomer represented by formula I is produced by reacting, e.g. a dicarboxylic acid derivative represented by formula III with an azobenzene derivative represented by formula IV (Z is an atomic group readily eliminable by undergoing the nucleophilic substitution reaction under Williamson's ether synthetic conditions) in the presence of a condensing agent. The resultant monomer can be sued as an optical recording material for an optical recording medium. The monomer is condensed with various aliphatic diols, diols, or the like, containing an aromatic ring to thereby afford a photoresponsive polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel photoresponsive compound, a method for producing the same, and an optical recording medium for recording a large amount of data information using the same.

[0002]

2. Description of the Related Art Rewritable optical disk recording devices of the phase change type, the magneto-optical type and the like are already widely used. These optical disk devices realize large-capacity recording by increasing the recording density by one digit or more as compared with general magnetic disk devices. However, the capacity of operating systems (OS) and application software has been increased due to higher functionality. It is said that it has sufficient performance for future large-capacity recording demands such as increase in capacity, huge capacity due to multi-media of documents and presentation data, digital recording of high-definition, high-density, long-time moving image video signal etc. I can not say. In such a high-density, large-capacity optical disk recording device,
In order to increase the recording density, a device such as reducing the beam spot diameter and shortening the distance between adjacent tracks or adjacent bits is used. A DVD-ROM is one that has already been put into practical use by the development of such technology.
DVD-ROM is 4.7 G on a 12 cm disk on one side
Byte data is stored. A writable and erasable DVD-RAM is capable of high-density recording of 5.2 Gbytes on both sides of a disk having a diameter of 12 cm by a phase change method. This can write and read information of a capacity equivalent to 4 times or more of a read-only CD-ROM and 1900 or more of a floppy disk. As described above, the density of optical discs is increasing year by year. However, on the other hand, the above-mentioned optical disc records data in a plane, so that it is limited by the diffraction limit of light and is approaching the physical limit of high-density recording (5 Gbit / in ² ). Three-dimensional (volume type) including depth direction for even larger capacity
Records are required.

[0003] As the above-mentioned volume type optical recording medium, a wavelength division multiplexing recording medium using a laminated body independently sensitive to a plurality of wavelengths or a photorefractive material medium (photorefractive material) capable of volume recording a hologram grating. Material media) are promising. Some photorefractive materials are known to have a high sensitivity and absorb a relatively weak light of a solid-state laser level, causing a change in the refractive index. It is expected to be used.

[0004] As this photorefractive material,
Conventionally, inorganic ferroelectric crystals such as barium titanate, lithium niobate, and BSO have been widely used. Although these materials exhibit high sensitivity and high efficiency photo-induced refractive index change effect (photorefractive effect), it is difficult to grow crystals, and many hard and brittle materials cannot be processed into arbitrary shapes. There were drawbacks such as difficulty in adjusting the sensitive wavelength.

In recent years, as a method for overcoming these drawbacks, a photorefractive material made of an organic material (hereinafter referred to as PR) has been proposed.
Sometimes called a material. ) Has been proposed. The following compounds A to D are typical organic photorefractive materials. Generally, the organic photorefractive material is: i) a charge generating material which receives light to generate a charge; ii) a charge transfer material which promotes movement of the generated charge in a medium; iii).
A dichroic organic dye sensitive to the electric field induced by charge transfer, iv) a polymeric substrate (binder) carrying these materials, and v) an additive (plasticizer, phase) that changes the physical properties of the substrate. Etc.). Some of these components play multiple roles, such as a charge transfer material / polymer substrate and a charge transfer material / plasticizer. Here, compound A (2,
4,7-Trinitrilofluorenone (TNF) is a charge generating material, compound B (poly (vinyl carbazole) (P
VK)) is a charge transfer material / polymer substrate (binder),
Compound C (N-ethylcarbazole (ECZ)) is a charge transfer material / plasticizer, compound D (2,5-dimethyl-4-
(4'-nitrophenyl) azo annealing (DMNPA
A)) functions as a dichroic organic dye.

[0006]

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FIG. 1 shows the mechanism of the refractive index change induced by light irradiation. The principle of the photorefractive effect is to irradiate a PR material with two coherent lightwaves and to use interference fringes I
(X) is formed. At a place where the light intensity is high, electrons at the donor level are excited into the conduction band, move by diffusion or drift, and are captured at a place where the light intensity is weak. Positive charges remain in places where the light intensity is strong, and negative charges accumulate in places where the light intensity is weak. This forms a charge distribution ρ (x), producing an electrostatic field E (x). As a result of the electro-optic effect due to this electrostatic field, a refractive index change Δn (x) occurs. The period of this refractive index change is the same as the period of the interference fringes, and this refractive index grating acts as a hologram diffraction grating. By such an action, positive and negative charges are generated from the charge generating material that has absorbed the light, and are separated into positive and negative by the charge transfer agent by the action of the external field where the charge is present, thereby generating an internal electric field. Due to this internal electric field, the orientation of the dichroic dye changes, and the distribution of the refractive index in the substrate changes.

By using this method, Meerholz et al. Of the University of Arizona have succeeded in developing a material exhibiting diffraction efficiency [Nature, 371, 49].
7 (1994)]. By applying such a material, it was considered that volume hologram recording with a high recording density was possible in principle.

On the other hand, since this material essentially uses the orientation of the dye due to an external electric field and its change due to light irradiation as a recording mechanism, there is a problem that the application of an external electric field is indispensable at the time of use. is there. This electric field was several hundred V · mm ^{−1 in} a study by Meerholz et al.
This is an extremely large factor, which is a major device restriction when this system is actually used as a recording device. Furthermore, in this material system, several kinds of different materials such as a charge generating material, a charge transfer agent, and a polymer substrate are mixed and used, so that a decrease in stability due to phase separation during recording or storage is a major problem. Become.

In order to avoid the above-mentioned problems, for example, S.I. Hvilsted et al. Have proposed using a polymer compound represented by the following compound E having liquid crystal forming properties to achieve hologram recording by writing a refractive index grating therein [Opt. Lett. , 17 [1
7], 12 (1992)]. In this material, it has been clarified that 330 gratings with a high refractive index can be written in 1 mm, for example, and it is expected that a high recording density will be achieved.

[0011]

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As a material capable of inducing dichroic refractive index to perform hologram recording, a polymer compound represented by the following general formula (α) ([M. Sato, M. Haya
kawa, K .; Nakagawa, K .; Mukaid
a, H .; Fujiwara, Macromol. Rap
id Commun. , 15, 21 (1994)]).

[0013]

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In this polymer compound, it is known that the liquid crystal-non-liquid crystal phase transition phenomenon occurs only in an extremely narrow region. For example, when two coherent laser beams are irradiated on a material made of this polymer compound to form an interference pattern in the material, the liquid crystal-non-liquid crystal is formed only in a region where the two laser beams strengthen each other. A refractive index modulation structure accompanying the transition is formed. In this modulation structure, the distance between the two maximum parts, that is, the period of the modulation structure should be compared with the wavelength region of the irradiation laser light, and it can be seen that this modulation structure is extremely fine. Further, this modulation structure is maintained even after the laser beam irradiation is stopped. This is because the rate of change between the liquid crystal structure and the non-liquid crystal structure thus formed is sufficiently slow at room temperature, and unless the heating is performed entirely or locally by laser light irradiation in the thermal mode, this modulation structure Is not lost. That is, this polymer compound is extremely promising as an optical memory material medium. The present inventors have also confirmed that extremely high-density hologram recording is possible by using a material composed of this compound as a medium.

[0015]

Although not all of the necessary and sufficient conditions on the molecular structure that provide a material capable of performing hologram recording as described above have been elucidated until now, at least the following are required. It is required to meet such requirements. That is, the material has photoisomerizable atomic groups. Also, this atomic group has a large dichroic ratio. The material used has liquid crystallinity in an appropriate temperature range as a whole. It has a molecular structure in which aromatic atomic groups are uniaxially arranged in the direction of the main chain, and a large refractive index dichroism is induced by its orientation change. The main chain contains a flexible molecular chain, and the arrangement of the main chain molecule changes due to a change in the molecular structure of the photoisomerizable atomic group. Materials known to date include an azobenzene structure as a light-sensitive atomic group, and an atomic group containing a cyano group in the azobenzene skeleton with good linearity that functions as a mesogen during liquid crystal formation. −
There are aliphatic polyesters and the like.

In the structure of these polymer compounds, there is a cyano group at the 4-position of azobenzene. In many low-molecular liquid crystals, the rigid linear structure, that is, the cyano group bonded to the core, is thought to have a significant steric or electronic contribution to the stabilization of the liquid crystal structure. There are also reports of polymer recording media [Meng, J. et al. Pol
ym. Sci. , B, Polym. Phys. Ed. ,
34, 1461 (1996); V. Crivell
o, Liq. Cryst. , 3 [2], 235 (198
8) etc.].

On the other hand, from the viewpoint of dye chemistry, an azo bond induces strong light absorption in a dye molecule, and a cyano group itself does not necessarily induce light absorption. Are classified into auxiliary chromophores whose light absorption is derived by being introduced into the chromophore. Therefore, it is expected that a polymer compound having a structure in which both are linked by a p-phenylene bond capable of π-electron conjugation will have strong light absorption. Actually, this polymer compound has an absorption maximum wavelength λm
ax is 365 nm, the extinction coefficient ε based on the repeating unit of the polymer compound is several hundred thousand, and the compound has strong light absorption in the visible light region. This is a major disadvantage when this material is used as a volume recording medium such as hologram recording. That is, the incident light is absorbed by molecules near the surface and cannot reach the inside, and as a result, no recording is formed. In addition, heat is generated by absorbing light, and this heat causes damage such as erasure of recording or whitening, bleaching, and black oxidation of the optical recording medium.

For this reason, when actually used as an optical recording medium, it is necessary to use a wavelength which does not absorb the light, which is a restriction when used as an actual memory system. Therefore, in order to obtain a better optical recording medium, it is necessary to develop a material that absorbs less light without impairing optical recording properties.

The present invention has been made in view of the above facts, and a first object of the present invention is to provide a novel compound useful as an optical recording material and a method for producing the same.
A second object of the present invention is to improve the memory property, modulation degree, multiplicity, and record retention without impairing the optical recording property, having a wide usable wavelength range, and reducing loss due to light absorption. An optical recording medium is provided. A third object of the present invention is to provide an optical recording medium suitable for hologram recording, especially for polarization hologram recording.

[0020]

SUMMARY OF THE INVENTION The present invention is directed to a polyester-based liquid crystal polymer containing a cyanoazobenzene derivative in a side chain thereof. The photoresponsive polyester represented by the general formula (4) has the same optical memory property as that of the existing liquid crystal polymer, has an absorption maximum of 20 nm shorter than that of the cyanoazobenzene type, and has an absorption of visible light. They have found that they are smaller, and have completed the present invention.

That is, the present invention provides: <1> a photoresponsive dicarboxylic acid monomer represented by the following general formula (1).

[0022]

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In the general formula (1), X is a lower alkyloxy group, a substituted or unsubstituted benzyloxy group, a substituted or unsubstituted phenyloxy group, an acid residue of a lower fatty acid, a substituted or unsubstituted benzoic acid Represents an acid residue or a halogen atom. Y represents a hydrogen atom or a lower alkyl group. m represents an integer of 1 to 3. n represents an integer of 2 to 18.

<2> A dicarboxylic acid derivative represented by the following general formula (2) is reacted with an azobenzene derivative represented by the following general formula (3) in the presence of a condensing agent to obtain a compound represented by the general formula (1). A method for producing a photoresponsive dicarboxylic acid monomer which produces the photoresponsive dicarboxylic acid monomer shown.

[0025]

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In the general formula (2), X represents a lower alkyloxy group, a substituted or unsubstituted benzyloxy group, a substituted or unsubstituted phenyloxy group, an acid residue of a lower fatty acid, a substituted or unsubstituted benzoic acid Represents an acid residue or a halogen atom. Y represents a hydrogen atom or a lower alkyl group. m represents an integer of 1 to 3.

[0027]

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In the general formula (3), Z represents an atomic group which can be easily eliminated by undergoing a nucleophilic substitution reaction under the conditions of Williamson's ether synthesis reaction. n shows the integer of 2-18.

<3> Photoresponsive polyester represented by the following general formula (4).

[0030]

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In the general formula (4), Y represents a hydrogen atom or a lower alkyl group. R is a substituted or unsubstituted aromatic;
Shows a hydrocarbon chain that is aliphatic or a mixture of both. m is 1
Represents an integer from to 3. n shows the integer of 2-18. p
Represents an integer of 5 to 2,000.

<4> The photoresponsive polyester according to claim 3, wherein R in the general formula (4) is a functional group represented by the following general formula (5).

[0033]

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In the general formula (5), U represents a hydrogen atom, a halogen atom, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted lower alkenyl group, or a substituted or unsubstituted lower alkynyl group. W is an ether bond,
It represents a thioether bond, a substituted imino bond, a ketone bond, a sulfone bond, or a sulfoxide bond. n is 1 to 4
Indicates an integer. l represents an integer of 2 to 18.

<5> An optical recording medium capable of optical recording utilizing a change in absorption or a change in refractive index of the optical recording material due to light irradiation or heat application, wherein the optical recording material is represented by the general formula (1). An optical recording medium comprising a polymer compound containing at least one of the photoresponsive dicarboxylic acid monomers shown as a structural unit.

<6> The photoresponsive dicarboxylic acid monomer represented by the above general formula (1) has a structural unit of at least 1
The optical recording medium according to <5>, wherein the high molecular compound contained is a photoresponsive polyester represented by the general formula (4).

<7> The optical recording medium according to <5> or <6>, wherein the optical recording is hologram recording.

<8> The optical recording medium according to <7>, wherein the hologram recording is a hologram recording that can be independently recorded when the polarization directions of the incident object light and the reference light are horizontal polarization and vertical polarization. .

<9> The optical recording medium according to any one of <5> to <8>, which is formed into a two-dimensional shape or a three-dimensional shape.

The photoresponsive dicarboxylic acid monomer represented by the general formula (1) and the photoresponsive polyester represented by the general formula (4), which are novel compounds of the present invention, have a cyanoazobenzene-based absorption maximum. 20n in comparison
m shorter and the absorption of visible light is smaller. This is presumably because the interaction of the alkyl group with the π-electron of the benzene ring, which is the source of light absorption, is significantly smaller than that of the cyano group.

The cyanobenzene structure contained in the photoresponsive dicarboxylic acid monomer represented by the general formula (1) and the photoresponsive polyester represented by the general formula (4) can be used as a mesogen in liquid crystal formation. The resulting oxyhesamethylene structure functions as a tail. On the other hand, since the main chain structure of this polymer contains a flexible hexamethylene chain, it does not hinder liquid crystal formation due to association of side chains, and the polymer as a whole exhibits liquid crystallinity.
Furthermore, the partial change in the alignment of the main chain itself is induced with the formation of the liquid crystal in the side chain, and the main chain contains a large amount of p-phenylene structure that increases the refractive index. Large refractive index dichroism is induced in the vertical direction.

On the other hand, the azo group causes cis-trans photoisomerization by light absorption. Cisated azobenzene no longer functions as a mesogen because of its bent structure. Therefore, this polymer functions as a photosensitive polymer whose liquid crystallinity is lost by light irradiation. At this time, various properties due to the liquid crystal properties, for example, dichroism of the refractive index in the main axis direction of the liquid crystal and in the direction perpendicular thereto are also lost. Such a property may be commonly found in a polymer compound having a structure in which a substituted azobenzene structure is linked to a main chain of a methylene chain. Although the reason is not clear, it is presumed that the cyano group is important but not necessarily essential for liquid crystal formation of this polymer compound. That is, it is presumed that the same property is exhibited even in the case of a methyl group having a steric size similar to that of a cyano group and having the same interaction between molecules as a cyano substituent.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION The photoresponsive dicarboxylic acid monomer represented by the following general formula (1) of the present invention will be described.
(Hereinafter, “Et” in the chemical formula indicates an ethyl group, and “P”
“r” represents a propyl group. )

[0044]

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In the general formula (1), X represents a lower alkyloxy group, a substituted or unsubstituted benzyloxy group, a substituted or unsubstituted phenyloxy group, an acid residue of a lower fatty acid, a substituted or unsubstituted benzoic acid Represents an acid residue or a halogen atom. Among these, a lower alkyloxy group, a substituted or unsubstituted phenyloxy group, an acid residue of a lower fatty acid, and a halogen atom are preferred. Examples of the substituent include a methyl group, an ethyl group, a halogen atom, a cyano group, and the like.

Examples of the lower alkyloxy group include a hydroxy group, a methyloxy group and an ethyloxy group. Examples of the benzyloxy group include a benzyloxy group, a methylbenzyloxy group, an ethylbenzyloxy group, and a chlorobenzyloxy group. Examples of the phenyloxy group include a phenyloxy group, a methylphenyloxy group, an ethylphenyloxy group, and a chlorophenyloxy group. Examples of the acid residue of the lower fatty acid include an acetyloxy group, a chloroacetyloxy group, a dichloroacetyloxy group, a fluoroacetyloxy group, a trifluoroacetyloxy group, a cyanoacetyloxy group, and the like. Examples of the acid residue of the benzoic acid include a benzoyloxy group, a chlorobenzoyloxy group, a fluorobenzoyloxy group, and a cyanobenzoyloxy group. Examples of the halogen atom include a chlorine atom and a bromine atom.

In the general formula (1), Y represents a hydrogen atom or a lower alkyl group. Examples of the lower alkyl group include a methyl group, an ethyl group, and a propyl group.

In the general formula (1), m is 1 to 3, preferably 1. n represents an integer of 2 to 18, preferably an integer of 4 to 12.

The photoresponsive dicarboxylic acid monomer represented by the general formula (1) is obtained by reacting a dicarboxylic acid derivative represented by the following general formula (2) with an azobenzene derivative represented by the following general formula (3) in the presence of a condensing agent. It is produced by reacting below.

[0050]

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In the general formula (2), X, Y and m are the same as X, Y and m in the general formula (1).

[0052]

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In the general formula (3), Z represents an atomic group which can be easily eliminated by undergoing a nucleophilic substitution reaction under ether synthesis reaction conditions.

Examples of the atomic group which can be easily eliminated by undergoing a nucleophilic substitution reaction under the above ether synthesis reaction conditions include a halogen atom, a tosyl group, a trifluoroacetyloxy group and the like. Among these, a bromine atom and a tosyl group are preferred.

In the general formula (3), n represents an integer of 2 to 18, preferably 4 to 12.

Examples of the condensing agent include sodium hydroxide,
Examples include potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, triethylamine, tributylamine, pyridine, 1,8-diaza [5,40] bicyclo-undecene-7, and the like. Among them, potassium carbonate, triethylamine and 1,8-diaza [5,40] bicyclo-undecene-7 are preferred.

The photoresponsive polyester represented by the following general formula (4), which is a novel compound that can be used as an optical recording material of the optical recording medium of the present invention, will be described.

[0058]

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In the general formula (4), Y, m and n are the same as Y, m and n in the general formula (1). p is 5
To 2000, preferably 5 to 500, more preferably 10 to 100.

In the general formula (4), R represents a substituted or unsubstituted aromatic or aliphatic or a hydrocarbon chain obtained by mixing both. Examples of the substituent include a methyl group, an ethyl group, a hydroxy group, a methoxy group, an ethoxy group, and a chlorine atom.

The above-mentioned substituted or unsubstituted aromatic or aliphatic hydrocarbons, or a hydrocarbon chain obtained by mixing both, have the following structural formulas.

[0062]

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The above-mentioned substituted or unsubstituted aromatic or aliphatic hydrocarbon chain or a mixture of both hydrocarbon chains has an ether bond,
It may contain a bifunctional atomic group containing a hetero atom such as a thioether bond, a substituted imino bond, a ketone bond, a sulfone bond, a sulfoxide bond (hereinafter, referred to as a bifunctional atomic group containing a hetero atom).

The substituted or unsubstituted aromatic or aliphatic or a mixed hydrocarbon chain containing a bifunctional atomic group containing a hetero atom is represented by the following general formulas (5) and (5-a). ) To (5-c). Among these, a functional group represented by the following general formula (5) is preferable. As the functional group represented by the following general formula (5), a functional group represented by the following general formula (5-d) is preferable.

[0065]

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[0066]

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In the general formula (5), U is a hydrogen atom, a halogen atom, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted lower alkenyl group, or a substituted or unsubstituted
Shows an unsubstituted lower alkynyl group. Among them, a hydrogen atom and a lower alkyl group are preferable. Examples of the substituent include a hydrogen atom, a fluorine atom, a chlorine atom, an alkyl group, and the like.

The halogen atom and the lower alkyl group are the same as those described above.

Examples of the lower alkenyl group include a vinyl group. As the lower alkynyl group,
And a propargyl group.

In the general formula (5), W represents an ether bond, a thioether bond, a substituted imino bond, a ketone bond, a sulfone bond or a sulfoxide bond. Among them, an ether bond and a ketone bond are preferable.

In the general formula (5), n represents an integer of 1 to 4, preferably 1 or 2. l represents an integer of 2 to 18, preferably 4 to 10. In addition, general formulas (5-b) to
L in (5-d) is the same as l in general formula (5).

The photoresponsive dicarboxylic acid monomer represented by the general formula (1) and the photoresponsiveness represented by the general formula (4), which are novel compounds that can be used as an optical recording material of the optical recording medium of the present invention. The method for producing polyester will be specifically described.

The photoresponsive dicarboxylic acid monomer represented by the general formula (1) can be synthesized as shown in the following scheme 1.

[0074]

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First, the p-toluidine (p-methylaniline) represented by the compound (1) is diazotized by the action of nitrite and an acid, and this is coupled with the phenol represented by the compound (2) to give the compound (3) 4-
Synthesize hydroxy-4-methylazobenzene. This was reacted with 1,6-dibromohexane represented by compound (4) under Williamson's ether synthesis reaction conditions to give 4- (6-bromohexyl) oxy-4-methyl represented by compound (5). Synthesize azobenzene. This was reacted with the diethyl ester of 3-hydroxyisophthalic acid represented by the compound (6) also under the reaction conditions for the synthesis of ether by Williamson to obtain one of the photoresponsive dicarboxylic acid monomers represented by the general formula (1). An azobenzene-bound isophthalic acid derivative represented by a certain compound (7) can be synthesized. The reaction conditions for Williamson's ether synthesis include reaction conditions in a protic polar solvent (methanol, ethanol, etc.), reaction conditions in an aprotic polar solvent (dimethylformamide, dimethylsulfoxide, etc.), phase transfer reaction Reaction conditions using the above can be selected.

The photoresponsive polyester represented by the general formula (4) can be synthesized as follows.
The derivative of azobenzene-bonded isophthalic acid represented by the compound (7), which is one kind of the photoresponsive dicarboxylic acid monomer represented by the general formula (1), is suitable as in the case of a general diester of an aromatic dicarboxylic acid. By condensing with various aliphatic diols, diols containing an aromatic ring, and bisphenol under suitable conditions, it is possible to lead to an azobenzene-bonded polyester. For example, by reacting with a diol derived from a bisphenol compound represented by the following general formula (6) by a high-temperature polycondensation method by transesterification, one kind of the photoresponsive polyester represented by the general formula (4) is obtained. A polyester compound represented by the following general formula (7) can be synthesized. Here, standard reaction conditions described in the literature can be selected as reaction conditions [Polymer Synthesis, edited by The Chemical Society of Japan (Experimental Chemistry Lecture 28, Maruzen (1992)) p220, Otsu, Kinoshita "Polymer" Synthetic Experimental Method "(Kagaku Doujin (1972)) p3
20]. In this case, better results can be obtained by using a known reaction catalyst such as calcium acetate, zinc acetate or antimony oxide which is effective in the high-temperature polycondensation method by transesterification as the reaction catalyst.

[0077]

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In the general formula (6), U, W, n and l are
The same as U, W, n and l in the general formula (5).

[0079]

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In the general formula (7), R represents the aforementioned general formula (5)
Is a functional group represented by

Hereinafter, specific examples of the photoresponsive dicarboxylic acid monomer represented by the general formula (1) and the photoresponsive polyester represented by the general formula (4) ((1-1) to (1--1)
13) and (4-1) to (4-20)), but the present invention is not limited to these specific examples.

[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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The optical recording medium of the present invention will be described. The optical recording medium of the present invention is an optical recording medium capable of optical recording utilizing a change in absorption or a change in refractive index of the optical recording material due to light irradiation or heat application, wherein the optical recording material has the general formula (1) ) Is a polymer compound containing at least one photoresponsive dicarboxylic acid monomer represented by the formula (1) as a structural unit.

The optical recording medium of the present invention may be composed of a substrate and a photosensitive layer made of the above-mentioned optical recording material, or may be made of the above-mentioned optical recording material using the whole optical recording medium as a photosensitive layer.

The polymer compound containing at least one photoresponsive dicarboxylic acid monomer represented by the general formula (1) as a structural unit includes the photoresponsive dicarboxylic acid monomer represented by the general formula (1): The general formula (5)
The photoresponsive polyester represented by the general formula (4) obtained by condensing with a functional group represented by the following formula (4) is preferable, and a photoresponsive dicarboxylic acid monomer represented by the general formula (1) is used. May be condensed with the above diol component. Examples of the other diol component include lower diols such as ethylene glycol and propylene glycol, polymer diols such as polyethylene glycol, polypropylene glycol and polytetrahydrofuran, and aromatic diols such as hydroquinone, bisphenol A and bisphenol P. No.

The substrate is not particularly limited as long as it is transparent and robust in the wavelength region to be used, and has no significant deterioration or dimensional change in ordinary temperature and humidity ranges. For example, soda glass, borosilicate glass , Potash glass, acrylic plate, polyester (PET) sheet, and the like.

The optical recording material may be added with an additive such as a phthalic ester for the purpose of improving the film forming property and the adhesiveness to the substrate.

In the optical recording medium of the present invention, in order to realize optical recording, the thickness of the photosensitive layer is preferably about 10 μm to 5000 μm, and more preferably 50 to 300 μm. Therefore, it is preferable that the optical recording material has optical properties such as light transmittance, flatness, and refractive index, and physical properties such as strength and dimensional stability.

The optical recording medium of the present invention is used for optical recording utilizing a change in absorption or a change in refractive index of an optical recording material caused by light irradiation or heat application.

Examples of the optical recording include hologram recording, light absorption modulation recording, light reflectance modulation recording, and the like.
Among these, hologram recording is an optical recording suitable for the optical recording medium of the present invention.

The hologram recording includes hologram recording in which a plurality of holograms can be recorded at a single location by changing the angle between the normal to the recording surface and the incident object light, and the position of the incident light with respect to the recording surface. A hologram recording that can record a plurality of holograms in an overlapped area by changing the hologram recording is given. However, a hologram recording suitable for the optical recording medium of the present invention is a hologram recording in which an Is a hologram recording capable of recording the hologram of FIG. Further, the optical recording medium of the present invention can record a hologram independently when the polarization directions of the incident object light and the reference light are horizontal polarization and vertical polarization.

Hereinafter, the principle of hologram recording will be briefly described together with an apparatus used for the hologram recording. Figure 2 shows the SCIE
NCE VOL. 265, p749, (1994) shows an optical system of a digital hologram memory. In this example, LiNbO ₃ 15 is used as a recording medium. Light emitted from the light source 6 is split by the beam splitter 12 into two light waves. The light transmitted through the beam splitter 12 becomes parallel light having a large diameter by the lens 10 and enters the spatial light modulator 4. The spatial light modulator 4 is controlled by the computer 11 and generates the signal light 1 having a two-dimensional intensity distribution. This signal light 1 is Fourier-transformed by the lens 7 and condensed on LiNbO ₃ 15. On the other hand, the light reflected by the beam splitter 12 is reflected by the mirrors 13 and 14, and the LiNbO ₃ 1
5 is incident. This is the reference light 2. As described above, the hologram recording is performed by simultaneously inputting the signal light 1 and the reference light 2 to the LiNbO ₃ 15. In reading the hologram, when only the reference light 2 is made to enter the LiNbO ₃ 15, the reference light 2 is as if the signal light 1 is LiNbO _3.
The signal light 1 is diffracted on the optical path of the signal light 1 as if it has passed through O ₃ 15, and is imaged on the camera 9 by the lens 8.

In the above-described hologram recording and digital hologram recording apparatuses, a spatial light modulator is used for data input, and a differential code method is used for displaying bit data. In the notation of data by the differential code method as shown in FIG. 3, two pixels are used as a pair, for example, 0 represents dark and light and 1 represents light and dark. When such a differential code method is used, the number of light and dark is always the same, so that the amount of object light passing through the spatial light modulator is also constant. Therefore, it is not necessary to adjust the intensity of the reference light for each page. Further, in the reproduction of the hologram, unevenness in the amount of light is apt to occur, and it is difficult to make a uniform division between the black and white levels. However, the differential code method only requires reading the edge, and is resistant to noise.

In the differential coding method, since one-bit data is displayed using at least two pixels, the pixel utilization efficiency is as low as 0.5. Therefore, there is a problem that the data density that can be recorded on one page is reduced. Furthermore, when the differential code method is used, a hologram reproduced image is captured by a two-dimensional light receiving element such as a CCD, converted into a serial electric signal, and then the edge is read electrically and converted into bit data. There is also a problem that the transfer speed is reduced. That is, even if a plurality of pieces of bit information can be read from the hologram in parallel, a high transfer rate cannot be achieved as a result by performing electrical data processing serially.

Therefore, the present inventors use a material which can record independently with S and P polarized light, thereby controlling the polarization direction of the signal light applied to the material to produce a single optical recording medium. It was proposed to record on a holographic recording medium and named it a polarization hologram recording method. According to this method, digital hologram recording can be performed at a high S / N ratio without using the above-described differential code method, and the substantial recording density can be improved twice as compared with the conventional method.

The optical recording medium of the present invention is preferably formed in a two-dimensional shape or a three-dimensional shape such as a sheet, tape, film, or disk. As a specific method, the optical recording material is dissolved in an aliphatic or aromatic halogen-based solvent such as chloroform, methylene chloride, o-dichlorobenzene, tetrahydrofuran, anisole, and acetophenone, an ether-based solvent, and the like.
From this solution, a transparent and tough film is formed on a substrate such as glass. Also, by heating and compressing the powder, pellet or flake-like solid of the optical recording material by a hot press method, it can be formed into a transparent and tough film-like shape on a substrate such as glass. These films can be used as they are or in a Free-Standing state peeled from the substrate.

Preferred embodiments of the optical recording medium of the present invention include the following optical recording media (1) to (5).

(1) An optical recording medium having a disk shape and capable of recording and reproducing by rotating the disk and scanning a writing / reading head over a moving radius. (2) An optical recording medium having a sheet-like shape, on which a read / write head can scan two-dimensionally to perform recording / reproduction. (3) An optical recording medium having a tape shape and capable of recording and reproducing by scanning a predetermined portion of the tape with a writing head while winding the tape. (4) It has a three-dimensional bulk shape,
An optical recording medium in which this is fixed on a fixed or movable base (stage), and the surface or the inside of which is scanned by a movable or fixed read / write head to perform recording and reproduction. (5) Disc-like material is laminated appropriately,
It has a two-dimensional shape such as a sheet shape or a card shape, a drum shape, or another three-dimensional shape, and is combined with the method described in the above (1) to (4) or a combination thereof. An optical recording medium capable of performing recording and reproduction by scanning with a read / write head by a method.

As the optical recording apparatus using the optical recording medium of the present invention, a known apparatus can be used, for example, an optical system shown in FIG. Li in the optical system shown in FIG.
Instead of NbO ₃ 15, an optical recording medium of the present invention which is appropriately formed can be provided to perform recording and reproduction of a hologram.

[0107]

The present invention will be specifically described below with reference to examples. The present invention is not limited to the embodiment unless it exceeds the gist of the present invention.

(Synthesis of diethyl 5-hydroxyisophthalate) 182 g (1 mol) of 5-hydroxyisophthalic acid, 1500 ml of ethanol
Take 10 ml of concentrated sulfuric acid and heat to reflux for 24 hours to react. After completion of the reaction, the system is concentrated to about 1/2 by a rotary evaporator. When the obtained colorless viscous solution is poured into a cold sodium hydrogencarbonate solution of about 20%, the droplets first float in the solution, but immediately solidify to obtain a white bulky crude product. This is filtered off and dried under reduced pressure (yield 229 g (96%)).
This is recrystallized from ethanol to obtain 190 g of diethyl 5-hydroxyisophthalate (80% yield). The obtained compound was measured for infrared absorption spectrum (IR), nuclear magnetic resonance (NMR), and melting point. The measurement results are shown below.

IR: 3100 cm ^-1 (broad, hydroxyl group) 1723 cm ^-1 (ester carbonyl group) NMR: δ = 1.40 (3H, t, ester methyl) 4.37 (2H, q, ethyl ester methylene) 7 0.8-7.95 (3H, m, aromatic) Melting point: 68 ° C

(Synthesis of 4′-hydroxy-4 ″ -methyl-azobenzene) 750 ml of 6N hydrochloric acid was placed in a 3 liter beaker, and 107 g (1 mol) of p-anisidine (4-methylaniline) finely ground was added thereto. Get in,
The mixture is sufficiently suspended by stirring, and about 300 g of ice is added thereto to cool the system. On the other hand, 80 g of sodium nitrite (1.
16 mol) is dissolved in 500 ml of water. 400 ml of a sodium nitrite solution is introduced into the suspension over about 20 minutes, and after completion of the dropwise addition, the solution is stirred at about 5 ° C. for 1 hour. To this solution, a solution prepared by dissolving 94 g (1 mol) of phenol in 1 liter of 2N potassium hydroxide solution is gradually added, and the mixture is allowed to react overnight. After completion of the reaction, the precipitate formed was separated by filtration and dried under reduced pressure to obtain crude 4′-
Hydroxy-4 ″ -methyl-azobenzene 210 g
(Almost quantitative). This was used for the next reaction without purification. The maximum absorption wavelength (λmax) of this compound was 345 nm.

(4 '-(6-bromohexyl) oxy-
Synthesis of 4 ″ -methyl-azobenzene) In a 2 liter three-necked flask equipped with a mechanical stirrer, 4′-hydroxy-4 ″ -methyl-
Take 42.4 g (0.2 mol) of azobenzene, 448 g (2 mol) of 1,6-dibromohexane and 212 g (1.5 mol) of anhydrous potassium carbonate, and add 800 m of acetone.
Add 1 and stir to suspend. The reaction system is heated until acetone is refluxed to react hydroxyazobenzene with bromoalkane. After reacting for 20 hours, insoluble salts are removed by filtration, and the system is concentrated to about 1/3 with a rotary evaporator. When this system is cooled in a refrigerator, the generated 4 '-(6-bromohexyl) oxy-4''-methyl-azobenzene is crystallized. After filtering the product, a small amount of cold acetone, cold ether, n-
After sequentially washing with hexane, the crude 4′-
38.1 g of (6-bromohexyl) oxy-4 ″ -methyl-azobenzene are obtained. Yield 38 g (50.8 yield)
%). This was recrystallized from ethanol to obtain 32 g of 4 '-(6-bromohexyl) oxy-4''-methyl-azobenzene (yield 42%). According to the analysis by high performance liquid chromatography, the purity was 98.6% or more. The obtained compound was measured for infrared absorption spectrum (IR) and nuclear magnetic resonance (NMR). The measurement results are shown below.

IR: 1230 cm ^-1 (ether) 1723 cm ^-1 (ester carbonyl group) NMR: δ = 1.5-1.9 (8H, m) 4.2-4.5 (7H, m) 7.8 _{-7.95 (4H, A 2 X 2} , _{aromatic) 7.75-7.95 (4H, A 2 X} 2, aromatic)

(Synthesis of 4,4'-bis- [6-chlorohexyloxy] -diphenyl ether) In a 300 ml eggplant flask, 20.2 g (0.1 mol) of 4,4'-dihydroxy-diphenyl ether, 6-chloro-1 −
Take 21.2 g (0.22 mol) of hexanol and 41.4 g (0.3 mol) of potassium carbonate, add 100 ml of N, N-dimethylformamide, stir and suspend. The system is heated to 150 ° C. in an oil bath and reacted for 24 hours. After completion of the reaction, the system was poured into 1 liter of water containing a small amount of hydrochloric acid, and the generated white powdery substance was filtered off and dried to obtain 31 g of crude 4,4′-bis- [6-chlorohexyloxy] -diphenyl ether. (71% yield). This was recrystallized from water-N, N-dimethylformamide and purified to give 4,4'-bis- [6-chlorohexyloxy]-.
26 g of diphenyl ether are obtained. The infrared absorption spectrum (IR) of the obtained compound was measured. The measurement results are shown below.

IR: 3040 cm ^-1 (aromatic CH) 2970, 2940 cm ^-1 (aliphatic CH) 1230 cm ^-1 (ether)

(Synthesis of 4,4'-bis- [6-chlorohexyloxy] -diphenyl ketone) In a 300 ml eggplant flask, 21.4 g (0.1 mol) of 4,4'-dihydroxy-diphenyl ether, 6-chloro- Take 21.2 g (0.22 mol) of 1-hexanol and 41.4 g (0.3 mol) of potassium carbonate, add 100 ml of N, N-dimethylformamide, and stir to suspend. The system is heated to 150 ° C. in an oil bath and reacted for 24 hours. After completion of the reaction, the system was poured into 1 liter of water containing a small amount of hydrochloric acid, and the generated white powdery substance was filtered off and dried to obtain 33 g of crude 4,4′-bis- [6-chlorohexyloxy] -diphenyl ether. (73.2% yield). This was recrystallized from water-N, N-dimethylformamide to obtain 27 g of purified 4,4'-bis- [6-chlorohexyloxy] -diphenyl ether. The infrared absorption spectrum (IR) of the obtained compound was measured. The measurement results are shown below.

IR: 3040 cm ^-1 (aromatic CH) 2970, 2940 cm ^-1 (aliphatic CH) 1230 cm ^-1 (ether)

[Example 1] (Synthesis of diethyl 5- [6- {4 '-(4 "-methyl-phenylazo) phenoxy} hexyloxy] -isophthalate) 16.6 g of diethyl hydroxyisophthalate (0.07 mol
l) 4 '-(6-Bromohexyl) oxy-4''-
26.1 g (0.07 mol) of methyl-azobenzene,
Take 15.1 g (0.11 mol) of anhydrous potassium carbonate and add 300 ml of acetone thereto. This system is 24
The mixture is reacted by heating under reflux for an hour. After the completion of the reaction, the system was poured into 1500 ml of cold water, and the resulting 5- [6- {4′-
The diethyl (4 ″ -methyl-phenylazo) phenoxy {hexyloxy] -isophthalate is filtered off and dried under reduced pressure. Yield 35.1 g (83%). This was recrystallized twice from acetone to give the desired product, 5- [6- {4'-
30.1 g of diethyl (4 ″ -methyl-phenylazo) phenoxy {hexyloxy] -isophthalate (80.
1%). According to the analysis by high performance liquid chromatography, the purity was 98.5% or more. The obtained compound was measured for infrared absorption spectrum (IR) and nuclear magnetic resonance (NMR). The measurement results are shown below.

IR: 3100 cm ^-1 (broad, hydroxyl group) 3040 cm ^-1 (aromatic CH) 2970, 2940 cm ^-1 (aliphatic CH) 1723 cm ^-1 (ester carbonyl group) 1230 cm ^-1 (ether) NMR: δ = 1.40 (3H, t) 4.37 (9H, m, ethyl ester methylene) 7.8-7.95 (11H, m, aromatic)

Example 2 (5- [6- {4 ′-(4 ″ -methyl-phenylazo) phenoxy} hexyloxy] -diethyl isophthalate and 4,4′-bis- [6-chlorohexyloxy ]
-Synthesis of polyester from diphenyl ether)
4. [6- {4 '-(4 "-methyl-phenylazo) phenoxy} hexyloxy] -diethyl isophthalate
43 g (0.1 mol), 4.39 g of 4,4′-bis- [6-chlorohexyloxy] -diphenyl ether
(0.1 mol), 0.1 g of anhydrous zinc acetate was placed in a 100 ml three-necked flask equipped with a vacuum depressurizing device and a stirrer, and stirred and heated at 160 ° C. for 2 hours under a nitrogen atmosphere at about 10 Torr. React under reduced pressure for 20 minutes.
Then, the temperature is raised to 180 ° C. while gradually reducing the pressure of the system to 2 Torr over 30 minutes. After completion of the reaction, the system is dissolved in chloroform, and the solution is poured into methanol to take out a crude polymer. After reprecipitating it again, hot methanol,
After boiling and washing with hot water, the product is dried under reduced pressure to take out the desired polyester. Yield 9.01 g (94% yield). The intrinsic viscosity (η _{sp / c} ) of the obtained polyester, elemental analysis,
Absorption maximum wavelength (λ _max ), absorption edge (λ cut-off)
Was measured. The measurement results are shown below.

Η _{sp / c} = 0.34 (in 1,2-dichloroethane at 30 ° C.) Elemental analysis: C; 70.99 H; 6.50 N;
55 (theoretical calculated value): C; 71.72 H; 6.68
N; 4.59 λ _max = 350 nm λ cut-off = 420 nm

Example 3 (5- [6- {4 ′-(4 ″ -methyl-phenylazo) phenoxy} hexyloxy] -diethyl isophthalate and 4,4′-bis- [6-chlorohexyloxy ]
Synthesis of polyester from diphenyl ketone) As a monomer, instead of 4,4'-bis- [6-chlorohexyloxy] -diphenyl ether, 4,4'-bis-
A desired polyester was obtained in the same manner as in Example 2 except that a considerable amount of [6-chlorohexyloxy] -diphenyl ketone was used (8.99 g (yield 93).
%)). Intrinsic viscosity (η _{sp / c} ) of the obtained polyester,
Elemental analysis, maximum absorption wavelength (λ _max ), absorption edge (λ cut
-Off) was measured. The measurement results are shown below.

Η _{sp / c} = 0.23 (30 ° C. in 1,2-dichloroethane) Elemental analysis: C; 70.86 H; 6.41 N;
89 (theoretical calculated value): C; 71.42 H; 6.50
N; 4.67 λ _max = 355 nm λ cut-off = 430 nm

Example 4 (Hologram Recording Using Polyester Synthesized in Example 2) A sample in which the polyester synthesized in Example 2 was applied on a glass plate as a thin film using the optical system shown in FIG. Was used to perform hologram recording. That is, LiNbO in FIG.
₃ Place the sample in place of 15 and place the signal light 1
And a hologram generated by interference with the reference light 2 was recorded. At this time, the sample surface was arranged such that the angle between the signal light 1 and the reference light 2 was 45 degrees.

As a result, it was found that hologram recording was possible even when any one of the incident lights having the wavelengths of 532 nm and 515 nm was used. That is, when the sample is irradiated with the signal light 1 and the reference light 2 having arbitrary pattern information generated by the spatial light modulator 4 for about 0.1 second, the pattern shown in the spatial modulator 4 is reproduced. I understand.
Furthermore, it was found that multiplex recording of holograms was possible on a single location in this sample. In other words, when recording multiple holograms by changing the angle between the normal to the sample surface and the incident light, different holograms can be recorded and reproduced when the angles differ from each other by 0.1 degree or more. (Recording / reproduction of angle multiplexed hologram).

Further, in order to check the dependence of the polarization direction of the incident light on the hologram, the beam splitter 12 is replaced with a polarization beam splitter, and only s-polarized light or p-polarized light is extracted to the reference light 2 side. The extracted light has a polarization characteristic opposite to that of the reference light 2, that is, p-polarized light or s-polarized light.
, A half-wave plate was arranged, and the polarization direction was rotated by 90 degrees. When the hologram is recorded in such a manner that the reference light 2 and the signal light 1 become s-polarized light or p-polarized light, even when the angle formed between the signal light 1 or the reference light 2 and the sample surface is the same, It was found that hologram recording / reproduction was possible independently (recording / reproduction of polarization multiplexed hologram).

[Example 5] (Hologram recording using polyester synthesized in Example 3) Example 4 was repeated except that the polyester synthesized in Example 3 was used instead of the polyester synthesized in Example 2 as a sample. When a recording-reproducing experiment of an angle multiplexed hologram and a polarization multiplexed hologram was performed in the same manner as in the above, the same result as in Example 4 was obtained.

Reference Example 5 (Hologram recording using polyester compound represented by general formula (α)) A polyester compound represented by general formula (α) was used as a sample instead of the polyester synthesized in Example 2. A recording-reproduction experiment of an angle multiplexed hologram was performed in the same manner as in Example 4, except for using the hologram.

As a result, when incident light having a wavelength of 532 nm was used, the same multiplex hologram recording / reproduction as in Examples 4 and 5 was possible. On the other hand, the wavelength 515n
When m incident light is used, hologram recording / reproduction is possible, but the S / N ratio of the reproduced hologram is:
It was significantly inferior to Examples 4 and 5. This is because the polymer compound represented by the general formula (α) has a cyano group, and therefore has a longer wavelength than the polyester synthesized in Examples 2 and 3 (the absorption maximum wavelength). λ _max = 365 nm, the absorption peak is shifted to the longer wavelength side by 10 to 20 nm as a whole, and has a gentler absorption at the longer wavelength), the sample absorbs the light, and the heat generated thereby erases the recording. Or, it is considered that the sample was damaged. In fact, in the sample after the experiment, damage such as whitening, bleaching of the sample surface, and black oxidation were confirmed.

The novel compound of the present invention is suitable for a hologram recording medium without impairing optical recording properties, has a wide usable wavelength range, has little loss due to light absorption, and has excellent multiplicity and record retention. Things.

[0130]

As described above, the present invention can provide a novel compound useful as an optical recording material and a method for producing the same. In addition, an optical recording medium that has excellent memory properties, modulation degree, multiplicity, record retention, and a hologram, without impairing optical recording properties, has a wide usable wavelength range, and has little loss due to light absorption. An optical recording medium suitable for recording, in particular, polarization hologram recording can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram showing a photorefractive effect, that is, a mechanism of a refractive index change induced by light irradiation.

FIG. 2 is a diagram showing an optical system of a digital hologram memory.

FIG. 3 is a diagram showing a concept of recording by a differential code method.

[Explanation of symbols]

Reference Signs List 1 signal light 2 reference light 3 diffracted light 4 spatial light modulator 5 optical recording medium 6 light source 7 Fourier transform lens 8 Fourier transform lens 9 two-dimensional light receiving element 10 collimating lens 11 computer 12 beam splitter 13 mirror 14 mirror 15 LiNbO ₃

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Katsunori Kono 430 Nakaicho Sakai, Ashigara-gun, Kanagawa Prefecture Inside Green X-Tech Fuji Xerox Co., Ltd. F term (reference) 2H111 EA04 EA12 EA23 EA32 EA37 EA40 EA43 FB42 FB54 FB59 2K008 AA04 BB04 BB06 CC01 CC03 DD12 FF17 HH13 HH26 4J029 AA03 AB01 AB07 AC01 AD01 AE04 BF23 DB01 B01B01B01B01

Claims (9)

[Claims] 1. A photoresponsive dicarboxylic acid monomer represented by the following general formula (1). Embedded image In the general formula (1), X represents a lower alkyloxy group, a substituted or unsubstituted benzyloxy group, a substituted or unsubstituted phenyloxy group, an acid residue of a lower fatty acid, or an acid residue of a substituted or unsubstituted benzoic acid. Represents a group or a halogen atom.
Y represents a hydrogen atom or a lower alkyl group. m represents an integer of 1 to 3. n represents an integer of 2 to 18. 2. A dicarboxylic acid derivative represented by the following general formula (2) and an azobenzene derivative represented by the following general formula (3) are reacted in the presence of a condensing agent to give a compound represented by the above general formula (1). A method for producing a photoresponsive dicarboxylic acid monomer that produces a photoresponsive dicarboxylic acid monomer. Embedded image In the general formula (2), X represents a lower alkyloxy group, a substituted or unsubstituted benzyloxy group, a substituted or unsubstituted phenyloxy group, an acid residue of a lower fatty acid, or an acid residue of a substituted or unsubstituted benzoic acid. Represents a group or a halogen atom. Y represents a hydrogen atom or a lower alkyl group. m is 1
Represents an integer from to 3. Embedded image In the general formula (3), Z represents an atomic group which can be easily eliminated by undergoing a nucleophilic substitution reaction under the Williamson ether synthesis reaction conditions. n shows the integer of 2-18. 3. A photoresponsive polyester represented by the following general formula (4). Embedded image In the general formula (4), Y represents a hydrogen atom or a lower alkyl group. R represents a substituted or unsubstituted aromatic or aliphatic or a hydrocarbon chain obtained by mixing both. m represents an integer of 1 to 3. n shows the integer of 2-18. p is 5 to 20
Indicates an integer of 00. 4. The photoresponsive polyester according to claim 3, wherein R in the general formula (4) is a functional group represented by the following general formula (5). Embedded image In the general formula (5), U represents a hydrogen atom, a halogen atom, a substituted or unsubstituted lower alkyl group, a substituted or unsubstituted lower alkenyl group, or a substituted or unsubstituted lower alkynyl group. W represents an ether bond, a thioether bond, a substituted imino bond, a ketone bond, a sulfone bond, or a sulfoxide bond. n represents an integer of 1 to 4. l represents an integer of 2 to 18. 5. An optical recording medium capable of optical recording utilizing a change in absorption or a change in refractive index of the optical recording material due to light irradiation or heat application, wherein the optical recording material is represented by the general formula (1). An optical recording medium comprising a polymer compound containing at least one photoresponsive dicarboxylic acid monomer as a structural unit. 6. The photoresponsive polyester represented by the general formula (4), wherein the polymer compound containing at least one photoresponsive dicarboxylic acid monomer represented by the general formula (1) as a structural unit. Item 6. An optical recording medium according to item 5. 7. The optical recording medium according to claim 5, wherein the optical recording is a hologram recording. 8. The optical recording medium according to claim 7, wherein the hologram recording is a hologram recording capable of recording independently when the polarization directions of the incident object light and the reference light are horizontal polarization and vertical polarization. 9. The optical recording medium according to claim 5, wherein the optical recording medium is formed into a two-dimensional shape or a three-dimensional shape.