JP2008003583A - Optical recording material and optical recording medium using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical recording material, which can solve a problem of recording density in an optical recording medium, and an optical recording medium using the optical recording material. <P>SOLUTION: The optical recording material comprises a compound having a structure represented by general formula (I). The optical recording medium contains the optical recording material in a recording layer. Recording is carried out by photodissociating a compound constituting the optical recording material and comprising a luminescent group and a photodissociating protective group, and reproduction is carried out by reading a difference in luminescence intensity between before the photodissociation and after the photodissociation. In the formula (I), A represents a fluorescence emitting group upon the dissociation of B; X represents a divalent binding group; B represents a photodissociative protective group; and n is an integer of 1-6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an optical recording material comprising a compound having a structure in which a fluorescent group and a photolabile protecting group are bonded, and an optical recording medium containing the optical recording material in a recording layer. Specifically, an optical recording material comprising a compound in which a photolabile protecting group is bonded to a specific light-emitting group and the light emission intensity is changed by light irradiation, and an optical recording medium containing the optical recording material in a recording layer About.
The present invention also relates to a recording / reproducing method for the optical recording medium and a novel compound constituting the optical recording material.

  Optical recording using laser light has been developed in recent years because it can store and reproduce high-density information recording. An example of the optical recording medium is an optical disk. In general, an optical disc performs high-density information recording by irradiating a thin recording layer provided on a circular substrate with a focused laser beam. The recording is performed by causing thermal deformation such as decomposition, evaporation, and dissolution in the recording layer at the location due to absorption of the irradiated laser beam energy. Information reproduction is performed by reading a difference in reflectance between a portion where deformation has occurred and a portion where deformation has not occurred with laser light. However, this method has a limit in recording density.

  In order to solve such problems, extensive research has been conducted on optical recording materials and recording media using emission intensity changes so far (for example, Patent Documents 1 and 2 and Non-Patent Documents 1 and 2). 2).

  Further, for the purpose of further improving the recording capacity, so-called “three-dimensional optical memory” is used which records at a very high spatial resolution in any three-dimensional space in a recording medium by using multiphoton absorption for recording and reproducing information. Many attempts have been made public (for example, Non-Patent Document 3). Some of them include a combination of the above-described change in emission intensity and multiphoton absorption, but recorded information is not stably stored at room temperature; the change in emission intensity is small and the signal S / N ratio is not good. It is not practical because it is sufficient; the components are complicated; and the like (for example, Patent Documents 3 to 11).

On the other hand, in the bio field, by utilizing two-photon absorption, which is one of the multiphoton absorption phenomena for a long time, a photo-sensitive protective group (hereinafter referred to as a photolabile protective group) is bound to a physiologically active substance, Studies have been actively conducted to generate a physiologically active substance by irradiating light to a substance that has lost its function, so-called “caged compound” (for example, Non-Patent Documents 4 to 7). Non-Patent Document 8 describes a compound in which a photolabile protecting group is bound to a fluorescent dye matrix.
Special table 2001-507137 JP-A-2005-8781 US Pat. No. 5,268,862 Special table 2003-529180 Special table 2005-517769 Special table 2005-520272 JP 2003-27040 A JP2003-29376 JP 2004-352770 A JP 2005-29726 A JP2005-100606 Science, Vol. 245, p843 (1989) Opt. Commun. Vol. 212, p45 (2002) Opt. Lett. Vol. 16, p1780 (1991) Proc. Nat. Act. Sci. USA, Vol. 91, p6629 (1994) Neuron, Vol. 18, p351 (1997) Neuron, Vol. 19, p465 (1997) Proc. Nat. Act. Sci. USA, Vol. 96, p11932 (1999) J. et al. Am. Chem. Soc. Vol. 128, p3831 (2006)

The inventions described in Non-Patent Documents 4 to 8 relate to a technique for activating a physiologically active substance inactivated by a photolabile protecting group by photodissociation, and in a hydrophilic buffer solution having a pH of about 7 as in vivo. The function was confirmed by. None of the compounds described in Non-Patent Documents 4 to 7 have luminescent properties. In addition, the compound described in Non-Patent Document 8 has a fluorescent dye matrix bonded to a physiologically active substance for the purpose of imparting two-photon absorption, but is not intended to impart luminescence properties.
Therefore, there has never been an example in which these compounds are applied to the above-described optical recording materials and three-dimensional optical memories that are excellent in solubility in organic solvents and are required to be contained in the recording layer in a solid state.

  The present invention has been made paying attention to the problem of recording density in an optical recording medium, and provides an optical recording material capable of solving the problem of recording density in an optical recording medium, and an optical recording medium using the same. The purpose is to do.

As a result of various studies for improving the recording density, the present inventor has come up with the idea of applying a compound whose light emission intensity is changed by light irradiation to optical recording, and has reached the present invention.
That is, the gist of the present invention is as follows.

[1] An optical recording material comprising a compound having a structure in which at least one luminescent group and one photolabile protecting group are bonded.

〔式(Ｉ)中、Ａは発光性基を表し、Ｘは２価の結合基を表し、Ｂは光解離性保護基を表し、ｎはｕは１〜６の整数である。〕 [2] The optical recording material according to [1], comprising a compound having a structure represented by the following general formula (I).

[In formula (I), A represents a luminescent group, X represents a divalent linking group, B represents a photolabile protecting group, and n is an integer of 1-6. ]

[3] The optical recording material according to [1] or [2], wherein the luminescent group has multiphoton absorption.

[4] The optical recording material according to any one of [1] to [3], wherein the luminescent group is a fluorescent group.

[5] The optical recording material according to any one of [1] to [4], wherein the emission intensity increases after light irradiation.

〔式(II)中、
Ｒ^１及びＲ^２は各々独立に、水素原子、ハロゲン原子、ニトロ基、置換基を有していてもよいアルキル基、置換基を有していてもよいアルコキシ基、又は置換基を有していてもよい芳香環基を表し、
Ｘは２価の結合基を表し、
Ｂは光解離性保護基を表し、
ａは１〜３の整数を表す。
Ｚは水素原子、ハロゲン原子、シアノ基、置換基を有していてもよいアルキル基、又は−（Ａｒ^１）_ｒ−（Ｘ−Ｂ）_ｓ（ここで、Ａｒ^１は置換基を有していてもよい芳香環基を表し、Ｘは２価の結合基を表し、Ｂは光解離性保護基を表し、ｒ及びｓは各々独立に、０又は１であり、Ｒ^１とＡｒ^１は結合して６員環を形成していてもよい。）を表す。〕 [6] The optical system according to any one of [2] to [5], wherein the compound having a structure represented by the general formula (I) is a compound represented by the following general formula (II): Recording material.

(In the formula (II),
R ¹ and R ² each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a photolabile protecting group,
a represents an integer of 1 to 3.
Z is a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, or — (Ar ¹ ) _r — (X—B) _s (where Ar ¹ has a substituent). And X represents a divalent linking group, B represents a photolabile protecting group, r and s are each independently 0 or 1, and R ¹ and Ar ¹ are bonded. And may form a 6-membered ring). ]

〔式(III)中、
Ｒ^３及びＲ^４は各々独立に、水素原子、ハロゲン原子、ニトロ基、置換基を有していてもよいアルキル基、置換基を有していてもよいアルコキシ基、又は置換基を有していてもよい芳香環基を表し、
Ｘは２価の結合基を表し、
Ｂは光解離性保護基を表し、
ｔは０〜４の整数であり、ｕは０〜６の整数である。〕 [7] The optical recording material according to any one of [2] to [5], wherein the compound having a structure represented by the general formula (I) is a compound represented by the following general formula (III).

[In the formula (III),
R ³ and R ⁴ each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a photolabile protecting group,
t is an integer of 0 to 4, and u is an integer of 0 to 6. ]

〔式(IV)中、
Ｙは−Ｏ−、又は−Ｓ−を表し、
Ａｒ^２及びＡｒ^３は各々独立に、置換基を有していてもよい芳香環基を表し、
Ｘは２価の結合基を表し、
Ｂは光解離性保護基を表し、
ｖ及びｗは各々独立に、０〜４の整数である。〕 [8] The optical recording material according to any one of [2] to [5], wherein the compound having a structure represented by the general formula (I) is a compound represented by the following general formula (IV).

[In the formula (IV),
Y represents —O— or —S—;
Ar ² and Ar ³ each independently represents an aromatic ring group which may have a substituent,
X represents a divalent linking group,
B represents a photolabile protecting group,
v and w are each independently an integer of 0 to 4. ]

〔式（Ｖ）〜（VII）の芳香環は更に置換基を有していてもよい。
式(VIII)において、Ｒ^９，Ｒ^１０，Ｒ^１１は各々独立に任意の置換基を表すが、Ｒ^９，Ｒ^１０，Ｒ^１１の少なくとも１つは置換基を有していても良いアルキル基である。〕 [9] The photolabile protecting group B is any one selected from the group consisting of groups represented by the following general formulas (V), (VI), (VII) and (VIII) [2] to [ 8] The optical recording material according to any one of [8].

[The aromatic rings of the formulas (V) to (VII) may further have a substituent.
In formula (VIII), R ⁹ , R ¹⁰ and R ¹¹ each independently represents an arbitrary substituent, but at least one of R ⁹ , R ¹⁰ and R ¹¹ may be an alkyl group which may have a substituent. It is. ]

[10] An optical recording medium comprising the recording layer containing the optical recording material according to any one of [1] to [9].

[11] The recording is performed by photodissociating a compound having a light emitting group and a photolabile protecting group constituting the optical recording material, and reproduction is performed by reading a change in emission intensity before and after the photodissociation. The method for recording / reproducing an optical recording medium according to [10].

〔式(II)中、
Ｒ^１及びＲ^２は各々独立に、水素原子、ハロゲン原子、ニトロ基、置換基を有していてもよいアルキル基、置換基を有していてもよいアルコキシ基、又は置換基を有していてもよい芳香環基を表し、
Ｘは２価の結合基を表し、
Ｂは下記一般式(Ｖ)、(VI)、(VII)、又は(VIII)で表される基を表し、
ａは１〜３の整数を表す。
Ｚは水素原子、ハロゲン原子、シアノ基、置換基を有していてもよいアルキル基、又は−（Ａｒ^１）_ｒ−（Ｘ−Ｂ）_ｓ（ここで、Ａｒ^１は置換基を有していてもよい芳香環基を表し、Ｘは２価の結合基を表し、Ｂは下記一般式(Ｖ)、(VI)、(VII)、又は(VIII)で表される基を表し、ｒ及びｓは各々独立に、０又は１であり、Ｒ^１とＡｒ^１は結合して６員環を形成していてもよい。）を表す。

（式（Ｖ）〜（VII）の芳香環は更に置換基を有していてもよい。
式(VIII)において、Ｒ^９，Ｒ^１０，Ｒ^１１は各々独立に任意の置換基を表すが、Ｒ^９，Ｒ^１０，Ｒ^１１の少なくとも１つは置換基を有していても良いアルキル基である。）〕 [12] A compound represented by the following general formula (II):

(In the formula (II),
R ¹ and R ² each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a group represented by the following general formula (V), (VI), (VII), or (VIII);
a represents an integer of 1 to 3.
Z is a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, or — (Ar ¹ ) _r — (X—B) _s (where Ar ¹ has a substituent). X represents a divalent linking group, B represents a group represented by the following general formula (V), (VI), (VII), or (VIII), r and s each independently represents 0 or 1, and R ¹ and Ar ¹ may combine to form a 6-membered ring.

(The aromatic rings of formulas (V) to (VII) may further have a substituent.
In formula (VIII), R ⁹ , R ¹⁰ and R ¹¹ each independently represents an arbitrary substituent, but at least one of R ⁹ , R ¹⁰ and R ¹¹ may be an alkyl group which may have a substituent. It is. )]

  According to the present invention, information is recorded with light having a wavelength that can be absorbed by the recording material before recording, and the recorded information is emitted by irradiating with light having a wavelength that can be absorbed by the recording material after recording. , An optical recording material that can be read by detecting the difference in emission intensity between the recorded portion and the unrecorded portion at that time, and can solve the problem of recording density in the optical recording medium, and optical recording using the same A medium can be provided. In addition, high-density nondestructive reading is possible, and the optical recording material of the present invention is an irreversible material, so that it has good recording storage stability and is practical. In addition, when the optical recording material of the present invention absorbs multiphotons, nondestructive recording can be performed at an arbitrary position in a three-dimensional space with extremely high spatial resolution, and recorded information can be read out with a difference in emission intensity. Therefore, the ultimate high density recording is considered possible.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiment, and various modifications may be made within the scope of the invention. it can.

In the present invention, the aromatic ring means a ring having aromaticity, that is, a ring having a (4m + 2) π electron system (m is a natural number). The skeletal structure is usually an aromatic ring composed of a 5- or 6-membered ring, a single ring or 2 to 6 condensed rings, including an aromatic hydrocarbon ring, an aromatic heterocyclic ring, an anthracene ring. , Condensed rings such as a carbazole ring and an azulene ring are also included. The “... ring group” such as “aromatic ring group” is a monovalent substituent obtained by removing one hydrogen atom from such a ring such as an aromatic ring.
In the present invention, “may have a substituent” means that one or more substituents may be present.

The optical recording material of the present invention comprises a compound having a structure in which at least one luminescent group and one photolabile protecting group are bonded.
The compound having a structure in which at least one luminescent group and one photolabile protecting group constituting the optical recording material of the present invention are bonded includes at least one multiluminescent photoluminescent group. And a compound having a structure in which one photolabile protecting group is bonded, particularly a compound having a structure represented by the following general formula (I) (hereinafter sometimes referred to as “compound (I)”). Preferably there is.

〔式(Ｉ)中、Ａは発光性基を表し、Ｘは２価の結合基を表し、Ｂは光解離性保護基を表し、ｎはｕは１〜６の整数である。〕

[In formula (I), A represents a luminescent group, X represents a divalent linking group, B represents a photolabile protecting group, and n is an integer of 1-6. ]

[Compound (I)]
The compound (I) suitable for the present invention is described below.
<Luminescent group A>
In the general formula (I), A representing a light-emitting group has the property of emitting photons having energy different from the absorbed photons by simultaneously absorbing one or more photons. There is no particular limitation, and specific examples include a group having a coumarin skeleton, a fluorescein skeleton, or a benzooxadiazole or benzothiadiazole skeleton.
This luminescent group A is preferably a fluorescent group having multiphoton absorption.

<Divalent linking group X>
X representing a divalent linking group is not particularly limited as long as it has a property of forming two covalent bonds via X, and specific examples thereof include, for example, -O-,- S-, -NR < ⁰ >-, etc. are mentioned. From the viewpoint of ease of synthesis, -O- or -NR ⁰ -is preferable. R ⁰ represents a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or an aromatic ring group which may have a substituent. To express. Specific examples include those described later as R ⁰ in the general formula (II).

<Photolabile protecting group B>
B representing the photolabile protecting group may be any as long as it has a property of being dissociated by absorption of light, and is not particularly limited. Chem. Soc. Perkin Trans1, 125, 2002; Synthesis, 1 page, 1980; Org. Photochem. 9, 225, 1987; Trends Biotechnol. , 18, 64 pages, 2000, and the like. Specific examples include a 2-nitrobenzyl group, a coumarylmethyl group, a 4-hydroxyphenacyl group, or a carboxylic acid ester group.

  The number n of the photolabile protecting groups B bonded to one luminescent group A is not particularly limited as long as it is 1 or more. However, it is usually 1 to 6 because of availability of raw materials and organic synthesis. Yes, preferably 1-4.

  Here, light emission obtained by exciting the optical recording material of the present invention by light irradiation or the like mainly includes fluorescence and phosphorescence, but is not limited to these unless it exceeds the gist.

  As the compounds represented by the general formula (I), the light emission intensity of the luminescent group is large, and the wavelength at which the measurement sensitivity is high in a silicon photodetector in which the emission wavelength is usually used, that is, usually 300 to 1100 nm, particularly Since it is desirable to have an emission wavelength of preferably 400 to 1000 nm, specifically, a compound represented by the following general formula (II) as a compound in which A representing a luminescent group is a group having the coumarin skeleton ( Hereinafter referred to as “compound (II)”) is a compound represented by the following general formula (III) (hereinafter referred to as “compound (II)”) wherein A represents a luminescent group is a group having the fluorescein skeleton. III) ")) is a compound represented by the following general formula (IV) as a compound in which A representing a luminescent group is a group having a benzooxadiazole or benzothiadiazole skeleton. (Sometimes referred to as the "compound (IV)".) Things are particularly preferred, respectively.

(In the formula (II),
R ¹ and R ² each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a photolabile protecting group,
a represents an integer of 1 to 3.
Z is a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, or — (Ar ¹ ) _r — (X—B) _s (where Ar ¹ has a substituent). And X represents a divalent linking group, B represents a photolabile protecting group, r and s are each independently 0 or 1, and R ¹ and Ar ¹ are bonded. And may form a 6-membered ring). ]

[In the formula (III),
R ³ and R ⁴ each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a photolabile protecting group,
t is an integer of 0 to 4, and u is an integer of 0 to 6. ]

[In the formula (IV),
Y represents —O— or —S—;
Ar ² and Ar ³ each independently represents an aromatic ring group which may have a substituent,
X represents a divalent linking group,
B represents a photolabile protecting group,
v and w are each independently an integer of 0 to 4. ]

{About Compound (II)}
<R ⁰ , R ¹ , R ² >
Here, R ⁰ refers to R ⁰ possessed by —NR ⁰ — as X described in the section of formula (I).
Specific examples of the halogen atom for R ⁰ , R ¹ , and R ² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and the alkyl group has 1 to 8 carbon atoms. Specific examples include methyl group, ethyl group, propyl group, iso-propyl group, butyl group, iso-butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl group and the like. In addition, the alkoxy group preferably has 1 to 8 carbon atoms, and specifically includes a methoxy group, an ethoxy group, a propoxy group, an iso-propoxy group, a butoxy group, an iso-butoxy group, and a sec-butoxy group. Group, tert-butoxy group, hexyloxy group, octyloxy group and the like. Specific examples of the aromatic ring group include benzene ring, naphthalene ring, anthracene ring. Furan ring, thiophene ring, pyridine ring, quinoline ring, benzofuran ring, and a group derived from a benzothiophene ring.

Moreover, the alkyl group, alkoxy group, and aromatic ring group of R ⁰ , R ¹ , and R ² may further have a substituent. The substituent which R ⁰ , R ¹ and R ² may further have may be any substituent as long as it satisfies the function of the present invention. Specifically, the following [substitution Examples include groups exemplified in the group W].

[Substituent group W]
Halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom)
Nitro group Hydroxy group Cyano group Carboxyl group Sulfo group Alkyl group which may have a substituent (methyl group, ethyl group, propyl group, isopropyl group, butyl group, iso-butyl group, sec-butyl group, tert-butyl Group, hexyl group, octyl group, tetradecahydroanthranyl group and the like, usually carbon number such as 1-20, preferably 1-10 linear or branched, cyclopropyl group, cyclohexyl group, cyclohexenyl group, etc. A cycloalkyl group having a number of usually 3 to 20, preferably 5 to 10)
The alkenyl group (vinyl group, propenyl group, butenyl group, 2-methyl-1-propenyl group, hexenyl group, octenyl group, etc.) having an optionally substituted alkenyl group is usually 2-20, preferably 2-10. Linear or branched)
Alkynyl group which may have a substituent (Ethynyl group, propynyl group, butynyl group, 2-methyl-1-propynyl group, hexynyl group, octynyl group and the like usually have 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms) Linear or branched)
An aryl group which may have a substituent (an aryl group having 6 to 18 carbon atoms, preferably 6 to 10 carbon atoms, such as a phenyl group, anthranyl group, phenanthryl group and ferrocenyl group)
Heterocyclic group which may have a substituent (a heteroaryl group consisting of a 5-6 membered monocyclic ring or a 2-6 condensed ring, a 5-6 membered monocyclic ring or a 2-6 condensed ring) Examples of heteroatoms include nitrogen atoms, oxygen atoms, sulfur atoms, etc. Specifically, 5-membered rings such as thienyl groups, pyridyl groups, 2-piperidinyl groups, 2-piperazinyl groups. And 6-membered rings such as benzothienyl group, carbazolyl group, quinolinyl group, octahydroquinolinyl group, etc.
Alkoxy group which may have a substituent (methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, iso-butoxy group, sec-butoxy group, tert-butoxy group, hexyloxy group, octyloxy group And the like are usually 1-9, preferably 2-8)
An optionally substituted (hetero) aryloxy group (phenoxy group, naphthyloxy group, etc., usually 6-18, preferably 6-10 aryloxy groups, 2-thienyloxy group, 2 A heteroaryloxy group having a carbon number of -furyloxy group, 2-quinolyloxy group and the like, usually 5-18, preferably 5-10, and including heteroatoms selected from nitrogen atom, oxygen atom, sulfur atom, etc. Can be mentioned)
Alkylthio group which may have a substituent (methylthio group, ethylthio group, propylthio group, isopropylthio group, butylthio group, iso-butylthio group, sec-butylthio group, tert-butylthio group, hexylthio group, octylthio group, etc. (A carbon number is 1-9 normally, Preferably the thing of 2-8 is mentioned.)
An arylthio group which may have a substituent (an arylthio group having 6 to 18, preferably 6 to 10 carbon atoms, such as a phenylthio group or a naphthylthio group, a 2-thienylthio group, a 2-furylthio group, or a 2-quinolylthio group. And a heteroarylthio group having 5 to 18 carbon atoms, preferably 5 to 10 carbon atoms, and a hetero atom including a nitrogen atom, an oxygen atom, a sulfur atom, etc.
An optionally substituted alkoxycarbonyl group (a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, a tert-butoxycarbonyl group, an acetyloxy group, a benzoyloxy group, etc. 20, preferably 2 to 10)
An optionally substituted (hetero) aryloxycarbonyl group (phenoxycarbonyl group, naphthyloxycarbonyl group and the like having an aryloxycarbonyl group having usually 6 to 18, preferably 6 to 10 carbon atoms, such as 2-thienyl The carbon number of the oxycarbonyl group, 2-furyloxycarbonyl group, 2-quinolyloxycarbonyl group and the like is usually 5 to 18, preferably 5 to 10, and the hetero atom is selected from a nitrogen atom, an oxygen atom, a sulfur atom, etc. And heteroaryloxycarbonyl groups including those)
An amino group (ethylamino group, dimethylamino group, methylethylamino group, dibutylamino group, piperidyl group and the like having 2 to 20 carbon atoms, preferably 3 to 10 carbon atoms, which may have a substituent. , A diphenylamino group, a dinaphthylamino group, a naphthylphenylamino group, a ditolylamino group and the like, an arylamino group having 6 to 30 carbon atoms, preferably 6 to 15 carbon atoms, a di (2-thienyl) amino group, a di (2- A heteroarylamino group containing 5 to 30 carbon atoms, such as a furyl) amino group, preferably 6 to 15 and selected from a nitrogen atom, an oxygen atom, a sulfur atom, etc. as a heteroatom, phenyl (2-thienyl) amino And arylheteroarylamino groups having 11 to 30, preferably 12 to 16 carbon atoms such as groups)
An acyl group which may have a substituent (acyl groups having 1 to 30 carbon atoms such as acetyl group, benzoyl group, formyl group and pivaloyl group, preferably 1 to 20 acyl groups)
An acyloxy group which may have a substituent (acyloxy groups such as acetoxy group and benzoyloxy group having 1 to 30, preferably 1 to 20 carbon atoms)
An acylamino group which may have a substituent (an acylamino group having 1 to 30, preferably 1 to 20 carbon atoms, such as an acetylamino group or a benzoylamino group)
An ureido group which may have a substituent (a ureido group having 1 to 30, preferably 1 to 20 carbon atoms, such as a methylureido group, a ureido group, and a phenylureido group).
Sulfonamide group which may have a substituent (such as methanesulfonamide group, benzenesulfonamide group and the like, a sulfonamide group having 1 to 30, preferably 1 to 20 carbon atoms)
A carbamoyl group which may have a substituent (carbamoyl group such as carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, etc., having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms)
An optionally substituted sulfamoyl group (sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group and the like, such as a carbamoyl group having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms. )
Optionally substituted sulfamoylamino group (sulfamoylamino group, ethylsulfamoylamino group, dimethylsulfamoylamino group, tolsulfamoylamino group, etc., preferably 1-30 carbon atoms, preferably 1-20 carbamoylamino groups)
A sulfonyl group which may have a substituent (a sulfonyl group having 1 to 30, preferably 1 to 20 carbon atoms such as a methanesulfonyl group and a phenylsulfonyl group)
Sulfinyl group which may have a substituent (e.g., ethanesulfinyl group, phenylsulfinyl group, etc., sulfinyl group having 1-30 carbon atoms, preferably 1-20 carbon atoms)

In particular, as R ⁰ , a hydrogen atom is generally used, but the above alkyl group is preferable from the viewpoint of solubility and heat-and-moisture resistance.

R ¹ is preferably a hydrogen atom, an alkyl group, or a halogen atom.

R ² is preferably a hydrogen atom, an alkyl group, or a halogen atom.

<Z>
Examples of the halogen atom and alkyl group of Z include the same as those in R ⁰ , R ¹ and R ² , and Ar when Z is — (Ar ¹ ) _r — (X—B) _s Specific examples of the aromatic ring group ¹ include groups derived from a benzene ring, naphthalene ring, anthracene ring, furan ring, thiophene ring, pyridine ring, quinoline ring, benzofuran ring, benzothiophene ring, and the like. Examples of the group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, nitro group, hydroxy group, carboxy group, methyl group, ethyl group, propyl group, iso-propyl group, butyl group, iso- C1-C8 alkyl groups such as butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl group, methoxy group, ethoxy group, propoxy group, is - propoxy group, a butoxy group, iso- butoxy group, sec- butoxy group, tert- butoxy group, hexyloxy group, an alkoxy group having 1 to 8 carbon atoms such as octyloxy group.

  The photolabile protecting group B will be described later.

  a is preferably 1 to 3, and more preferably 1. When a is 2 or more, the two or more X-B groups may be the same or different. From the viewpoint of ease of organic synthesis and availability of raw materials, when a is 1, the substitution position of -XB is preferably 6th or 7th, and when a is 2 or more, It is preferable that at least the 6-position and the 7-position are substituted with -XB.

Specific examples of the 6-membered ring that may be formed by combining R ¹ and Ar ¹ include a benzene ring and an α-pyrone ring.

Z is particularly represented by the general formula (V) described later on the benzene ring as Ar ¹ via —O— or —NR ⁰ — (wherein R ⁰ is as described above) as X. And a photolabile protecting group B bonded thereto are preferred.

{About Compound (III)}
The halogen atom, alkyl group, alkoxy group, aromatic ring group and substituents that they may have in R ³ and R ⁴ are the same as those in R ⁰ , R ¹ and R ² of the general formula (II). And X is the same as in general formula (II). The photolabile protecting group B will be described later. In the formula (III), when two BX groups and t and u are 2 or more, two or more R ³ and R ⁴ may be the same or different. .

From the viewpoint of ease of synthesis and solubility in a coating solvent, R ³ and R ⁴ are each independently preferably a hydrogen atom, an alkyl group or a halogen atom, and X is —NR ⁰ — (where R ⁰ is the same as described above). And t and u are each independently preferably 0 to 2.

{About Compound (IV)}
Examples of the aromatic ring group of Ar ² and Ar ³ and the substituent thereof are the same as those in Ar ¹ of the general formula (II) (however, a divalent group). With respect to X, the same as those in the general formula (II) can be mentioned. The photolabile protecting group B will be described later. In the formula (IV), the two BX groups may be the same or different from each other.

Ar ² and Ar ³ are each independently preferably a phenylene group, a naphthylene group, an anthranylene group, a phenanthrylene group, a pyrenylene group, or a divalent heterocyclic group derived from a thiophene, pyridine, furan, galbazole, or quinoline ring. Is preferably —NR ⁰ — (R ⁰ is as described above), and v + w is preferably 2-6.

{Regarding Photolabile Protecting Group B in Compounds (II), (III), and (IV)}
As the photolabile protecting group B, a group represented by the following general formula (V) (hereinafter sometimes referred to as “2-nitrobenzyl group (V)”) as the 2-nitrobenzyl group, The group represented by the following general formula (VI) as the coumarylmethyl group (hereinafter sometimes referred to as “coumarylmethyl group (VI)”) is also represented by the following general formula (VII) as the 4-hydroxyphenacyl group. A group represented by the following general formula (VIII) as the carboxylic acid ester group (hereinafter sometimes referred to as “4-hydroxyphenacyl group (VII)”). Each of which is sometimes referred to as “ester group (VIII)”).

[The aromatic rings of the formulas (V) to (VII) may further have a substituent.
In formula (VIII), R ⁹ , R ¹⁰ and R ¹¹ each independently represents an arbitrary substituent, but at least one of R ⁹ , R ¹⁰ and R ¹¹ may be an alkyl group which may have a substituent. It is. ]

Specific examples of the substituent that the aromatic rings of formulas (V) to (VII) may further have and R ^{9 to} R ¹¹ of formula (VIII) are those exemplified in the above-mentioned [Substituent group W]. Is mentioned.

In addition, when the substituent which the aromatic rings of formulas (V) to (VII) may further have and the groups of R ^{9 to} R ¹¹ of formula (VIII) further have a substituent, And those exemplified in the above-mentioned [Substituent group W].

<Preferred example of 2-nitrobenzyl group (V)>
The 2-nitrobenzyl group (V) preferably has no substituent, or preferably has an alkyl group or an alkoxy group as a substituent, and when it has a substituent, the number of substituents is preferably 1 or 2, The substitution position is preferably 4-position and 5-position. When there are two or more substituents, the two or more substituents may be the same or different.

  Specific examples of the 2-nitrobenzyl group (V) include 2-nitrobenzyl group, 2-nitro-6-fluorobenzyl group, 2-nitro-4-chlorobenzyl group, 2-nitro-5-chlorobenzyl. Group, 2-nitro-6-chlorobenzyl group, 2-nitro-4-bromobenzyl group, 2,4-dinitrobenzyl group, 2-nitro-5-hydroxybenzyl group, 2-nitro-4-carboxybenzyl group, 2-nitro-3-methylbenzyl group, 2-nitro-4-methylbenzyl group, 2-nitro-6-methylbenzyl group, 2-nitro-4,5-dimethoxybenzyl group, 2-nitro-3,4, 5-trimethoxybenzyl group, 2-nitro-4-dodecyloxy-5-methoxybenzyl group, 2-nitro-4-ethoxycarbonylbenzyl group, 2-nitro-4-tert-butyl Butoxycarbonyl benzyl, 2-nitro-4-methylamino-carbonyl benzyl group, 2-nitro-4-phenylbenzyl group, a 2-nitro-5-benzyloxybenzyl group.

<Preferred example of coumaryl methyl group (VI)>
The coumarylmethyl group (VI) preferably has no substituent or preferably has a halogen atom, a hydroxy group, an alkyl group or an alkoxy group as the substituent, and the number of substituents is preferably 1 or 2, The 6th and 7th positions are preferred. When there are two or more substituents, the two or more substituents may be the same or different.

  Specific examples of the coumarylmethyl group (VI) include 7-hydroxycoumarin-4-ylmethyl group, 7-methoxycoumarin-4-ylmethyl group, 7-methoxymethoxycoumarin-4-ylmethyl group, and 7-hydroxycarbonylmethoxycoumarin. -4-ylmethyl group, 7-n-propoxycarbonylmethoxycoumarin-4-ylmethyl group, 7-tert-butoxycarbonylmethoxycoumarin-4-ylmethyl group, 7-dimethylaminocoumarin-4-ylmethyl group, 7-diethylaminocoumarin- 4-ylmethyl group, 7-ethoxycarbonylaminocoumarin-4-ylmethyl group, 7-tert-butoxycarbonylmethylaminocoumarin-4-ylmethyl group, 6-bromo-7-hydroxycoumarin-4-ylmethyl group, 6-bromo- 7-acetyloxy Examples include a coumarin-4-ylmethyl group, a 6-ethyl-7-hydroxycoumarin-4-ylmethyl group, and a 6,7-dimethoxycoumarin-4-ylmethyl group.

<Preferred example of 4-hydroxyphenacyl group (VII)>
The 4-hydroxyphenacyl group (VII) preferably has no substituent, or preferably has an alkyl group or an alkoxy group as a substituent, and when it has a substituent, the number of substituents is preferably 1 or 2. . When there are two or more substituents, the two or more substituents may be the same or different.

  Specific examples of the 4-hydroxyphenacyl group (VII) include 4-hydroxyphenacyl group, 2,4-dihydroxyphenacyl group, 2,3,4-trihydroxyphenacyl group, 2,4,6 -Trihydroxyphenacyl group, 2,4-dihydroxy-3-methylphenacyl group, 2,4-dihydroxy-5-methylphenacyl group, 2,4-dihydroxy-5-ethylphenacyl group, 2,4- Dihydroxy-5-n-hexylphenacyl group, 3,4-dihydroxy-5-nitrophenacyl group, 3,5-dimethyl-4-hydroxyphenacyl group, 3-methoxy-4-hydroxyphenacyl group, 3, Examples include 5-dimethoxy-4-hydroxyphenacyl group.

<Preferred example of carboxylate group (VIII)>
The alkyl group represented by R ⁹ , R ¹⁰ , R ^{11 in} the general formula (VIII) preferably has 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, an n-propyl group, an iso- Examples include propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl group and the like.

  Specific examples of the carboxylic acid ester group (VIII) include an iso-propoxycarbonyl group, a tert-butoxycarbonyl group, and a tert-amyloxycarbonyl group.

{Photoacid generator}
When the photolabile protecting group B of the compounds (I) to (IV) in the present invention is a carboxylic acid ester group (VIII), the optical recording material of the present invention includes a photoacid generator that generates an acid by light irradiation. It is preferable to use an agent in combination.
Examples of the photoacid generator in that case include salts of BF ₄ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ , ClO ₄ ^{− and the} like such as diazonium salt, phosphonium salt, sulfonium salt and iodonium salt, and diazomethane derivatives. Preferred photoacid generators include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium hexafluorophosphate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium tetrafluoroborate, bis (cyclohexylsulfonyl) diazomethane, bis ( p-toluenesulfonyl) diazomethane and the like.
These may be used alone or in combination of two or more.

{Molecular weight of compounds (I), (II), (III), (IV)}
The molecular weight of the compound (I), preferably the compounds (II), (III) and (IV) is usually 10,000 from the viewpoints of easiness of synthesis, stability of the compound, solubility in a solvent, compatibility with a polymer and the like. Or less, preferably 6000 or less.
The compound (I), preferably the compounds (II), (III), and (IV) are usually preferably insoluble in water for the purpose of improving the storage stability of the recording medium. Here, “water-insoluble” means that the solubility in water at 25 ° C. and 1 atm is usually 0.1% by weight or less, preferably 0.01% by weight or less.
Also, why the compound (I), preferably the compounds (II), (III), and (IV) is easy to handle in the process of producing the recording medium and can improve the performance of recording / reproducing characteristics by controlling the concentration Therefore, it is preferable that the solubility in the coating solvent is high. Here, the high solubility in the coating solvent means that the solubility in the coating solvent at room temperature is usually 0.01% by weight or more, preferably 0.1% by weight or more.

{Specific examples of compounds (II), (III), (IV)}
Specific examples of the compounds (II), (III), and (IV) are shown below, but the present invention is not limited to the following specific examples as long as the gist thereof is not exceeded.

In the above specific examples, “B ₁ ”, “B ₂ ”, “B ₃ ”, and “B ₄ ” are the photolabile protecting groups shown below.

{Synthesis Method of Compounds (II), (III), (IV)}
Examples of the reaction for linking the luminescent group A and the photolabile protecting group B include, for example, Greene, Protective Groups In Organic Synthesis 3rd Ed. Published by Wiley, by Larock, Comprehensive Organic Transformations 2nd Ed. A well-known method described in Wiley publication etc. can be used.

(a) When the divalent linking group X is —O— For example, the hydroxide of the luminescent group A and the halide of the photolabile protecting group B (particularly preferably, bromide, chloride, reaction site at one point) In contrast, a base (specifically, potassium carbonate, sodium carbonate, cesium carbonate, sodium methoxide, hydrogen) in a solvent such as acetone, dioxane, tetrahydrofuran, N, N-dimethylformamide and the like. Inorganic bases such as sodium hydride, potassium tert-butoxy, sodium tert-butoxy, lithium reagents such as lithium di (isopropyl) amide, lithium di (trimethylsilyl) amide, n-BuLi, sec-BuLi, tert-BuLi, and organic bases such as triethylamine ) In the presence of stirring at room temperature to the reflux temperature of the solvent. Although the reaction time varies depending on the substrate, it is preferably about 1 to 10 hours. The end point of the reaction is confirmed by thin layer chromatography, high performance liquid chromatography or the like, and the end point is judged. After completion of the reaction, the reaction solution is cooled to room temperature and poured into ice water. Extraction with ethyl acetate, methylene chloride, chloroform, diethyl ether or the like gives a crude product. This can be purified by column chromatography to obtain the desired product. The reaction and purification are more preferably performed while blocking light.

(b) When the divalent linking group is —NR ⁰ — For example, the amine compound of the luminescent group A (amine may be mono-substituted or unsubstituted) and the halide of the photolabile protecting group B ( Particularly preferably, bromide, chloride, and about 1 to 1.5 equivalents per reaction site) in a solvent such as acetone, dioxane, tetrahydrofuran, N, N-dimethylformamide and the like (specifically, , Potassium carbonate, sodium carbonate, cesium carbonate, sodium hydroxide, potassium hydroxide, sodium methoxide, sodium hydride, tert-butoxypotassium, tert-butoxysodium and other inorganic bases, lithium di (isopropyl) amide, lithium di (trimethylsilyl) Amides, lithium reagents such as n-BuLi, sec-BuLi, tert-BuLi, and organics such as triethylamine In the presence of a base) (addition of a phase transfer catalyst may be preferable), the mixture is stirred at room temperature to the reflux temperature of the solvent. Although the reaction time varies depending on the substrate, it is preferably about 1 to 10 hours. The end point of the reaction is confirmed by thin layer chromatography, high performance liquid chromatography or the like, and the end point is judged. After completion of the reaction, the reaction solution is cooled to room temperature and poured into ice water. Extraction with ethyl acetate, methylene chloride, chloroform, diethyl ether or the like gives a crude product. This can be purified by column chromatography to obtain the desired product. The reaction and purification are more preferably performed while blocking light.

  Alternatively, the amine compound of the luminescent group A and the aldehyde compound of the photolabile protecting group B precursor are made non-catalytic, or an acid (for example, an inorganic acid such as acetic acid, sulfuric acid, nitric acid, hydrochloric acid, p-TsOH) In the presence of an organic acid such as PPTS), when no solvent or solvent is used, methanol and ethanol are added and heated to produce an imine intermediate. The imine intermediate is reduced with an reducing agent (for example, a weak reducing agent such as sodium borohydride) to obtain the target compound. This method is particularly useful for unsubstituted amines. The reduction reaction and the purification are more preferably performed while blocking light.

{Information recording / reproduction mechanism of compound (I)}
The compound (I) according to the present invention specifically exemplified by the general formula (II), (III), or (IV) is used as an optical recording material in which the luminescent group A is protected against photodissociation before light irradiation. Protected by the group B, no light emission or little light emission, but the photodissociation protecting group B is dissociated by light irradiation, thereby recording information, while the light-emitting group A by light irradiation is recorded. Since the light-emitting matrix having a light source emits strong light and reads the light, the recorded information can be reproduced. Thus, the optical recording material of the present invention comprising such a compound (I) Is suitable for use in a recording layer of an optical recording medium.
Further, depending on the properties of the luminescent group A, even when the photodissociation protecting group B is bonded, light is emitted, and information is recorded by light irradiation. On the other hand, the luminescent matrix having the luminescent group A does not emit fluorescence. In some cases, the recorded information can be reproduced by reading the difference in light emission intensity.

[Optical recording medium]
The optical recording medium of the present invention contains the optical recording material of the present invention as described above in a recording layer.
In the present invention, the optical recording material can be used for a recording layer of an optical recording medium, for example, by applying a coating liquid containing the optical recording material on a transparent substrate and drying it. In addition, resin pellets containing a predetermined amount of the optical recording material are prepared in advance, a recording layer is prepared by a method such as press or injection molding using the resin pellets, and mechanical strength is increased only by the recording layer. The function as a substrate may be given together by securing.
In this case, the optical recording material is not limited to one type, and two or more types may be used in combination.
That is, the optical recording medium of the present invention contains only one type of the compound (I), preferably compounds (I), (II), (III), which is the optical recording material of the present invention, in the recording layer. Alternatively, two or more kinds may be mixed and used in any combination and ratio.

  As the coating liquid or resin pellet for forming the recording layer according to the present invention, a singlet oxygen quencher or recording is used together with the optical recording material in order to provide stability and light resistance as the recording layer. A sensitivity improver or the like may be contained.

  Examples of the singlet oxygen quencher include chelate compounds of acetylacetonate, bisphenyldithiol, salicylaldehyde oxime, bisdithio-α-diketone, and transition metals, and one or more of these are used in combination. Used.

  Examples of the recording sensitivity improver include metal compounds in which a metal such as a transition metal is included in the compound in the form of atoms, ions, clusters, and the like. For example, ethylenediamine complex, azomethine complex, phenylhydroxyamine And organometallic compounds such as metal complex, phenanthroline complex, dihydroxyazobenzene complex, dioxime complex, nitrosoaminophenol complex, pyridyltriazine complex, acetylacetonate complex, metallocene complex, etc. Species or two or more are used in combination.

  The coating liquid preferably contains a binder in order to improve the film formability. Examples of the binder include acrylic resins, methacrylic resins, polyvinyl alcohol, polyvinyl pyrrolidone, ketone resins, nitrocellulose, cellulose acetate, polyvinyl butyral, polycarbonate, and the like, and one or more of these may be used in combination. Used.

  The coating liquid is prepared by dissolving the optical recording material of the present invention, the binder, and, if necessary, the singlet oxygen quencher, the recording sensitivity improver and the like in a solvent.

  The solvent is not particularly limited as long as it does not attack the transparent substrate described later. For example, ketone alcohol solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone, methyl cellosolve, ethyl Cellosolve solvents such as cellosolve, chain hydrocarbon solvents such as n-hexane and n-octane, alicyclic rings such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, n-butylcyclohexane, t-butylcyclohexane and cyclooctane Hydrocarbon solvents, ether solvents such as diisopropyl ether and dibutyl ether, perfluoroalkyl alcohol solvents such as tetrafluoropropanol, octafluoropentanol and hexafluorobutanol, methyl lactate, ethyl lactate, Hydroxy ester solvents and the like of methyl butyrate, one or two or more of them may be used in combination. Among these, perfluoroalkyl alcohol solvents such as tetrafluoropropanol, octafluoropentanol and hexafluorobutanol are preferred from the industrial aspect, and tetrafluoropropanol is particularly preferred.

  The concentration of the optical recording material of the present invention in the coating liquid is usually 0.01% by weight or more, preferably 0.1% by weight or more, particularly preferably based on the total solid content in the coating liquid. It is 0.5% by weight or more, usually 50% by weight or less, preferably 5% by weight or less.

  Moreover, as the transparent substrate on which the coating liquid is applied and the recording layer is formed, a transparent substrate with respect to the laser beam to be used, such as glass and various plastics, is preferably used. Examples of plastics include acrylic resin, methacrylic resin, polycarbonate resin, vinyl chloride resin, vinyl acetate resin, nitrocellulose, polyester resin, polyethylene resin, polypropylene resin, polyimide resin, polystyrene resin, epoxy resin, etc. A polycarbonate resin is preferable from the viewpoint of cost, moisture absorption resistance, and the like, and its injection-molded plate is more preferable. The resin material is also preferable when a recording layer is formed by a method such as press or injection molding using resin pellets and the function as a substrate is also provided by ensuring mechanical strength only by the recording layer. Used.

  Examples of the method for applying the coating liquid on the transparent substrate include a doctor blade method, a cast method, a spin coating method, and a dipping method. Among these, spin coating is performed from the viewpoint of mass productivity and cost. The method is preferred.

  The thickness of the recording layer formed on the transparent substrate is not particularly limited, but is usually 5 nm to 50 μm, preferably 10 nm to 10 μm, and more preferably 50 nm to 5 μm.

  In addition, when the recording layer is made by a method such as press or injection molding using resin pellets and the function as a substrate is given by securing the mechanical strength only by the recording layer, the thickness of the recording layer The thickness is usually 100 μm to 20 mm, preferably 200 μm to 10 mm.

  As the optical recording medium in the present invention, an undercoat layer may be provided on the transparent substrate, and the coating liquid may be applied and dried thereon to form a recording layer. A metal reflective layer and a protective layer made of gold, silver, aluminum, or an alloy thereof may be provided on the layer to form a highly reflective medium. In this case, silver is preferable as the metal.

  In that case, the metal reflective layer is formed by vapor deposition, sputtering, ion plating, etc., and further improves the adhesion between the recording layer and the metal reflective layer, or increases the reflectance. Therefore, an intermediate layer may be provided between both layers. In addition, for example, an ultraviolet curable resin is used for forming the protective layer.

  The concentration of the optical recording material of the present invention (that is, compound (I), preferably compounds (I), (II), (III)) in the recording layer containing the optical recording material of the present invention is In the case of a recording layer formed by applying and drying the coating liquid, it is preferably 0.01 to 100% by weight, particularly preferably 0.1 to 50% by weight. 0.01 to 95% by weight, and particularly preferably 1 to 25% by weight. If the optical recording material concentration is lower than this range, sufficient recording / reproduction characteristics cannot be obtained. If the optical recording material concentration is large, the resin concentration as a binder is relatively low in the case of a recording layer made of resin pellets, and sufficient strength cannot be obtained. .

[Recording / reproducing method of optical recording medium of the present invention]
The recording / reproducing method of the optical recording medium of the present invention comprises irradiating recording light to photodissociate the optical recording material of the present invention, that is, compound (I), preferably compounds (I), (II), (III). And recording by reading the light emission intensity change before and after photodissociation.

  The recording light used in the optical recording medium of the present invention may be any wavelength that excites the dissociation reaction of the photodissociating group, but for high-density recording, the shorter the wavelength, the more preferable is a laser having a wavelength of 350 to 530 nm. Light is preferred. Typical examples of such laser light include blue laser light with center wavelengths of 405 nm and 410 nm, blue-green high-power semiconductor laser light with center wavelength of 515 nm, and the like. Further, by using a long-wavelength laser beam having a wavelength of about 500 to 900 nm and performing three-dimensional recording using two-photon absorption of the optical recording material, higher density recording can be performed.

The reproduction light used in the optical recording medium of the present invention may be any wavelength that can excite the luminescent group. However, in order to reproduce information recorded at a high density, the shorter the wavelength, the more preferable. Laser light having a wavelength of 350 to 530 nm is preferable. Typical examples of such laser light include laser light used for the recording light. Further, by using a laser beam having a wavelength of about 500 to 900 nm and performing three-dimensional reproduction using the multiphoton absorption characteristics of the optical recording material, higher density reproduction is possible.
Note that it is preferable to use the same laser light for the recording light and the reproducing light because the system is simplified.
In order to avoid deterioration (decomposition) of the optical recording material of the present invention due to reproduction light and deterioration of the unrecorded portion (photodissociation) particularly when the recording light and the reproduction light are close in wavelength, the optical recording material of the present invention is used. The reproduction light irradiation intensity used for the recording medium is preferably sufficiently smaller than the recording light, and the reproduction light irradiation intensity is 1/5 or less, preferably 1/50 or less of the recording light irradiation intensity. It is preferable to do.

The optical recording medium of the present invention has a large change in emission intensity obtained by photodissociation of the optical recording material of the present invention by light irradiation, and a sufficient S / N ratio can be obtained with a small number of constituent elements. Information is stored stably at room temperature.
Here, the emission intensity change refers to an emission spectrum emitted from a recording medium by irradiating the recording medium with light having a wavelength of about 250 to 400 nm using a fluorescence spectrometer (for example, “F-4500” manufactured by Hitachi, Ltd.). , And the rate of change in emission intensity near the emission peak before and after light irradiation, which is usually 5 or more, preferably 10 or more, and particularly preferably 20 or more.
Also, the term “stable storage at normal temperature” means that, when left in a high-temperature and high-humidity environment at 80 ° C. and 85% RH for 100 hours, the change in emission intensity of the light-irradiated recording portion is usually within 50%, preferably 25% Say that it is within.

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

Example 1
(Synthesis of Specific Example Compound II-1)

  0.8 g of 3- (p-aminophenyl) -7-aminocoumarin and 1.38 g of potassium carbonate are dissolved in 30 ml of N-methylpyrrolidone, heated to 110 ° C. with stirring, and at 110 ° C., o-nitrobenzyl chloride. 2.28 g was added and the mixture was heated and stirred for 5 hours, then cooled to 25 ° C., the reaction solution was discharged into 100 ml of water, extracted with ethyl acetate, the acetic acid solution was dried over sodium sulfate, concentrated, silica Was purified by column chromatography (eluent: ethyl acetate / toluene = 1/4) to obtain 0.29 g of the specific compound II-1 as the target product.

-Visible part absorption (λmax): 384 nm (toluene)
Fluorescence emission peak wavelength (excitation wavelength: 325 nm): 473 nm (toluene)
Mass spectrum DEI (positive mode) method: m / z = 522 (M ⁺ ), 520, 387, 339, 311

<Evaluation of two-photon absorption cross section>
Two-photon absorption cross-sectional evaluation is described in Kato, S .; Matsumoto, T .; Ishi-I, T. Thiemann, T .; Shigeiwa, M .; Gorohmaru, H .; Maeda, S .; Yamashita, Y .; ; Mataka, S .; Chem. Commun. The method was the same as that described in Supporting Information of 2004, 2342-2343. A femtosecond titanium sapphire laser (wavelength: 800 nm, pulse width: 120 fs, repetition rate: 1 kHz, output: 2 mJ / pulse) is used as a measurement light source, and the two-photon absorption cross section is measured by appropriately attenuating the output from the laser. did. When changing the laser wavelength, laser light having a predetermined wavelength was obtained using a wavelength converter (TOPAS). For the measurement, the Z-scan method was used to change the excitation light density in the range of 1 to 40 GW / cm ² . As a measurement sample, a solution in which the compound was dissolved in DMSO at a concentration of 5 mmol / l was used, and this solution was put into a 4-cm transparent 1 cm square quartz cell for measurement.
Specific compound II-1 had a two-photon absorption cross-section at a wavelength of 800 nm of 2 [GM] and a two-photon absorption cross-section at a wavelength of 650 nm of 88 [GM].

Example 2
(Production of optical recording medium and change in fluorescence intensity)
0.5 mg of the specific example compound II-1 synthesized in Example 1 was weighed, and a 5 wt% solution (solvent: 3-hydroxy-3-methyl-) of an acrylic resin (“Acrypet VH-5” manufactured by Mitsubishi Rayon) was used. 2-butanone) was dissolved in 1 g to prepare a coating solution. This coating solution is dropped on a polycarbonate substrate having a thickness of 0.6 mm, left to stand for one day and air-dried, and further dried at a temperature of 100 ° C. for 30 minutes to produce an optical recording medium having a recording layer with a thickness of 10 μm. did.

The fluorescence emission of the obtained optical recording medium was measured with a spectrofluorometer (“F-4500” manufactured by Hitachi, Ltd.), and the fluorescence emission spectrum is shown in FIG. 1 (curve a). Next, a spot-type ultraviolet irradiation device (“Spot Cure UIS-50101AA” manufactured by USHIO INC.), An ultra-high pressure mercury lamp (“USH-500BY1” manufactured by USHIO INC., Main wavelength: 365 nm, irradiation intensity: 300 mW / cm ²⁾ )) After irradiating ultraviolet rays for 1 second and 20 seconds using the spectrofluorometer, the excitation wavelength is 325 nm (in FIG. 1, the excitation wavelength is 325 nm, its multiple wavelength is 650 nm, and the wavelength from the polycarbonate substrate is 350 nm). Fluorescence emission at the peak is also mixed in the spectrum.), And the fluorescence emission spectrum after 1 second irradiation is shown as curve b, and the fluorescence emission spectrum after 20 seconds irradiation is shown as curve c in FIG. Show.
Almost no fluorescence was observed in the curve a, but in the curves b and c, the fluorescence emission intensity having a peak near the wavelength of 470 nm of the recording medium significantly increased.
The fluorescence intensity change rate (contrast) at a wavelength of 520 nm before and after ultraviolet irradiation was about 70 times.
Moreover, the relationship between the weight% of the specific example compound II-1 with respect to the acrylic resin and the fluorescence peak intensity and the fluorescence intensity change rate (contrast) before and after the ultraviolet irradiation for 20 seconds is shown in FIG.

Also, an optical recording medium prepared in the same manner except that the acrylic resin is changed to an acrylic resin “Optrez OZ1100 (manufactured by Hitachi Chemical)” is irradiated with ultraviolet rays for 20 seconds, and then heated at a high temperature and high humidity of 80 ° C. and 85% RH. The peak intensity change when stored below is shown in FIG.
As is apparent from these results, the optical recording medium using the optical recording material of the present invention is extremely excellent in the magnitude of the emission intensity change (contrast) and the storage stability of recorded information.

Further, using the same laser and optical system as those used for the evaluation of the two-photon absorption cross section, a laser beam having an average output of 45 mW / cm ² is condensed to about 1 mm in diameter, and an optical recording medium (acrylic resin “acrylic resin“ acrylic resin ” The recording layer was used for 100 seconds. Thereafter, the optical recording medium is placed in a dark box and irradiated with ultraviolet rays using a handy UV lamp (“ASUV“ SLUV-6 ”manufactured by ASONE, irradiation light principal wavelength: 365 nm, irradiation surface intensity: 0.05 mW / cm ² ). As a result, it was possible to confirm a clear fluorescent spot having the same size as the beam diameter from the portion irradiated with the laser beam.

Example 3
(Specific Example Compound II-21)

Visible part absorption (λmax): 319 nm (toluene)
Fluorescence emission peak wavelength (excitation wavelength: 325 nm): 380 nm (toluene)

Using Example Compound II-21 as an optical recording material, an optical recording medium was prepared in the same manner as in Example 2 (using acrylic resin “Acrypet VH-5”). Similarly, fluorescence before and after UV irradiation was used. The spectrum is shown in FIG.
In addition, the two-photon absorption cross section of the specific example compound II-21 at a wavelength of 650 nm was 3 [GM].
In this optical recording medium, as in Example 2, almost no fluorescence was observed before the ultraviolet irradiation, but after the ultraviolet irradiation, the fluorescence emission intensity having a peak near the wavelength of 380 nm was significantly increased. The fluorescence intensity change rate (contrast) at a wavelength of 380 nm before and after UV irradiation was about 12 times.

Example 4
(Specific Example Compound III-1)

-Visible part absorption (λmax): 457 nm (toluene)
Fluorescence emission peak wavelength (excitation wavelength: 325 nm): 550 nm (toluene)

An optical recording medium having a recording layer with a thickness of 10 μm was produced in the same manner as in Example 2 (using acrylic resin “Acrypet VH-5”) using the specific compound III-1 as an optical recording material. Similarly, the fluorescence spectra before and after UV irradiation are shown in FIG.
In addition, the two-photon absorption cross section of the specific example compound III-1 at a wavelength of 650 nm was 5 [GM].
In this optical recording medium, fluorescence emission was observed before the ultraviolet irradiation, but after the ultraviolet irradiation, the fluorescence emission intensity having a peak near the wavelength of 550 nm was significantly reduced. The fluorescence intensity change rate (contrast) at a wavelength of 550 nm before and after the ultraviolet irradiation was about 8 times.

6 is a chart showing fluorescence emission spectra before and after recording with ultraviolet light on the optical recording medium produced in Example 2. FIG. 6 is a graph showing the relationship between the weight% of a specific example compound with respect to the acrylic resin of the optical recording medium produced in Example 2, and the fluorescence peak intensity and the fluorescence intensity change rate (contrast) before and after ultraviolet irradiation for 20 seconds. 6 is a chart showing fluorescence emission spectra before and after recording with ultraviolet light on the optical recording medium produced in Example 3. FIG. 6 is a chart showing fluorescence emission spectra before and after recording with ultraviolet light on the optical recording medium produced in Example 4. FIG. Example 2 shows the change in peak intensity when an optical recording medium produced using an acrylic resin “Optrez OZ1100” is irradiated with ultraviolet rays for 20 seconds and then stored at 80 ° C. and 85% RH under high temperature and high humidity. It is a chart.

Claims (12)

  An optical recording material comprising a compound having a structure in which at least one luminescent group and one photolabile protecting group are bonded. The optical recording material according to claim 1, comprising a compound having a structure represented by the following general formula (I).

[In formula (I), A represents a luminescent group, X represents a divalent linking group, B represents a photolabile protecting group, and n is an integer of 1-6. ]   The optical recording material according to claim 1, wherein the luminescent group has multiphoton absorption.   4. The optical recording material according to claim 1, wherein the luminescent group is a fluorescent luminescent group.   The optical recording material according to any one of claims 1 to 4, wherein the emission intensity increases after light irradiation. 6. The optical recording material according to claim 2, wherein the compound having a structure represented by the general formula (I) is a compound represented by the following general formula (II).

(In the formula (II),
R ¹ and R ² each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a photolabile protecting group,
a represents an integer of 1 to 3.
Z is a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, or — (Ar ¹ ) _r — (X—B) _s (where Ar ¹ has a substituent). And X represents a divalent linking group, B represents a photolabile protecting group, r and s are each independently 0 or 1, and R ¹ and Ar ¹ are bonded. And may form a 6-membered ring). ] 6. The optical recording material according to claim 2, wherein the compound having a structure represented by the general formula (I) is a compound represented by the following general formula (III).

[In the formula (III),
R ³ and R ⁴ each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a photolabile protecting group,
t is an integer of 0 to 4, and u is an integer of 0 to 6. ] 6. The optical recording material according to claim 2, wherein the compound having a structure represented by the general formula (I) is a compound represented by the following general formula (IV).

[In the formula (IV),
Y represents —O— or —S—;
Ar ² and Ar ³ each independently represents an aromatic ring group which may have a substituent,
X represents a divalent linking group,
B represents a photolabile protecting group,
v and w are each independently an integer of 0 to 4. ] 9. The photolabile protecting group B is any one selected from the group consisting of groups represented by the following general formulas (V), (VI), (VII) and (VIII): The optical recording material according to 1.

[The aromatic rings of the formulas (V) to (VII) may further have a substituent.
In formula (VIII), R ⁹ , R ¹⁰ and R ¹¹ each independently represents an arbitrary substituent, but at least one of R ⁹ , R ¹⁰ and R ¹¹ may be an alkyl group which may have a substituent. It is. ]   An optical recording medium comprising the optical recording material according to claim 1 in a recording layer.   The recording is performed by photodissociating a compound having a light emitting group and a photolabile protecting group constituting the optical recording material, and reproduction is performed by reading a change in emission intensity before and after the photodissociation. Item 11. A method for recording and reproducing an optical recording medium according to Item 10. A compound represented by the following general formula (II):

(In the formula (II),
R ¹ and R ² each independently have a hydrogen atom, a halogen atom, a nitro group, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an aromatic ring group,
X represents a divalent linking group,
B represents a group represented by the following general formula (V), (VI), (VII), or (VIII);
a represents an integer of 1 to 3.
Z is a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, or — (Ar ¹ ) _r — (X—B) _s (where Ar ¹ has a substituent). X represents a divalent linking group, B represents a group represented by the following general formula (V), (VI), (VII), or (VIII), r and s each independently represents 0 or 1, and R ¹ and Ar ¹ may combine to form a 6-membered ring.

(The aromatic rings of formulas (V) to (VII) may further have a substituent.
In formula (VIII), R ⁹ , R ¹⁰ and R ¹¹ each independently represents an arbitrary substituent, but at least one of R ⁹ , R ¹⁰ and R ¹¹ may be an alkyl group which may have a substituent. It is. )]

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