WO2007125937A1

WO2007125937A1 - Photoreactive composition, optical material, optical recording material, volume hologram recording material, optical recording medium, and optical recording method therefor

Info

Publication number: WO2007125937A1
Application number: PCT/JP2007/058910
Authority: WO
Inventors: Makoto Takahashi; Yutaka Sasaki; Hideaki Ito; Jun Endo
Original assignee: Mitsubishi Chemical Corporation
Priority date: 2006-04-28
Filing date: 2007-04-25
Publication date: 2007-11-08
Also published as: TW200804968A; JPWO2007125937A1

Abstract

This invention provides a photoreactive composition which, when used in hologram recording, can realize reading of record without reducing a residual record capacity. The photoreactive composition comprises a sensitizer (A), which is exited upon photon absorption, and a polymer (B) containing a chemically convertible reactive group (C). In this case, the sensitizer (A) takes a reduced electron configuration relative to the reactive group (C).

Description

Specification

Photoreactive composition, optical material, optical recording material, volume hologram recording material, optical recording medium, and optical recording method thereof

Technical field

[0001] The present invention relates to a photoreactive composition, an optical material, an optical recording material, a volume hologram recording material, an optical recording medium, and an optical recording method thereof.

Background art

[0002] In recent years, hologram recording has been actively studied because high-density recording, multiple recording, and the like are possible. As such hologram recording, there are known those using an amplitude hologram that utilizes a change in transmittance of a recording material, and those that use a phase hologram that uses a change in refractive index or irregularity of a recording material. .

A known volume phase hologram recording material generally uses a photopolymer method in which radical polymerization or cationic polymerization is combined with a sensitizer as a write-once method that does not require wet treatment or bleaching treatment. The photopolymer method is a very simple method that can change the characteristics just by changing the monomer and the matrix to be combined.

[0004] However, in the conventional photopolymer method using a sensitizer, it is difficult to suppress volume shrinkage that occurs during recording.

Therefore, as an improvement in the suppression of such volume shrinkage, there is a study on holographic recording technology that combines an isomerization reaction by a rearrangement reaction rather than a polymerization reaction (see Patent Documents 1 and 2).

In addition, it has also been proposed to apply a two-photon absorption optical material (see Patent Document 3) or a two-stage absorption optical material (see Non-Patent Document 1) to hologram recording.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-318433

Patent Document 2: Japanese Patent Application Laid-Open No. 2004-78224

Patent Document 3: Japanese Patent Laid-Open No. 2005-99416

Non-Patent Literature l: The Journal of Physical Chemistry 1981, 85, 123. Disclosure of the Invention Problems to be solved by the invention

However, in the case where hologram recording is performed by the techniques described in Patent Documents 1 to 3 and Non-Patent Document 1, when the recording unit is exposed by reproduction light during reading, the hologram of the recording unit changes, The recorded contents were destroyed.

The present invention was devised in view of the above problems, and by providing a gate function, a photoreactive composition that enables reading of a record without destroying the recorded content when used for holographic recording. An object is to provide an optical material, an optical recording material, a volume hologram recording material, an optical recording medium, and an optical recording method thereof.

Means for solving the problem

[0007] As a result of intensive studies to solve the above-mentioned problems, the present inventor used a photoreactive composition having a sensitizer and a polymer having a reactive group as the material of the hologram recording medium, and Non-destructive readout function (that is, a function capable of reading a record without destroying the recorded content) by using a sensitizer having a reduced electron configuration with respect to the reactive group The present inventors have found that a hologram recording medium having the above can be realized and completed the present invention.

[0008] That is, the gist of the present invention contains a sensitizer (A) excited by absorbing photons, and a polymer (B) having a reactive group (C) capable of causing chemical conversion, The sensitizer (A) resides in a photoreactive composition characterized in that it has a reduced electron configuration with respect to the reactive group (C) (claim 1).

At this time, it is preferable that the sensitizer (A) is excited by absorbing two or more photons (claim 2). The sensitizer (A) is preferably excited by absorbing photons of different wavelengths having a force of 2 or more (claim 3).

[0010] Further, the sensitizer (A) is excited to a singlet excited state by absorbing the photons of the first excitation light, and then transitions to the lowest triplet excited state by intersystem crossing, Subsequently, by absorbing photons of the second excitation light having a wavelength different from that of the first excitation light, the multistage excitation type sensitization is excited to a triplet excited state higher than the lowest triplet excited state. The body is preferred (claim 4).

[0011] When the sensitizer (A) is excited, the reaction is caused by the contribution of the excited sensitizer (A). It is preferred that the reactive group (c) undergoes chemical conversion to change the optical properties of the photoreactive composition (Claim 5).

Further, it is preferable that the chemical conversion is an isomeric reaction (claim 6).

[0012] Another gist of the present invention resides in an optical material comprising the photoreactive composition (claim 7).

Still another subject matter of the present invention lies in an optical recording material characterized in that it also has the above-mentioned optical material force (claim 8).

[0013] Still another subject matter of the present invention lies in a volume holographic recording material characterized in that the optical recording material force is also provided (claim 9).

Still another subject matter of the present invention lies in an optical recording medium comprising a layer containing the optical recording material (claim 10).

[0014] Still another subject matter of the present invention lies in an optical recording method for an optical recording medium, wherein the excitation light is irradiated to the layer of the optical recording medium. ). At this time, it is preferable to irradiate reference light together with the excitation light, and record a hologram on the layer by interference between the excitation light and the reference light (claim 12).

The invention's effect

[0015] According to the present invention, when used for hologram recording, a photoreactive composition capable of reading a record without destroying the recorded content, an optical material using the composition, and an optical recording material Further, it is possible to provide a volume hologram recording material, an optical recording medium, an optical recording method thereof, and a hologram recording method.

Brief Description of Drawings

[0016] FIG. 1 is a diagram schematically showing how electrons move due to photon absorption.

[FIG. 2] FIG. 2 is a diagram schematically showing how electrons move due to photon absorption.

[FIG. 3] FIG. 3 is a diagram schematically showing how electrons move due to photon absorption.

FIG. 4 is a diagram showing an example of changes in the sensitizer and the reactive group at the time of reading when the sensitizer has an oxidized electron configuration with respect to the reactive group.

[FIG. 5] FIG. 5 (a) to FIG. 5 (c) show the sensitizer and reactive group at the time of readout when the sensitizer has an oxidized electron configuration with respect to the reactive group, respectively. Example of electronic configuration FIG.

FIG. 6 is a diagram showing an example of changes in sensitizer (A) and reactive group (C) during readout in the photoreactive composition of the present invention.

[FIG. 7] FIG. 7 (a) to FIG. 7 (c) are examples of the electron arrangement of the sensitizer (A) and the reactive group (C) at the time of readout in the photoreactive composition of the present invention, respectively. FIG.

[FIG. 8] FIG. 8 (a) to FIG. 8 (c) are sensitizers at the time of writing when the reactive group (C) is activated by reduction in the photoreactive composition of the present invention, respectively. FIG. 4 is a diagram illustrating an example of an electron configuration of (A) and a reactive group (C).

[FIG. 9] FIGS. 9 (a) to 9 (c) are sensitizers at the time of writing when the reactive group (C) is activated by energy transfer in the photoreactive composition of the present invention, respectively. It is a figure showing an example of the electronic arrangement | positioning of (A) and a reactive group (C).

FIG. 10 is a diagram schematically showing an outline of a measurement system used in Example 1 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Hereinafter, the present invention will be described with reference to embodiments, examples, and the like. However, the present invention is not limited to the following embodiments, examples, and the like, and may be arbitrarily selected without departing from the gist of the present invention. It can be changed and implemented.

[0018] [I. Photoreactive Composition]

The photoreactive composition of the present invention is a sensitizer that is excited by absorbing photons (hereinafter referred to as “excitation light”, which is light that can also excite the sensitizer (A) as appropriate). A) and a polymer (B) are contained. Further, the polymer) has a reactive group (C) capable of causing chemical conversion.

The symbols “(A)”, “(B)”, and “(C)” that appear here are symbols for distinguishing sensitizers, polymers, and reactive groups. The photoreactive composition of the present invention may contain other components as long as the effects of the present invention are not significantly impaired.

However, in the photoreactive composition of the present invention, the sensitizer (A) has a reduced electron configuration with respect to the reactive group (C). Here, when the sensitizer (A) has a reduced electron configuration with respect to the reactive group (C), the sensitizer (A) can donate electrons to the reactive group (C). Specifically, the highest occupied orbit of the sensitizer (A) (Highest Occ upied Molecular Orbital (HOMO) is higher in energy than the highest occupied orbital of the reactive group (C)!

[0020] [1-1. Sensitizer (A)]

The sensitizer (A) is a substance (a whole compound or a part that exerts its sensitizing action) that is excited by absorbing photons upon irradiation with excitation light. In the photoreactive composition of the present invention, when the sensitizer (A) is appropriately excited, electron or energy transfer occurs due to the contribution of the excited sensitizer (A), and the reactive group. The chemical conversion of (C) is occurring.

[0021] However, as the sensitizer (A), one having a reduced electron configuration with respect to the reactive group (C) is used. Here, the electron configuration of the sensitizer (A) and the reactive group (C) can be confirmed by measurement of acid reduction potential.

[0022] As the sensitizer (A), for example, a known sensitizer can be used. Here, the term “sensitizer”! Means a molecule, and the term “sensitizer (A)” means the whole or a part of a molecule. Examples of compounds that can be used as the sensitizer (A) include synthetic dyes, natural pigments, aromatic compounds, and heterocyclic compounds.

Specific examples of synthetic dyes include atalidine dyes, azo dyes, alizarin dyes, anthraquinone dyes, indigoid dyes, carbo dyes, xanthene dyes, quinoline dyes, quinonimine dyes, diphenylmethane dyes, stilbene dyes, thiazoles. Examples include dyes, triphenyl methane dyes, nitro dyes, nitroso dyes, pyrazolone dyes, methine dyes, and sulfur dyes.

[0023] Specific examples of natural pigments include carotene, flavones, quinones, xanthones, petas-azine, blood pigments (such as porphyrins), chlorophyll, phenazine, phenoxane derivatives, and indole derivatives. .

[0024] Furthermore, specific examples of the aromatic compound include condensed aromatic rings, oligophenylenes, and conjugated genes.

Specific examples of the heterocyclic compound include coumarin, azacoumarin, quinoline, azaquinoline, oxazonole, benzoxazonole, oxazionole, furan, benzofuran, pyrazoline, phthalimide, naphthalimide, pteridine, oligothiophene, heterocyclic salt And so on. In addition, as the sensitizer (A), it is also possible to use a dye such as cyanine, merocyanine, phthalocyanine, porphyrin, xanthene, triallylmethane, acylolidine, azine, chlorophyll.

Among these, benzophenone, oligothiophene, tetrazine, force rubazole, porphyrin, and the like are particularly preferable because they can function as a multistage excitation sensitizer (described later).

In addition, for example, the portion exhibiting the sensitizing action of these exemplified compounds is used as the sensitizer (A).

The sensitizer (A) may be used alone or in combination of two or more in any combination and ratio.

[0026] Among the sensitizers (A), those which are excited by absorbing two or more photons (multiphoton absorption) (for example, a multiphoton absorbing compound or a portion thereof) are preferable. As will be described later, in the photoreactive composition of the present invention, the non-destructive readout function is realized by the combination of the sensitizer (A) and the reactive group (C) that affects the acid-reducibility. If the sensitizer (A) is excited by absorbing two or more photons (for example, a multiphoton absorbing compound or a portion thereof), the sensitizer (A) itself has a nondestructive readout function. This is because it can be realized more stably.

Hereinafter, this multiphoton absorption will be described in detail.

[0027] Multiphoton absorption refers to an orbital level that is sufficient to supply the reactant (in the present invention, reactive group (C)) with the energy necessary to initiate the reaction (chemical conversion). It is forcibly excited by absorbing a plurality of photons simultaneously or stepwise into the sensitizer. Multiphoton absorption includes (a) one that absorbs light emitted from a single wavelength light source (see Figs. 1 and 2) and (b) one that absorbs light emitted from multiple light sources of different wavelengths ( (See Fig. 3)

[0028] (a) Multiphoton absorption that absorbs light emitted from a single wavelength light source

Multiphoton absorption that absorbs light emitted from a single wavelength light source includes (i) a singlet excited state (S1) force that supplies energy to the reactive group (C), and (ii) a singlet excited state. From (S1) to the triplet excited state (T1) due to intersystem crossing, energy is transferred from there to the reactive group (C). Some supply one.

[0029] In the case of (i), the minimum amount of photon energy required is the amount of energy ΔE from the ground state (SO) to the-singlet excited state (S 1).

On the other hand, in the case of (ii), the singlet excited state (S1) that can give the triplet excited state (T1) from the ground state (SO) even if energy is lost during intersystem crossing. An energy amount Δ E up to the orbital level is required, which is higher than (i).

[0030] This point will be described in detail by taking as an example the case where two photons are absorbed and the sensitizer (A) is excited.

Fig. 1 is a diagram schematically showing how electrons move due to photon absorption. In Fig. 1, the ground state (SO) and the singlet excited state (S1) represent the existing energy states. The virtual state (Sx) represents an energy state that is one photon higher than the ground state (SO). However, since the virtual state (Sx) is set temporarily and not in the existing energy state, electrons cannot move to the virtual state.

[0031] Absorption in the case of (i) is an absorption called simultaneous multiphoton absorption (in this example, simultaneous two-photon absorption). As shown in Fig. 1, when excitation is performed, the sensitizer (A) is irradiated with light (excitation light) and absorbs the two photons, thereby basing the sensitizer (A) on the base. The electrons in the state (SO) move to the singlet excited state (S1). As a result, the sensitizer (A) is excited and can react with the reactive group (C).

In this way, in simultaneous two-photon absorption, it is sufficient if the actual excited state exists at twice the energy level of the photon used for excitation, so there is no absorption in the absorption spectrum, and the region (non-resonant region) It is possible to excite molecules using light of a wavelength of. The case where two-photon absorption occurs nonlinearly using light with a wavelength in the non-resonant region is called non-resonant two-photon absorption.

[0032] The efficiency of this non-resonant two-photon absorption is proportional to the square of the photoelectric field applied to the sensitizer (A) (the two-photon absorption squared characteristic). For this reason, in a three-dimensional space, two-photon absorption occurs only in a region where the applied light intensity is high, and no two-photon absorption occurs in a region where the light intensity is low. Therefore, non-resonant two-photon absorption is derived from this square characteristic in comparison with linear absorption where excitation occurs at all positions in proportion to the intensity of the applied photoelectric field. Since excitation occurs only in a predetermined region, the spatial resolution is significantly improved.

[0033] Normally, when non-resonant two-photon absorption is induced, a laser having a wavelength longer than the wavelength region where linear absorption is performed (that is, the wavelength region where one-photon absorption exists) and having no absorption. Often uses light. For this reason, it is possible to use a laser in a transparent region (that is, a laser that emits laser light in a wavelength region where there is no one-photon absorption) as a light source of excitation light, and the laser light is subjected to absorption and scattering. Without reaching the inside of the photoreactive yarn and the product.

In the example described above, the case of two-photon absorption that absorbs two photons has been described as an example, but the same advantage can be obtained in multi-photon absorption that absorbs three or more photons.

[0034] Further, when non-resonant two-photon absorption is induced, there is no particular limitation on the two-photon absorption cross section indicating the two-photon absorption, but usually 100GM or more, preferably 1000GM or more, more preferably 10000GM. A sensitizer (A) having the above is preferred. The evaluation method of the two-photon absorption cross section is as follows. The evaluation of the two-photon absorption cross-section of a compound is performed with reference to the open-chamber type Z-scan method described in Reference I (IEEE J. Quant. Electron. 26 (1990) 760). As a light source for measuring the two-photon absorption cross section, a Ti: sapphire laser and an optical parametric oscillator laser pumped by the laser are used. The pulse width of the light source pulse is 110 femtoseconds to 130 femtoseconds, the pulse repetition frequency is 76 Hz, and the average power is ^10-1QQ mW. The wavelength range is 570ηπ! Measure at ~ 1200nm. As described in Document I, the measurement is performed by converging the pulse laser beam from the light source with a lens, scanning the sample to be measured in the direction of travel of the laser beam (Z axis), and Measure the transmittance at the sample position. From the obtained transmittance curve, incident average power, incident wavelength, incident pulse width, sample concentration, sample thickness, etc. in each sample position, refer to Document II (Chem. Phys. Lett. 372, 386 (2003)). A two-photon absorption cross section is obtained by the method described. Note that the 1GM, means molecules, photons each one per 1 X 10- ⁵ ° cm ⁴ 'seconds ^{(1GM = 1 X 10- 5 °} cm 4' the s / (molecule 'photon)) .

Next, absorption in the case of (ii) will be described. Figure 2 shows the movement of electrons associated with photon absorption. It is a figure which shows a mode typically. In FIG. 2, the same reference numerals as those in FIG. 1 denote the same elements as in FIG.

In the case of (ii) as well, the sensitizer (A) is irradiated with excitation light and absorbs two photons, so that electrons in the ground state (SO) move to the singlet excited state (SI). To do. However, in the case of (ii), the electrons in the singlet excited state (S1) move to the triplet excited state (T1) due to intersystem crossing. Thus, the sensitizer (A) is excited and can react with the reactive group (C).

[0036] In the case of (ii), the occurring absorption phenomenon is simultaneous multiphoton absorption, and non-resonant two-photon absorption is possible as in the case of (i) above. You can get the benefits of However, in the case of (ii), energy is lost when the intersystem crossing occurs from the singlet excited state (S1) to the triplet excited state (T1), so the sensitizer (A) is excited. In order to do this, higher energy is required than in (i).

[0037] In any of the above cases (i) and (ii), the energy corresponding to the energy amount ΔE from the ground state (SO) to the necessary excited state (S1 or T1) is used by using a plurality of photons. Will be forcibly supplied. Therefore, any sensitizer (A) can be used as long as it is a compound having absorption and a portion thereof (a portion that exhibits a sensitizing action).

[0038] However, in reality, if multiphoton absorption in the ultraviolet region is used, the energy is too high, and the sensitizer (A) and the reactive group (C) itself, or other components may be destroyed. There is. In addition, when an optical recording medium is produced with the photoreactive composition of the present invention, the constituent members of the optical recording medium such as a support may be damaged.

On the other hand, when infrared light is used as excitation light, the energy is too low, and a large number of photons are required to supply the sensitizer (A) with energy necessary for excitation of the sensitizer (A). In particular, the efficiency can be significantly reduced.

[0039] Therefore, sensitization suitable for multiphoton absorption that absorbs light emitted from a single wavelength light source. As the body (A), for example, a compound having absorption in the visible region is preferably used. For example, dyes such as cyanine, merocyanine, phthalocyanine, ponolephyrin, xanthene, triarinolemethane, asylidine, azine, chlorophyll, aromatic compounds such as condensed aromatic rings, oligophenolene, conjugated gen, coumarin, azacoumarin, quinoline, azaquinoline. And heterocyclic compounds such as oxazole, benzoxazole, oxadiol, furan, benzofuran, pyrazoline, phthalimide, naphthalimide, pteridine, and heterocyclic salts. In addition, a portion that exhibits the sensitizing action of these exemplified compounds can be used as a sensitizer (.

[0040] (b) Multiphoton absorption that absorbs light emitted from light sources of different wavelengths

Multistage absorption is an example of multiphoton absorption that absorbs light emitted from a plurality of light sources having different wavelengths. This is because the sensitizer (A) changes from the ground state (SO) to the singlet excited state (S1) by absorbing the photons of the first light (first excitation light) emitted from the first light source. By being excited and then transitioning to the lowest triplet excited state (T1) by intersystem crossing, followed by absorbing photons of the second light (second excitation light) emitted from the second light source This is a phenomenon in which the lowest triplet excited state (T1) is excited to a higher triplet excited state (Tn). It is assumed that the first light and the second light have different wavelengths. In this case, it is sufficient if the triplet excited state (Tn) is an orbital level having sufficient energy for the initiation of the reaction, from this triplet excited state (Tn) to the reactive group (C) for the initiation of the reaction. Of energy is supplied.

[0041] With regard to this multi-stage absorption, the case where two photons are absorbed and the sensitizer (A) is excited will be described in detail.

FIG. 3 is a diagram schematically showing how electrons move due to photon absorption. In FIG. 3, the same reference numerals as those in FIGS. 1 and 2 denote the same elements as those in FIGS.

This multistage absorption is an absorption called stepped multiphoton absorption (in this example, stepped two-photon absorption). As shown in Figure 3, during excitation, the sensitizer (A) was in the ground state (SO) of the sensitizer (A) by absorbing one photon of the first light. Electrons move to the singlet excited state (S1). After that, due to intersystem crossing, electrons existing in the singlet excited state (S1) move to the lowest triplet excited state (T1). [0042] Thereafter, the sensitizer (A) absorbs one photon of the second light. By absorbing this photon (second photon), electrons in the lowest triplet excited state (T1) of the sensitizer (A) become triplet excited states (Tn) at higher energy levels. Move to. As a result, the sensitizer (Α) is excited and can react with the reactive group (C).

[0043] In the stepwise multiphoton absorption system, the wavelength of the first light causing the first stage excitation is shorter than the wavelength of the second light causing the second stage excitation (high energy). Is preferred. In addition, when the sensitizer (Α) also excites the ground state (SO) force to the singlet excited state (S 1), it absorbs light of the second wavelength only weakly or not at all. Is preferred.

[0044] The orbital level of the singlet excited state (S1) in the first stage or Z and the lowest triplet excited state (T1) passing through the intersystem crossing from there is the reactive group (C) starting chemical conversion. It is preferable that the orbital level does not have enough energy to be able to start chemical conversion only after being excited to the triplet excited state (Tn) via the second stage excitation. . By selecting such a system, it is not possible to supply sufficient energy to the reactive group (C) with only one of the first light and the second light, and irradiation with light of both wavelengths. It is possible to add a so-called "light gate function" that can start chemical conversion of the reactive group (C) for the first time.

That is, as described above, stepwise multiphoton absorption is caused by the addition of actual excitation. For this reason, the excitation wavelength of the first photon (that is, the wavelength of the first light) must be generated unless it is in a region where there is absorption (resonance region). For this reason, when the sensitizer (A) that generates stepwise two-photon absorption is used, the optical recording medium (hologram recording medium) formed from the photoreactive composition of the present invention is required for excitation after recording. Even if only one wavelength (that is, either the first light or the second light) of the two wavelengths of excitation light (that is, the first light or the second light) is irradiated, the sensitization is performed. The body (A) is never excited.

In the above example, the case of two-photon absorption in which two photons are absorbed has been described as an example. However, the same advantage can be obtained in stepped multiphoton absorption in which three or more photons are absorbed.

[0046] Sensitizers (A) suitable for such stepwise multiphoton absorption include (1) singlet excited state (S (1) Long lifetime, (2) —low fluorescence in the singlet excited state (S 1), that is, good intersystem crossing efficiency, and (3) lowest triplet excited state (T1) Examples include compounds that have a long life span and satisfy at least one of them. It is more preferable that the above requirements are satisfied more. Specific examples of suitable sensitizers (A) that satisfy such requirements include ponorephrine, oligothiophene, xanthene, phthalocyanine, coumarin, oxazole, benzophenone, oligophenolene, and pyrene. In addition, a portion that exhibits the sensitizing action of the compounds shown in these examples can also be used as the sensitizer (A).

[0047] Regarding the sensitizer (A) suitable for stepwise multiphoton absorption, the quantum yield (Φ) in the triplet excited state is not particularly limited, but is preferably 0.5 or more, more preferably 0. . 7 or more

T

More preferably, 0.9 or more is desirable. The triplet-triplet molar extinction coefficient (ε) in the wavelength region of the excitation light of the second stage of the sensitizer (A) is not particularly limited, but is preferred.

Τ

<Ί or more than 10,000, more preferred <ί or more than 50, 000, more preferred <ί or more, more than 100,000 power is desirable. The quantum yield of the triplet excited state (Φ)

Evaluation method of Τ and triplet single triplet molar extinction coefficient (ε) ί, III (J. Chem. Soc., Faraday Trans. 1, 73 (197 τ

7) Use the method described in 1319). At this time, the third harmonic or fourth harmonic of the Q-switch YAG laser is used as the laser light source.

[0048] In multiphoton absorption that absorbs light emitted from a plurality of light sources having different wavelengths, each stage of excitation (eg, first stage excitation, second stage excitation, etc.) is independent of each other. As described in “(a) Multi-photon absorption that absorbs light emitted from a single wavelength”, it may occur by absorbing a plurality of photons of each wavelength.

[0049] Further, when a sensitizer (A) that is excited by multiphoton absorption (for example, a multiphoton absorption compound or a portion thereof) is used, optical recording is performed using the photoreactive composition of the present invention. When a medium is manufactured, recording and reproduction can be performed with excitation light having a relatively long wavelength with respect to the optical recording medium. For this reason, it is possible to record and replay using a long wavelength laser that is inexpensive and easily available without using a short wavelength laser that is generally expensive and difficult to obtain. Advantages such as the ability to suppress side reactions that are likely to occur with ultraviolet light and recording with good recording quality can be obtained. [0050] Among the multiphoton absorptions described above, stepwise multiphoton absorption is preferable because an optical gate function can be realized. Therefore, as the sensitizer (A), among the multiphoton absorbing compound or a part thereof, a multistep excitation type multiphoton absorption compound (multistage excitation sensitizer) that generates stepwise multiphoton absorption or a part thereof is used. It is preferable to use the part as a sensitizer (A).

[0051] Further, when the sensitizer (A) absorbs two or more photons as described above, it is preferably excited by absorbing two or more different photons. Here, the type of photon wavelength means that the wavelengths are different from each other by 30 nm or more, preferably 50 nm or more. When the wavelength of the photon absorbed by the sensitizer (A) is two or more, stepwise multi-photon absorption is possible, and the photoreactive composition of the present invention has an advantage that a photogate function can be realized. be able to. The use of the first excitation light and the second excitation light in the above-described stepwise two-photon absorption is an example of two or more photon wavelengths.

[0052] The content of the sensitizer (A) contained in the photoreactive composition of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired. 0.001% by weight or more, preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and usually 50% by weight or less, preferably 40% by weight or less, more preferably 30% by weight or less. . If the amount of the sensitizer (A) is too small, the sensitivity may decrease. If the amount is too large, absorption of light used for recording and reproduction increases, and light may not reach the depth direction.

In the case where the sensitizer (A) is a part of a compound (for example, a functional group), the sensitizer (A) is included in the polymer) unless the effects of the present invention are impaired. Also good. When the sensitizer (A) is contained in the polymer (B), the sensitizer (A) is heavy as a part of the main chain that may be contained in the polymer (B) as a side chain. It may be contained in coalescence (B).

[0053] Further, there is no limitation on the ratio of the sensitizer (A) to the reactive group (C).

[0054] [I 2. Polymer (B) and Reactive Group (C)]

Any polymer (B) may be used as long as it is a polymer (polymer) having a reactive group (C) capable of causing a predetermined chemical conversion. Here, the reactive group (C) will be described first, and then the polymer) will be described.

[0055] The reactive group (C) is a group of atoms that can substantially participate in chemical conversion, and causes chemical conversion. Any group can be used. There is no limitation on the chemical transformation in which the reactive group (C) is generated. Any appropriate chemical transformation can be used depending on the use of the photoreactive composition of the present invention. However, it is preferable that the reactive group (C) causes chemical conversion when the sensitizer (A) is appropriately excited. Therefore, it is preferable that the chemical transformation of the reactive group (C) occurs due to the contribution of the excited sensitizer (A).

[0056] Among the chemical transformations of the reactive group (C), organic reactions can be mentioned as examples of suitable ones. Among these, photoreaction, polymerization reaction, polymer reaction and the like are particularly preferable.

For example, examples of the photoreaction include an isomerization reaction, a transfer reaction, a cyclization reaction, a dimerization reaction, a hydrogen abstraction reaction, and an addition reaction.

Specific examples of suitable chemical transformations are given below. In the chemical transformations exemplified below, the reactions between the compounds are exemplified, but in these chemical transformations, some of the exemplified compounds function as reactive groups (C) and the reaction proceeds. Should be seen. Therefore, when the chemical transformation exemplified here is applied to the reactive group (C), a moiety that causes a chemical change of the exemplified compound (this part corresponds to the reactive group (C)) is taken as the compound. Instead of chemical conversion.

[0057] Examples of isomeric reactions include isomerization reactions of olefins, azo compounds, and carbonyl compounds.

Specific examples of isomerization reactions of olefins include cis-trans isomerization reactions (eg, cis-trans isomerism such as stilbene, 1,3 pentagen, cyclic olefin, olefins conjugated with carboleyl, and nitrogen compounds). Ii reaction). Further, the isomerization reaction of the azo compound includes a cis-trans isomerization reaction.

[0058] Examples of the rearrangement reaction include rearrangement reaction of olefin, polyene, and enone compounds, and photorearrangement reaction of carbo-louie compound.

Specific examples of such rearrangement reactions of olefin and polyene include rearrangement reactions that occur during cyclization and isomerization reactions due to intramolecular rearrangement of protons, rearrangement reactions of di-π methane compounds (for example, 1,4 pentagen derivatives). A rearrangement reaction that occurs during the formation of bulucyclopropane by the reaction, a rearrangement reaction that occurs during the formation of cyclopropane by the photorearrangement of cyclic π-methane (for example, the rearrangement reaction of norbornagen-quadricicrane) Etc.)) and the like.

[0059] Further, for example, rearrangement reactions of enone compounds include rearrangement reactions that occur during 1,2-aryl and lumiketone rearrangements in α, β-cyclohexenone, photorearrangement reactions of cyclopentenone, β, Photorearrangement reaction of γ-enone, rearrangement reaction of Genony compound (rearrangement reaction that occurs during the formation of bicyclohexenone or hydroxyketone from 2,5 cyclohexagenone; hetero 2,5 cyclohexagenone, 2, 4 -Rearrangement reaction that occurs during the rearrangement and ring cleavage reaction of cyclohexagenone; Rearrangement reaction that occurs during the photochemical reaction of trobolone (cycloheptatrienone).

[0060] Further, for example, the photorearrangement reaction of a carbo-Louis compound includes a photorearrangement reaction that occurs in the formation reaction of ketene and aldehyde by decomposition of a cyclic ketone, and a carbon monoxide elimination reaction from a carbonyl compound. Photorearrangement reaction that occurs during the reaction, and photorearrangement reaction that occurs during the formation reaction of the cyclic ether by ring expansion reaction of the cyclic ketone.

[0061] Examples of the cyclization reaction include a cyclization reaction of Gen and Trien, a photocyclization reaction of stilbene and a derivative thereof, and an intermolecular photocyclization reaction of olefin.

For example, the cyclization reaction of gen and triene includes the cyclization reaction that occurs during the formation reaction of cyclobutane by the intramolecular cyclization reaction of non-conjugated gen, and the formation of cyclobutene by intramolecular cyclization of conjugated gen. Examples include a cyclization reaction that occurs during the reaction, a cyclization reaction of cyclic conjugation, a ring formation reaction having triene by ring opening of bicyclohexagen, and a cyclization reaction of heterogene and triene.

[0062] Further, for example, photocyclization reaction of stilbene and its derivative includes photocyclization reaction that occurs in the synthesis reaction of phenanthrene, photocyclization reaction of azobenzene-aniline derivative, photocyclization of stilbene having anthrone and heterocycle And the like.

[0063] Further, the intermolecular photocyclization reaction of olefins includes intermolecular photocyclization reaction between conjugated olefin and olefin, intermolecular photocyclization reaction that occurs in the photoaddition reaction to enony compound, and olefin to acetylene. And the intermolecular photocyclization reaction that occurs during the addition reaction of olefins to the aromatic ring.

[0064] Examples of the dimerization reaction include the photodimerization reaction of olefin.

As a specific example, the photodimerization reaction of olefin is the dimer of alkylolefin. Of divinylcyclobutane by the dimerization of cyclobutane by the dimerization of cyclobutane by the dimerization of cyclobutane, the dimerization of cyclobutane by the dimerization of aromatic olefin, Photodimer reaction that occurs during the formation reaction, photodimer reaction that occurs during the formation reaction of cyclobutane due to the dimerization of the enone compound (for example, the photodimer reaction of a chain enone compound; Photodimer reaction of tenone, cyclohexenone, heterocycle, etc .; photodimer reaction of quinone compounds), photodimer reaction of fumaric acid and maleic acid with their derivatives.

[0065] Examples of the hydrogen abstraction reaction include a hydrogen abstraction reaction of a carbonyl compound.

For example, the hydrogen abstraction reaction of a carbonyl compound includes an intramolecular hydrogen abstraction reaction of an aromatic ketone, a hydrogen abstraction reaction that occurs during the formation reaction of cyclobutanol from a cycloalkyl ketone, and a cyclic ketone. Abstraction reaction during bicycloalcohol formation reaction from α-diketones, hydrogen abstraction reaction within α-diketone molecule, hydrogen bow I extraction reaction within α, β unsaturated ketone molecule, ortho-substituted aromatic ketone Examples include a hydrogen abstraction reaction that occurs during the cyclization and enantiomer reaction, a hydrogen abstraction reaction that occurs during the intramolecular cyclization reaction of phthalimide, and a hydrogen abstraction reaction that occurs during the reduction reaction of carbonyl.

[0066] Examples of the addition reaction include an addition reaction of a carbonyl compound to olefin.

For example, the addition reaction of carbonyl compounds to olefins includes addition reactions that occur during the formation of oxetane by reaction with electron-rich olefins; carbonyl compounds and lack of electrons. Addition reaction that occurs during the formation reaction of oxetane by reaction with olephine; Addition reaction that occurs during the formation reaction of oxetane by intramolecular addition reaction of unsaturated ketone; By addition reaction of ketone having electron withdrawing group to olefin Addition reactions that occur during the formation reaction of oxetane; addition reactions to olefins such as benzoquinone, fluoroketone, and nitrobenzene.

[0067] Other chemical conversions include photoreactions of aromatic compounds. Examples of photoreactions of aromatic compounds include isomeric reactions of benzene and its derivatives, Isomerization reaction of gin and its derivatives, addition reaction to aromatic ring, synthesis reaction of substituted phenol and arlin by photofleece rearrangement, photosubstitution reaction of aromatic compound (nucleophilic reaction of nitroaromatic compound, And photo-substitution reaction of benzene and its analogues, photo-substitution reaction of poly-substituted benzene, photo-addition and substitution reaction to benzo-tolyl).

[0068] Examples of the polymerization reaction include addition polymerization reaction, transition metal catalyzed polymerization reaction, ring-opening polymerization reaction, cyclopolymerization reaction, polycondensation reaction, polyaddition / addition condensation reaction, and the like. Examples of the addition polymerization include radical polymerization reactions (for example, radical polymerization reactions of ethylene, vinyl chloride, butyl acetate, vinylidene chloride, styrene, butadiene, methacrylic monomers, acrylic monomers, acrylonitrile, etc.); cationic polymerization reactions ( For example, cationic polymerization reaction such as styrene, isobutene, butyl ether, N-bulu force rubazole), ion polymerization reaction (eg, cation polymerization reaction such as styrene, butadiene, methacrylic monomer, acrylic monomer, nitroethylene) And ionic polymerization reactions.

[0069] The transition metal catalyzed polymerization reaction includes, for example, a polymerization reaction using a Zeiggler-Natta catalyst (for example, a catalytic polymerization reaction of olefin, styrene, acetylene, gen, etc.), or a polymerization reaction using a metathesis catalyst. (For example, catalytic polymerization reaction of cyclic olefin, alkyne, gen, etc.).

Examples of the ring-opening polymerization reaction include a ring-opening polymerization reaction of a cyclic monomer.

[0070] Further, as the polymer reaction, for example, a crosslinking reaction (for example, an epoxy-amine reaction, an epoxy mercaptan reaction, an unsaturated ester-amine reaction, an unsaturated ester-mercaptan reaction, a hydrocycle reaction, a urethanization reaction, etc.); dendrimer And the like.

[0071] Among the above chemical transformations, isomerization reaction and rearrangement reaction are preferred. By using a reactive group (C) that generates an isomerization reaction or a rearrangement reaction, it is possible to obtain the advantage that it is not dependent on the surrounding environment where the free volume is small.

[0072] In addition, as the chemical conversion, it is also preferable to use one that changes the optical properties of the photoreactive composition of the present invention by the chemical conversion. That is, the sensitizer (A) is excited In such a case, it is preferable to employ a compound in which the reactive group (C) is chemically converted by the contribution of the excited sensitizer (A) and the optical properties of the photoreactive composition of the present invention are changed. ,. Examples of the optical characteristics that change include refractive index and Abbe number (reverse dispersion ratio). Among them, refractive index is preferable. As a result, the photoreactive composition of the present invention can be suitably used as a hologram recording material.

[0073] Examples of chemical transformations that can change the optical properties of the photoreactive composition as described above include addition reactions, isomerization reactions, rearrangement reactions, cyclization reactions, and the like. Of these, isomerization reaction, rearrangement reaction, and cyclization reaction are preferable in order to greatly change the refractive index.

Specific examples of particularly preferred isomerization reactions include cis-trans isomerization reactions, and among them, more preferable reactions include cis-trans isomerization reactions of azo compounds.

Further, specific examples of particularly suitable rearrangement reactions include intramolecular rearrangement reactions of olefin and polyene. Among them, a more preferable reaction is a rearrangement reaction from norbornagen to quadricyclane.

Furthermore, specific examples of particularly suitable cyclization reactions include intermolecular photocyclization reactions, and among them, more preferred reactions include intermolecular photocyclization reactions of anthracene.

In these chemical transformations, it is not clear which part of the photoreactive composition acts as the reactive group (C), but at least the part involved in the chemical transformation reaction acts as the reactive group (C). It is presumed that

[0074] Further, when the refractive index changes as a change in optical characteristics, there is no limit to the degree to which the refractive index changes, but usually 0.001 or more, preferably 0.01 or more, more preferably 0.05 or more. Chemical transformations that cause this change are preferred. This is because the greater the change in refractive index, the higher the multiplicity of recording and the larger the recording capacity per unit volume.

[0075] Specific examples of the reactive group (C) that causes chemical conversion as described above include a norbornagen group.

[0076] In particular, it is preferable to use porphyrin as the sensitizer (A) and norbornagen group as the reactive group (C). As the reactive group (C), one kind may be used alone. Two or more kinds may be used in any combination and in any ratio. Accordingly, the polymer) may have two or more kinds of reactive groups (C).

[0077] The molecular weight of the reactive group (C) is not limited.

[0078] Furthermore, there is no limit to the number of reactive groups (C) that one polymer (B) has.

[0079] Next, the polymer) will be described.

The polymer) is a polymer having a reactive group (C). At this time, the reactive group (C) may be contained in the polymer (B) as a part of the main chain which may be contained in the polymer (B) as a side chain. Further, it may contain a reactive group (C) that is not contained in the polymer.

[0080] The polymer (B) may be a polymer obtained by polymerizing only one kind of monomer, or may be a copolymer obtained by copolymerizing two or more kinds of monomers in an arbitrary combination and ratio. ! / Further, there is no limitation on the type of polymerization, and a polymer obtained by any type of polymerization method such as block polymerization, random polymerization, graft polymerization or the like can be used. Furthermore, the polymer) may be linear or branched.

[0081] Examples of suitable polymers (B) include polymetatalylate, polyacrylate, polystyrene, polyester, polyamide, polyurethane, polycarbonate, polyetherol, cenorelose esterol, poly (polyacrylate) having a reactive group (C). Vininoles Estenore, Polyvinylenoatenore, Polysiloxane, Polyolefin derivatives and the like.

The polymer (B) may be used alone or in combination of two or more in any combination and ratio.

[0082] Among them, the viewpoint of improving the sensitivity upon photoexcitation is that the polymer is optically transparent in the spectral region (that is, in the wavelength region) absorbed by the sensitizer (A). Is preferred. That is, the polymer) preferably has no significant absorption at the wavelength of excitation light (excitation wavelength). Specifically, the haze of the polymer (B) at a thickness of 1 mm is usually 30% or less, preferably 10% or less, more preferably 5% or less. The haze is preferably as small as possible, and the lower limit is 0%.

[0083] The polymer (B) is preferably one that does not interfere with the chemical conversion of the reactive group (C). That is, the reactive group (C) is converted into a component other than the reactive group (C) in the molecular structure of the polymer (B). It is preferable that the academic conversion is not disturbed.

[0084] Furthermore, the polymer (B) may have a substituent other than the reactive group (C) as long as the effects of the present invention are not significantly impaired. In addition, the substituent may be used alone or in combination of two or more in any combination and ratio.

[0085] Further, the weight average molecular weight of the polymer (B) is not limited, and any force as long as the effect of the present invention is not significantly impaired. Usually 1000 or more, preferably 3000 or more, more preferably 5000 or more, and further Preferably it is 10,000 or more. There is no particular upper limit. If the molecular weight is too small, the archive life may be shortened. The weight average molecular weight of the polymer (B) can be measured by GPC (gel permeation chromatography).

[0086] Among them, the viewpoint power to increase the archive life when the photoreactive composition of the present invention is used as an optical recording material or a volume hologram recording material is that the micro-Brownian motion of the polymer (B) is in use. It is preferable to make it smaller. To achieve this, the polymer

The glass transition temperature Tg of (B) is suitably 20 ° C or higher, preferably 30 ° C or higher, more preferably 50 ° C or higher, and usually 300 ° C or lower, preferably 290 ° C or lower. More preferably, it is 280 ° C or lower.

[0087] The content of the polymer (B) contained in the photoreactive composition of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired.

[0088] Further, there is no limitation on the synthesis method of the polymer (B). For example, the polymer (B) can be produced by bonding the reactive group (C) to an arbitrary polymer (polymer before bonding the reactive group (C)). Examples of the reaction performed during the synthesis include urethanization, esterification, etherification, sulfidation, carboxylic acid epoxy reaction, amine-epoxy reaction, thiol epoxy reaction, amidation reaction, acid anhydride-amine reaction, and the like. .

[0089] [1-3. Other ingredients]

In addition to the sensitizer (A) and polymer (B) described above, the photoreactive composition of the present invention may contain other components (additives).

As the additive, for example, an arbitrary additive may be used for the purpose of controlling the excitation of the sensitizer (A) (controlling the excitation wavelength and excitation energy), controlling the reaction, and improving the characteristics. Absent. As an additive for controlling excitation of the sensitizer (A), for example, a sensitization aid is used. Can be mentioned. Examples of the additive for controlling the reaction include an initiator, a chain transfer agent, a polymerization terminator, a compatibilizing agent, and a reaction auxiliary agent. Further, additives for improving the properties include dispersants, antifoaming agents, plasticizers, preservatives, stabilizers and the like.

[0090] The amount of the additive used is arbitrary as long as the effects of the present invention are not significantly impaired. However, the concentration in the photoreactive composition of the present invention is usually 0.001% by weight or more, preferably 0.01% by weight or more, and usually 30% by weight or less, preferably 10% by weight or less.

[0091] [1-4. Action]

In the photoreactive composition of the present invention, since the sensitizer (A) has a reduced electron configuration with respect to the reactive group (C), it is used for an optical recording medium such as a hologram recording medium. In addition, it is possible to read the record without destroying the recorded content. The reason why such an excellent advantage can be obtained is assumed as follows.

FIG. 4 shows an example of changes in the sensitizer and the reactive group at the time of readout when the sensitizer has an oxidized electron configuration with respect to the reactive group! FIG. FIGS. 5 (a) to 5 (c) show the sensitizer and reactive group at the time of readout when the sensitizer has an oxidized electron configuration with respect to the reactive group. It is a figure showing an example of electronic arrangement | positioning. Further, FIG. 6 is a diagram showing an example of changes in the sensitizer (A) and the reactive group (C) during readout in the photoreactive composition of the present invention. FIG. 7 (a) to FIG. 7 (c) show the electron configuration of the sensitizer (A) and the reactive group (C) at the time of readout, respectively, in the photoreactive composition of the present invention. It is a figure showing an example.

[0093] As an example of an optical recording medium, a composition having a sensitizer (such as sensitizer (A)) and a substance having a reactive group (such as reactive group (C)) (such as polymer (B)) Assume that a volume hologram recording medium is formed using

First, the case where the sensitizer has an oxidized electron configuration with respect to the reactive group will be described. In order to read the information recorded on the volume hologram recording medium, the volume hologram recording medium is irradiated with reading light (reproduction light).

[0094] When the readout light is irradiated, the sensitizer is excited (see stepl in Fig. 4). At this time, the electrons in the occupied orbit AO of the sensitizer move to an intermediate empty orbit Ax according to the intensity of the readout light (see Fig. 5 (a)). As a result, an occupant orbit AO of the sensitizer becomes empty, and electrons enter. (See Fig. 5 (b)).

[0095] In this example, the sensitizer has an oxidized electron configuration with respect to the reactive group, so the occupied orbital AO of the sensitizer has an energy level higher than the occupied orbital CO of the reactive group. Low. For this reason, electrons move from the occupied orbit CO of the reactive group to the occupied orbit AO of the sensitizer in which the vacancy is generated, as indicated by the solid line arrow in FIG. 5 (b). This electron transfer oxidizes the reactive group (see step 2 in Fig. 4). As shown in Fig. 5 (c), the oxidized reactive group becomes an excited state in which only one electron is present in the occupied orbital CO, and thus becomes an active state that can cause chemical mutation.

[0096] Reactive groups that have become active may cause chemical transformations. If the reactive group undergoes chemical conversion, the recorded content may be destroyed. In other words, the chemical conversion is a force that occurs when information is written. When this chemical conversion occurs when information is read, the program of the recording section changes and the recorded contents are destroyed.

In FIGS. 5 (a) to 5 (c), A1 and C1 indicate the vacant orbitals of the sensitizer and the reactive group, respectively.

On the other hand, when a volume hologram recording medium is formed using the photoreactive composition of the present invention, it is as follows. That is, at the time of reading information, when the reading light is irradiated to the volume hologram recording medium, the sensitizer (A) is excited (see stepl in FIG. 6). At this time, electrons in the occupied orbit AO of the sensitizer (A) move to an intermediate air path Ax corresponding to the intensity of the readout light (see Fig. 7 (a)). As a result, a space is generated in the occupied orbit AO of the sensitizer (A) and electrons can enter (see Fig. 7 (b)).

However, in the photoreactive composition of the present invention, the sensitizer (A) has a reduced electron configuration with respect to the reactive group (C). Occupied orbital AO has a higher energy level than the occupied orbital CO of the reactive group (C). For this reason, electrons do not move from the occupied orbit CO of the reactive group (C) to the occupied orbit AO of the sensitizer (A) in which the vacant space is generated. Furthermore, if the intermediate empty orbit AX is made lower than the empty orbit C1 of the reactive group (C) by keeping the energy of the readout light within an appropriate range, etc. (that is, the sensitizer (A) If the electron in the occupied track AO is not given too much energy), the electron may not move from the intermediate track Ax to the empty track C 1 of the reactive group (C). (See dashed arrow in Figure 7 (b)). Therefore, the electrons that have moved to the intermediate empty orbit Ax move to the occupied orbit AO of the sensitizer (A) as shown by the solid line arrow in FIG. 7 (b). In this way, the sensitizer (A) relaxes and returns to the state before excitation (see Fig. 7 (c)), and the reactive group (C) is not oxidized. ) Remains inactive (see step 2 in Figure 6). Therefore, the recorded content is not destroyed without the reactive group (C) causing a chemical transformation.

In FIGS. 7 (a) to 7 (c), A1 represents an empty orbit of the sensitizer (A).

[0100] As described above, it is presumed that the photoreactive composition of the present invention can read a record without destroying the recorded content. As will be described later, the reactive group (C) undergoes chemical transformation when irradiated with appropriate excitation light. That is, in the photoreactive composition of the present invention, chemical reaction can be caused to the reactive group (C) by using light of a certain predetermined condition, and the reactive group (C) is not exposed to light of other conditions. If no chemical conversion occurs! /, It is possible to realize the function (ie, optical gate function). Specifically, the energy force that the irradiated light gives to the sensitizer (A) Chemical conversion occurs depending on whether the intermediate empty orbit Ax is higher or lower than the empty orbit C1 of the reactive group (C). It is possible to control whether or not.

[0101] The photoreactive composition of the present invention, when used for hologram recording, excites the sensitizer (A) and contributes to the reactive group (C) by the contribution of the excited sensitizer (A). It is possible to write information by converting the data. The mechanism is explained below with an example.

[0102] As a mechanism for causing the reactive group (C) to undergo chemical conversion due to the contribution of the excited sensitizer (A), for example, when the reactive group (C) is activated by reduction, and the reactive group (C) is activated by energy transfer ( And C) becomes active.

First, the case where the reactive group (C) is activated by reduction will be described.

FIG. 8 (a) to FIG. 8 (c) show the sensitizer (A) and reaction at the time of writing when the reactive group (C) is activated by reduction in the photoreactive composition of the present invention, respectively. It is a figure showing an example of the electronic arrangement of group (C). In FIGS. 8 (a) to 8 (c), AO and A1 represent the occupant and empty orbital electron configurations of the sensitizer (A), respectively, and CO and C1 represent the groups of the reactive group (C). Represents the electronic arrangement of the horoscope and the empty orbit, respectively. In this example, when information is written, the photoreactive composition of the present invention is irradiated with recording light, and the sensitizer (A) absorbs photons of this recording light. Then, as shown in Fig. 8 (a), the energy of the photon is used to move electrons in the occupied orbit AO of the sensitizer (A) to the empty orbit A1 (Fig. 8 (a ) Arrow). As a result, the electrons in the occupied orbit AO of the sensitizer (A) move to the empty orbit A1 as shown in FIG. 8 (b).

[0104] The electrons moved to the vacant orbit A1 of the sensitizer (A) then move to the vacant orbit C1 of the reactive group (C) as shown by the arrows in FIG. 8 (b). That is, the reactive group (C) also receives electrons from the sensitizer (A) and is reduced.

As a result, as shown in FIG. 8 (c), the reactive group (C) has electrons in the vacant orbit C1, and becomes active. Therefore, the reactive group (C) that has become active thereafter undergoes chemical transformation. Therefore, if information is written using this chemical conversion, a volume hologram recording medium can be formed using the photoreactive composition of the present invention. That is, in this volume hologram recording medium, information can be written when the sensitizer (A) absorbs photons.

Next, the case where the reactive group (C) is activated by energy transfer will be described.

FIG. 9 (a) to FIG. 9 (c) show the sensitizer (A) and reaction during writing when the reactive group (C) is activated by energy transfer in the photoreactive composition of the present invention, respectively. It is a figure showing an example of the electronic arrangement of group (C). In FIGS. 9 (a) to 9 (c), AO and A 1 represent the occupant and empty orbital electron configurations of the sensitizer (A), respectively, and CO and C1 represent the reactive group (C). Represents the electronic configuration of the occupied orbit and empty orbit, respectively.

Also in this example, when writing information, the photoreactive composition of the present invention is irradiated with recording light, and the sensitizer (A) absorbs photons of this recording light. The energy of the photon is the same as that explained in the example of reduction using Fig. 8 (a) above, as shown in Fig. 9 (a), the electrons in the occupied orbit AO of the sensitizer (A). Is used to move to orbit A1 (see arrow in Fig. 9 (a)). As a result, the electrons in the occupied orbit AO of the sensitizer (A) move to the empty orbit A1 as shown in FIG. 9 (b). Along with this, a space is generated in the occupied track AO of the sensitizer (A).

[0107] The electrons that have moved to the empty orbit A1 of the sensitizer (A) are then shown by solid arrows in Fig. 9 (b). As shown, move to the empty orbital CI of the reactive group (C). At this time, since there is an energy difference between the air trajectory A 1 of the sensitizer (A) and the air trajectory C 1 of the reactive group (C), the energy ( + Δ Ε) occurs. By using this energy (+ Δ Ε) as the energy (Δ E ′) for moving electrons from the occupied orbital CO of the reactive group (C) to the occupied orbital AO of the sensitizer (A), In FIG. 9 (b), the electrons move from the occupied orbital CO of the reactive group (C) to the occupied orbital AO of the sensitizer (A), as indicated by the dashed arrows.

[0108] Due to the above-mentioned electron movement, as shown in Fig. 9 (c), in the sensitizer (A), two electrons exist in the occupied orbit AO, and no electrons exist in the empty orbit A1. It becomes. On the other hand, in the reactive group (C), one electron exists in each of the occupied orbital CO and the empty orbital C1. The reactive group (C) that has an electron in the vacant orbit C1 becomes active. Accordingly, the reactive group (C) that is subsequently activated undergoes chemical transformation.

[0109] In this example, no oxidation or reduction occurs without any change in the number of electrons of the sensitizer (A) and the reactive group (C). However, the sensitizer (A) force also causes the transfer of energy (Δ Ε— Δ Ε ') to the reactive group (C). As a result, the reactive group (C) is excited by this transferred energy. It will be. This is why the reactive group (C) is activated by energy transfer in this example.

[0110] Therefore, if the information is written using the chemical conversion of the reactive group (C) activated by this energy transfer, the information can be written using the photoreactive composition of the present invention. Thus, a volume hologram recording medium that can be used can be formed. That is, this volume hologram recording medium can also write information by the photosensitizer absorbing the photons.

[0111] Further, according to the photoreactive composition of the present invention, it is possible to lengthen the one-life eve life when a volume hologram recording medium is used. Specifically, how much archive life can be obtained is not uniform depending on the composition of the photoreactive composition, the usage environment of the volume hologram recording medium, and the like. However, the information written on the volume hologram recording medium using the photoreactive composition of the present invention is usually at least 3 years, preferably at least 10 years, more preferably at least 30 years at room temperature (25 ° C). Have an archive life of.

[0112] The reason why such a long archive life could be realized is not clear, but this book According to the inventors' investigation, it is presumed that the reactive group (C) is bonded to the polymer (B). That is, since the polymer (B) has the reactive group (C), a cooperative interaction works, and it is assumed that a long archive life is realized.

[0113] [II. Applications]

The photoreactive composition of the present invention can be used as a material in any industrial field. Of these, use as an optical material is preferable because the characteristics of the photoreactive composition of the present invention can be effectively utilized.

When the photoreactive composition of the present invention is used as an optical material, the photoreactive composition of the present invention alone can coexist with other components that can be used as an optical material, together with the photoreactive composition, It may be used as an optical material. There are no restrictions on the other components. For example, it is possible to use a light dispersing agent, a coloring material, or the like. The amount of other components used is also arbitrary.

[0114] The use of the optical material is arbitrary, but it is particularly preferable to use it as an optical recording material. The optical recording material is preferably used as a volume hologram recording material. This makes it possible to effectively utilize the advantages of the photoreactive composition of the present invention described above.

[0115] [III. Optical Recording Medium]

The optical recording medium of the present invention is formed by using the photoreactive composition of the present invention as an optical recording medium or a volume hologram recording material. As long as it is configured to include the photoreactive composition of the present invention as the material for recording information, the specific configuration is not limited and is arbitrary.

Hereinafter, an embodiment of the optical recording medium of the present invention will be described in detail.

[0116] The optical recording medium of the present embodiment includes a recording layer formed of an optical recording material. The optical recording material is a material containing at least the photoreactive composition of the present invention. The optical recording medium is configured to include a support and other layers as necessary.

[0117] [III 1. Recording layer]

The recording layer is a layer on which information is recorded. Information is usually recorded as a hologram. In the optical recording medium of the present embodiment, the recording layer contains the photoreactive composition of the present invention. It is made of an optical recording material.

[0118] The optical recording material may be formed of the photoreactive composition of the present invention alone, but may contain other components as required. Further, how much other components are contained is arbitrary as long as the effects of the present invention are not significantly impaired.

Specific examples of other components include acrylic, polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, polystyrene, cellulose acetate, polyurethane and the like. These may contain only one type, or two or more types may be used in any combination and ratio. The present invention is not limited to the above specific examples.

[0119] The thickness of the recording layer is not limited. Usually, the thickness of the recording layer varies depending on the recording method. However, in the optical recording medium, the thickness of the recording layer is usually 1 μm or more, preferably 10 μm or more, and usually 1 cm or less, preferably 2000 μm or less. If the recording layer is too thick, the selectivity of each hologram may be lowered during multiplex recording on an optical recording medium, and the degree of multiplex recording may be reduced. If the recording layer is too thin, it is difficult to form the entire recording layer uniformly, and it is difficult to perform multiplex recording with a uniform diffraction efficiency of each hologram and a high SZN ratio.

[0120] [III 2. Support]

Usually, the optical recording medium has a support, and the recording layer and other layers are laminated on the support to constitute the optical recording medium.

The support is usually required to have the necessary strength and durability. Although there is no restriction | limiting in the shape, Usually, it forms in flat form or a film form.

[0121] Further, the material constituting the support is not limited and may be transparent or opaque.

Examples of transparent materials include organic materials such as acrylic, polyethylene terephthalate film, polyethylene naphthoate, polycarbonate, polyethylene, polystyrene, and cellulose acetate; and inorganic materials such as glass, silicon, and quartz. Among these, polycarbonate, acrylic, polyester, glass and the like are preferable, and acrylic, polycarbonate, and glass are more preferable. [0122] On the other hand, when an opaque material is cited as the support material, a metal such as aluminum; a metal such as gold, silver, or aluminum on the transparent support, or magnesium fluoride, zirconium oxide, etc. And those coated with a dielectric material.

[0123] The thickness of the support is not limited. However, usually 0. lmn! It is preferably ~ lmm. If the support is too thin, the mechanical strength of the optical recording medium may be insufficient, and if it is too thick, the cost may increase.

[0124] In addition, the surface of the support may be subjected to a surface treatment. This surface treatment is usually performed to improve the adhesion between the support and the recording layer. Examples of surface treatment include corona discharge treatment and forming a layer for surface treatment. Here, examples of the layer for the surface treatment include a layer formed from a halogen phenol or a partially hydrolyzed vinyl chloride-vinyl acetate copolymer (such as an undercoating layer and an undercoat layer). .

[0125] Furthermore, the surface treatment may be performed for purposes other than the improvement of adhesiveness. Examples include a reflective coating process that forms a reflective coating layer made of a metal such as gold, silver, or aluminum; a dielectric coating process that forms a dielectric layer such as magnesium fluoride or zirconium oxide. Is mentioned. These layers may be formed as a single layer or two or more layers.

[0126] Further, the support may be provided only on one or both of the upper and lower sides of the recording layer of the optical recording medium of the present invention. However, in the case where supports are provided on both the upper and lower sides of the recording layer, at least one of the supports is transparent so as to transmit active energy rays (excitation light, reference light, reproduction light, etc.).

In the case of an optical recording medium having a transparent support on both sides of the recording layer, a transmissive or reflective hologram can be recorded. In addition, when a support having reflection characteristics on one side is used, a reflection hologram can be recorded.

[0127] Furthermore, the support may be provided with a pattern for data address. The patterning method is not limited. For example, the support itself may be formed with irregularities, or a pattern may be formed on a reflective layer (described later), or a combination of these methods may be used. However, it is not necessary to have a support as long as the support layer is not essential and the recording layer and other layers have the required strength and durability.

[0128] [III 3. Other layers]

In addition to the recording layer and the support described above, other layers may be provided on the optical recording medium. For example, a protective layer, a reflective layer, an antireflection layer (antireflection film), or the like may be provided.

[0129] The protective layer is a layer for preventing adverse effects such as a decrease in sensitivity due to oxygen and deterioration in storage stability. There is no restriction | limiting in the specific structure of a protective layer, It is possible to apply a well-known thing arbitrarily. For example, a protective layer can be formed of a layer having a water-soluble polymer and the like.

[0130] The reflective layer is formed when the optical recording medium is configured in a reflective type. In the case of a reflective optical recording medium, the reflective layer may be formed between the support and the recording layer, or may be formed on the outer surface of the support. It is preferable to be between the layers.

[0131] Further, in any of the transmission type and reflection type optical recording media, an antireflection film may be provided on the side where the recording light and the reading light enter and exit, or between the recording layer and the support. . The antireflection film functions to improve the light utilization efficiency and suppress the generation of ghost images.

[0132] [III 4. Manufacturing Method]

There is no limitation on the method of manufacturing the optical recording medium.

For example, it can be produced by coating the photoreactive composition of the present invention on a support without solvent and forming a recording layer. At this time, any coating method can be used. Specific examples include spray method, spin coating method, wire bar method, dip method, air knife coating method, roll coating method, blade coating method, doctor roll coating method and the like.

In forming the recording layer, in particular, when forming a thick recording layer, it is also possible to use a method of placing in a mold and molding, or a method of coating on a release film and punching the mold.

[0133] Alternatively, the photoreactive composition of the present invention and a solvent or additive may be mixed to prepare a coating solution, which may be coated on a support and dried to form a recording layer. good. In this case, any coating method can be used. For example, the same method as described above can be used. Can be adopted.

Although there is no limitation on the solvent, it is usually preferable to use a solvent that has sufficient solubility for the components used, gives good coating properties, and does not attack a support such as a resin substrate. ,.

[0134] Examples of solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and methyl amyl ketone; aromatic solvents such as toluene and xylene; methanol, ethanol, propanol Alcohol solvents such as n-butanol, heptanol, hexanol, diacetone alcohol, furfuryl alcohol; ketone alcohol solvents such as diacetone alcohol, ₃ -hydroxy- ₃ -methyl-2-butanone; tetrahydrofuran, dioxane, etc. Ether solvents; Halogen solvents such as dichloromethane, dichloroethane, chloroform, etc .; Cellosolve solvents such as methyl solvosolve, ethinorecero soleb, butinorecellosolve, methyl cecrosolve acetate, ethilce solvate acetate; Propylene such as polyethylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol dimethyl ether Glycol solvents: Ethyl acetate, butyl acetate, amyl acetate, butyl acetate, ethylenic glycol diacetate, jetyloxalate, ethyl pyruvate, ethyl 2-hydroxybutyrate ethyl acetate, methyl lactate, ethyl lactate, Ester solvents such as methyl 2-hydroxyisobutyrate and methyl 3-methoxypropionate; tetrafluoropropanol, otata fanolopene Perfluoroalkyl alcohol solvents such as tananol, hexafnoreorobutanol monole; High polar solvents such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide; n-hexane, n-octane Chain hydrocarbon solvents such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, tert-butylcyclohexane, cyclooctane, etc .; or these And mixed solvents.

[0135] As the solvent, one kind may be used alone, and two kinds or more may be used in optional combination and ratio. Moreover, there is no restriction | limiting in the usage-amount of a solvent. However, from the viewpoint of coating efficiency and handleability, it is preferable to prepare a coating solution having a solid content concentration of about 1% by weight to 1000% by weight.

[0136] Furthermore, when the photoreactive composition of the present invention is thermoplastic, the photoreactive composition of the present invention is molded by, for example, an injection molding method, a sheet molding method, a hot press method, etc. When the photoreactive composition of the present invention is low in volatile components (light) thermosetting, the recording layer is produced by molding the photoreactive composition of the present invention by, for example, a reaction injection molding method or a liquid injection molding method. can do. In this case, if the molded body has sufficient thickness, rigidity, strength, etc., the molded body can be used as it is as an optical recording medium.

[0137] In addition, as a method for producing an optical recording medium, for example, a method of producing a recording layer by applying a photoreactive composition melted by heat onto a support, and cooling and solidifying the composition, A method in which a photoreactive composition is applied to a support and cured by thermal polymerization to form a recording layer, and a liquid photoreactive composition is applied to a support and cured by photopolymerization. And a method of manufacturing the recording layer by forming the recording layer.

[0138] The optical recording medium manufactured in this way can take the form of a self-supporting slab or a disk, and can be used for a three-dimensional image display device, a diffractive optical element, a large-capacity memory, and the like.

[0139] [III 5.Recording 'playback method]

Both writing (recording) and reading (reproduction) of information with respect to the optical recording medium are performed by light irradiation.

In recording, the recording layer is irradiated with excitation light from the sensitizer (A), that is, light corresponding to the excitation wavelength of the sensitizer (A), as a recording light. Convert (C) to record information. On the other hand, when reproducing information, the reproducing light is irradiated onto the recording layer, and the transmitted light is read if it is a transmissive optical recording medium, and the reflected light is read if it is a reflective optical recording medium. , Play back information.

[0140] When information is recorded on the optical recording medium as a hologram such as a volume hologram, the recording layer is irradiated with reference light together with recording light (also called object light). If the recording light and the reference light are caused to interfere with each other in the recording layer, the interference fringes are recorded as chemical conversion of the reactive group (C) in the recording layer. For example, the reactive group (C) In other words, when the photoreactive composition of the present invention causes a change in refractive index, interference fringes are recorded as a difference in refractive index in the recording layer. A hologram is recorded on the recording layer by the interference fringes recorded in the recording layer.

[0141] In the case where information is recorded by exciting the sensitizer (A) by stepwise multiphoton absorption, for example, the recording light is used as the first and second lights. The reference light may be used as the first and second light, or one of the recording light and the reference light may be used as the first light and the other as the second light.

[0142] When reproducing a hologram recorded on the recording layer, the recording layer is irradiated with predetermined reproduction light (usually reference light). The irradiated reproduction light is diffracted according to the interference fringes. Since this diffracted light contains the same information as that of the recording layer, it is possible to reproduce the information recorded on the recording layer by reading the diffracted light.

[0143] However, the reference light and the reproduction light have wavelengths and intensities that do not cause excitation of the sensitizer (A) and the reactive group (C) by themselves. As a result, non-destructive reading at the time of reproduction, which has been difficult to realize in the past, becomes possible, and an optical recording medium having an optical gate function can be obtained.

Note that the wavelength range of the recording light, the reproduction light, and the reference light is arbitrary depending on each application, and may be in the infrared region, visible light region, or ultraviolet region. Among these lights, preferred are solid lasers such as ruby, glass, Nd—YAG (neodymium yttrium aluminum garnet), Nd—YV04 (neodymium yttrium vanadium tetraoxide); Diode lasers such as GaAs and InGaAs; gas lasers such as helium neon, argon, krypton, excimer, and CO;

2

Lasers that are excellent in monochromaticity and directivity, such as one-on-one. The laser used may be a pulse laser or a continuous wave laser! / ヽ

[0145] Further, the recording light, the reproducing light, and the reference light are V, and the deviation is not limited to the irradiation amount, so long as it can be recorded and reproduced. However, if the amount is extremely small, the chemical conversion of the reactive group (C) is too incomplete, and the heat resistance and mechanical properties of the recording layer may not be fully expressed. Of photoreactive compositions can cause degradation There is. Therefore, the recording light, the reproduction light and the reference light are usually 0.1 to 20 JZC m ² according to the composition of the recording layer forming composition, the type of polymerization initiator of the reactive group (C), and the blending amount. Irradiate in the range of.

Example

[0146] Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following examples, and may be arbitrarily modified without departing from the gist of the present invention. be able to. Mn represents a number average molecular weight, and Mw represents a weight average molecular weight.

[0147] [Synthesis Example 1: Synthesis of polymer (B)]

“; Synthesis and Photochemical Property of Polymers with Pendant Donor-Acceptor-Type Norbornadiene Moieties N. Kawasni ma; A. Kameyama; T. Nishikubo; T. Nagai:

A polymer (B) having a reactive group (C) was synthesized by an operation corresponding to the description on page 2 of “Photoresponsive Polymers, 1764, 2001”.

[0148] (Synthesis step 1: MTMPN (Synthesis of Methyl 1, 4, 5, 6-Tetramethyl-3-phenyl-2, 5-norbornadiene— 2-carboxylate))

In a 50 ml flask equipped with a condenser, put Methyl 3-phenylprop-2 -ynolate (MPP) (8 g, 50 mmol) and 1, 2, 3, 4— Tetramethyl— 1, 3- cyclopentadiene (12 g, 1 OOmmol), The mixture was reacted at 100 ° C for 8 hours while stirring with a magnetic stirrer. The crude product was purified by silica gel column chromatography, and the solvent was removed to obtain the target product MTMPN as a pale yellow oil. Yield was 13 g (92% yield) o

[0149] (Synthesis step 2: Synthesis of TMPNC (1, 4, 5, 6-Tetramethyl-3-phenyl-2, 5— norbo rnadiene— 2— car Doxylic acid))

MTMPN (3.36 g, 12 mmol) and potassium hydroxide (2.4 g, 36 mmol) were dissolved in a mixed solvent of methanol Z water = 25 Z5 (ml) and stirred at room temperature for 48 hours for hydrolysis. After completion of the reaction, it was diluted with water, transferred to a separatory funnel, washed twice with dichloromethane, and then transferred to a triangular flask. This was acidified with hydrochloric acid, and the precipitated crude product was collected by filtration and washed with dichlorometa. And dissolved in a separatory funnel. This was washed several times with water, transferred to an Erlenmeyer flask and dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was recrystallized from dichloromethane z hexane to obtain the desired product. The yield was 1.92 g (yield 60%).

[0150] (Synthesis step 3: Synthesis of polystyrene (PSt) polymer substituted with norbornagen) Poly (P chloromethylolstyrene) (Mn = 2.6 X 10 ⁴ , Mw / Mn = l. 40) (3 07 g, 2 Ommol) and TMPNC (5.49 g, 22 mmol) dissolved in dimethyl sulfoxide (DMSO; 40 ml). 1,8 diazabicyclo [5, 4, 0] -7 undecene (DBU; 3.2 g, 22 mmo 1 ) Was added here and heated at 70 ° C for 6 hours. After completion of the reaction, it was reprecipitated in a large amount of methanol, and the solid collected by filtration was reprecipitated twice more with tetrahydrofuran Zmethanol, and then the solvent was completely removed with a vacuum dryer to obtain the desired product. The yield was 5.4 g (yield 70%). This is called NBD-PS.

[0151] [Example 1]

Sensitizer (A) uses 5, 10, 15, 20-tetra [3,5 bis (trifluoromethyl) phenol]-21H, 23H porphyrin platinum (II), and polymer (B Using NBD-PS synthesized in Synthesis Example 1 as above, a sample was produced as an optical recording medium as follows.

That is, NBD-PS (1. Og) synthesized in Synthesis Example 1 and 5, 10, 15, 20-tetra [3,5 bis (trifluoromethyl) phenol] 21H, 23H-porphyrin platinum (II) (50 mg) was used as a tetrahydrofuran solution, cast on a glass substrate, and dried to form a 200 / zm thick film as a sample.

[0152] The specific method of casting is as follows. It was cast on a slide glass substrate and left to stand in the dark at room temperature for 12 hours to dry. After that, it was dried by heating in an oven at 80 ° C for 2 hours. After drying by heating, place a Teflon (registered trademark) film with a thickness of 50 m on both sides of the slide glass as a spacer and heat it in an oven at 80 ° C for 1 hour by fixing it with another glass slide with a cover and a clip. Thus, a smooth recording medium (sample) having a thickness of 50 m was obtained.

[0153] [Example 2] <Sample preparation>

As the sensitizer (A), 2, 2,: 5,2 "-terthiophene (2, 2,: 5,2" -Terthiophene) (manufactured by Wako Pure Chemical Industries, Ltd.) is used, and a polymer ( Using NBD-PS synthesized in Synthesis Example 1 as B), a sample was produced as an optical recording medium as follows. That is, NBD—PS (1. Og) synthesized in Synthesis Example 1 and 2, 2,: 5, 2 ”-terthiophene (2 mg) were mixed with methyl ethyl ketone Z toluene = 1. 8/1. 2 (ml ), And cast on a glass substrate and dried to form a 50 / zm-thick film as a sample.

The casting method was the same as in Example 1.

[Example 3]

As the sensitizer (A), 2, 2,: 5,2 "-terthiophene (2, 2,: 5,2" -Terthiophene) (manufactured by Wako Pure Chemical Industries, Ltd.) is used, and a polymer ( Poly (vinyl cinnamate) (manufactured by Aldrich, average Mw = 200000 (GPC measurement)) was used as B), and a sample was prepared as an optical recording medium as follows.

That is, Poly (vinyl cinnamate) (1. Og) and 2, 2 ,: 5, 2, 1 terthiophene (2 mg), methyl ethyl ketone / toluene = 1. 8/1. 2 (ml) The sample was dissolved in a mixed solvent, cast on a glass substrate, and dried to form a 50-m thick film as a sample.

The casting method was the same as in Example 1.

[0155] [Example 4]

As the sensitizer (A), 2, 2 ,: 5, 2 "-Terthiophene-5-Carboxaldehyde (2, 2,: 5, 2" -Terthiophene-5-carboxaldehyde) (manufactured by Tokyo Chemical Industry Co., Ltd.) is used. A sample was prepared as an optical recording medium in the following manner using Polyvinyl cinnamate (Aldrich, average Mw = 200000 (GPC measurement)) as the polymer (B).

That is, Poly (vinyl cinnamate) (1.0 g) and 2, 2 ,: 5, 2, 1 terthiophene (2 mg), methyl ethyl ketone / toluene = 1. 8/1. 2 (ml) The sample was dissolved in a mixed solvent, cast on a glass substrate, and dried to form a 50-m thick film as a sample.

The casting method was the same as in Example 1.

[0156] [Example 5] 1,4 bis [2- (5-phenyloxazolyl)] benzene (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the sensitizer (A), and the NBD— synthesized in Synthesis Example 1 above as the polymer (B) — A sample was prepared as an optical recording medium using PS as follows.

That is, NBD-PS (1. Og) and 1,4-bis [2- (5-phenyloxazolyl)] benzene (2 mg) synthesized in Synthesis Example 1 were converted to methyl ethyl ketone Z toluene = 1. 8 / 1. Dissolved in 2 (ml) of mixed solvent, cast on a glass substrate and dried to form a 50 m thick film as a sample.

The casting method was the same as in Example 1.

[0157] [Example 6]

Using 4, 4, -bis (jetylamino) benzophenone (Hodogaya Chemical Co., Ltd.) as the sensitizer (A), and using NBD-PS synthesized in Synthesis Example 1 as the polymer (B) A sample was prepared as an optical recording medium as follows.

That is, NBD-PS (1. Og) synthesized in Synthesis Example 1 and 4,4′-bis (jetylamino) benzophenone (2 mg) were mixed with methyl ethyl ketone Z toluene = 1. 8/1. ) Was dissolved in a mixed solvent, cast on a glass substrate and dried to form a 50 m thick film, which was used as a sample.

The casting method was the same as in Example 1.

[Example 7]

As the sensitizer (A), 2, 2,: 5,2 "-terthiophene (2, 2,: 5,2" -Terthiophene) (manufactured by Wako Pure Chemical Industries, Ltd.) is used, and a polymer ( As B), polysilane (trade name: Ogsol SI-10-10, manufactured by Osaka Gas Co., Ltd.) was used to prepare a sample as an optical recording medium as follows.

That is, polysilane (1. Og) and 2, 2 ': 5, 2 "-terthiophene (2 mg) were dissolved in a mixed solvent of methyl ethyl ketone Z toluene = 1. 8/1. A film with a thickness of 50 m was formed by casting and drying on top, and used as a sample.

The casting method was the same as in Example 1.

[0159] <Measurement>

FIG. 10 is a diagram schematically showing an outline of the measurement system used in this example. The light source for hologram recording is a diode that excites the Nd—YV04 crystal with a diode, and uses a non-linear optical crystal LiB 2 O (also referred to as “LBO”) to obtain 532 nm light.

3 5

Verdi—V2) (hereinafter referred to as “Laserl”) and a diode laser capable of obtaining light of 405 nm (manufactured by SONY) (hereinafter referred to as “Laser2” as appropriate) were used.

[0160] Light [L1] with a wavelength of 532 nm emitted from Laserl is split by a polarizing beam splitter [PBS], and each split light is reflected by mirrors [M1, M2] to form an angle between two beams Was crossed on the recording surface so as to be 50.00 °. In FIG. 10, light emitted from Lase rl is indicated by a broken line.

At this time, the bisector of the angle formed by the two beams is perpendicular to the recording surface, and the vibration planes of the electric field vectors of the two beams obtained by the division are two intersecting lines. It was made to be parallel to the plane containing the beam.

[0161] Simultaneously irradiating the recording surface of the light [L1] with a wavelength of 532 nm from Laserl, irradiating the light [L2] with a wavelength of 405 nm from Laser2, reflecting it with the mirror [M3], and The recording surface was irradiated. At this time, the light [L2] having a wavelength of 405 nm was irradiated to the intersecting region of the light [L1] of 532 nm on the recording surface so as to be perpendicular to the recording surface. In FIG. 10, the light emitted from Laser 2 is indicated by a one-dot chain line. The light [L2] that passed through the sample [Sample] was made to strike the beam stock [BS].

Thereby, the hologram was recorded on the recording layer of the sample [Sample] by the interference of the light [L1, L2] from Laserl and Laser2.

[0162] After recording the hologram, the 405 nm light [L2] is blocked, and one of the two 532 nm lights [L1] obtained by the division is blocked, and recording is performed at the same angle as during recording. The diffracted light irradiated on the surface was recorded using a power meter (not shown) and a detector (Newport 2930-C, 918-SL) [PD1, PD2]. The diffraction efficiency of a hologram is given by the ratio of the diffracted light intensity to the incident light intensity.

[0163] <Result>

Table 1 below shows the results of measuring the sample prepared by the above preparation method using the above measurement method. In each of the above embodiments, the beam irradiation intensity during recording is L Recording was performed with the aserl beam intensity set to lWcm- ² and the Laser2 set to 80mWcm- ² . The irradiation time of Laserl and Laser2 was 3000 seconds in Example 1, 500 / second in Example 2, and 200 / second in Examples 3-7!

[table 1]

[Table 1: Measurement results of diffraction efficiency]

[0164] From the above results, it was shown that diffraction efficiency was obtained for each sample, and that the recording material could be subjected to holodal recording.

In any of the above-described embodiments, the recording state does not change even if the sample after recording is exposed to 532 nm light [L1]. In the absence of 405 nm gate light [L2], It became apparent that no recording occurred and no light was exposed to the readout light. This confirmed that non-destructive reading is possible.

[Example 8]

(Measurement of excitation energy of sensitizer (A) 2, 2 ': 5, 2 "-terthiophene and polymer (B))

Using the method described in the literature m (j. Chem. Soc., Faraday Trans. 1, 73 (1977) 1319), the sensitizer (A) 2, 2 ': 5, 2 "-terthiophene Tl-Tn absorption was measured, and the third or fourth harmonic of a Q-switched YAG laser was used as the laser source, and the phosphorescence when falling from T1 to SO was measured. The absorption edge of Tl—Tn absorption is 600 nm, and the T1 30 energy was found to be 72011111. These results indicated that the 30-1¾ energy was 33011111.

[0167] Next, the phosphorescence of NBD-PS, which is the polymer (B), when falling from T1 to SO was measured in the same manner. As a result, the T1-S0 energy was found to be 400 nm.

[0168] From these results, the Tl level of the sensitizer (Α) 2, 2 ': 5, 2 "-terthiophene has sufficient energy to chemically change the reactive group of the polymer NBD PS. However, it has been experimentally shown that the energy for starting the reaction is supplied to the reactive group only after reaching the Tn level. Industrial applicability

The present invention can be used in any industrial field, but is particularly suitable for use in an optical recording medium such as a hologram recording medium.

[0170] Although the invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

This application is based on a Japanese patent application filed on April 28, 2006 (Japanese Patent Application No. 2006-12 6394), which is incorporated by reference in its entirety.

Claims

The scope of the claims

[I] A sensitizer (A) excited by absorbing photons,

A polymer (B) having a reactive group (C) capable of causing chemical conversion, and

The sensitizer (A) has a reduced electron configuration with respect to the reactive group (C).

A photoreactive composition characterized by the above.

[2] The sensitizer (A) is excited by absorbing two or more photons

The photoreactive composition according to claim 1, wherein:

[3] The photoreactive composition according to claim 2, wherein the sensitizer (A) is excited by absorbing two or more photons having different wavelengths.

[4] The sensitizer (A) is excited to the singlet excited state by absorbing the photons of the first excitation light, and then transitions to the lowest triplet excited state by intersystem crossing. A multi-stage excitation type sensitizer that is excited to a triplet excited state higher than the lowest triplet excited state by absorbing photons of the second excitation light having a wavelength different from that of the first excited light. The photoreactive composition according to claim 3, wherein

[5] When the sensitizer (A) is excited, the reactive group is contributed by the excited sensitizer (A).

(C) undergoes chemical conversion, and the optical properties of the photoreactive composition change.

The photoreactive composition according to any one of claims 1 to 4, wherein the photoreactive composition is characterized by that.

[6] The chemical transformation is an isomerization reaction

The photoreactive composition according to any one of claims 1 to 5, wherein

[7] The photoreactive composition according to any one of claims 1 to 6 is contained.

An optical material characterized by the above.

[8] The optical material according to claim 7.

An optical recording material characterized by the above.

[9] The optical recording material according to claim 8.

A volume hologram recording material characterized by the above.

[10] A layer comprising the optical recording material according to claim 8

An optical recording medium characterized by the above.

[II] The excitation light is applied to the layer of the optical recording medium according to claim 10. An optical recording method for recording on an optical recording medium.

Irradiate reference light together with the excitation light, and record a hologram on the layer by interference between the excitation light and the reference light.

12. The method of optical recording onto an optical recording medium according to claim 11,