JP4465167B2 - Three-dimensional optical recording medium recording method, three-dimensional optical recording medium reproducing method - Google Patents

Description

  The present invention relates to a two-photon absorption foam material having a large non-resonant two-photon absorption cross-section and generating a gas by non-resonant two-photon absorption to create a bubble, a three-dimensional refractive index modulation material using the same, and a three-dimensional The present invention relates to an optical recording medium and the like.

  In general, the nonlinear optical effect is a non-linear optical response proportional to the square of the applied photoelectric field, the third power or more, and a second-order nonlinear optical effect proportional to the square of the applied photoelectric field. For example, second harmonic generation (SHG), optical rectification, photorefractive effect, Pockels effect, parametric amplification, parametric oscillation, optical sum frequency mixing, and optical difference frequency mixing are known. The third-order nonlinear optical effect proportional to the cube of the applied photoelectric field includes third harmonic generation (THG), optical Kerr effect, self-induced refractive index change, two-photon absorption, and the like.

  Many inorganic materials have been found so far as nonlinear optical materials exhibiting these nonlinear optical effects. However, inorganic materials are very difficult to put into practical use because so-called molecular design for optimizing desired nonlinear optical characteristics and various physical properties necessary for device fabrication is difficult. On the other hand, organic compounds can be optimized not only for the desired nonlinear optical properties by molecular design, but also for other physical properties, so they are highly practical and attract attention as promising nonlinear optical materials. Collecting.

  In recent years, the third-order nonlinear optical effect has attracted attention among the nonlinear optical characteristics of organic compounds, and among these, non-resonant two-photon absorption has attracted attention. Two-photon absorption is a phenomenon in which a compound is excited by simultaneously absorbing two photons, and the case where two-photon absorption occurs in an energy region where there is no (linear) absorption band of the compound is called non-resonant two-photon absorption. . In the following description, two-photon absorption refers to non-resonant two-photon absorption even if not specified.

By the way, the efficiency of non-resonant two-photon absorption is proportional to the square of the applied photoelectric field (square characteristic of two-photon absorption). For this reason, when a two-dimensional plane is irradiated with a laser, two-photon absorption occurs only at a position where the electric field strength is high in the central portion of the laser spot, and two-photon absorption is completely absent in a portion where the electric field strength is weak in the peripheral portion. Does not happen. On the other hand, in the three-dimensional space, two-photon absorption occurs only in the region where the electric field strength at the focal point where the laser light is collected by the lens is large, and no two-photon absorption occurs in the region outside the focal point because the electric field strength is weak. . Compared with linear absorption where excitation occurs at all positions in proportion to the intensity of the applied photoelectric field, non-resonant two-photon absorption results in excitation at only one point inside the space due to this square characteristic. , The spatial resolution is significantly improved.
Usually, when inducing non-resonant two-photon absorption, a short-pulse laser in the near-infrared region, which is longer than the wavelength region in which the (linear) absorption band of the compound exists and does not have absorption, is often used. The so-called transparent near-infrared light is used, so that the excitation light can reach the inside of the sample without being absorbed or scattered, and because of the square characteristic of non-resonant two-photon absorption, one point inside the sample has an extremely high spatial resolution. Can be excited.

On the other hand, optical information recording media (optical discs) capable of recording information only once by laser light are known. Write-once CDs (so-called CD-Rs) and write-once DVDs (so-called DVD-Rs). Etc. have been put to practical use.
For example, the typical structure of DVD-R is such that the guide groove (pre-groove) for tracking the irradiated laser beam is narrower than half of CD-R (0.74-0.8 μm). Further, a recording layer made of a dye is formed on a transparent disk-shaped substrate, and usually a light reflecting layer is formed on the recording layer, and a protective layer is further formed if necessary.
Information is recorded on the DVD-R by irradiating visible laser light (usually in a range of 630 nm to 680 nm), and the irradiated portion of the recording layer absorbs the light and the temperature rises locally. A change (e.g., pit generation) occurs and changes its optical properties. On the other hand, reading (reproduction) of information is also performed by irradiating a laser beam having the same wavelength as the recording laser beam, and the portion where the optical characteristics of the recording layer have changed (recorded portion) and the portion that has not changed (unrecorded) Information is reproduced by detecting the difference in reflectance from the (part). This difference in reflectivity is based on so-called “refractive index modulation”. The greater the difference in refractive index between the recorded portion and the non-recorded portion, the greater the ratio of the reflectance of light, that is, the S / N ratio of reproduction. Larger and preferable.

Recently, networks such as the Internet and high-definition TV are rapidly spreading. In addition, HDTV (High Definition Television) will soon be broadcast, and there is an increasing demand for a large-capacity recording medium for easily and inexpensively recording image information of 50 GB or more, preferably 100 GB or more for consumer use.
Furthermore, for business use such as computer backup use and broadcast backup use, an optical recording medium capable of recording large-capacity information of about 1 TB or more at high speed and at low cost is required.
Under such circumstances, a conventional two-dimensional optical recording medium such as a DVD-R is about 25 GB at most even if the recording / reproducing wavelength is shortened due to the physical principle, and is sufficiently large enough to meet future demands. It cannot be said that capacity can be expected.

Under such circumstances, a three-dimensional optical recording medium has attracted attention as an ultimate high-density, high-capacity recording medium. Three-dimensional optical recording media can be recorded in dozens or hundreds of layers in the three-dimensional (film thickness) direction, resulting in tens or hundreds of times the ultra-high density and ultra-high capacity recording of conventional two-dimensional recording media. That is what we are trying to achieve. In order to provide a three-dimensional optical recording medium, it is necessary to be able to access and write at an arbitrary place in the three-dimensional (film thickness) direction. As a means for this, a method using a two-photon absorption material and holography (interference) There is a method of using.
In a three-dimensional optical recording medium using a two-photon absorption material, so-called bit recording is possible over tens or hundreds of times based on the physical principle described above, and higher density recording is possible. It can be said to be the ultimate high-density, high-capacity optical recording medium. As a three-dimensional optical recording medium using a two-photon absorbing material, a method of reading with fluorescence using a fluorescent substance for recording / reproduction (Lewitch, Eugene, Polis et al., Special Table 2001-524245 [Patent Document 1], Pavel, Eugen et al., Japanese Translation of PCT International Publication No. 2000-512061 [Patent Document 2], a method of reading by absorption or fluorescence using a photochromic compound (Korotif, Nikolai Ai et al. U. Ladimir et al., JP 2001-508221 [Patent Document 4]) and the like have been proposed, but none of the specific two-photon absorption materials are presented, and two-photons presented abstractly. Examples of absorbing compounds also use two-photon absorbing compounds with extremely low two-photon absorption efficiency. Furthermore, non-destructive readout and long-term storage stability of recording There are problems such as the S / N ratio of the reproduction, it can not be said to be a method of utility as an optical recording medium.
In particular, in terms of non-destructive reading, long-term storage stability of recording, etc., it is preferable to use an irreversible material to reproduce by changing the reflectance (refractive index). There were no disclosed examples.

Also, three-dimensional recording by refractive index modulation is performed in Kawada Jun, Kawada Yoshimasa, JP-A-6-28672 [Patent Document 5], Kawada Kei, Kawada Yoshimasa et al. And JP-A-6-118306 [Patent Document 6]. However, there is no description of a method using a two-photon absorption foam material.
JP-T-2001-524245 Special table 2000-512061 gazette Special table 2001-522119 gazette Special table 2001-508221 gazette JP-A-6-28672 JP-A-6-118306

If the foaming is generated using the excitation energy obtained by non-resonant two-photon absorption, and as a result, the refractive index can be modulated at the laser focal point and the non-focal point, it is refracted at an arbitrary place in the three-dimensional space with a very high spatial resolution. Rate modulation can occur, and application to a three-dimensional optical recording medium considered as the ultimate high-density recording medium is also possible. Furthermore, since non-destructive readout is possible and the material is an irreversible material, it can be expected to have good storage stability and is practical. In addition, it can be applied to three-dimensional displays and optical materials. However, currently available two-photon absorption compounds have a low two-photon absorption capability, so a very high-power laser is required as a light source and a long recording time is required. In particular, for use in a three-dimensional optical recording medium, it is essential to construct a two-photon absorption compound that can generate bubbles with high sensitivity in order to achieve a high transfer rate.
Further, no two-photon absorption compound and foamable compound or foamable portion having a function of generating bubbles by using excitation energy by two-photon absorption to achieve three-dimensional refractive index modulation has not been disclosed so far. Construction of such materials is also essential.

  An object of the present invention is to provide a two-photon absorption foam material having a large non-resonant two-photon absorption cross-section and generating a gas by non-resonant two-photon absorption to create a bubble, a three-dimensional refractive index modulation material using the same, and It is to provide a three-dimensional optical recording medium, a three-dimensional display, an optical material, and the like. Another object is to provide a three-dimensional refractive index modulation method and a three-dimensional optical recording medium recording / reproducing method.

As a result of intensive studies by the inventors, the above object of the present invention has been achieved by the following means.
The present invention has the following (32) to (37) and a citation relationship therewith, but other matters are also described for reference in understanding the present invention.

(1) A two-photon absorption foaming material comprising at least a two-photon absorption compound, wherein gas is generated and bubbles are generated with the two-photon absorption of the two-photon absorption compound.
(2) The two-photon absorption foam material according to (1), wherein the two-photon absorption compound has a foaming site.
(3) The two-photon absorption foam material according to (1), which has a foamable compound separately from the two-photon absorption compound.
(4) The gas is any of N ₂ , CO, CO ₂ , SO ₂ , SO ₃ , N ₂ O, NO, NO ₂ , O ₂ , H ₂ , NH ₃ , and iC ₄ H _8. The two-photon absorption foam material according to any one of (1) to (3), which is characterized. The gas is generated from the foamable part (2) or the foamable compound (3).
(5) The gas is any one of N ₂ , CO ₂ , SO ₂ , SO ₃ , NO ₂ , O ₂ , and iC ₄ H _8. The two-photon absorption foam material described.
(6) The two-photon absorption foam according to any one of (1) to (5), wherein the gas is any one of N ₂ , CO ₂ , SO ₂ , SO ₃ , and iC ₄ H _8. material.
(7) The two-photon absorption foam material according to any one of (1) to (6), wherein the gas is either N ₂ or CO ₂ .
(8) The foamable site of (2) or the foamable compound of (3) is represented by the following general formula (11) or (12), The two-photon absorption foam material described.

In the general formula (11), R ²¹ and R ²² each independently represent a hydrogen atom or a substituent, and G represents —N═N—, —C (O) —, —OC (O) —, —OS (O )-, -S (O) _2- , -OS (O) _2- . R ²¹ and R ²² may be linked to form a ring.
When the general formula (11) indicates a foaming site, it is linked to the two-photon absorption compound by either covalent bond, ionic bond, or coordinate bond at either or both of R ^{21 and} R ²² .
In the general formula (12), R ²³ represents an aryl group or a heterocyclic group, and X ¹¹ represents an anion. When the general formula (12) indicates an effervescent site, R ²³ is linked to the two-photon absorption compound by any of a covalent bond, an ionic bond, and a coordination bond, or X ¹¹ is an anionic two-photon absorption compound It is.
(9) In the general formula (11), G represents any of —N═N—, —OC (O) —, —S (O) ₂ , and —OS (O) ₂ —. (8) The two-photon absorption foaming material according to the description.
(10) The two-photon absorption foamed material according to (8) or (9), wherein in the general formula (11), G represents any one of -N = N- and -OC (O)-.
(11) In the general formula (11), R ²¹ and R ²² are each independently an alkyl group, alkenyl group, cycloalkyl group, aryl group, heterocyclic group, alkoxy group, aryloxy group, or amino group. The two-photon absorption foam material according to any one of (8) to (10), wherein
(12) The two-photon absorption foam material according to any one of (1) to (11), wherein the two-photon absorption compound is an organic dye.
(13) The two-photon absorption foam material according to any one of (1) to (12), wherein the two-photon absorption compound is a methine dye or a phthalocyanine dye.
(14) The two-photon absorption compound is represented by any one of (1) to (13), wherein the two-photon absorption compound is represented by a cyanine dye, a merocyanine dye, an oxonol dye, a phthalocyanine dye, or the following general formula (1): 2 photon absorbing foam material.
General formula (1)

Wherein the ^{R 1, R 2, R 3} , R 4 each independently represents a hydrogen atom or a substituent, and combines some of the ^{R 1, R 2, R 3} , R 4 are mutually the ring May be formed. n and m each independently represent an integer of 0 to 4, and when n and m are 2 or more, a plurality of R ¹ , R ² , R ³ and R ⁴ may be the same or different. However, n and m are not 0 simultaneously. X ¹ and X ² each independently represent an aryl group, a heterocyclic group, or a group represented by General Formula (2).
General formula (2)

In the formula, R ⁵ represents a hydrogen atom or a substituent, R ⁶ represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group, and Z ¹ represents an atomic group forming a 5- or 6-membered ring. .
(15) The two-photon absorption foaming material according to (14), wherein in the compound represented by the general formula (1), R ¹ and R ³ are linked to form a ring.
(16) The two-photon absorption foaming material according to (14), wherein in the compound represented by the general formula (1), R ¹ and R ³ are linked to form a cyclopentanone ring together with a carbonyl group. .
(17) The two-photon absorption described in (14) to (16), wherein X ¹ and X ² of the compound represented by the general formula (1) are each independently represented by the general formula (2) Foam material.
(18) In the compound represented by the general formula (1), X ¹ and X ² are each independently represented by the general formula (2), R ⁶ is an alkyl group, and the ring formed by Z ¹ is It is an indolenine ring, azaindolenine ring, pyrazoline ring, benzothiazole ring, thiazole ring, thiazoline ring, benzoxazole ring, oxazole ring, oxazoline ring, benzimidazole ring, thiadiazole ring, quinoline ring The two-photon absorption foam material according to any one of (14) to (17).
(19) In the compound represented by the general formula (1), X ¹ and X ² are each independently represented by the general formula (2), R ⁶ is an alkyl group, and the ring formed by Z ¹ is The two-photon absorption foam material according to any one of (14) to (18), which is represented by any one of an indolenine ring, an azaindolenine ring, a benzothiazole ring, a benzoxazole ring, and a benzimidazole ring .
(20) In (14), the cyanine dye is represented by the following general formula (3), the merocyanine dye is represented by the following general formula (4), and the oxonol dye is represented by the general formula (5). The two-photon absorption foam material according to (14).

In the general formulas (3) to (5), Za ₁ , Za ₂ and Za ₃ each represent an atomic group forming a 5-membered or 6-membered nitrogen-containing heterocycle, and Za ₄ , Za ₅ and Za ₆ are each 5 A group of atoms forming a member or six-membered ring is represented. Ra ₁ , Ra ₂ and Ra ₃ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
Ma _{1 to} Ma ₁₄ each independently represent a methine group, may have a substituent, and may form a ring with another methine group. na ¹ , na ² and na ³ are each 0 or 1, and ka ¹ and ka ³ each represents an integer of 0 to 3. When ka ¹ is 2 or more, the plurality of Ma ₃ and Ma ₄ may be the same or different. When ka ³ is 2 or more, the plurality of Ma ₁₂ and Ma ₁₃ may be the same or different. ka ² represents an integer of 0 to 8, and when ka ² is 2 or more, a plurality of Ma ₁₀ and Ma ₁₁ may be the same or different.
CI represents an ion that neutralizes the electric charge, and y represents a number necessary for neutralizing the electric charge.
(21) The two-photon absorption foam material according to any one of (1) to (20), wherein the two-photon absorption compound has at least one hydrogen bonding group.
(22) The two-photon absorption foam material according to (21), wherein the hydrogen bonding group is a —COOH group or a —CONH ₂ group in (21).
(23) The two-photon absorption foam according to any one of (1) to (22), wherein the size of the generated bubbles is in the range of 50 nm to 5 μm in (1) to (22) material.
(24) The two-photon absorption foaming material according to (23), wherein the size of the bubbles generated in (23) is in the range of 100 nm to 2 μm.
(25) The two-photon according to any one of (1) to (24), wherein, in (1) to (24), bubbles are generated in a reaction that does not depend on thermal decomposition, that is, in a photon mode. Absorbent foam material.
(26) A three-dimensional refractive index modulation material using the two-photon absorption foam material according to any one of (1) to (25).
(27) A three-dimensional optical recording medium comprising the two-photon absorption foam material according to any one of (1) to (25).
(28) A write-once three-dimensional optical recording medium comprising the two-photon absorption foaming material according to any one of (1) to (25).
(29) A three-dimensional display comprising the two-photon absorption foam material according to any one of (1) to (25).
(30) An optical material comprising the two-photon absorption foam material according to any one of (1) to (25).
(31) The two-photon absorption foam material according to any one of (1) to (25) is irradiated with laser light having a wavelength longer than the linear absorption band of the two-photon absorption compound and having no linear absorption. A three-dimensional refractive index modulation method by causing foaming due to gas generation using two-photon absorption induced by gas.
(32) The two-photon absorption foam material according to any one of (1) to (25) is irradiated with laser light having a wavelength longer than the linear absorption band of the two-photon absorption compound and having no linear absorption. Then, the two-photon absorption induced in the laser focus part (recording part) causes foaming due to gas generation, and the three-dimensional refraction due to the refractive index change with the non-focus part (non-recording part, non-foaming part). A three-dimensional optical recording medium recording method, wherein rate modulation is used for recording.
(33) The two-photon absorption foam material according to any one of (1) to (25) is irradiated with laser light having a wavelength longer than the linear absorption band of the two-photon absorption compound and having no linear absorption. Then, the two-photon absorption induced in the laser focus part (recording part) is used to cause foaming due to gas generation, and three-dimensional due to the change in the light absorption rate with the non-focus part (non-recording part, non-foaming part). Three-dimensional optical recording medium recording method, characterized in that optical absorptance modulation is used for recording.
(34) In (32), reproduction is performed by irradiating light onto a three-dimensional optical recording medium that has been recorded with bubbles, and detecting a difference in reflectance between the recording unit and the non-recording unit. -Dimensional optical recording medium reproduction method.
(35) Although the power or pulse shape is the same as or different from the laser used at the time of recording in (32), the same laser is used to irradiate the recorded three-dimensional optical recording medium with bubbles, and the recording unit is not A three-dimensional optical recording medium reproducing method, wherein reproduction is performed by detecting a difference in reflectance in a recording unit.
(36) In (33), reproduction is performed by irradiating light onto a three-dimensional optical recording medium that has been recorded with air bubbles, and detecting a difference in light absorption between the recording unit and the non-recording unit. 3D optical recording medium playback method.
(37) Although the power or pulse shape is the same as or different from the laser used at the time of recording in (33), the same laser is used to irradiate the recorded three-dimensional optical recording medium with bubbles, and the recording unit is not A three-dimensional optical recording medium reproducing method, wherein reproduction is performed according to a difference in the light absorption rate in a recording unit.

  By using the two-photon absorption foaming material of the present invention, the refractive index or the absorptance can be three-dimensionally modulated at the laser focal portion (recording portion) and the non-focusing portion (non-recording portion). Application to 3D displays, optical materials, etc. is possible.

The present invention provides a three- dimensional optical recording medium using a two-photon absorption foam material that has at least a two-photon absorption compound, generates a gas along with the two-photon absorption of the two-photon absorption compound, and creates bubbles. recording method, is a three-dimensional optical recording medium reproducing how, for reference in understanding the present invention, for the other matters, as described.
The two-photon absorption foam material that foams by the two-photon absorption of the present invention (generates gas to create bubbles) will be described below.
The two-photon absorption foam material of the present invention preferably comprises at least a two-photon absorption compound and a foamable portion or foamable compound that generates (foams) bubbles using the excitation energy thereof, and further, if necessary, a polymer Additives such as a binder made of a compound, a polymerizable monomer, a polymerizable oligomer, a crosslinking agent, a heat stabilizer, a plasticizer, and a solvent are preferably used.

  As a preferable form of the two-photon absorption foam material of the present invention, at least a two-photon absorption compound having a foaming part is included, and when the two-photon absorption is brought into an excited state, the foaming part generates a gas to generate bubbles. There is a two-photon absorbing foam material characterized in that In that case, even if the two-photon absorption compound (preferably organic dye) chromophore itself becomes a foaming site, the foaming site is connected to or close to the two-photon absorption compound chromophore part by any of covalent bond, coordination bond, or ionic bond. It may be used in the form.

On the other hand, as another preferable embodiment of the two-photon absorption foam material of the present invention, at least a two-photon absorption compound and a two-photon absorption compound are different from each other, and the two-photon absorption compound is absorbed by two-photon absorption. There is a two-photon absorption foam material characterized in that after the excited state is generated, the foamable compound foams (generates gas to create bubbles) by energy transfer or electron transfer with the foamable compound.
In the case of the energy transfer mechanism, either a Forster mechanism in which energy transfer occurs from a singlet excited state caused by two-photon absorption of a two-photon absorption compound or a Dexter type mechanism in which energy transfer occurs from a triplet excited state. both are fine. In that case, in order for energy transfer to occur efficiently, the excitation energy of the two-photon absorption compound is preferably larger than the excitation energy of the foamable compound.

On the other hand, in the case of an electron transfer mechanism, either a mechanism in which electron transfer occurs from a singlet excited state caused by two-photon absorption by a two-photon absorption compound or a mechanism in which electron transfer occurs from a triplet excited state may be used. .
Further, the excited state of the two-photon absorption compound may give electrons to the foamable compound or may receive electrons. When electrons are given from the excited state of the two-photon absorption compound, in order for the electron transfer to occur efficiently, the orbital (LUMO) energy of the excited electron in the excited state of the two-photon absorption compound is the energy of the LUMO orbital of the foamable compound. Higher than that.
When the two-photon absorption compound excited state receives electrons, the electron orbit (HOMO) energy in the excited state of the two-photon absorption compound is higher than the energy of the HOMO orbital of the foamable compound in order for the electron transfer to occur efficiently. Is preferably low.

In the two-photon absorption foam material of the present invention, the size of the generated bubbles is preferably in the range of 10 nm to 100 μm, more preferably in the range of 50 nm to 5 μm, and in the range of 100 nm to 2 μm. Is more preferable.
Further, in order to enable the reproduction of the recording material by changing the reflection, scattering, diffraction, etc. of the light, or to make it function as an optical material, it should be 1/20 to 20 times the irradiation light wavelength. The size is preferably 1/10 to 10 times, and more preferably 1/5 to 5 times.

In the two-photon absorption foam material of the present invention, it is particularly preferable from the viewpoint of high sensitivity that foaming by performing two-photon absorption occurs in a reaction that does not involve thermal decomposition, that is, in a photon mode.
That is, it is preferable to create bubbles by a mechanism different from the method that is practically used in the existing CD-R and DVD-R, particularly when considering the writing transfer speed in the recording material.

  First, the two-photon absorption compound in the two-photon absorption foam material of the present invention will be described.

The two-photon absorption compound of the present invention is a compound that performs non-resonant two-photon absorption (a phenomenon in which two photons are simultaneously excited in an energy region where no (linear) absorption band of the compound exists).
In particular, when the two-photon absorption foam material of the present invention is applied to a three-dimensional optical recording medium or a three-dimensional display, two-photon absorption is performed with high sensitivity to achieve a high transfer (recording) speed. There is a need for a two-photon absorption compound that can be produced well. The efficiency with which a two-photon absorption compound performs two-photon absorption is represented by a two-photon absorption cross section δ and is defined by 1GM = 1 × 10 ⁻⁵⁰ cm ⁴ s / photon. The two-photon absorption cross-sectional area δ of the two-photon absorption compound in the two-photon absorption foam material of the present invention is preferably 100 GM or more from the viewpoint of improving the writing speed, reducing the size of the laser and reducing the cost, and more preferably 1000 GM or more. More preferably, it is more preferably 5000 GM or more, and most preferably 10,000 GM or more.

The two-photon absorption compound of the present invention is preferably an organic compound.
In the present invention, when a specific moiety is referred to as a “group”, unless otherwise specified, it may be substituted with one or more (up to the maximum possible) substituents. It means that it is not necessary. For example, “alkyl group” means a substituted or unsubstituted alkyl group. Moreover, the substituent which can be used for the compound in the present invention may be any substituent regardless of the presence or absence of substitution.
In the present invention, when a specific moiety is referred to as “ring”, or when “group” includes “ring”, it may be monocyclic or condensed unless otherwise specified. May not be substituted.
For example, the “aryl group” may be a phenyl group, a naphthyl group, or a substituted phenyl group.

The two-photon absorption compound of the present invention is more preferably an organic dye. In addition, a pigment | dye here is a general term with respect to the compound which has a part of absorption in visible region (400-700 nm) or near-infrared region (700-2000 nm).
Any two-photon absorption dye may be used in the present invention. For example, cyanine dye, hemicyanine dye, streptocyanine dye, styryl dye, pyrylium dye, merocyanine dye, trinuclear merocyanine dye, tetranuclear merocyanine dye, rhodacyanine dye, complex Cyanine dye, complex merocyanine dye, allopolar dye, arylidene dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye, azurenium dye, coumarin dye, ketocoumarin dye, styrylcoumarin dye, pyran dye, anthraquinone dye, quinone dye, tri Phenylmethane dye, diphenylmethane dye, xanthene dye, thioxanthene dye, phenothiazine dye, phenoxazine dye, phenazine dye, azo color Azomethine dye, fluorenone dye, diarylethene dye, spiropyran dye, fulgide dye, perylene dye, phthaloperylene dye, indigo dye, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye, quinophthalone dye, porphyrin dye, azaporphyrin dye, Chlorophyll dyes, phthalocyanine dyes, condensed aromatic dyes, styrenic dyes, metallocene dyes, metal complex dyes, phenylene vinylene dyes, stilbazolium dyes, more preferably cyanine dyes, hemicyanine dyes, streptocyanine dyes, styryl dyes, Pyrylium dye, merocyanine dye, trinuclear merocyanine dye, tetranuclear merocyanine dye, rhodacyanine dye, complex cyanine dye, complex dye Cyanine dyes, allopolar dyes, arylidene dyes, oxonol dyes, hemioxonol dyes, squalium dyes, croconium dyes, azurenium dyes, coumarin dyes, ketocoumarin dyes, styrylcoumarin dyes, pyran dyes, anthraquinone dyes, quinone dyes, triphenylmethane dyes, Diphenylmethane dye, thioxanthene dye, phenothiazine dye, phenoxazine dye, phenazine dye, azo dye, azomethine dye, perylene dye, phthaloperylene dye, indigo dye, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye, quinophthalone dye, Porphyrin dye, azaporphyrin dye, chlorophyll dye, phthalocyanine dye, condensed aromatic dye, styrenic dye, metallocene A dye, a metal complex dye, or a stilbazolium dye, and more preferably a cyanine dye, hemicyanine dye, streptocyanine dye, styryl dye, pyrylium dye, merocyanine dye, trinuclear merocyanine dye, tetranuclear merocyanine dye, rhodacyanine dye, complex cyanine dye , Complex merocyanine dye, allopolar dye, arylidene dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye, azurenium dye, ketocoumarin dye, styrylcoumarin dye, pyran dye, anthraquinone dye, quinone dye, triphenylmethane dye, diphenylmethane Dye, thioxanthene dye, phenothiazine dye, phenoxazine dye, phenazine dye, azo dye, azomethine dye, indigo Element, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye, quinophthalone dye, azaporphyrin dye, chlorophyll dye, phthalocyanine dye, condensed aromatic dye, metallocene dye, or metal complex dye, more preferably Cyanine dye, hemicyanine dye, streptocyanine dye, styryl dye, pyrylium dye, merocyanine dye, arylidene dye, oxonol dye, squalium dye, ketocoumarin dye, styrylcoumarin dye, pyran dye, thioxanthene dye, phenothiazine dye, phenoxazine dye, phenazine A dye, an azo dye, a polyene dye, an azaporphyrin dye, a chlorophyll dye, a phthalocyanine dye, or a metal complex dye, more preferably cyanide dye. Dyes and merocyanine dyes, arylidene dyes, oxonol dyes, squarylium dyes, azo dyes or phthalocyanine dyes, still more preferred are cyanine dyes, merocyanine dyes or oxonol dyes, and most preferably a cyanine dye.

  For more information on these dyes, see FMHarmer, “Heterocyclic Compounds-Cyanine Dyes and Related Compounds”, John Willie &・ John Wiley & Sons-New York, London, 1964, DMSturmer, "Heterocyclic Compounds-Special Topics in Heterocyclic Compounds-Special topics in repeating chemistry), Chapter 18, Section 14, 482-515, John Wiley & Sons-New York, London, 1977, "Rods Chemistry of Carbon Compounds (Rodd's Chemistry of Carbon Compounds), 2nd.Ed vol. IV, part B, 1977, Chapter 15, pages 369 to 422, published by Elsevier Science Publishing Company Inc., New York, and the like.

  Specific examples of the cyanine dye, merocyanine dye, or oxonol dye include those described in F.M. Harmer, Heterocyclic Compounds-Cyanine Dyes and Related Compounds, John & Wiley & Sons, New York, London, 1964.

  The general formulas of cyanine dye and merocyanine dye are those shown in (XI) and (XII) on pages 21 and 22 of US Pat. No. 5,340,694 (however, the number of n12 and n15 is not limited and is an integer of 0 or more) (Preferably an integer of 0 to 4)).

When the two-photon absorption compound of the present invention is a cyanine dye, it is preferably represented by the general formula (3).

In the general formula (3), Za ₁ and Za ₂ each represent an atomic group forming a 5-membered or 6-membered nitrogen-containing heterocycle. The 5-membered or 6-membered nitrogen-containing heterocycle formed is preferably an oxazole nucleus having 3 to 25 carbon atoms (hereinafter referred to as C number) (for example, 2-3-methyloxazolyl, 2-3-ethyloxazolyl). , 2-3,4-diethyloxazolyl, 2-3-methylbenzoxazolyl, 2-3-ethylbenzoxazolyl, 2-3-sulfoethylbenzoxazolyl, 2-3-sulfopropyl Benzoxazolyl, 2-3-methylthioethylbenzoxazolyl, 2-3-methoxyethylbenzoxazolyl, 2-3-sulfobutylbenzoxazolyl, 2-3-methyl-β-naphthoxazolyl 2-3-methyl-α-naphthoxazolyl, 2-3-sulfopropyl-β-naphthoxazolyl, 2-3-sulfopropyl-β-naphthoxazolyl, 2-3- ( -Naphthoxyethyl) benzoxazolyl, 2-3,5-dimethylbenzoxazolyl, 2-6-chloro-3-methylbenzoxazolyl, 2-5-bromo-3-methylbenzoxazolyl, 2- 3-ethyl-5-methoxybenzoxazolyl, 2-5-phenyl-3-sulfopropylbenzoxazolyl, 2-5- (4-bromophenyl) -3-sulfobutylbenzoxazolyl, 2-3 -Dimethyl-5,6-dimethylthiobenzoxazolyl), thiazole nuclei having 3 to 25 carbon atoms (for example, 2-methylthiazolyl, 2-3-ethylthiazolyl, 2-3-sulfopropylthiazolyl, 2- 3-sulfobutylthiazolyl, 2-3,4-dimethylthiazolyl, 2-3,4,4-trimethylthiazolyl, 2-3-carboxyethylthiazolyl, 2 -3-methylbenzothiazolyl, 2-3-ethylbenzothiazolyl, 2-3-butylbenzothiazolyl, 2-3-sulfopropylbenzothiazolyl, 2-3-sulfobutylbenzothiazolyl , 2-3-methyl-β-naphthothiazolyl, 2-3-sulfopropyl-γ-naphthothiazolyl, 2-3- (1-naphthoxyethyl) benzothiazolyl, 2-3,5-dimethylbenzothiazolyl, 2-6-chloro -3-methylbenzothiazolyl, 2-6-iodo-3-ethylbenzothiazolyl, 2-5-bromo-3-methylbenzothiazolyl, 2-3-ethyl-5-methoxybenzothiazolyl 2-5-phenyl-3-sulfopropylbenzothiazolyl, 2-5- (4-bromophenyl) -3-sulfobutylbenzothiazolyl, 2-3-dimethyl-5,6- Dimethylthiobenzothiazolyl), imidazole nucleus having 3 to 25 carbon atoms (for example, 2-1,3-diethylimidazolyl, 2-1,3-dimethylimidazolyl, 2-1-methylbenzimidazolyl, 2- 1,3,4-triethylimidazolyl, 2-1,3-diethylbenzimidazolyl, 2-1,3,5-trimethylbenzimidazolyl, 2-6-chloro-1,3-dimethylbenzimidazolyl, 2-5,6-dichloro- 1,3-diethylbenzimidazolyl, 2-1,3-disulfopropyl-5-cyano-6-chlorobenzimidazolyl, etc.), C10-30 indolenine nucleus (for example, 3,3-dimethylindolenine) ), A quinoline nucleus having 9 to 25 carbon atoms (for example, 2-1-methylquinolyl, 2-1-ethylquinolyl) 2-1-methyl 6-chloroquinolyl, 2-1,3-diethylquinolyl, 2-1-methyl-6-methylthioquinolyl, 2-1-sulfopropylquinolyl, 4-1-methylquinolyl, 4-1 And sulfoethylquinolyl, 4-1-methyl-7-chloroquinolyl, 4-1,8-diethylquinolyl, 4-1-methyl-6-methylthioquinolyl, 4-1-sulfopropylquinolyl, etc.) , A C 3-25 selenazole nucleus (for example, 2-3methylbenzoselenazolyl etc.), a C 5-25 pyridine nucleus (for example, 2-pyridyl etc.) and the like can be mentioned. In addition, thiazoline nucleus, oxazoline nucleus, selenazoline nucleus, tellurazoline nucleus, tellurazole nucleus, benzotelrazole nucleus, imidazoline nucleus, imidazo [4,5-quino Zarin] nucleus, an oxadiazole nucleus, a thiadiazole nucleus, a tetrazole nucleus, may be mentioned pyrimidine nucleus.

  These may be substituted, and the substituent is preferably, for example, an alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, benzyl, 3- Sulfopropyl, 4-sulfobutyl, carboxymethyl, 5-carboxypentyl), alkenyl group (preferably having 2 to 20 carbon atoms, such as vinyl, allyl, 2-butenyl, 1,3-butadienyl), cycloalkyl group (preferably C 3-20, for example cyclopentyl, cyclohexyl), aryl groups (preferably C 6-20, for example phenyl, 2-chlorophenyl, 4-methoxyphenyl, 3-methylphenyl, 1-naphthyl), heterocyclic groups ( Preferably C number 1-20, for example pyridyl, thienyl, furyl, thiazolyl, imida Yl, pyrazolyl, pyrrolidino, piperidino, morpholino), alkynyl group (preferably having 2 to 20 carbon atoms, such as ethynyl, 2-propynyl, 1,3-butadiynyl, 2-phenylethynyl), halogen atom (for example, F, Cl Br, I), amino group (preferably C 0-20, for example, amino, dimethylamino, diethylamino, dibutylamino, anilino), cyano group, nitro group, hydroxyl group, mercapto group, carboxyl group, sulfo group, Phosphonic acid group, acyl group (preferably C 1-20, such as acetyl, benzoyl, salicyloyl, pivaloyl), alkoxy group (preferably C 1-20, such as methoxy, butoxy, cyclohexyloxy), aryloxy group (Preferably C number 6-26, for example, phenoxy, 1 Naphthoxy), alkylthio group (preferably C number 1-20, for example, methylthio, ethylthio), arylthio group (preferably C number 6-20, for example, phenylthio, 4-chlorophenylthio), alkylsulfonyl group (preferably C number) 1-20, such as methanesulfonyl, butanesulfonyl), arylsulfonyl groups (preferably C6-6, such as benzenesulfonyl, paratoluenesulfonyl), sulfamoyl groups (preferably C0-20, such as sulfamoyl, N-methylsulfamoyl, N-phenylsulfamoyl), carbamoyl group (preferably having 1 to 20 carbon atoms, for example, carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-phenylcarbamoyl), acylamino group (Preferably C number 1 -20, such as acetylamino, benzoylamino), imino group (preferably C 2-20, such as phthalimino), acyloxy group (preferably C 1-20, such as acetyloxy, benzoyloxy), alkoxycarbonyl group (preferably Is a C2-20, such as methoxycarbonyl, phenoxycarbonyl), a carbamoylamino group (preferably a C1-20, such as carbamoylamino, N-methylcarbamoylamino, N-phenylcarbamoylamino), more preferably Is an alkyl group, aryl group, heterocyclic group, halogen atom, cyano group, carboxyl group, sulfo group, alkoxy group, sulfamoyl group, carbamoyl group, alkoxycarbonyl group.

  These heterocycles may be further condensed. Preferred examples of the condensed ring include a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, and a thiophene ring.

More preferably, the 5- or 6-membered nitrogen-containing heterocyclic ring formed by Za ₁ and Za ₂ is an oxazole nucleus, an imidazole nucleus, a thiazole nucleus, or an indolenine ring, and more preferably an oxazole nucleus, an imidazole nucleus, or an indolenine ring. A ring, most preferably an oxazole nucleus.

Ra ₁ and Ra ₂ are each independently a hydrogen atom or an alkyl group (preferably having a C number of 1 to 20, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, benzyl, 3-sulfopropyl. , 4-sulfobutyl, 3-methyl-3-sulfopropyl, 2′-sulfobenzyl, carboxymethyl, 5-carboxypentyl), alkenyl group (preferably having 2 to 20 carbon atoms, for example, vinyl, allyl), aryl group ( Preferably C number 6-20, for example, phenyl, 2-chlorophenyl, 4-methoxyphenyl, 3-methylphenyl, 1-naphthyl), heterocyclic group (preferably C number 1-20, for example, pyridyl, thienyl, furyl , Thiazolyl, imidazolyl, pyrazolyl, pyrrolidino, piperidino, morpholino), more preferably alkyl. Group (preferably 3-sulfopropyl, 4-sulfobutyl, 3-methyl-3-sulfopropyl, 2'-sulfobenzyl) (preferably C 1 -C 6 alkyl group) or a sulfoalkyl group is.

Ma _{1 to} Ma ₇ each represent a methine group and may have a substituent (examples of preferred substituents are the same as examples of substituents on Za ₁ and Za ₂ ), and preferably an alkyl group as a substituent , Halogen atom, nitro group, alkoxy group, aryl group, nitro group, heterocyclic group, aryloxy group, acylamino group, carbamoyl group, sulfo group, hydroxy group, carboxy group, alkylthio group, cyano group, etc. More preferably, it is an alkyl group.
Ma _{1 to} Ma ₇ are preferably an unsubstituted methine group or an alkyl group (preferably having a C number of 1 to 6) substituted methine group, more preferably an unsubstituted, ethyl group-substituted, or methyl group-substituted methine group.
Ma _{1 to} Ma ₇ may be linked to each other to form a ring, and preferred examples of the ring formed include a cyclohexene ring, a cyclopentene ring, a benzene ring, and a thiophene ring.

na ¹ and na ² is 0 or 1, preferably both 0.

ka ¹ represents an integer of 0 to 3, more preferably ka ¹ represents ¹ to 3, and further preferably ka ¹ represents 1 or 2.
When ka ¹ is 2 or more, a plurality of Ma ₃ and Ma ₄ may be the same or different.

  CI represents an ion that neutralizes the electric charge, and y represents a number necessary for neutralizing the electric charge.

  When the two-photon absorption compound of the present invention is a merocyanine dye, it is preferably represented by the general formula (4).

In the general formula (4), Za ₃ represents an atomic group forming a 5- or 6-membered nitrogen-containing heterocycle (preferred examples are the same as Za ₁ and Za ₂ ), and these may be substituted (preferred substitution) examples of groups are the same as examples of the substituent on Za1, Za _2)), these heterocyclic rings may be further condensed with another ring.

The 5-membered or 6-membered nitrogen-containing heterocyclic ring formed by Za ₃ is more preferably an oxazole nucleus, an imidazole nucleus, a thiazole nucleus, or an indolenine ring, and more preferably an oxazole nucleus or an indolenine ring.

Za ₄ represents an atomic group forming a 5-membered or 6-membered ring. The ring formed from Za ₄ is a part generally called an acidic nucleus, and is defined by James, The Theory of the Photographic Process, 4th edition, Macmillan, 1977, p. 198. Za ₄ is preferably 2-pyrazolone-5-one, pyrazolidine-3,5-dione, imidazolin-5-one, hydantoin, 2 or 4-thiohydantoin, 2-iminooxazolidine-4-one, 2-oxazoline- 5-one, 2-thiooxazoline-2,4-dione, isorhodanine, rhodanine, indan-1,3-dione, thiophen-3-one, thiophen-3-one-1,1-dioxide, indoline-2-one , Indoline-3-one, 2-oxoindazolium, 5,7-dioxo-6,7-dihydrothiazolo [3,2-a] pyrimidine, 3,4-dihydroisoquinolin-4-one, 1,3 -Dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, coumarin-2,4-dione, indazolin-2-one, pyri Examples include nuclei such as do [1,2-a] pyrimidine-1,3-dione, pyrazolo [1,5-b] quinazolone, and pyrazolopyridone.
More preferably, the ring formed from Za ₄ is 2-pyrazolone-5-one, pyrazolidine-3,5-dione, rhodanine, indan-1,3-dione, thiophen-3-one, thiophen-3-one- 1,1-dioxide, 1,3-dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, coumarin-2,4-dione, more preferably pyrazolidine-3,5-dione, Indan-1,3-dione, 1,3-dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, most preferably pyrazolidine-3,5-dione, barbituric acid, 2- Thiobarbituric acid.

The ring formed from Za ₄ may be substituted (preferred examples of the substituent are the same as the examples of the substituent on Za ₃ ). More preferably, the substituent is preferably an alkyl group, an aryl group, a heterocyclic group, a halogen. An atom, a cyano group, a carboxyl group, a sulfo group, an alkoxy group, a sulfamoyl group, a carbamoyl group, and an alkoxycarbonyl group.

  These heterocycles may be further condensed. Preferred examples of the condensed ring include a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, and a thiophene ring.

Ra ₃ is each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group (preferred examples are the same as Ra ₁ and Ra ₂ ), more preferably an alkyl group (preferably having 1 to 6 carbon atoms). Alkyl group) or a sulfoalkyl group (preferably 3-sulfopropyl, 4-sulfobutyl, 3-methyl-3-sulfopropyl, 2′-sulfobenzyl).

Ma _{8 to} Ma ₁₁ each represent a methine group and may have a substituent (examples of preferred substituents are the same as examples of substituents on Za ₁ and Za ₂ ), and preferably an alkyl group as a substituent , Halogen atom, nitro group, alkoxy group, aryl group, nitro group, heterocyclic group, aryloxy group, acylamino group, carbamoyl group, sulfo group, hydroxy group, carboxy group, alkylthio group, cyano group, etc. More preferably, it is an alkyl group.
Ma _{8 to} Ma ₁₁ are preferably an unsubstituted methine group or an alkyl group (preferably having a C number of 1 to 6) substituted methine group, more preferably an unsubstituted, ethyl group-substituted, or methyl group-substituted methine group.
Ma _{8 to} Ma ₁₁ may be linked to each other to form a ring, and preferred examples of the ring formed include a cyclohexene ring, a cyclopentene ring, a benzene ring, and a thiophene ring.

na ³ is 0 or 1, preferably 0.

ka ² represents an integer of 0 to 8, preferably an integer of 0 to 4, more preferably an integer of 2 to 4.
When ka ² is 2 or more, the plurality of Ma ₁₀ and Ma ₁₁ may be the same or different.

  CI represents an ion that neutralizes the electric charge, and y represents a number necessary for neutralizing the electric charge.

  When the two-photon absorption compound of the present invention is an oxonol dye, it is preferably represented by the general formula (5).

In the general formula (5), Za ₅ and Za ₆ each represent a group of atoms forming a 5-membered or 6-membered ring (preferred examples are the same as Za ₄ ), and these may be substituted (examples of preferred substituents). Is the same as the example of the substituent on Za ₄ ), and these heterocyclic rings may be further condensed.
More preferably, the ring formed from Za ₅ and Za ₆ is more preferably 2-pyrazolone-5-one, pyrazolidine-3,5-dione, rhodanine, indan-1,3-dione, thiophen-3-one, thiophene-3. -One-1,1-dioxide, 1,3-dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, coumarin-2,4-dione, more preferably barbituric acid, 2- Thiobarbituric acid, most preferably barbituric acid.

Ma _{12 to} Ma ₁₄ each represent a methine group and may have a substituent (preferred examples of the substituent are the same as the examples of the substituent on Za ₅ and Za ₆ ), and the substituent is preferably alkyl. Group, halogen atom, nitro group, alkoxy group, aryl group, nitro group, heterocyclic group, aryloxy group, acylamino group, carbamoyl group, sulfo group, hydroxy group, carboxy group, alkylthio group, cyano group, etc. More preferred are an alkyl group, a halogen atom, an alkoxy group, an aryl group, a heterocyclic group, a carbamoyl group and a carboxy group, and further preferred are an alkyl group, an aryl group and a heterocyclic group.
Ma _{12 to} Ma ₁₄ are preferably unsubstituted methine groups.
Ma _{12 to} Ma ₁₄ may be linked to each other to form a ring, and preferred examples of the ring formed include a cyclohexene ring, a cyclopentene ring, a benzene ring, and a thiophene ring.

ka ³ represents an integer from 0 to 3, preferably an integer from 0 to 2, more preferably 1 or 2, and most preferably 2.
When ka ³ is 2 or more, Ma ₁₂ and Ma ₁₃ may be the same or different.

  CI represents an ion that neutralizes the electric charge, and y represents a number necessary for neutralizing the electric charge.

Moreover, it is also preferable that the compound of this invention is represented by General formula (1).

In the general formula (1), R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom or a substituent, and the substituent is preferably an alkyl group (preferably having a C number of 1 to 20, for example, Methyl, ethyl, n-propyl, isopropyl, n-butyl, n-pentyl, benzyl, 3-sulfopropyl, 4-sulfobutyl, 3-methyl-3-sulfopropyl, 2'-sulfobenzyl, carboxymethyl, 5-carboxy Pentyl), an alkenyl group (preferably C 2-20, such as vinyl, allyl), a cycloalkyl group (preferably C 3-20, such as cyclopentyl, cyclohexyl), an aryl group (preferably C 6-20, For example, phenyl, 2-chlorophenyl, 4-methoxyphenyl, 3-methylphenyl, 1-naphthyl), a heterocyclic group (preferably Ku is C 1-20, for example, pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl, pyrrolidino, piperidino, morpholino).
R ¹ , R ² , R ³ and R ⁴ are preferably a hydrogen atom or an alkyl group. Some (preferably two) of R ¹ , R ² , R ³ and R ⁴ may be bonded to each other to form a ring. In particular, R ¹ and R ³ are preferably bonded to form a ring, and the ring formed with the carbonyl carbon atom is preferably a 6-membered ring, a 5-membered ring or a 4-membered ring, and a 5-membered ring or A 4-membered ring is more preferable, and a 5-membered ring is most preferable.

In General formula (1), n and m represent the integer of 0-4 each independently, Preferably the integer of 1-4 is represented. However, n and m are not 0 simultaneously.
When n and m are 2 or more, a plurality of R ¹ , R ² , R ³ and R ⁴ may be the same or different.

X ¹ and X ² are independently an aryl group [preferably a C 6-20, preferably a substituted aryl group (for example, a substituted phenyl group, a substituted naphthyl group, a substituent of Ma ₁ to Ma ₇ as an example of a substituent, preferably And more preferably an alkyl group, an aryl group, a heterocyclic group, a halogen atom, an amino group, a hydroxyl group, an alkoxy group, an aryloxy group, an aryl group substituted with an acylamino group, and more preferably an alkyl group Represents an aryl group substituted with an amino group, a hydroxyl group, an alkoxy group or an acylamino group, and most preferably a phenyl group substituted with a dialkylamino group or a diarylamino group at the 4-position. In this case, a plurality of substituents may be linked to form a ring, and examples of a preferable ring to be formed include a julolidine ring], a heterocyclic group (preferably having 1 to 20 carbon atoms, preferably 3 to 8 membered ring, More preferably a 5- or 6-membered ring such as pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl, pyrrolyl, indolyl, carbazolyl, phenothiazino, pyrrolidino, piperidino, morpholino, more preferably indolyl, carbazolyl, pyrrolyl, phenothiazino. It may be substituted, and preferred substituents are the same as those in the case of the aryl group) or a group represented by the general formula (2).

In the general formula (2), R ⁵ represents a hydrogen atom or a substituent (preferred examples are the same as those of R ^{1 to} R ⁴ ), preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom.
R ⁶ represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group (preferable examples of these substituents are the same as R ^{1 to} R ⁴ ), preferably an alkyl group (preferably having a C number of 1 to 6 alkyl groups).

Z ¹ represents an atomic group forming a 5- or 6-membered ring.
The heterocycle formed is preferably an indolenine ring, azaindolenine ring, pyrazoline ring, benzothiazole ring, thiazole ring, thiazoline ring, benzoxazole ring, oxazole ring, oxazoline ring, benzimidazole ring, imidazole ring, thiadiazole ring Quinoline ring, pyridine ring, more preferably indolenine ring, azaindolenine ring, pyrazoline ring, benzothiazole ring, thiazole ring, thiazoline ring, benzoxazole ring, oxazole ring, oxazoline ring, benzimidazole ring, thiadiazole ring A quinoline ring, most preferably an indolenine ring, an azaindolenine ring, a benzothiazole ring, a benzoxazole ring, or a benzimidazole ring.
The heterocycle formed by Z ¹ may have a substituent (examples of preferred substituents are the same as the examples of substituents on Za ₁ and Za ₂ ), and more preferably an alkyl group, aryl A group, a heterocyclic group, a halogen atom, a carboxyl group, a sulfo group, an alkoxy group, a carbamoyl group, and an alkoxycarbonyl group.

X ¹ and X ² are each preferably an aryl group or a group represented by the general formula (2), more preferably an aryl group substituted with a dialkylamino group or a diarylamino group at the 4-position, or a general formula (2) Represented by the group represented.

The two-photon absorption compound of the present invention preferably has a hydrogen bonding group in the molecule. Here, the hydrogen-bonding group represents a group that donates hydrogen or a group that accepts hydrogen in a hydrogen bond, and a group having both properties is more preferable.
Further, the compound having a hydrogen bonding group of the present invention preferably has an associative interaction by the interaction between hydrogen bonding groups in a solution or in a solid state, and may be an intramolecular interaction or an intermolecular interaction. The interaction is more preferable.

The hydrogen bonding group of the present invention is preferably —COOH, —CONHR ¹¹ , —SO ₃ H, —SO ₂ NHR ¹² , —P (O) (OH) OR ¹³ , —OH, —SH, —NHR. ¹⁴ , —NHCOR ¹⁵ , or —NR ¹⁶ C (O) NHR ¹⁷ . Here, R ¹¹ and R ¹² are each independently a hydrogen atom or an alkyl group (preferably having a carbon atom number (hereinafter referred to as C number) of 1 to 20, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, n -Pentyl, benzyl, 3-sulfopropyl, 4-sulfobutyl, carboxymethyl, 5-carboxypentyl), alkenyl group (preferably C2-20, such as vinyl, allyl), aryl group (preferably C6 20, for example, phenyl, 2-chlorophenyl, 4-methoxyphenyl, 3-methylphenyl, 1-naphthyl), a heterocyclic group (preferably having 1 to 20 carbon atoms, such as pyridyl, thienyl, furyl, thiazolyl, imidazolyl, pyrazolyl) , pyrrolidino, piperidino, morpholino), - represents COR ¹⁸ or _{^{-SO 2 R 19, R 13 ~R}} 19 is Respectively independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group (preferred examples above are the same as R ^11, R ^12).

R ¹¹ preferably represents a hydrogen atom, an alkyl group, an aryl group, a —COR ¹⁸ group, or a SO ₂ R ¹⁹ group. In this case, R ¹⁸ and R ¹⁹ are preferably an alkyl group or an aryl group.
R ¹¹ is more preferably a hydrogen atom, an alkyl group, or a —SO ₂ R ¹⁹ group, and most preferably a hydrogen atom.
R ¹² preferably represents a hydrogen atom, an alkyl group, an aryl group, a —COR ¹⁸ group, or a SO ₂ R ¹⁹ group. In this case, R ¹⁸ and R ¹⁹ are preferably an alkyl group or an aryl group.
R ¹² is more preferably a hydrogen atom, an alkyl group or a —COR ¹⁸ group, and most preferably a hydrogen atom.
R ¹³ preferably represents a hydrogen atom, an alkyl group, or an aryl group, more preferably a hydrogen atom.
R ¹⁴ preferably represents a hydrogen atom, an alkyl group or an aryl group.
R ¹⁵ preferably represents an alkyl group or an aryl group.
Preferably the R ¹⁶ represents a hydrogen atom, preferably a hydrogen atom, an alkyl group, an aryl group as R ^17.

More preferably, it is any one of —COOH, —CONHR ¹¹ , —SO ₂ NHR ¹² , —NHCOR ¹⁵ , —NR ¹⁶ C (O) NHR ¹⁷ , and more preferably —COOH, —CONHR ^11. , —SO ₂ NHR ¹² , and most preferably —COOH or —CONH ₂ .

The two-photon absorption compound of the present invention may be used in a monomer state or in an associated state.
Here, the dye chromophores are fixed in a specific spatial arrangement by a bond such as a covalent bond or a coordinate bond, or various intermolecular forces (hydrogen bond, van der Waals force, Coulomb force, etc.) This state is generally referred to as an association (or aggregation) state.
The two-photon absorption compound of the present invention has two or more chromophores that perform two-photon absorption in a molecule even when used in an intermolecular association state, and is used in a state in which they absorb two-photons in an intramolecular association state. May be.

For reference, the meeting is explained below. As for the association, for example, James, “The Theory of the Photographic Process”, 4th edition, Macmillan Publishers, 1977, Chapter 8, 218. -222 pages and "J-Aggregates" written by Takayoshi Kobayashi (World Scientific Publishing Co. Pte. Ltd., published in 1996). .
A monomer means a monomer. From the viewpoint of the absorption wavelength of the aggregate, the aggregate whose absorption shifts to a short wavelength with respect to monomer absorption is defined as an H aggregate (the dimer is specially called a dimer), and the aggregate whose shift is shifted to a long wavelength. Called coalescence.

  From the viewpoint of the structure of the aggregate, in the brick aggregate, when the deviation angle of the aggregate is small, it is called a J aggregate, but when the deviation angle is large, it is called an H aggregate. A detailed description of brickwork aggregates can be found in Chemical Physics Letters, Vol. 6, page 183 (1970). In addition, there is a ladder or staircase aggregate as an aggregate having a structure similar to that of a brickwork aggregate. Ladder or staircase structures are described in detail in Zeitschiff for Physikaliche Chemie, Vol. 49, p. 324 (1941).

Moreover, as what forms other than a brickwork aggregate | assembly, the aggregate | assembly (it can call an arrowhead aggregate | assembly) etc. which take an arrow (Herringbone) structure etc. are known.
The Herringbone association is described in Charles Reich, Photographic Science and Engineering Vol. 18, No. 3, p. 335 (1974). Has been. The arrowhead aggregate has two absorption maxima derived from the aggregate.

Whether or not it is in an associated state can be confirmed by a change in absorption (absorption λmax, ε, absorption type) from the monomer state as described above.
The compound of the present invention may be either short-wavelength (H-association) or long-wavelength (J-association) or both by association, but it is more preferable to form a J-aggregate.

The intermolecular association state of a compound can be formed in various ways.
For example, in a solution system, an aqueous solution to which a matrix such as gelatin is added (for example, 0.5 wt% gelatin / compound 10 ⁻⁴ M aqueous solution), an aqueous solution to which a salt such as KCl is added (for example, KCl 5% · compound 2 × 10 ⁻³ M A method of dissolving the compound in an aqueous solution), a method of dissolving the compound in a good solvent and adding a poor solvent later (for example, DMF-water system, chloroform-toluene system, etc.) and the like.
Examples of film systems include polymer dispersion systems, amorphous systems, crystal systems, and LB film systems.
Furthermore, molecules can be adsorbed, chemically bonded, or self-assembled into bulk or fine particle (μm to nm size) semiconductors (eg, silver halide, titanium oxide, etc.), bulk or fine particle metals (eg, gold, silver, platinum, etc.). Inter-association states can also be formed. Spectral sensitization by cyanine dye J-associative adsorption on silver halide crystals in a color silver salt photograph utilizes this technique.
The number of compounds involved in the intermolecular association may be two or a very large number of compounds.

  Although the preferable specific example of the two-photon absorption compound used by this invention is given to the following, this invention is not limited to these.

  Next, the foamable compound or foamable part in the two-photon absorption foam material of the present invention will be described in detail.

The gas generated from the foaming compound part or foaming part of the present invention to create bubbles may be any gas, but preferably N ₂ , CO, CO ₂ , SO ₂ , SO ₃ , N ₂ O , NO, NO ₂ , O ₂ , H ₂ , NH ₃ , iC ₄ H ₈ , more preferably N ₂ , CO ₂ , SO ₂ , SO ₃ , NO ₂ , O ₂ , iC ₄ H ₈ , more preferably N ₂ , CO ₂ , SO ₂ , SO ₃ , or iC ₄ H ₈ , and most preferably N ₂ or CO ₂ .

  The foamable compound or foamable part of the present invention is preferably represented by the general formula (11) or (12).

In the general formula (11), R ²¹ and R ²² each independently represent a hydrogen atom or a substituent (preferred examples are the same as Za1), preferably an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. Represents an alkoxy group, an aryloxy group, or an amino group. R ²¹ and R ²² may be linked to form a ring.

In general formula (11), G represents —N═N—, —C (O) —, —OC (O) —, —OS (O) —, —S (O) ₂ —, —OS (O) _2. -N = N-, -OC (O)-, -S (O) ₂ , -OS (O) _2- is more preferable, -N = N is more preferable. It represents either-or -OC (O)-.

When the general formula (11) indicates a foaming site, it is linked to the two-photon absorption compound by either covalent bond, ionic bond, or coordinate bond at either or both of R ^{21 and} R ²² .

In the general formula (12), R ²³ represents an aryl group or a heterocyclic group.
When R ²³ is an aryl group, the aryl group may be condensed or may have a substituent. Preferred examples of the substituent include an example of a substituent on Za ₁ . When R ²³ is an aryl group, the aryl group is preferably an unsubstituted or optionally substituted phenyl group.
When R ²³ is a heterocyclic group, the hetero group may be condensed or may have a substituent. Preferred examples of the substituent include an example of a substituent on Za ₁ . When R ²³ is a heterocyclic group, the heterocyclic ring is preferably an aromatic ring, such as a pyridine ring, pyrimidine ring, triazine ring, pyrrole ring, pyrazole ring, imidazole ring, thiazole ring, isothiazole ring, oxazole ring, Oxazole ring, thiophene ring, furan ring, thiadiazole ring, oxadiazole ring, triazole ring, tetrazole ring are more preferable, pyridine ring, pyrrole ring, pyrazole ring, imidazole ring, thiazole ring, isothiazole ring, oxazole ring , Isoxazole ring, thiadiazole ring, oxadiazole ring, and triazole ring are more preferable.

In the general formula (12), X ¹¹ represents an anion, and preferably F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , OH ⁻ , SO ₄ ²⁻ , CO ₃ ²⁻ , NO ₃ ⁻ , H ₂ PO _3. ^- , HPO ₃ ²⁻ , BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , ClO ₄ ⁻ , trifluoromethanesulfonate, methanesulfonate, benzenesulfonate, tosylate, tetra (pentafluorophenyl) borate and the like.
When the general formula (12) indicates an effervescent site, R ²³ is linked to the two-photon absorption compound by any of a covalent bond, an ionic bond, and a coordination bond, or X ¹¹ is an anionic two-photon absorption compound It is.

  The foamable compound or foamable part of the present invention is more preferably represented by the general formula (11).

  Specific examples of the foamable compound of the present invention are shown below, but the present invention is not limited thereto.

In the two-photon absorption foam material of the present invention, a binder is preferably used.
The binder is usually used for the purpose of improving the film formability of the composition, the uniformity of the film thickness, and the stability during storage. As the binder, those having good compatibility with the two-photon absorption compound and the foamable compound are preferable.
As the binder, a solvent-soluble thermoplastic polymer is preferable and can be used alone or in combination with each other.
The binder has a reactive site and may be cross-linked or hardened by reacting with a cross-linking agent, a polymerizable monomer or an oligomer. In this case, the reactive site includes an ethylenically unsaturated group represented by an acrylic group and a methacryl group as a radical reactive site, an oxirane compound, an oxetane compound, a vinyl ether group as a cationic reactive site, and a carboxyl group as a condensation polymerization reaction site. Preferred are acids, alcohols, amines and the like.

Preferred binders for use in the present invention include, for example, acrylate and alpha-alkyl acrylate esters and acidic polymers and interpolymers (eg, polymethyl methacrylate and polyethyl methacrylate, methyl methacrylate and other (meth) acrylic acid alkyl esters). Polymers), polyvinyl esters (eg, polyvinyl acetate, polyacetic acid / vinyl acrylate, polyacetic acid / vinyl methacrylate and hydrolyzable polyvinyl acetate), ethylene / vinyl acetate copolymers, saturated and unsaturated polyurethanes, butadiene And isoprene polymers and copolymers and polyglycols having a weight average molecular weight of approximately 4,000 to 1,000,000, high molecular weight poly (ethylene oxide), epoxides (eg epoxies having acrylate or methacrylate groups) Compound), polyamide (for example, N-methoxymethyl polyhexamethylene adipamide), cellulose ester (for example, cellulose acetate, cellulose acetate succinate and cellulose acetate butyrate), cellulose ether (for example, methyl cellulose, ethyl cellulose, ethyl benzyl cellulose) ), Polycarbonate, polyvinyl acetal (polyvinyl butyral and polyvinyl formal), polyvinyl alcohol, polyvinyl pyrrolidone, acid-containing polymers and copolymers that function as suitable binders in US Pat. No. 3,458,311 and US Pat. No. 4,273. , 857, and the like.
In addition, polystyrene polymers and copolymers such as acrylonitrile, maleic anhydride, acrylic acid, methacrylic acid and esters thereof, vinylidene chloride copolymers (eg vinylidene chloride / acrylonitrile copolymers, vinylidene chloride / methacrylate copolymers) Polymers, vinylidene chloride / vinyl acetate copolymer), polyvinyl chloride and copolymers (eg, polyvinyl chloride / acetate, vinyl chloride / acrylonitrile copolymer), polyvinyl benzal synthetic rubber (eg, butadiene / acrylonitrile copolymer) , Acrylonitrile / butadiene / styrene copolymer, methacrylate / acrylonitrile / butadiene / styrene copolymer, 2-chlorobutadiene-1,3 polymer, chlorinated rubber, styrene / butadiene / styrene, styrene / Isoprene / styrene block copolymers), copolyesters (eg, polymethylene glycols of the formula HO (CH2) nOH, where n is an integer from 2 to 10), and (1) hexahydroterephthalic acid, sebacic acid And terephthalic acid, (2) terephthalic acid, isophthalic acid and sebacic acid, (3) terephthalic acid and sebacic acid, (4) produced from the reaction product of terephthalic acid and isophthalic acid, and (5) the glycol and (i) a mixture of terephthalic acid, isophthalic acid and sebacic acid and (ii) a copolyester prepared from terephthalic acid, isophthalic acid, sebacic acid and adipic acid), poly N-vinylcarbazole and copolymers thereof, and Examples include carbazole-containing polymers as disclosed in Journal of Polymer Science: Polymer Chemistry Edition, Vol. 18, pages 9-18 (1979) by Kamogawa et al.
As the binder used for the two-photon absorption foam material of the present invention, a binder having a refractive index of 1.5 or more is preferable.

  In the two-photon absorption foaming material of the present invention, additives such as a polymerizable monomer, a polymerizable oligomer, a crosslinking agent, a heat stabilizer, a plasticizer, and a solvent can be appropriately used as necessary.

  Preferable examples when using a polymerizable monomer, a polymerizable oligomer, and a crosslinking agent for the two-photon absorption foaming material of the present invention include those described in Japanese Patent Application No. 2003-82732.

A heat stabilizer can be added to the two-photon absorption foam material of the present invention in order to improve the storage stability during storage.
Useful heat stabilizers include hydroquinone, phenidone, p-methoxyphenol, alkyl and aryl substituted hydroquinones and quinones, catechol, t-butylcatechol, pyrogallol, 2-naphthol, 2,6-di-t-butyl-p. -Cresol, phenothiazine, chloranneal and the like. The dinitroso dimers described in Pazos US Pat. No. 4,168,982 are also useful.

  Plasticizers are used to change the adhesion, flexibility, hardness, and other mechanical properties of the two-photon absorbing foam material. Examples of the plasticizer include triethylene glycol dicaprylate, triethylene glycol bis (2-ethylhexanoate), tetraethylene glycol diheptanoate, diethyl sebacate, dibutyl suberate, tris (2-ethylhexyl) phosphate, Examples include tricresyl phosphate and dibutyl phthalate.

The two-photon absorption foam material of the present invention may be prepared by a conventional method. For example, the above-mentioned essential components and optional components can be prepared as they are or by adding a solvent as necessary.
Examples of the solvent include ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, acetone and cyclohexanone, ester solvents such as ethyl acetate, butyl acetate, ethylene glycol diacetate, ethyl lactate and cellosolve acetate, carbonization such as cyclohexane, toluene and xylene. Hydrogen solvent, ether solvents such as tetrahydrofuran, dioxane, diethyl ether, cellosolv solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, dimethyl cellosolve, methanol, ethanol, n-propanol, 2-propanol, n-butanol, diacetone Alcohol solvents such as alcohol, fluorine solvents such as 2,2,3,3-tetrafluoropropanol, dichloromethane, chloroform, 1,2-dichloro Halogenated hydrocarbon solvents such as Roetan, N, an amide-based solvents such as N- dimethylformamide.
The two-photon absorbing foam material can be applied directly onto the substrate, spin coated, or cast as a film and then laminated to the substrate by conventional methods. The solvent used can be removed by evaporation during drying.

The refractive index of a colorless organic compound is usually in the range of 1.4 to 1.6. Furthermore, an organic dye may give a refractive index exceeding 2 near the absorption wavelength. On the other hand, the refractive index of gas is 1.
Therefore, by using the excitation energy obtained by the two-photon absorption, foaming is caused by the above-described method, so that the refractive index can be greatly modulated at the laser focus part (recording part) and the non-focus part (non-recording part). Refractive index modulation can be caused at an arbitrary place in space with extremely high spatial resolution.
As a result, when the recording material is irradiated with light, reproduction can be performed by changing the reflectivity by refractive index modulation, and application to a three-dimensional optical recording medium considered to be the ultimate high-density recording medium is also possible. . Furthermore, since non-destructive readout is possible and the material is an irreversible material, it can be expected to have good storage stability and is practical. In particular, it is expected to be applied to a write-once (write-once) three-dimensional optical recording medium.
In addition, it can be applied to three-dimensional displays and optical materials (retardation films, diffraction gratings, antireflection films, lenses, etc.).

  Further, not only refractive index modulation but also reproduction using an absorption difference between a bubble in a recording part and a two-photon absorption dye in a non-recording part is possible, and a three-dimensional display can be provided. is there.

  In the two-photon absorption foam material of the present invention, foaming is performed using two-photon absorption induced by irradiation with laser light having a wavelength longer than the linear absorption band of the two-photon absorption compound and having no linear absorption. It is preferable to make it.

The laser that can be used in the present invention is not particularly limited. Specifically, a solid-state laser such as Ti-sapphire having an oscillation wavelength near a central wavelength of 1000 nm, a fiber laser, a CD-R having an oscillation wavelength near 780 nm, or the like. However, it is preferable to use a semiconductor laser, a solid-state laser, a fiber laser, a semiconductor laser, a solid-state laser, a GaN laser near 405 nm, etc. used in a DVD-R having an oscillation wavelength in the range of 620 to 680 nm. it can.
In addition, a solid SHG laser such as a YAG / SHG laser having an oscillation wavelength in the visible light region, a semiconductor SHG laser, or the like can be preferably used.
The laser used in the present invention may be a pulsed laser or a CW laser.

  When applying the two-photon absorption foam material of the present invention to a three-dimensional optical recording medium, there are a method of reproducing by irradiating light and reproducing by a difference in reflectance due to refractive index modulation, and a method of reproducing by a difference in absorptance. The light used in this case is preferably laser light, and it is more preferable to reproduce using the same laser used for recording, although the power or pulse shape is the same or different.

[Example]
Hereinafter, specific embodiments of the present invention will be described based on experimental results. Of course, the present invention is not limited to these examples.

  Synthesis of the two-photon absorption compound of the present invention

(1) Synthesis of D-73

  The two-photon absorption compound D-73 of the present invention can be synthesized by the following method.

  14.3 g (40 mmol) of the quaternary salt [1] was dissolved in 50 ml of water, 1.6 g (40 mmol) of sodium hydroxide was added, and the mixture was stirred at room temperature for 30 minutes. Extraction was performed 3 times with ethyl acetate, dried over magnesium sulfate and concentrated to obtain 9.2 g of methylene-based [2] oil (yield: 100%).

  3.97 g (40 mmol) of dimethylaminoacrolein [3] was dissolved in 50 ml of acetonitrile, and 6.75 g (44 mmol) of phosphorus oxychloride was added dropwise while cooling to 0 ° C., followed by stirring at 0 ° C. for 10 minutes. Subsequently, 9.2 g of acetonitrile solution of methylene base [2] was dropped, and the mixture was stirred at 35 ° C. for 4 hours. After pouring into 100 ml of ice water, 16 g of sodium hydroxide was added and refluxed for 10 minutes. After cooling, the mixture was extracted 3 times with ethyl acetate, dried over magnesium sulfate and concentrated. Purification by silica gel column chromatography (developing solvent: ethyl acetate: hexane = 1: 10 → 1: 3) gave 4.4 g (39% yield) of an aldehyde [4] oil.

  Cyclopentanone 0.126 g (1.5 mmol) and aldehyde [4] 0.85 g (3 mmol) were dissolved in 30 ml of dehydrated methanol and refluxed in a dark atmosphere under a nitrogen atmosphere. After homogenization, 0.69 g (3.6 mmol) of 28% sodium methoxide methanol solution was added, and the mixture was further refluxed for 6 hours. After cooling, the precipitated crystals were separated by filtration and washed with methanol to obtain 0.50 g (yield 54%) of D-73 dark green crystals. The structure was confirmed by NMR spectrum, MS spectrum and elemental analysis.

(2) Synthesis of D-84

  The two-photon absorption compound D-84 of the present invention can be synthesized by the following method.

  Cyclopentanone 33.6 g (0.4 mol), DBN 2 ml, and N, N-dimethylformamide dimethyl acetal 400 g were refluxed for 5 days. After concentration, acetone was added and cooled to separate crystals, which were then washed with cold acetone to obtain 32.4 g of crystals [5] (yield 42%).

[5] 0.78 g (4 mmol), quaternary salt [6] 2.78 g (8 mmol) and 20 ml of pyridine were refluxed for 4 hours in a dark place under a nitrogen atmosphere. After cooling, ethyl acetate was added and the crystals were separated and washed with ethyl acetate. The crystals were dispersed in methanol and separated by filtration to obtain 2.14 g (yield 56%) of the desired deep blue crystals of D-84.
The structure was confirmed by NMR spectrum, MS spectrum and elemental analysis.

  In addition, other two-photon absorption compounds represented by the general formula (1) of the present invention can also be synthesized by D-73 and D-84, Tetrahedron. Lett., 42, 6129, (2001), etc. It can be synthesized according to the method described in 1.

(3) Synthesis of D-1

  The two-photon absorption compound D-1 of the present invention can be synthesized by the following method.

  Benzoxazole [7] 52.25 g (0.2 mol) and propane sultone [8] 45.75 g (0.375 mol) were heated and stirred at 140 ° C. for 4 hours. After cooling, acetone was added and the crystals were separated and washed with acetone to obtain 70.42 g (yield 85%) of a quaternary salt [9].

66.2 g (0.2 mol) of quaternary salt [9], 200 ml of triethyl orthopropionate [10], 200 ml of pyridine and 80 ml of acetic acid were heated and stirred at 120 ° C. for 1 hour. After cooling, decantation washing was performed 3 times with ethyl acetate. When dissolved in 100 ml of methanol and stirred, a solution of 4.0 g (50 mmol) of sodium acetate / 20 ml of methanol was added and the resulting crystals were separated. Further, the product was dispersed in methanol and filtered to obtain 31.36 g (yield: 43.4%) of the intended vermilion crystal of D-1.
The structure was confirmed by NMR spectrum, MS spectrum and elemental analysis.

(4) Synthesis of D-42

  The two-photon absorption compound D-42 of the present invention can be synthesized by the following method.

Quaternary salt [11] 2.81 g (10 mmol), [12] 6.67 g (30 mmol), acetic anhydride 10 g, and acetonitrile 50 ml were refluxed for 30 minutes. After concentration, decantation with ethyl acetate was performed to obtain a crude product of anil form [13].
To the crude product of anil [13], 2.00 g (10 mmol) of thiobarbituric acid [14], 3.0 g (30 mmol) of triethylamine and 100 ml of ethanol were added and refluxed for 1 hour. After concentration, the residue was purified by silica gel column chromatography (developing solvent: chloroform: methanol = 20: 1 → 10: 1), and further recrystallized from methanol-isopropyl alcohol to obtain 2.55 g of the target D-42 crystal. (Total yield 41.3%) was obtained.
The structure was confirmed by NMR spectrum, MS spectrum and elemental analysis.

(5) Synthesis of D-56

  The two-photon absorption compound D-56 of the present invention can be synthesized by the following method.

Barbituric acid [15] 3.12 g (20 mmol), [16] 2.85 g (10 mmol) and triethylamine 4.1 g (40 mmol) were dissolved in DMF 30 ml, and the mixture was stirred at room temperature for 2 hours. Crystals produced by adding dilute hydrochloric acid were filtered, washed with water and dried to obtain 2.99 g (yield: 80.0%) of the desired D-56 crystals.
The structure was confirmed by NMR spectrum, MS spectrum and elemental analysis.

  In addition, other cyanine dyes, merocyanine dyes, oxonol dyes, etc. are also described by FM Harmer, Heterocyclic Compounds-Cyanine Dyes and Related Compounds, John & Wiley & Sons, New York, London, 1964, DMSturmer, Heterocyclic Compounds- Special Topics in Heterocyclic It can be synthesized according to the method described in Chemistry, Chapter 18, Section 14, pages 482 to 515, John & Wiley & Sons, New York, London, etc.

  However, the synthesis method of the two-photon absorption compound of the present invention is not limited to this.

  Many of the foamable compounds of the present invention are commercially available or can be synthesized by known methods.

[Three-dimensional refractive index modulation and absorption modulation evaluation by two-photon absorption foaming material]

Next, a three-dimensional refractive index modulation method and a three-dimensional absorption rate modulation method by foaming caused by two-photon absorption of the two-photon absorption foaming material of the present invention will be described.
Sample 101 and comparative sample 1 of the two-photon absorption polymerizable composition of the present invention were prepared with the following compositions.

<Sample 101: Two-photon absorption foamable material composition of the present invention>
Two-photon absorption compound: D-128 1 part by mass Foaming compound: A-8 20 parts by mass Binder: Poly (butyl methacrylate-co-
Isobutyl methacrylate) 100 parts by mass Solvent: 300 parts by mass of chloroform <Comparative sample 1>
Foamable compound: A-8 20 parts by mass Binder: Poly (butyl methacrylate-co-, manufactured by Aldrich
Isobutyl methacrylate) 100 parts by mass Solvent: chloroform 300 parts by mass

Sample 101 and comparative sample 1 were bar-coated on a preparation glass plate, dried with a solvent, and then prepared with the preparation glass as an evaluation sample. The film thickness was about 10 μm.

For the performance evaluation of the two-photon absorption polymerizable composition of the present invention, a Ti: sapphire pulse laser (pulse width: 100 fs, repetition: 80 MHz, average output: 1 W, peak power: 100 kW) that can be measured in the wavelength range of 700 nm to 1000 nm ), The two-photon absorption polymerizable composition of the present invention was irradiated with the laser beam condensed with a lens of NA 0.6.
The irradiation wavelength used was a wavelength that maximizes the two-photon absorption cross section δ in a 10 ⁻⁴ M solution of the two-photon absorption compound.
Sample 101 and comparative sample 1 were irradiated with 720 nm laser light to cause two-photon absorption. As a result, in sample 101, bubble generation was confirmed at the laser focal point of the light irradiation part. When the laser beam of 720 nm was irradiated, the difference in reflectance was confirmed between the recording portion where bubbles were generated and the non-recording portion. Moreover, the change of the absorption rate of a recording part and a non-recording part was able to be confirmed visually.
In contrast, Comparative Sample 1 that does not contain the two-photon absorption compound D-128 of the present invention does not change anything even when irradiated with a 720 nm laser, and bubble generation is caused by the two-photon absorption compound being excited by two-photon absorption. It is clear that this happens by generating. Further, it was confirmed that by scanning the laser focus position in the horizontal and depth directions, foaming can be performed at an arbitrary place in the three-dimensional direction, and three-dimensional refractive index modulation and absorptance modulation are possible.

  The two-photon absorption compounds are D-5, D-22, D-41, D-56, D-58, D-73, D-75, D-77, D-117, D-118, D-123. , D-132, D-176, the foamable compound is changed to A-1, A-3, A-6, A-7, A-9, A-12, A-13, A-15, Even if it changed to A-18, it confirmed that it could foam similarly. Further, it was confirmed that foaming was possible even when the binder was changed to polymethyl methacrylate, polyvinyl acetate, cellulose acetate butyrate, polystyrene or the like.

Claims (13)

  The two-photon absorption compound has at least a two-photon absorption compound, a gas is generated with the two-photon absorption of the two-photon absorption compound, and a foam is formed in the two-photon absorption foam material. Irradiation with laser light having a long wavelength and no linear absorption causes foaming due to gas generation using two-photon absorption induced in the laser focus part (recording part), and non-focus part (non-recording part) A three-dimensional optical recording medium recording method, wherein a three-dimensional refractive index modulation by a change in refractive index with a non-foamed portion is used for recording.   The two-photon absorption compound has at least a two-photon absorption compound, a gas is generated with the two-photon absorption of the two-photon absorption compound, and a foam is formed in the two-photon absorption foam material. Irradiation with laser light having a long wavelength and no linear absorption causes foaming due to gas generation using two-photon absorption induced in the laser focus part (recording part), and non-focus part (non-recording part) A three-dimensional optical recording medium recording method, wherein three-dimensional absorptance modulation due to a change in optical absorptance with a non-foamed portion is used for recording. 2. The reproducing method according to claim 1, wherein the three-dimensional optical recording medium that has been recorded with bubbles is irradiated with light and the difference in reflectance between the recording part and the non-recording part is detected. A method for reproducing a three-dimensional optical recording medium. 3. The method of claim 1 , wherein the laser or the pulse shape is the same or different from the laser used during recording, but the same laser is used to irradiate the recorded three-dimensional optical recording medium with bubbles. A method for reproducing a three-dimensional optical recording medium, wherein reproduction is performed by detecting a difference in reflectance between a recording unit and a non-recording unit. 3. A three-dimensional optical recording medium recording method according to claim 2 , wherein reproduction is performed by irradiating light onto a three-dimensional optical recording medium that has been recorded with bubbles, and detecting a difference in the light absorption rate between the recording unit and the non-recording unit. A method for reproducing a three-dimensional optical recording medium. 3. In the three-dimensional optical recording medium recording method according to claim 2 , although the power or pulse shape is the same as or different from the laser used during recording, the same laser is used to irradiate the recorded three-dimensional optical recording medium with bubbles. A method for reproducing a three-dimensional optical recording medium, wherein reproduction is performed based on a difference in light absorption between the recording unit and the non-recording unit. The method according to any one of claims 1 to 6, the two-photon absorbing compound and having a foaming site. The two-photon absorbing foam material, apart from the two-photon absorption compound, a method according to any one of claims 1 to 6, characterized in that it has a foaming compound. The method according to any one of claims 1 to 8, the gas is characterized in that either _{N 2, CO 2, SO 2} , SO 3, NO 2, O 2 and i-C ₄ H _8. The method according to any one of claims 7 to 9, effervescent site or effervescent compound of claim 8 according to claim 7, characterized by being represented by the following general formula (11) or (12).

In general formula (11), R ²¹ and R ²² each independently represent a hydrogen atom or a substituent, and G represents —N═N—, —C (O) —, —OC (O) —, —OS (O )-, -S (O) _2- , -OS (O) _2- . R ²¹ and R ²² may combine to form a ring.
When the general formula (11) indicates a foaming site, it is linked to the two-photon absorption compound by either a covalent bond, an ionic bond, or a coordinate bond at either or both of R ^{21 and} R ²² .
In the general formula (12), R ²³ represents an aryl group or a heterocyclic group, and X ¹¹ represents an anion.
In the case where the general formula (12) represents an effervescent site, R ²³ is linked to the two-photon absorption compound by any of a covalent bond, an ionic bond and a coordination bond, or X ¹¹ is an anionic two-photon absorption compound It is. The method according to any one of claims 1 to 10, the two-photon absorbing compound characterized in that it is a methine dye or a phthalocyanine dye. The method according to any one of claims 1 to 11 , wherein the size of bubbles to be generated is in the range of 50 nm to 5 µm. The method according to any one of claims 1 to 12, the gas bubbles, characterized in that occur in a reaction that does not depend on thermal decomposition.