JP4963367B2 - Two-photon absorption material - Google Patents

Description

  The present invention relates to a two-photon absorption material, and to a two-photon absorption monomolecular material or a polymer material having a high two-photon absorption cross section.

A two-photon absorption material is a material that can excite molecules at wavelengths in the non-resonant region, and at this time, a material that has an actual excited state at twice the energy level of the photon used for excitation. It is.
By the way, the two-photon absorption phenomenon is a kind of third-order nonlinear optical effect, which is a phenomenon in which a molecule absorbs two photons simultaneously and transitions from a ground state to an excited state. Since Luc Bredas et al. Elucidated the relationship between molecular structure and mechanism in 1998 (Science, 281, 1653 (1998)), in recent years, research on materials having two-photon absorption ability has advanced.

  However, the transition efficiency of such two-photon simultaneous absorption is extremely low compared with one-photon absorption and requires extremely high power density photons. It has been confirmed that an ultra-short pulse laser of about femtosecond such as a mode-locked laser having high intensity (light intensity at the maximum emission wavelength) is used.

  The transition efficiency of two-photon absorption is proportional to the square of the applied photoelectric field (the two-photon absorption square characteristic). For this reason, when a laser is irradiated, two-photon absorption occurs only at a position where the electric field strength is high at the center of the laser spot, and no two-photon absorption occurs at a portion where the electric field strength is weak at the peripheral portion. In the three-dimensional space, two-photon absorption occurs only in a 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 to the linear absorption of one photon where excitation occurs at all positions in proportion to the intensity of the applied photoelectric field, the two-photon absorption is excited only at a pinpoint inside the space due to this square characteristic. Therefore, the spatial resolution is significantly improved.

  Utilizing this characteristic, research on a three-dimensional memory for recording bit data by causing a spectral change, a refractive index change or a polarization change by two-photon absorption at a predetermined position of a recording medium is underway. Since two-photon absorption occurs in proportion to the square of the intensity of light, a memory using two-photon absorption can reduce the spot size compared to a memory using one-photon absorption, and super-resolution recording. Is possible. In addition, from the characteristics of high spatial resolution derived from this square characteristic, development for applications such as a light limiting material, a cured material of a photo-curing resin for stereolithography, and a fluorescent dye material for a two-photon fluorescence microscope is being promoted.

  Furthermore, in the case of inducing two-photon absorption, it is possible to use a short-pulse laser in the near-infrared region that has a longer wavelength than the wavelength region in which the linear absorption band of the compound exists and does not have absorption. Since the near-infrared light of the so-called transparent region, which does not have a linear absorption band of the compound, is used, the excitation light can reach the inside of the sample without being absorbed or scattered, and because of the square characteristic of the two-photon absorption, Since pinpoints can be excited with high spatial resolution, two-photon absorption and two-photon emission are also expected in photochemotherapy applications such as two-photon contrast and two-photon photodynamic therapy (PDT) in biological tissues. In addition, research on upconversion lasing has been reported from the viewpoint of a wavelength conversion device because photons with higher energy than the energy of incident photons can be extracted by using two-photon absorption and two-photon emission.

  Many inorganic materials have been found so far as two-photon absorption materials. However, inorganic materials are very difficult to put into practical use because so-called molecular design for optimizing desired two-photon absorption characteristics and various physical properties necessary for device manufacture is difficult. On the other hand, organic compounds can be optimized not only for the desired two-photon absorption by molecular design, but also for other physical properties, making it highly practical and a promising two-photon absorption material. It attracts attention.

As conventional organic two-photon absorption materials, pigment compounds such as rhodamine and coumarin, compounds such as dithienothiophene derivatives and oligophenylene vinylene derivatives are known. However, the two-photon absorption cross-section showing the two-photon absorption capacity per molecule is small, and the two-photon absorption cross-section particularly when a femtosecond pulse laser is used is 200 (GM: × 10 ⁻⁵⁰ cm ⁴ · s · molecule Most of those less than ⁻¹ · photon ⁻¹ ) have not yet been put into practical use.

  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, the conventional two-dimensional optical recording medium such as DVD ± R is about 25 GB at most even if the recording / reproducing wavelength is shortened on the physical principle, and the recording is large enough to meet future requirements. 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 absorbing 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 absorption material, a method of reading with fluorescence using a fluorescent substance for recording and reproduction (see Patent Document 1 and Patent Document 2), a method of reading with absorption or fluorescence using a photochromic compound (See Patent Document 3 and Patent Document 4) and the like, but no specific two-photon absorption materials are presented, and examples of two-photon absorption compounds presented abstractly are also two-photon absorption. A two-photon absorption compound with extremely low efficiency is used.

Further, since the photochromic compounds used in these patent documents are reversible materials, there are problems in non-destructive reading, long-term storage stability of recording, S / N ratio of reproduction, and the like, a method that is practical as an optical recording medium I can't say that. In particular, in terms of non-destructive readout, long-term storage stability of recording, etc., it is preferable to reproduce by changing the reflectance (refractive index or absorption rate) or emission intensity using an irreversible material. There was no example that specifically disclosed the absorbent material.
Patent Document 5 and Patent Document 6 disclose a recording apparatus, a reproducing apparatus, a reading method, and the like that perform three-dimensional recording by refractive index modulation, but use a two-photon absorption three-dimensional optical recording material. There is no description of the method.

However, the prior art has the following problems.
1) Utilizing the two-photon absorption phenomenon enables various applications characterized by extremely high spatial resolution, but the two-photon absorption compounds available at the present time have a low two-photon absorption capability, and thus induce two-photon absorption. As an excitation light source, an expensive very high-power laser is required. Therefore, in order to realize a practical application using two-photon absorption using a small and inexpensive laser, development of a highly efficient two-photon absorption material is essential.
2) When the two-photon absorbing material is used as a solid, it has been used by dispersing in a polymer. However, there has been a problem that the quality changes due to the occurrence of coating film defects due to crystallization of the two-photon absorption material or segregation due to migration during long-term storage.

  As described above, the reaction is caused using the excitation energy obtained by non-resonant two-photon absorption, and as a result, the emission intensity when the laser focus (recording) part and the non-focus (non-recording) part are irradiated with light is determined. If modulation is possible with a method that cannot be rewritten, light emission intensity modulation can be generated at an arbitrary place in three-dimensional space with extremely high spatial resolution, and it can be applied to a three-dimensional optical recording medium that is considered to be the ultimate high-density recording medium. It becomes 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.

  However, the currently available two-photon absorption compounds have a low two-photon absorption capability, so that a very high-power laser is required as a light source and a long recording time is required. Especially for use in three-dimensional optical recording media, construction of a two-photon absorption three-dimensional optical recording material that can perform recording with two-photon absorption with high sensitivity to achieve a fast transfer rate. Is essential. For that purpose, the difference between the two-photon absorption compound that can absorb two-photons with high efficiency and generate an excited state, and the two-photon absorption optical recording material using a two-photon absorption compound excited state in some way. Although a material containing a recording component that can efficiently form a thin film is effective, such a material has hardly been disclosed so far, and it has been desired to construct such a material.

Special Table 2001-524245 (Levic, Eugene, Police, etc.) Special Table 2000-520206 (Pavel, Eugene et al.) Special Table 2001-522119 (Korotif, Nikolai Eye, etc.) Special Table 2001-508221 (Arsenoff, Vladimir, etc.) Japanese Patent Laid-Open No. 6-28672 (Kawada Akira, Kawada Yoshimasa) Japanese Patent Laid-Open No. 6-118306 (Akira Kawada, Yoshimasa Kawada, etc.)

The purpose of the present invention is to
1) An organic material that efficiently absorbs two-photons, that is, an organic material having a large two-photon absorption cross-section, that realizes a change in spectrum, refractive index, or polarization state with high sensitivity.
2) To provide an organic material having a stable quality with a large two-photon absorption cross section in which coating film defects (crystallization, migration) do not occur even during long-term storage.
An object of the present invention is to have at least a two-photon absorption compound having a large two-photon absorption cross-section, perform recording in a method that cannot be rewritten using two-photon absorption of the two-photon absorption compound, and then irradiate the recording material with light. Thus, the present invention provides a two-photon absorption three-dimensional optical recording material using a two-photon absorption optical recording material which is reproduced by detecting the difference in emission intensity.

As a result of intensive studies, the present inventors have found that the above problems can be solved by an arylamine compound containing a specific structural unit and a polymer thereof, and have reached the present invention.
That is, the present invention is a two-photon absorption material as described below.

( 1 ) A two-photon absorption material represented by the following general formula (III).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of thiophene, biphenyl, fluorene or anthracene,
Ar ₅ and Ar ₆ are each independently a substituted or unsubstituted aromatic hydrocarbon group,
x and y are integers of 1 or more and 4 or less, z is an integer of 1 or more and 5 or less,
R ₁ and R ₂ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group,
R ₃ is a hydrogen group, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, or a substituted or unsubstituted aryl group,
And, wherein x, the case y and the z is 2 or more, represented by a plurality of said R _1, said R ₂ and said R ₃ is independently (2) the following general formula (IV) Two-photon absorption material.

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
Ar ₅ and Ar ₆ are each independently a substituted or unsubstituted aromatic hydrocarbon group,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. And
And wherein v, the w, the x and the case y is 2 or more, a plurality of said ^{R 1,} said _{R 2,} wherein _{R 4} and wherein _{R 5} is two-photon absorption materials are independent.
( 3 ) A two-photon absorption material represented by the following general formula (V).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
Ar ₅ and Ar ₆ are each independently a substituted or unsubstituted aromatic hydrocarbon group,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ and R ₅ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group or a substituted or unsubstituted alkylthio group,
And wherein v, the w, the x and the case y is 2 or more, a plurality of said ^{R 1,} said _{R 2,} wherein _{R 4} and wherein _{R 5} is two-photon absorption materials are independent.

( 4 ) A two-photon absorption material comprising a polymer having a repeating unit represented by the following general formula (VIII).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
x and y are integers of 1 or more and 4 or less, z is an integer of 1 or more and 5 or less,
R ₁ and R ₂ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group,
R ₃ is a hydrogen group, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, or a substituted or unsubstituted aryl group,
When x, y, and z are 2 or more, the plurality of R ₁ , R _2, and R ₃ are independent of each other. )
( 5 ) A two-photon absorption material comprising a polymer having a repeating unit represented by the following general formula (IX).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. And
When v, w, x, and y are 2 or more, a plurality of R ₁ , R ₂ , R _4, and R ₅ are independent of each other. )
( 6 ) A two-photon absorption material comprising a polymer having a repeating unit represented by the following general formula (X).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ and R ₅ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group or a substituted or unsubstituted alkylthio group,
And wherein v, the w, the x and the case y is 2 or more, a plurality of the _{R 1,} before Symbol _{R 2,} wherein _{R 4} and wherein _{R 5} is two-photon absorption materials are independent.
( 7 ) A three-dimensional memory material comprising the two-photon absorption material according to any one of (1) to ( 6 ).
( 8 ) An optical limiting material comprising the two-photon absorption material according to any one of (1) to ( 6 ).
( 9 ) A photocurable resin curable material for photofabrication, comprising the two-photon absorbing material according to any one of (1) to ( 6 ).
( 10 ) A fluorescent dye material for a two-photon fluorescence microscope comprising the two-photon absorption material according to any one of (1) to ( 6 ).

1) Realization of a two-photon absorption compound with high photon absorption transition efficiency, practical use using a small and inexpensive laser (three-dimensional memory material, light limiting material, photocuring resin curing material for photofabrication, photochemotherapy Material, fluorescent dye material for two-photon fluorescence microscope, etc.) can be realized.
2) By using a two-photon absorption polymer in which sites having two-photon absorption ability are connected, coating film defects do not occur even during long-term storage, and stable quality can be obtained.

First, the two-photon absorption material of the present invention will be described.
The two-photon absorption material of the present invention has the structure of the arylamine compound represented by the general formulas (I) to (V) as a basic structure, and this structure can efficiently absorb two-photons.
Moreover, the two-photon absorption material of the present invention can be preferably used in the form of a polymer having a repeating unit represented by the general formulas (V) to (X).
Therefore, hereinafter, a method for producing an arylamine-based two-photon absorption polymer will be described.
The production method of the two-photon absorption polymer of the present invention includes, for example, Wittig-Horner reaction using aldehyde and phosphonate, Wittig reaction using aldehyde and phosphonium salt, Heck reaction using vinyl substituent and halide, amine and halogen The Ullmann reaction using a compound can be used, and can be produced by a known method. In particular, the Wittig-Horner reaction and the Wittig reaction are effective because of the simplicity of the reaction operation.

As an example, a method for producing a polymer in the present invention using a Wittig-Horner reaction will be described.
As shown in the following reaction formula, the polymer in the present invention is polymerized by mixing a solution in which the phosphonate ester compound and the aldehyde compound are present stoichiometrically and a base more than twice the molar amount thereof. The reaction proceeds and can be obtained.
In the case of producing the two-photon absorption polymer of the present invention, for example, a monomer having a combination of an arylamine moiety as A and an Ar ⁴ as B, or a monomer having a combination of Ar ⁴ as A and an arylamine moiety as B is used. May be used.

  The dialdehyde compound can be synthesized by various known reactions. For example, the following Vilsmeier reaction,

  Alternatively, a reaction between an aryllithium compound and a formylating agent such as DMF, N-formylmorpholine, N-formylpiperidine,

  Alternatively, the following Gatterman reaction,

  Alternatively, various oxidation reactions of hydroxymethyl compounds,

These reactions can be used to synthesize dialdehyde compounds.
The phosphonic acid diester compound can also be synthesized by various known reactions, but the following Michaelis-Arbuzov reaction is particularly easy.

  The base used in the above reaction is not particularly limited as long as a phosphonate carbanion is formed, and examples thereof include metal alkoxides, metal hydrides, and organic lithium compounds, such as potassium t-butoxide, sodium t-butoxide, lithium t. -Butoxide, potassium 2-methyl-2-butoxide, sodium 2-methyl-2-butoxide, sodium methoxide, sodium ethoxide, potassium ethoxide, potassium methoxide, sodium hydride, potassium hydride, methyllithium, ethyllithium Propyl lithium, n-butyl lithium, s-butyl lithium, t-butyl lithium, phenyl lithium, lithium naphthylide, lithium amide, lithium diisopropylamide and the like.

The amount of the base used in the reaction is usually only the same amount as the polymerization active point of the phosphonate ester compound, but an excessive amount can be used.
The above base may be added to the reaction system in a solid state or a suspension solution. However, it is particularly preferable to add the base as a homogeneous solution in order to improve the homogeneity of the resulting polymer. As the solvent for dissolving the base, a solvent that forms a stable solution with the base to be used must be selected, but as other factors, those having a high solubility of the base are preferable, and the high molecular weight product produced in the reaction system is also preferred. Those that do not impair the solubility in the reaction solvent are good. Further, the solvent in which the high molecular weight product to be formed dissolves well is good. Depending on the characteristics of the base used and the high molecular weight to be produced, generally known alcohols and ethers are used. It can be arbitrarily selected from a system, an amine system, a hydrocarbon solvent and the like.

  Examples of a combination of a base and a solvent for uniformly dissolving the base include, for example, a methanol solution of sodium methoxide, an ethanol solution of sodium ethoxide, a 2-propanol solution of potassium t-butoxide, and 2-methyl-2-methyl ester of potassium t-butoxide. Propanol solution, potassium t-butoxide in tetrahydrofuran, potassium t-butoxide in dioxane, n-butyllithium in hexane, methyllithium in ether, lithium t-butoxide in tetrahydrofuran, lithium diisopropylamide in cyclohexane, potassium bis There are various combinations of solutions including a toluene solution of trimethylsilylamide and the like, and some solutions are easily available as commercial products. From the viewpoint of mild reaction conditions and ease of handling, a metal alkoxide-based solution is preferably used, such as solubility of the polymer to be produced, ease of handling, efficiency of the reaction, solubility of the polymer to be produced, etc. From the viewpoint, an ether-based solution of metal t-butoxide is preferably used, and a tetrahydrofuran solution of potassium t-butoxide is more preferably used.

In the polymerization reaction, a base solution may be added to the solution of the phosphonate ester compound and the aldehyde compound, a solution of the phosphonate ester compound and the aldehyde compound may be added to the base solution, and may be added to the reaction system at the same time. There is no restriction on the order of addition.
The polymerization time in the above polymerization reaction may be appropriately set according to the reactivity of the monomers used or the molecular weight of the desired polymer, but is preferably 0.2 hours to 30 hours.
The reaction temperature in the above polymerization reaction does not need to be controlled and the polymerization reaction proceeds favorably at room temperature. However, it is possible to heat or cool to raise the reaction efficiency to a milder condition.
Moreover, it is also possible to add a molecular weight regulator in order to adjust the molecular weight in the above polymerization operation, or a sealing agent for sealing the end of the polymer as a terminal modifying group to the reaction system during the reaction, It can also be added at the start of the reaction. Therefore, a substituent based on a terminator may be bonded to the terminal of the arylamine polymer in the present invention.
Examples of the molecular weight regulator and terminal blocking agent include compounds having one reactive group such as diethyl benzylphosphonate and benzaldehyde.

The preferred molecular weight of the polymer of the present invention is 1,000 to 1,000,000, more preferably 2000 to 500,000 in terms of polystyrene-reduced number average molecular weight. When the molecular weight is too small, the film forming property such as the generation of cracks is deteriorated and the practicality becomes poor. On the other hand, when the molecular weight is too large, the solubility in a general organic solvent is deteriorated, the viscosity of the solution becomes high and the coating becomes difficult, which also causes a problem in practical use.
Also, a small amount of a branching agent can be added during the polymerization in order to improve the mechanical properties. The branching agent used is a compound having three or more polymerization reaction active groups (which may be the same or different). These branching agents may be used alone or in combination.

  The arylamine polymer obtained as described above is used after removing impurities such as the base used in the polymerization, unreacted monomer, terminal terminator, and inorganic salts generated during the polymerization. For these purification operations, conventionally known methods such as reprecipitation, extraction, Soxhlet extraction, ultrafiltration, dialysis and the like can be used.

Next, the two-photon absorbing compounds (I) to (V) and the repeating units (VI) to (X) of the polymer of the present invention will be described in detail.
In the present invention, the “aromatic hydrocarbon group” is referred to as a general term for a group of compounds having a benzene nucleus.
The substituted or unsubstituted aromatic hydrocarbon group Ar ^{1 in the} general formulas (I) and (VI) may be either a monocyclic group or a polycyclic group (a condensed polycyclic group or a non-condensed polycyclic group). The following can be mentioned.
Examples thereof include a phenyl group, a naphthyl group, a pyrenyl group, a fluorenyl group, an azulenyl group, an anthryl group, a triphenylenyl group, a chrycenyl group, a biphenyl group, and a terphenyl group. Examples of the divalent groups Ar ² and Ar ³ of the substituted or unsubstituted aromatic hydrocarbon group in the general formula (VI) include the divalent groups of the above substituted or unsubstituted aromatic hydrocarbon group. .

In addition, these groups having a cyclic structure (Ar ¹ , Ar ² , Ar ³ and Ar ⁴ ) may have various substituents as follows.
(1) Halogen atom, trifluoromethyl group, cyano group, nitro group.
(2) A linear or branched alkyl group or alkoxy group having 1 to 25 carbon atoms. These may be further substituted with a halogen atom, a cyano group, a phenyl group, a hydroxyl group, a carboxyl group, an alkoxy group, or an alkylthio group.
(3) Aryloxy group. (Examples include aryloxy groups having a phenyl group or a naphthyl group as the aryl group. These may contain a halogen atom as a substituent, and may be a linear or branched alkyl group or alkoxy having 1 to 25 carbon atoms. A phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methylphenoxy group, a 4-methoxyphenoxy group, and a 4-chlorophenoxy group. , 6-methyl-2-naphthyloxy group, etc.)
(4) An alkylthio group or an arylthio group. (Specific examples of the alkylthio group or arylthio group include a methylthio group, an ethylthio group, a phenylthio group, and a p-methylphenylthio group.)
(5) An alkyl-substituted amino group. (Specifically, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (p-tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And a urolidyl group.)
(6) Acyl group. (Specific examples of the acyl group include an acetyl group, a propionyl group, a butyryl group, a malonyl group, and a benzoyl group.)

  The two-photon absorbing compounds (I) to (V) and the polymers (VI) to (X) of the present invention are substituted with a halogen atom, a substituted or unsubstituted alkyl group, an alkoxy group or an alkylthio group on the aromatic ring. From the viewpoint of improving the solubility in a solvent, it preferably has a substituted or unsubstituted alkyl group, alkoxy group, or alkylthio group. If the number of carbons of these substituents increases, the solubility will be improved, but on the other hand, the properties such as charge transportability will decrease, so that the desired properties can be obtained within the range where the solubility is not impaired. It is preferred to select a substituent. Examples of suitable substituents in that case include alkyl groups, alkoxy groups and alkylthio groups having 1 to 25 carbon atoms. A plurality of the same substituents may be introduced, or a plurality of different substituents may be introduced. In addition, these alkyl groups, alkoxy groups and alkylthio groups are further halogen atoms, cyano groups, aryl groups, hydroxyl groups, carboxyl groups, linear, branched or cyclic alkyl groups having 1 to 12 carbon atoms, alkoxy groups or An aryl group substituted with an alkylthio group may be contained.

  Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, pentyl group, hexyl group, Heptyl, octyl, nonyl, decyl, 3,7-dimethyloctyl, 2-ethylhexyl, trifluoromethyl, 2-cyanoethyl, benzyl, 4-chlorobenzyl, 4-methylbenzyl, A cyclopentyl group, a cyclohexyl group, etc. can be mentioned as an example, As an alkoxy group and an alkylthio group, what made the alkoxy group and the alkylthio group by inserting an oxygen atom or a sulfur atom in the bond position of the said alkyl group is mentioned as an example. .

The two-photon absorption material of the present invention can be applied to various devices by itself or in a thin film mixed with various resins, or in bulk.
For example, in an optical disc, the thin film is in contact with a substrate, and the substrate material is polyethylene terephthalate, polycarbonate, polymethyl methacrylate, polyester, polyvinyl alcohol, glass or the like. In the case of stacking, the surface of the thin film is in contact with the intermediate layer (partition layer). Specific examples of the intermediate layer include polyolefins such as polypropylene and polyethylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, plastic films such as polyethylene terephthalate or cellophane film, and various photo-curing resins.
Next, even when applied to various optical devices and optical modeling devices, they are mixed with various resins or mixed with a photocurable resin.
Accordingly, the use requirement of the two-photon absorption material of the present invention is that the material is mixed with various resins or glass, or the interface of the two-photon absorption material layer is in contact with various resins or glass.
In other words, the two-photon absorption material of the present invention is in contact with various resins or glass at the micro level or the macro level.

(Application to three-dimensional multilayer optical memory using two-photon absorption material)
The two-photon absorption material of the present invention can be applied directly on the substrate by using a spin coater, roll coater or bar coater, or can be cast as a film and laminated on the substrate by a usual method. Thus, a two-photon absorption optical recording material can be obtained.
Here, “substrate” means any natural or synthetic support, preferably one that can exist in the form of a flexible or rigid film, sheet or plate.

Preferred examples of the substrate include polyethylene terephthalate, resin-primed polyethylene terephthalate, polyethylene terephthalate subjected to flame or electrostatic discharge treatment, cellulose acetate, polycarbonate, polymethyl methacrylate, polyester, polyvinyl alcohol, and glass. The substrate may be provided with a guide groove for tracking and address information in advance.
The solvent used can be removed by evaporation during drying. Heating or reduced pressure may be used for evaporation removal.

  Furthermore, a protective layer (intermediate layer) for blocking oxygen and preventing interlayer crosstalk may be formed on the two-photon absorption optical recording material. The protective layer (intermediate layer) is made of a plastic film or plate such as polypropylene, polyethylene, polyolefins such as polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyethylene terephthalate or cellophane film. Alternatively, the layers may be laminated together or the polymer solution may be applied. Further, a glass plate may be bonded. Further, an adhesive or a liquid substance may be present between the protective layer and the photosensitive film and / or between the base material and the photosensitive film in order to improve airtightness. Further, the protective layer (intermediate layer) between the photosensitive films may be provided with tracking guide grooves and address information in advance.

By focusing on an arbitrary layer of the above-described three-dimensional multilayer optical recording medium and performing recording and reproduction, it functions as the three-dimensional memory material of the present invention. Further, even if the layers are not separated by a protective layer (intermediate layer), three-dimensional recording in the depth direction is possible from the two-photon absorption dye characteristics.
Hereinafter, preferred embodiments (specific examples) of the three-dimensional multilayer optical memory will be described. However, the present invention is not limited to these embodiments, and any structure capable of three-dimensional recording (recording in a plane and a film thickness direction) can be used. Any other structure may be used. A schematic diagram of the recording / reproducing system of the three-dimensional multilayer optical memory is shown in FIG.

  In the recording medium (b) in the figure, a recording layer using the two-photon absorption compound of the present invention on a flat support (substrate 1) and an intermediate layer (protective layer) for preventing crosstalk are alternately 50 layers. Each layer is laminated, and each layer is formed by spin coating. The thickness of the recording layer is preferably 0.01 to 0.5 μm, and the thickness of the intermediate layer is preferably 0.1 μm to 5 μm. With this structure, the disk size is the same as the currently popular CD / DVD, and the terabyte class Can be realized. Further, a substrate 2 (protective layer) similar to the substrate 1 or a reflective layer made of a highly reflective material is formed by a data reproduction method (transmission / or reflection type).

A single beam is used at the time of recording, and in this case, ultrashort pulse light of femtosecond order can be used. At the time of reproduction, it is also possible to use light having a wavelength different from that of the beam used for data recording or light of the same wavelength with low output. Recording and playback can be performed in either bit units or page units, and parallel recording / playback using a surface light source, a two-dimensional detector, or the like is effective in increasing the transfer rate.
Note that a three-dimensional multilayer optical memory similarly formed according to the present invention may have a card shape, a plate shape, a tape shape, a drum shape, or the like.

(Application to optical limiting element using two-photon absorption material)
In optical communication and optical information processing, optical control such as modulation and switching is required to carry signals such as information with light. For this type of light control, an electro-light control method using an electric signal has been conventionally employed. However, the electro-optical control method has limitations such as a band limitation due to a CR time constant as in an electric circuit, a processing speed being limited due to a response speed of the element itself and a speed mismatch between an electric signal and an optical signal. In order to make full use of the broadband and high speed, which are the advantages of light, light-light control technology for controlling an optical signal with an optical signal becomes very important. An optical element manufactured by processing the two-photon absorption material of the present invention in response to this requirement utilizes an optical change such as transmittance, refractive index, absorption coefficient, etc. caused by irradiating light, and an electronic circuit. By modulating the intensity and frequency of light without using technology, it can be applied to optical switches in optical communications, optical exchange, optical computers, optical interconnections, and the like.

The optical limiting element that utilizes the optical characteristic change of the two-photon absorption material of the present invention that utilizes the optical characteristic change due to two-photon absorption is compared to the optical limiting element formed by a normal semiconductor material or one-photon excitation. An element with much higher response speed can be provided. Further, because of the high sensitivity, it is possible to provide an optical limiting element excellent in signal characteristics with a high S / N ratio.
FIG. 2 is an example of a light control element that optically switches a signal light having a wavelength that can be excited by one photon by exciting the two-photon absorbing material of the present invention with a control light having a wavelength that can be excited by two photons. . Although the form of the two-photon absorption material sandwiched between the protective layers is shown, this configuration does not limit the present invention.

  JP-A-8-320422 is cited as a known document of the light limiting element in the present invention. According to this, it is disclosed as an optical waveguide which forms a refractive index distribution by irradiating a light refractive index material whose refractive index changes with light irradiation with light having a wavelength whose refractive index changes. That is, a solid material dispersed in a material having a high two-photon absorption ability, a thin film, or a photocurable resin according to the present invention is arranged as an optical element, and is excited to an excited state by light of one wavelength (λ1). Further, by being excited from the state to the other state by the light of other wavelength (λ2), it is possible to design the optical waveguide using the refractive index change distribution according to the wavelength. Many of the two-photon absorption materials have fluorescence, and a fluorescent substance is arranged at one of the emission ends of the optical device or in the vicinity thereof, and excitation light (λ1) is emitted from the other, and excitation light and fluorescence ( A refractive index profile can also be formed by λ2). In this case, since the fluorescence is usually weaker than the excitation light, it is desirable to increase the sensitivity at the fluorescence wavelength. Examples of the fluorescent substance include those in which a fluorescent dye is dispersed in a photocurable substance.

(Application to stereolithography materials)
A schematic diagram of a two-photon stereolithography apparatus is shown in FIG. 3 and described below.
After passing the light from the near-infrared pulse laser light source 1 through the mirror scanner 5, it is condensed in the photocurable resin 9 using a lens, scanned with a laser spot, and induced near the focal point by inducing two-photon absorption. Is a two-photon micro stereolithography method in which the resin is cured to form an arbitrary three-dimensional structure.

  The pulsed laser beam is condensed by a lens, and a region with high photon density is formed in the vicinity of the focal point. At this time, since the total number of photons passing through each cross section of the beam is constant, when the beam is scanned two-dimensionally within the focal plane, the total light intensity in each cross section is constant. However, since the probability of occurrence of two-photon absorption is proportional to the square of the light intensity, a region where the generation of two-photon absorption is high is formed only near the condensing point where the light intensity is high. Thus, by condensing the pulsed laser light with the lens and inducing two-photon absorption, it is possible to limit the light absorption near the condensing point and to cure the resin in a pinpoint manner. Since the condensing point can be freely moved in the photocurable resin liquid by the Z stage 6 and the galvanometer mirror, a desired three-dimensional workpiece can be freely formed in the photocurable resin liquid.

The features of the two-photon stereolithography include the following items.
1) Processing resolution exceeding the diffraction limit: Processing resolution exceeding the diffraction limit of light can be realized by the nonlinearity of the two-photon absorption with respect to the light intensity.
2) Ultra-high speed modeling: When two-photon absorption is used, the photocurable resin does not cure in principle in the region other than the focal point. For this reason, the light intensity to be irradiated can be increased, and the beam scanning speed can be increased. For this reason, modeling speed can be improved about 10 times.
3) Three-dimensional processing: The photocurable resin is transparent to near-infrared light that induces two-photon absorption. Therefore, even when the focused light is condensed deeply into the resin, internal curing is possible. In the conventional SIH, when the beam is condensed deeply, the light intensity at the condensing point is reduced by light absorption, and the internal curing becomes difficult. In the present invention, these problems can be solved reliably. .
4) High yield: In the conventional method, there is a problem that the molded object is damaged or deformed due to the viscosity or surface tension of the resin. However, in this method, the problem is solved because the modeling is performed inside the resin.
5) Application to mass production: By using ultra-high speed modeling, it is possible to manufacture a large number of parts or movable mechanisms continuously in a short time.

  The photocurable resin for two-photon stereolithography is a resin having a characteristic of causing a two-photon polymerization reaction when irradiated with light and changing from a liquid to a solid. The main components are a resin component composed of an oligomer and a reactive diluent and a photopolymerization initiator (including a photosensitizing material as required). An oligomer is a polymer having a degree of polymerization of about 2 to 20, and has a large number of reactive groups at its ends. Further, a reactive diluent is added to adjust the viscosity, curability and the like. When irradiated with light, the polymerization initiator or photosensitizing material absorbs this two-photon, and a reactive species is generated directly from the polymerization initiator or through the photosensitizing material, to the reactive group of the oligomer or reactive diluent. React and initiate polymerization. Thereafter, a chain polymerization reaction takes place between them to form a three-dimensional cross-link, and in a short time, a solid resin having a three-dimensional network structure is formed.

  Photocurable resins are used in fields such as photocurable inks, photoadhesives, and layered three-dimensional modeling, and resins having various characteristics have been developed. In particular, in the layered three-dimensional modeling, (1) good reactivity, (2) small deposition shrinkage during curing, (3) excellent mechanical properties after curing, etc. are important. . These characteristics are equally important in this method. Therefore, resins developed for layered three-dimensional modeling that have two-photon absorption characteristics are also used as photocurable resins for two-photon photofabrication in this method. it can. As specific examples, acrylate-based and epoxy-based photocurable resins are often used, and urethane acrylate-based photocurable resins are particularly preferable.

  JP-A-2005-134873 can be cited as a publicly known document relating to optical modeling in the present invention. According to this, pulsed laser light is subjected to interference exposure on the surface of the photosensitive polymer film without passing through a mask. It is important that the pulsed laser beam is a pulsed laser beam in a wavelength region that allows the photosensitive polymer film to exhibit a photosensitive function. Therefore, the wavelength region of the pulsed laser light can be appropriately selected according to the type of the photosensitive polymer or the type of group or site that exhibits the photosensitive function in the photosensitive polymer. In particular, even if the wavelength of the pulsed laser light emitted from the light source is not in a wavelength region that causes the photosensitive polymer film to exhibit a photosensitive function, by utilizing a multiphoton absorption process upon irradiation with the pulsed laser light, The photosensitive polymer film can exhibit a photosensitive function.

  Specifically, when the pulsed laser light emitted from the light source is condensed and irradiated with the condensed pulsed laser light, multiphoton absorption (for example, two-photon absorption, three-photon absorption, four-photon absorption, Photosensitive polymer film even if the wavelength of the pulsed laser light emitted from the light source is not in a wavelength region that causes the photosensitive polymer film to perform a photosensitive function. Is substantially irradiated with a pulsed laser beam in a wavelength region that causes the photosensitive polymer film to exhibit a photosensitive function. As described above, the pulsed laser beam for the interference exposure may be substantially a pulsed laser beam in a wavelength region that causes the photosensitive polymer film to exhibit the photosensitive function, and the wavelength is appropriately selected depending on the irradiation conditions. can do. For example, the high-efficiency two-photon absorbing material of the present invention is used as a photosensitizing material, dispersed in an ultraviolet curable resin, etc., and a photosensitive solid, and only the focal spot is cured using the two-photon absorption ability of the photosensitive solid. It is possible to obtain an ultra-precise three-dimensional structure using

  The two-photon absorption material of the present invention can be used as a two-photon absorption polymerization initiator or a two-photon absorption photosensitizer. Compared to conventional two-photon absorption materials (two-photon absorption polymerization initiators or two-photon absorption photosensitizers), the two-photon absorption sensitivity is high, so high-speed modeling is possible, and the laser light source is small and inexpensive as an excitation light source. Can be used for practical applications that can be mass-produced.

(Application to two-photon fluorescence microscope using two-photon absorption material)
A two (multi) photon excitation laser scanning microscope collects and scans a near-infrared pulse laser on the sample surface, and detects fluorescence generated by excitation by two (multi) photon absorption there. It is a microscope to obtain
A schematic diagram of the basic configuration of the two-photon excitation laser scanning microscope is shown in FIG.
A laser light source 1 that emits a sub-picosecond monochromatic coherent light pulse having a near-infrared wavelength, a light beam conversion optical system 2 that changes a light beam from the laser light source to a desired size, and a light beam converted by the light beam conversion optical system is an objective lens. A scanning optical system 3 for condensing and scanning the image plane, an objective lens system 4 for projecting the collected converted light beam onto the sample surface 5, and a photodetector 7.

The pulsed laser light is focused by the light beam conversion optical system and the objective lens system through the dichroic mirror 6 and focused on the sample surface, thereby being induced by the two-photon absorption fluorescent material in the sample by two-photon absorption. Give rise to fluorescence. The sample surface is scanned with a laser beam, the fluorescence intensity at each location is detected by a light detection device such as a light detector 7, and a three-dimensional fluorescent image is plotted by a computer based on the obtained position information. Is obtained. As the scanning mechanism, for example, a laser beam may be scanned using a movable mirror such as a galvanometer mirror, or a sample including a two-photon absorption material placed on a stage may be moved.
With such a configuration, it is possible to obtain high resolution in the optical axis direction by utilizing the nonlinear effect of two-photon absorption itself. In addition, if a confocal pinhole plate is used, higher resolution (both in-plane and in the optical axis direction) can be obtained.
Fluorescent dyes for two-photon fluorescence microscopy are used by staining or dispersing specimens, and can be used not only for industrial applications but also for three-dimensional imaging microimaging of biological cells, etc. Compounds with absorption cross sections are desired

  Japanese Patent Laid-Open No. 9-230246 is cited as a known document of the two-photon fluorescence microscope in the present invention. For example, a scanning fluorescent microscope includes a laser irradiation optical system that emits collimated light expanded to a desired size, and a substrate on which a plurality of condensing elements are formed. A beam splitter that transmits a long wavelength and reflects a short wavelength is disposed between the substrate on which the light condensing element is formed and the objective lens system, so as to coincide with the image position of the system. The surface is characterized by generating fluorescence by multiphoton absorption. With such a configuration, it is possible to obtain high resolution in the optical axis direction by utilizing the nonlinear effect of multiphoton absorption itself. In addition, if a confocal pinhole plate is used, higher resolution (both in-plane and in the optical axis direction) can be obtained. Such a two-photon optical element uses, as the optical element, a solid material dispersed in a material having a high two-photon absorption ability, a thin film, or a photocurable resin of the present invention, just like the above-described light control element. Is possible.

  The two-photon absorption material of the present invention can be used as a two-photon absorption fluorescent material for a two-photon excitation laser scanning microscope. Compared to conventional two-photon absorption fluorescent materials, it has a large two-photon absorption cross-sectional area, so that it exhibits high two-photon absorption characteristics at a low concentration. Therefore, according to the present invention, not only a highly sensitive two-photon absorption material can be obtained, but there is no need to increase the intensity of light applied to the material, and deterioration and destruction of the material can be suppressed. The adverse effect on the properties of other components can also be reduced.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by these examples unless it exceeds the gist.

Synthesis example 1
Synthesis of polymer 1

A 100 ml four-necked flask was charged with 0.852 g (2.70 mmol) of dialdehyde and 1.525 g (2.70 mmol) of diphosphonate shown in the above reaction formula, and purged with nitrogen, and 75 ml of tetrahydrofuran was added. To this solution, 6.75 ml (6.75 mmol) of a 1.0 moldm- ³ tetrahydrofuran solution of potassium t-butoxide was added dropwise and stirred at room temperature for 2 hours, and then diethyl benzylphosphonate and benzaldehyde were sequentially added, followed by further stirring for 2 hours. About 1 ml of acetic acid was added to terminate the reaction, and the solution was washed with water. After the solvent was distilled off under reduced pressure, purification by reprecipitation was performed using tetrahydrofuran and methanol to obtain 1.07 g of polymer 1. The yield was 73%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 84.25% (84.02%), H: 8.20% (7.93%), N: 2.33% (2.45%).
The glass transition temperature determined from differential scanning calorimetry was 116.9 ° C.
The number average molecular weight in terms of polystyrene measured by gel filtration chromatography (GPC) was 8500, and the weight average molecular weight was 20000.

Synthesis example 2
Synthesis of polymer 2

The same operation as in Synthesis Example 1 was performed, and 518.3 mg of Polymer 2 was obtained from 419.5 mg (1.00 mmol) of the dialdehyde and 564.5 mg (1.00 mmol) of the diphosphonate. The yield was 62%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 85.18% (85.55%), H: 8.03% (7.63%), N: 2.10% (2.08%).
The glass transition temperature determined from differential scanning calorimetry was 133 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 39200, and the weight average molecular weight was 116000.

Synthesis example 3
Synthesis of polymer 3

The same operation as in Synthesis Example 1 was performed to obtain 1.32 g of the polymer 3 from 1.00 g (2.40 mmol) of the dialdehyde and 1.35 g (2.40 mmol) of the diphosphonate. The yield was 82%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 85.33% (85.55%), H: 7.86% (7.63%), N: 2.30% (2.08%).
The glass transition temperature determined from differential scanning calorimetry was 151.9 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 44400, and the weight average molecular weight was 118,000.

Synthesis example 4
Synthesis of polymer 4

In a 200 ml four-necked flask, 0.872 g (2.648 mmol) of the above dialdehyde and 1.495 g (2.648 mmol) of diphosphonate were placed, and the atmosphere was purged with nitrogen to 80 ml of tetrahydrofuran and 14.1 mg (0.132 mmol) of benzaldehyde. Was added. To this solution, 8.00 ml (8.00 mmol) of a 1.0 moldm- ³ tetrahydrofuran solution of potassium t-butoxide was added dropwise and stirred at room temperature for 2 hours, and then 60.5 mg (0.265 mmol) of diethyl benzylphosphonate was added. Stir for 1 hour. About 1 ml of acetic acid was added to complete the reaction, and the reaction solution was washed with water. After the solvent was distilled off under reduced pressure, purification by reprecipitation was performed using tetrahydrofuran and methanol to obtain 1.328 g of polymer 5. The yield was 86%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 83.80% (84.06%), H: 8.60% (8.90%), N: 2. 15% (2.39%).
The glass transition temperature determined from differential scanning calorimetry was 122.1 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 13200, and the weight average molecular weight was 32500.

Synthesis example 5
Synthesis of polymer 5

The same operation as in Synthesis Example 4 was performed to obtain 0.74 g of the polymer 7 from 1.00 g (2.48 mmol) of the dialdehyde and 1.40 g (2.48 mmol) of the diphosphonate. The yield was 45%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 85.56 (85.27%), H: 8.02% (7.78%), N: 2.01% (2.12%).
The number average molecular weight in terms of polystyrene measured by GPC was 22700, and the weight average molecular weight was 51900.

Synthesis Example 6
Synthesis of polymer 6

The same operation as in Synthesis Example 4 was performed to obtain 1.473 g of the polymer 8 from 0.872 g (2.648 mmol) of the dialdehyde and 1.495 g (2.648 mmol) of the diphosphonate. The yield was 95%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 84.25% (84.06%), H: 8.75% (8.90%), N: 2.23% (2.39%).
The glass transition temperature determined from differential scanning calorimetry was 135.8 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 15400, and the weight average molecular weight was 39900.

Synthesis example 7
Synthesis of polymer 7

The same operation as in Synthesis Example 4 was performed to obtain 2.72 g of the polymer 11 from 2.12 g (5.50 mmol) of the dialdehyde and 2.63 g (5.50 mmol) of the diphosphonate. The yield was 89%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 90.89% (90.77%), H: 6.50% (6.71%), N: 2.22% (2.52%).
The number average molecular weight in terms of polystyrene measured by GPC was 3700, and the weight average molecular weight was 8,000.

Synthesis Example 8
Synthesis of polymer 8

The same operation as in Synthesis Example 4 was performed to obtain 2.34 g of the polymer 12 from 2.12 g (5.50 mmol) of the dialdehyde and 2.50 g (5.50 mmol) of the diphosphonate. The yield was 80%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 90.64% (90.35%), H: 6.82% (7.01%), N: 2.55% (2.63%).
The number average molecular weight in terms of polystyrene measured by GPC was 5,500, and the weight average molecular weight was 13,300.

Synthesis Example 9
Synthesis of polymer 9

A 200 ml four-necked flask was charged with 0.835 g (2.648 mmol) of the dialdehyde and 1.241 g (2.648 mmol) of diphosphonate, and purged with nitrogen to 80 ml of tetrahydrofuran and 14.1 mg (0.132 mmol) of benzaldehyde. Was added. To this solution, 8.00 ml (8.00 mmol) of a 1.0 moldm-3 tetrahydrofuran solution of potassium t-butoxide was added dropwise, followed by stirring at room temperature for 0.5 hours and then refluxing for 3 hours. 60.5 mg (0.265 mmol) of diethyl benzylphosphonate was added, and the mixture was further refluxed for 1 hour. After allowing to cool, about a few drops of acetic acid were added to terminate the reaction, and the reaction solution was added dropwise to water. The precipitated solid was filtered off and purified by reprecipitation using tetrahydrofuran and methanol to obtain 0.83 g of polymer 13. The yield was 66%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 83.01% (83.32%), H: 7.01% (6.99%), N: 2.89% (2.94%), S: 6 80% (6.76%).
The glass transition temperature determined from differential scanning calorimetry was 163.4 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 7900, and the weight average molecular weight was 17,200.

Synthesis Example 10
Synthesis of polymer 10

The same operation as in Synthesis Example 9 was performed to obtain 0.918 g of the polymer 14 from 1.021 g (2.648 mmol) of the dialdehyde and 1.241 g (2.648 mmol) of the diphosphonate. The yield was 62%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 83.55% (83.62%), H: 7.74% (7.94%), N: 2.63% (2.57%), S: 6 0.02% (5.87%).
The glass transition temperature determined from differential scanning calorimetry was 125.9 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 15500, and the weight average molecular weight was 48700.

Synthesis Example 11
Synthesis of polymer 11

The same operation as in Synthesis Example 9 was performed to obtain 0.817 g of polymer 15 from 1.106 g (2.648 mmol) of the dialdehyde and 1.241 g (2.648 mmol) of diphosphonate. The yield was 53%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 85.52% (85.22%), H: 7.00% (6.80%), N: 2.15% (2.42%), S: 5 .50% (5.55%).
The glass transition temperature determined from differential scanning calorimetry was 186.9 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 11800, and the weight average molecular weight was 28400.

Synthesis Example 12
Synthesis of polymer 12

The same operation as in Synthesis Example 4 was performed, and 1.386 g of the polymer 12 was obtained from 0.837 g (2.655 mmol) of the dialdehyde and 1.485 g (2.655 mmol) of the diphosphonate. The yield was 81%, and the elemental analysis values were as follows.
Elemental analysis value (calculated value); C: 90.11 (89.81%), H: 7.92% (8.01%), N: 2.01% (2.18%).
The glass transition temperature determined from differential scanning calorimetry was 182.9 ° C.
The number average molecular weight in terms of polystyrene measured by GPC was 14400, and the weight average molecular weight was 42600.
1.682 g of polymer 18 was obtained from 1.681 g (2.648 mmol) of diphosphonate. Yield 85%.

[Example 1]
In the above Synthesis Example 12, a compound having a repetition number n of 1 was synthesized by the following reaction scheme under the synthesis conditions according to Synthesis Example 12. Concentration of the compound 0.01 (mol / l) A tetrahydrofuran solution was prepared, and the two-photon absorption cross section was measured by the following two-photon absorption cross-section evaluation method.

[Examples 2 to 4]
Similarly, in the above Synthesis Example 5, Synthesis Example 8 and Synthesis Example 10, a compound having a repetition number n of 1 was synthesized. A tetrahydrofuran solution having a concentration of the compound of 0.01 (mol / l) was prepared, and the two-photon absorption cross section was measured by the following two-photon absorption cross-section evaluation method.
A tetrahydrofuran solution having a concentration of the compound of 0.01 (mol / l) was prepared, and the two-photon absorption cross section was measured by the following two-photon absorption cross-section evaluation method.

[Examples 5 to 10]
The polymer obtained in Synthesis Example 1, Synthesis Example 3, Synthesis Example 5, Synthesis Example 6, Synthesis Example 10, and Synthesis Example 12 was converted into a molecular weight, and the concentration was 0.01 (mol / l). ) A tetrahydrofuran solution was prepared, and the two-photon absorption cross section was measured by the following two-photon absorption cross-section evaluation method.
Concentration of the compound 0.01 (mol / l) A tetrahydrofuran solution was prepared, and the two-photon absorption cross section was measured by the following two-photon absorption cross-section evaluation method.

[Comparative Example 1]
Using the compound shown by the following compound (20), a tetrahydrofuran solution was prepared so that the concentration was 0.01 (mol / l), and the two-photon absorption was evaluated by the following two-photon absorption cross-section evaluation method. The cross-sectional area was measured.
Concentration of the compound 0.01 (mol / l) A tetrahydrofuran solution was prepared, and the two-photon absorption cross section was measured by the following two-photon absorption cross-section evaluation method.

[Evaluation method of two-photon absorption cross section]
A schematic diagram of the measurement system is shown in FIG.
Measurement light source: femtosecond titanium sapphire laser Wavelength: 800 nm Pulse width: 100 fs
Repetition: 80 MHz Optical power: 800 mW
Measuring method: Z scan method Light source wavelength: 800 nm Cuvette inner diameter: 10 mm
Measurement optical power: about 500 mW Repeat frequency: 80 MHz
Condensing lens: f = 75 mm Condensing diameter: 40-50 μm
A quartz cell filled with the sample solution was placed in the collected optical path portion, and Z-scan measurement was performed by moving the position along the optical path.

The transmittance was measured, and the nonlinear absorption coefficient was determined from the result by the theoretical formula (I).
T = [ln (1 + I ₀ L ₀ β)] / I ₀ L ₀ β (I)
(In the above formula, T is transmittance (%), I ₀ is excitation light density [GW / cm ² ],
L ₀ represents the sample cell length [cm], and β represents the nonlinear absorption coefficient [cm / GW]. )
From this nonlinear absorption coefficient, the two-photon absorption cross section δ was determined by the following formula (II). (The unit of δ is 1GM = 1 × 10 ⁻⁵⁰ cm ⁴ · s · molecule ⁻¹ · photon ⁻¹ .)
δ = 1000 × hνβ / NACβ (II)
(In the above formula, h is Planck's constant [J · s],
ν is the frequency [s ⁻¹ ] of the incident laser beam, NA is the Avogadro number,
C represents the solution concentration [mol / L]. )

<Evaluation results>
The evaluation results are shown in Table 1.

As shown in the table above, the two-photon absorption compound (low molecular compound and polymer thereof) of the present invention had a transition efficiency 4 to 8 times higher than that of the conventional material.
From this, if the compound having the excellent two-photon absorption characteristics of the present invention is applied, a higher-grade three-dimensional memory material, a light-limiting material, a photocurable resin curing material, a photochemotherapy material, two A fluorescent dye material for a photon fluorescence microscope can be realized.

  The two-photon absorption material of the present invention can be suitably used as a three-dimensional memory material, a light-limiting material, a curing material of a photocurable resin for optical modeling, a material for photochemotherapy, and a fluorescent dye material for a two-photon fluorescence microscope.

FIG. 2 is a schematic diagram (a) of a recording / reproducing system for a three-dimensional multilayer optical memory and a schematic sectional view (b) of the recording medium. It is a figure which shows the light control element using a two-photon absorption material. It is the schematic of the apparatus of the two-photon stereolithography. It is the schematic of the basic composition of a two-photon excitation laser scanning microscope. It is the schematic which shows the measurement system of a two-photon absorption cross section.

Explanation of symbols

(About Figure 3)
DESCRIPTION OF SYMBOLS 1 Light source of near-infrared pulsed laser light which is transparent with respect to photocuring resin liquid 2 Shutter 3 which controls excess light temporally 3 D filter 4 Mirror scanner 5 Z stage 6 Lens 7 as condensing means Computer 8 Light Curable resin liquid 9 Stereolithography (about Fig. 4)
DESCRIPTION OF SYMBOLS 1 Laser light source 2 Light beam conversion optical system 3 Scanning optical system 4 Objective lens system 5 Sample surface 6 Dichroic mirror 7 Photodetector

Claims (10)

A two-photon absorption material represented by the following general formula (III).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of thiophene, biphenyl, fluorene or anthracene,
Ar ₅ and Ar ₆ are each independently a substituted or unsubstituted aromatic hydrocarbon group,
x and y are integers of 1 or more and 4 or less, z is an integer of 1 or more and 5 or less,
R ₁ and R ₂ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group,
R ₃ is a hydrogen group, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, or a substituted or unsubstituted aryl group,
When x, y and z are 2 or more, the plurality of R ₁ , R ₂ and R ₃ are independent from each other. A two-photon absorption material represented by the following general formula (IV).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
Ar ₅ and Ar ₆ are each independently a substituted or unsubstituted aromatic hydrocarbon group,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. And
And wherein v, the w, the x and the case y is 2 or more, a plurality of said ^{R 1,} said _{R 2,} wherein _{R 4} and wherein _{R 5} is two-photon absorption materials are independent. A two-photon absorption material represented by the following general formula (V).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
Ar ₅ and Ar ₆ are each independently a substituted or unsubstituted aromatic hydrocarbon group,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ and R ₅ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group or a substituted or unsubstituted alkylthio group,
And wherein v, the w, the x and the case y is 2 or more, a plurality of said ^{R 1,} said _{R 2,} wherein _{R 4} and wherein _{R 5} is two-photon absorption materials are independent. A two-photon absorption material comprising a polymer having a repeating unit represented by the following general formula (VIII).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
x and y are integers of 1 or more and 4 or less, z is an integer of 1 or more and 5 or less,
R ₁ and R ₂ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group,
R ₃ is a hydrogen group, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alkylthio group, or a substituted or unsubstituted aryl group,
When x, y, and z are 2 or more, the plurality of R ₁ , R _2, and R ₃ are independent of each other. ) A two-photon absorption material comprising a polymer having a repeating unit represented by the following general formula (IX).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted alkylthio group. And
When v, w, x and y are 2 or more, a plurality of R ₁ , R ₂ , R ₄ and R ₅ are independent from each other. ) A two-photon absorption material comprising a polymer having a repeating unit represented by the following general formula (X).

(In the above formula,
Ar ₄ is a substituted or unsubstituted divalent group of benzene, thiophene, biphenyl, fluorene or anthracene,
v is an integer of 1 to 3, w, x and y are integers of 1 to 4.
R ₁ , R ₂ , R ₄ and R ₅ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group or a substituted or unsubstituted alkylthio group,
And wherein v, the w, the x and the case y is 2 or more, a plurality of the _{R 1,} before Symbol _{R 2,} wherein _{R 4} and wherein _{R 5} is two-photon absorption materials are independent. Three dimensional memory material including two-photon absorption material according to any one of claims 1-6. The light limiting material containing the two-photon absorption material in any one of Claims 1-6 . Curing material for stereolithography photocurable resin containing a two-photon absorption material according to any one of claims 1-6. Two-photon fluorescence microscopy fluorescent dye material comprises a two-photon absorption material according to any one of claims 1-6.

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