Compound, recording medium, information recording method, and information reading method

Abstract

A compound in one aspect of the present disclosure is represented by formula (1). In formula (1), R1 to R4 are each independently a hydrocarbon group which may have a substituent. # imgabs0 #

Description

Technical Field

[0001] The present disclosure relates to a compound, a recording medium, a method for recording information, and a method for reading information. Background Art

[0002] Products that use compounds that generate gas by thermal decomposition are known. One example is an optical information recording medium. In an optical information recording medium, recording is performed by degrading the recording layer using a laser. Degrading the recording layer typically means decomposing the material in the recording layer such as a light absorbing pigment or resin. If the material decomposes, shape changes such as bumps and openings occur, and the reflectivity of light changes before and after recording. Therefore, for recording, the decomposition of the material is important, and research related to the thermal decomposition behavior of the recording layer is actively being carried out. For example, a material that generates gas during thermal decomposition can be used to form gaps in the recording layer. By forming gaps, the refractive index difference before and after recording is expanded. In this way, clear recording marks can be formed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-221841

[0006] Non-patent literature

[0007] Non-patent document 1: Shuichi Maeda, "Chemical pigment chemistry and optical disks of organic optical recording materials", Kyoritsu Publishing, 2013, pp. 54-60 Summary of the invention

[0008] Problems to be solved by the invention

[0009] There is a need for novel compounds that generate gases by thermal decomposition.

[0010] Means for solving problems

[0011] The compound in one embodiment of the present disclosure is represented by the following formula (1).

[0012] [Chemical formula number 1]

[0013]

[0014] In the formula (1), R 1 To R 4 Each of them is independently a hydrocarbon group which may have a substituent.

[0015] Effects of the Invention

[0016] The present disclosure provides novel compounds that generate gases by thermal decomposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1A It is a flowchart related to the method of recording information using a recording medium containing the compound according to one embodiment of the present disclosure.

[0018] Figure 1B It is a flowchart related to the method of reading information using the recording medium containing the compound related to one embodiment of the present disclosure.

[0019] Figure 2 is a compound 1 represented by formula (5) 1 H-NMR spectrum.

[0020] Figure 3 is a compound 2 represented by formula (7) 1 H-NMR spectrum.

[0021] Figure 4 is a compound 3 represented by formula (8) 1 H-NMR spectrum.

[0022] Figure 5 is a compound 4 represented by formula (9) 1 H-NMR spectrum.

[0023] Figure 6 is a compound 5 represented by formula (10) 1 H-NMR spectrum. DETAILED DESCRIPTION

[0024] (Insights that form the basis of this disclosure)

[0025] In recent years, in the field of optical information recording media, from the perspective of the diffraction limit of the focused laser, in order to achieve a finer light focusing point, a laser with a short wavelength is used. In the specifications of the Blu-ray (registered trademark) disc, a laser with a central wavelength of 405nm is used. During recording, the recording layer absorbs the laser and releases the absorbed light energy as heat. Using this heat, the recording layer decomposes to form a recording mark. For example, in the case of an optical information recording medium that uses an organic material for the recording layer, the light absorbing pigment absorbs the laser and generates heat, and using this heat, the light absorbing pigment or the material around the light absorbing pigment decomposes. Thus, a recording mark is formed.

[0026] Patent Document 1 discloses that a compound having a substituent that generates a gas upon thermal decomposition is used for a recording layer of an optical information recording medium.

[0027] Non-Patent Document 1 discloses that a decarbonation reaction is preferred in formation of a recording mark by gas generation in an optical information recording medium.

[0028] However, high-speed recording is required for optical information recording media. To achieve high-speed recording, a short laser irradiation time must be used to form a recording mark. However, if the laser irradiation time becomes shorter, the light absorption of the recording layer decreases, thereby reducing the heat generation. Therefore, for high-speed recording, the property of thermal decomposition at low temperatures is required.

[0029] The present inventors have conducted intensive studies and have newly found that a compound represented by the formula (1) described below generates gas and decomposes at low temperatures.

[0030] (Overview of one aspect of the present disclosure)

[0031] The compound according to the first embodiment of the present disclosure is represented by the following formula (1).

[0032] [Chemical formula number 2]

[0033]

[0034] In the formula (1), R 1 To R 4 Each of them is independently a hydrocarbon group which may have a substituent.

[0035] The first embodiment relates to compounds that can be thermally decomposed to produce carbon dioxide.

[0036] In the second embodiment of the present disclosure, for example, according to the compound related to the first embodiment, the hydrocarbon group may be an alkyl group, an unsaturated hydrocarbon group or an aryl group.

[0037] The second embodiment involves compounds that can be thermally decomposed to produce carbon dioxide.

[0038] In the third aspect of the present disclosure, for example, the compound according to the first aspect can be represented by the following formula (2).

[0039] [Chemical formula number 3]

[0040]

[0041] In the formula (2), R 5 To R 9 Each of the above-mentioned atoms independently contains at least one atom selected from the group consisting of H, C, N, O, F, P, S, Cl, I and Br.

[0042] According to a third embodiment, the compound can be thermally decomposed at a temperature below 150°C, for example.

[0043] In the fourth embodiment of the present disclosure, for example, according to the compound involved in the third embodiment, the R 5 To the R 9Independently of each other, they may be a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a group containing an oxygen atom, a group containing a nitrogen atom, a group containing a sulfur atom, a group containing a silicon atom, a group containing a phosphorus atom, or a group containing a boron atom.

[0044] In the fifth aspect of the present disclosure, for example, the compound according to the first aspect can be represented by the following formula (3) or (4).

[0045] [Chemical formula number 4]

[0046]

[0047] In the formula (4), L includes at least one atom selected from the group consisting of C, N, O, P, S and Si.

[0048] According to the fourth or fifth embodiment, the compound can be thermally decomposed at, for example, 150° C. or less.

[0049] In the sixth aspect of the present disclosure, for example, the compound according to the first aspect can be represented by the following formula (5).

[0050] [Chemical formula number 5]

[0051]

[0052] The compound according to the sixth aspect of the present disclosure can be thermally decomposed at 150° C. or lower.

[0053] In the seventh aspect of the present disclosure, for example, the compound according to any one of the first to sixth aspects can be used for a device utilizing light having a wavelength of 390 nm or more and 420 nm or less.

[0054] The compound according to the seventh aspect of the present disclosure generates gas by thermal decomposition and is therefore suitable as a material for a device utilizing light and / or heat.

[0055] An eighth aspect of the present disclosure provides a recording medium comprising the compound according to any one of the first to seventh aspects.

[0056] The recording medium according to the eighth aspect is capable of recording information at high speed.

[0057] The ninth aspect of the present disclosure relates to a method for recording information, comprising: preparing a light source that emits light having a wavelength of 390 nm to 420 nm; and focusing the light from the light source and irradiating the light to a recording layer in a recording medium containing the compound according to any one of the first to seventh aspects.

[0058] The information recording method according to the ninth aspect of the present disclosure can record information at a high speed.

[0059] The tenth scheme of the present disclosure involves a method for reading information, for example, a method for reading information recorded using the recording method involved in the ninth scheme, and the reading method includes: irradiating light to a recording layer in the recording medium to thereby measure the optical properties of the recording layer; and reading information from the recording layer.

[0060] In an eleventh aspect of the present disclosure, for example, according to the information reading method of the tenth aspect, the optical characteristic may be the intensity of fluorescent light emitted from the recording layer.

[0061] According to the information reading method according to the tenth or eleventh aspect, the recording layer on which the information is recorded can be easily identified.

[0062] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments.

[0063] (Implementation Method)

[0064] The compound A of the present embodiment is represented by the following formula (1).

[0065] [Chemical formula number 6]

[0066]

[0067] In formula (1), R 1 To R 4 Each of them is independently a hydrocarbon group which may have a substituent.

[0068] The hydrocarbon group is an alkyl group or an unsaturated hydrocarbon group.

[0069] The carbon number of the alkyl group is not particularly limited, for example, it is 1 or more and 20 or less. From the viewpoint of being able to easily synthesize compound A, the carbon number of the alkyl group may be 1 or more and 10 or less, or 1 or more and 5 or less. Sometimes, the carbon number of the alkyl group may be 7 or more. By adjusting the carbon number of the alkyl group, the solubility of compound A in a solvent or a resin composition can be adjusted. The alkyl group may be linear, branched, or cyclic. At least one hydrogen atom contained in the alkyl group may be substituted by a group containing at least one atom selected from N, O, P, and S. As the alkyl group, methyl, ethyl, propyl, butyl, 2-methylbutyl, pentyl, hexyl, 2,3-dimethylhexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecanyl, eicosyl, 2-methoxybutyl, 6-methoxyhexyl, etc. may be listed.

[0070] The unsaturated hydrocarbon group contains unsaturated bonds such as carbon-carbon double bonds and carbon-carbon triple bonds. The number of unsaturated bonds contained in the unsaturated hydrocarbon group is, for example, greater than 1 and less than 5. The carbon number of the unsaturated hydrocarbon group is not particularly limited, for example, greater than 2 and less than 20, greater than 2 and less than 10, or greater than 2 and less than 5. The unsaturated hydrocarbon group may be linear, branched, or cyclic. At least one hydrogen atom contained in the unsaturated hydrocarbon group may be substituted by a group containing at least one atom selected from N, O, P, and S. Examples of the unsaturated hydrocarbon group include vinyl, ethynyl, and allyl.

[0071] The compound A represented by formula (1) can be thermally decomposed to generate carbon dioxide. The thermal decomposition temperature of the compound A is not particularly limited, and may be 150° C. or less. The thermal decomposition temperature of the compound A may be, for example, in the range of 100° C. to 150° C., or in the range of 115° C. to 145° C. or less. By setting the thermal decomposition temperature to 100° C. or more, the optical recording medium containing the compound A can withstand a heat resistance test at a predetermined temperature.

[0072] When compound A is solid at room temperature (5°C to 35°C) and atmospheric pressure, a thin film can be formed by dissolving or dispersing compound A in a solvent to prepare a solution and applying the solution to a substrate. The ability to form a thin film using a wet method is advantageous for mass production of products using compound A.

[0073] The thermal decomposition temperature of compound A can be measured by thermogravimetric analysis. 10 wt% thermal decomposition temperature (Td 10 ) is the temperature showing a weight loss of 10 wt % in thermogravimetric analysis.

[0074] In formula (1), the atom adjacent to the carbon of the carbonyl group is a sulfur atom (S). Specifically, the atom adjacent to the carbon of the carbonyl group is a sulfur atom (S), and the sulfur atom constitutes a sulfonyl group (-SO2-). Due to the electron-withdrawing property of the sulfonyl group, the bonding between the carbon atom of the carbonyl group and the sulfur atom of the sulfonyl group is weakened. It is believed that this contributes to the reduction of the thermal decomposition temperature of compound A.

[0075] In formula (1), R 2 To R 4 The bonded carbon is a tertiary carbon atom. Such a structure enables the generation of carbon dioxide during thermal decomposition of the compound represented by formula (1).

[0076] In formula (1), R 2 To R 4 Each has a carbon atom bonded to a tertiary carbon atom. A hydrogen atom is bonded to at least one of these carbon atoms. According to such a structure, when the compound represented by formula (1) is thermally decomposed, the carbon atoms from the tertiary carbon atom and R 2 To R 4An olefin can be generated together with carbon dioxide. A typical example of a group having such characteristics is a BOC group (tert-butoxycarbonyl group).

[0077] Compound A may have a property of not absorbing light in a specific wavelength range. The molar absorption coefficient ε of compound A for light in the specific wavelength range may be less than 1×10 2 mol -1 ·L·cm -1 In this case, compound A can be easily used in an optical recording medium that uses light in this wavelength range to record and read information, and it is easy to realize multilayering of the optical recording medium. The specific wavelength range is, for example, 390 nm or more and 420 nm or less, for example, 405 nm.

[0078] Examples of the compound A represented by the formula (1) include compounds represented by the following formula (2).

[0079] [Chemical formula number 7]

[0080]

[0081] In formula (2), R 5 To R 9 Each of the above-mentioned atoms independently contains at least one atom selected from the group consisting of H, C, N, O, F, P, S, Cl, I and Br.

[0082] In formula (2), R 5 To R 9 The following descriptions about the group containing nitrogen atom, the group containing oxygen atom, the group containing phosphorus atom, and the group containing sulfur atom can also be applied to R in formula (1): 1 To R 4 .

[0083] Examples of the halogen atom include F, Cl, Br, and I. In this specification, a halogen atom may be referred to as a halogen group.

[0084] The number of carbon atoms in the hydrocarbon group is not particularly limited, and may be, for example, 1 to 20, 1 to 10, or 1 to 5. By adjusting the number of carbon atoms in the hydrocarbon group, the solubility of the compound A in a solvent or a resin composition can be adjusted. The hydrocarbon group may be linear, branched, or cyclic.

[0085] The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0086] Examples of the hydrocarbon group include an aliphatic saturated hydrocarbon group, an alicyclic hydrocarbon group, an aliphatic unsaturated hydrocarbon group, and the like. The aliphatic saturated hydrocarbon group may be an alkyl group. Examples of the aliphatic saturated hydrocarbon group include -CH3, -CH2CH3, -CH2CH2CH3, -CH(CH3)2, -CH(CH3)CH2CH3, -C(CH3)3, -CH2CH(CH3)2, -(CH2)3CH3, -(CH2)4CH3, -C(CH2CH3)(CH3)2, -CH2C(CH3)3, -(CH2)5CH3, -(CH2)6CH3, -(CH2)7CH3, -(CH2)8CH3, -(CH2)9CH3, -(CH2) 10 CH3, -(CH2) 11 CH3, -(CH2) 12 CH3, -(CH2) 13 CH3, -(CH2) 14 CH3, -(CH2) 15 CH3, -(CH2) 16 CH3, -(CH2) 17 CH3, -(CH2) 18 CH3, -(CH2) 19 Examples of alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl. Examples of aliphatic unsaturated hydrocarbon groups include -CH=CH2, -C≡CH, -C≡CCH3, -C(CH3)=CH2, -CH=CHCH3, and -CH2CH=CH2.

[0087] The so-called halogenated hydrocarbon group means a group in which at least one hydrogen atom contained in the hydrocarbon group is replaced by a halogen atom. The halogenated hydrocarbon group may be a group in which all hydrogen atoms contained in the hydrocarbon group are replaced by halogen atoms. Examples of the halogenated hydrocarbon group include halogenated alkyl groups and halogenated alkenyl groups.

[0088] Examples of the halogenated alkyl group include -CF3, -CH2F, -CH2Br, -CH2Cl, -CH2I, and -CH2CF3. Examples of the halogenated alkenyl group include -CH=CHCF3.

[0089] The group containing an oxygen atom is, for example, a substituent having at least one selected from a hydroxyl group, a carboxyl group, an aldehyde group, an ether group, an acyl group, and an ester group.

[0090] As a substituent having a hydroxyl group, for example, a hydroxyl group itself and a hydrocarbon group having a hydroxyl group can be listed. In the substituent, the hydroxyl group can be deprotonated to -O -As the hydrocarbon group having a hydroxyl group, there are -CH2OH, -CH(OH)CH3, -CH2CH(OH)CH3, -CH2C(OH)(CH3)2 and the like.

[0091] As a substituent having a carboxyl group, for example, a carboxyl group itself and a hydrocarbon group having a carboxyl group can be listed. Among the substituents, the carboxyl group can be deprotonated to -CO2 - As hydrocarbon groups having a carboxyl group, -CH2CH2COOH, -C(COOH)(CH3)2, -CH2CO2 - wait.

[0092] Examples of the substituent having an aldehyde group include an aldehyde group itself and a hydrocarbon group having an aldehyde group. Examples of the hydrocarbon group having an aldehyde group include -CH=CHCHO and the like.

[0093] As the substituent having an ether group, for example, an alkoxy group, a halogenated alkoxy group, an alkenyloxy group, an ethylene oxide group, and a hydrocarbon group having at least one of these functional groups can be listed. At least one hydrogen atom contained in the alkoxy group can be substituted by a group containing at least one atom selected from N, O, P and S. As the alkoxy group, a methoxy group, an ethoxy group, a 2-methoxyethoxy group, a butoxy group, a 2-methylbutoxy group, a 2-methoxybutoxy group, a 4-ethylthiobutoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, a tridecyloxy group, a tetradecyloxy group, a pentadecyloxy group, a hexadecyloxy group, a heptadecyloxy group, an octadecyloxy group, a nonadecyloxy group, an eicosyloxy group, -OCH2O can be listed. - 、-OCH2CH2O - 、-O(CH2)3O - Examples of halogenated alkoxy groups include -OCHF2, -OCH2F, -OCH2Cl, etc. Examples of alkenyloxy groups include -OCH=CH2, etc. Examples of hydrocarbon groups having a functional group such as an alkoxy group include -CH2OCH3, -C(OCH3)3, 2-methoxybutyl, 6-methoxyhexyl, etc.

[0094] Examples of the substituent having an acyl group include an acyl group itself and a hydrocarbon group having an acyl group. Examples of the acyl group include -COCH3 and the like. Examples of the hydrocarbon group having an acyl group include -CH=CHCOCH3 and the like.

[0095] As a substituent having an ester group, for example, an alkoxycarbonyl group, an acyloxy group, and a hydrocarbon group having at least one of these functional groups can be listed. As an alkoxycarbonyl group, -COOCH3, -COO(CH2)3CH3, -COO(CH2)7CH3, etc. can be listed. As an acyloxy group, -OCOCH3, etc. can be listed. As a hydrocarbon group having a functional group such as an acyloxy group, -CH2OCOCH3, etc. can be listed.

[0096] The group containing a nitrogen atom is, for example, a substituent having at least one selected from an amino group, an imino group, a cyano group, an azido group, an amide group, a carbamate group, a nitro group, a cyanamide group, an isocyanate group, and an oxime group.

[0097] Examples of substituents having an amino group include primary amino groups, secondary amino groups, tertiary amino groups, quaternary amino groups, and hydrocarbon groups having at least one of these functional groups. In the substituents, the amino group may be protonated. Examples of tertiary amino groups include -N(CH3)2. Examples of hydrocarbon groups having functional groups such as primary amino groups include -CH2NH2, -CH2N(CH3)2, -(CH2)4N(CH3)2, -CH2CH2NH3 + 、-CH2CH2NH(CH3)2 + 、-CH2CH2N(CH3)3 + wait.

[0098] Examples of the substituent having an imino group include the imino group itself and a hydrocarbon group having an imino group. Examples of the imino group include -N=CCl2 and the like.

[0099] Examples of the substituent having a cyano group include a cyano group itself and a hydrocarbon group having a cyano group. Examples of the hydrocarbon group having a cyano group include -CH2CN, -CH=CHCN, and the like.

[0100] Examples of the substituent having an azide group include an azide group itself and a hydrocarbon group having an azide group.

[0101] As a substituent having an amide group, for example, an amide group itself and a hydrocarbon group having an amide group can be listed. As an amide group, -CONH2, -NHCHO, -NHCOCH3, -NHCOCF3, -NHCOCH2Cl, -NHCOCH(CH3)2, etc. can be listed. As a hydrocarbon group having an amide group, -CH2CONH2, -CH2NHCOCH3, etc. can be listed.

[0102] Examples of the substituent having a carbamate group include a carbamate group itself and a hydrocarbon group having a carbamate group. Examples of the carbamate group include -NHCOOCH3, -NHCOOCH2CH3, and -NHCO2(CH2)3CH3.

[0103] Examples of the substituent having a nitro group include the nitro group itself and a hydrocarbon group having a nitro group. Examples of the hydrocarbon group having a nitro group include -C(NO2)(CH3)2 and the like.

[0104] Examples of the substituent having a cyanamide group include a cyanamide group itself and a hydrocarbon group having a cyanamide group. The cyanamide group is represented by -NHCN.

[0105] Examples of the substituent having an isocyanate group include an isocyanate group itself and a hydrocarbon group having an isocyanate group. The isocyanate group is represented by -N=C=O.

[0106] Examples of the substituent having an oxime group include an oxime group itself and a hydrocarbon group having an oxime group. The oxime group is represented by -CH=NOH.

[0107] The group containing a sulfur atom is, for example, a substituent having at least one selected from a thiol group, a thioether group, a sulfinyl group, a sulfonyl group, a sulfinyl group, a sulfonic acid group, an acylthio group, a sulfenamide group, a sulfonamide group, a thioamide group, a thiocarbamate group and a thiocyanate group.

[0108] Examples of the substituent having a thiol group include a thiol group itself and a hydrocarbon group having a thiol group. The thiol group is represented by -SH.

[0109] As a substituent having a thioether group, for example, an alkylthio group, an alkyldisulfide group, an alkenylthio group, an alkynylthio group, a thiirane group, and a hydrocarbon group having at least one of these functional groups can be listed. At least one hydrogen atom contained in the alkylthio group can be substituted by a halogen group. As an alkylthio group, -SCH3, -S(CH2)F, -SCH(CH3)2, -SCH2CH3, etc. can be listed. As an alkyldisulfide group, -SSCH3, etc. can be listed. As an alkenylthio group, -SCH=CH2, -SCH2CH=CH2, etc. can be listed. As an alkynylthio group, -SC≡CH, etc. can be listed. As a hydrocarbon group having a functional group such as an alkylthio group, -CH2SCF3, etc. can be listed.

[0110] Examples of the substituent having a sulfinyl group include a sulfinyl group itself and a hydrocarbon group having a sulfinyl group. Examples of the sulfinyl group include -SOCH3 and the like.

[0111] As the substituent having a sulfonyl group, for example, a sulfonyl group itself and a hydrocarbon group having a sulfonyl group can be listed. As the sulfonyl group, -SO2CH3 can be listed. As the hydrocarbon group having a sulfonyl group, -CH2SO2CH3, -CH2SO2CH2CH3, etc. can be listed.

[0112] As a substituent having a sulfinyl group, for example, a sulfinyl group itself and a hydrocarbon group having a sulfinyl group can be listed. In this substituent, the sulfinyl group can be deprotonated to -SO2 - status.

[0113] As the substituent having a sulfonic acid group, for example, the sulfonic acid group itself and a hydrocarbon group having a sulfonic acid group can be listed. In the substituent, the sulfonic acid group can be deprotonated to -SO3 - status.

[0114] Examples of the substituent having an acylthio group include an acylthio group itself and a hydrocarbon group having an acylthio group. Examples of the acylthio group include -SCOCH3 and the like.

[0115] Examples of the substituent having a sulfenamide group include the sulfenamide group itself and a hydrocarbon group having a sulfenamide group. Examples of the sulfenamide group include -SN(CH3)2 and the like.

[0116] Examples of the substituent having a sulfonamide group include the sulfonamide group itself and a hydrocarbon group having a sulfonamide group. Examples of the sulfonamide group include -SO2NH2, -NHSO2CH3, and the like.

[0117] As a substituent having a thioamide group, for example, a thioamide group itself and a hydrocarbon group having a thioamide group can be listed. As a thioamide group, -NHCSCH3 can be listed. As a hydrocarbon group having a thioamide group, -CH2SC(NH2)2 can be listed. + wait.

[0118] Examples of the substituent having a thiourethane group include a thiourethane group itself and a hydrocarbon group having a thiourethane group. Examples of the thiourethane group include -NHCSNHCH2CH3 and the like.

[0119] Examples of the substituent having a thiocyanate group include the thiocyanate group itself and a hydrocarbon group having a thiocyanate group. Examples of the hydrocarbon group having a thiocyanate group include -CH2SCN and the like.

[0120] The group containing a silicon atom is, for example, a substituent having at least one selected from a silyl group and a siloxy group.

[0121] As a substituent having a silyl group, a silyl group itself and a hydrocarbon group having a silyl group can be listed. As a silyl group, -Si(CH3)3, -SiH(CH3)2, -Si(OCH3)3, -Si(OCH2CH3)3, -SiCH3(OCH3)2, -Si(CH3)2OCH3, -Si(N(CH3)2)3, -SiF(CH3)2, -Si(OSi(CH3)3)3, -Si(CH3)2OSi(CH3)3, etc. can be listed. As a hydrocarbon group having a silyl group, -(CH2)2Si(CH3)3, etc. can be listed.

[0122] Examples of the substituent having a silyloxy group include the silyloxy group itself and a hydrocarbon group having a silyloxy group. Examples of the hydrocarbon group having a silyloxy group include -CH2OSi(CH3)3 and the like.

[0123] The group containing a phosphorus atom is, for example, a substituent having at least one selected from a phosphine group and a phosphono group.

[0124] As a substituent having a phosphino group, for example, a phosphino group itself and a hydrocarbon group having a phosphino group can be listed. As a phosphino group, -PH2, -P(CH3)2, -P(CH2CH3)2, -P(C(CH3)3)2, -P(CH(CH3)2)2, etc. can be listed.

[0125] Examples of the substituent having a phosphonyl group include a phosphonyl group itself and a hydrocarbon group having a phosphonyl group. Examples of the hydrocarbon group having a phosphonyl group include -CH2PO(OCH2CH3)2 and the like.

[0126] The group containing a boron atom is, for example, a substituent having a boronic acid group. Examples of the substituent having a boronic acid group include a boronic acid group itself and a hydrocarbon group having a boronic acid group.

[0127] Specific examples of the compound A represented by the formula (1) include compounds represented by the following formula (3) or formula (4).

[0128] [Chemical formula number 8]

[0129]

[0130] In formula (4), L contains at least one atom selected from C, N, O, P, S and Si.

[0131] As further specific examples of the compound A represented by the formula (1), there can be mentioned compounds represented by the following formula (5).

[0132] [Chemical formula number 9]

[0133]

[0134] The compound represented by the formula (3), (4) or (5) can be thermally decomposed at, for example, 150° C. or lower.

[0135] The method for synthesizing the compound represented by formula (5) is not particularly limited. The compound represented by formula (5) can be synthesized, for example, by the following method.

[0136] First, a compound represented by the following formula (6) is prepared: The compound is 4,4'-thiobisthiophenol.

[0137] [Chemical formula number 10]

[0138]

[0139] Next, the compound represented by formula (6) is reacted with a compound having a tert-butoxycarbonyl group. Next, the reaction product is reacted with sodium hypochlorite pentahydrate as an oxidant. Thus, sulfur is oxidized to become a sulfonyl group, and a compound represented by formula (5) is obtained.

[0140] The terminal group of the compound represented by formula (5) is a tert-butoxycarbonyl group. The tert-butoxycarbonyl group generates a mixed gas of carbon dioxide and isobutylene when decomposed. In this specification, a compound that generates gas when decomposed is referred to as a gas generating material.

[0141] Compound A represented by formula (1) can be used as a component of a gas generating material, for example. That is, the present disclosure provides a gas generating material comprising compound A represented by formula (1) from another aspect. The gas generating material, for example, comprises compound A as a main component. The so-called "main component" means the component that is contained most in the gas generating material in terms of weight ratio. The gas generating material, for example, is substantially formed by compound A. "Substantially formed by..." means that other components that change the essential characteristics of the mentioned material are excluded. However, in addition to compound A, the gas generating material may also contain impurities. The gas generating material is used for devices or chemical products that need to be deformed or deteriorated due to heat.

[0142] The gas generating material functions as a recording mark forming material for an optical information recording medium, for example. In particular, the gas generating material containing compound A has a low thermal decomposition temperature and generates gas at low temperatures. Therefore, if the gas generating material containing compound A is used for an optical information recording medium, a recording mark can be formed at a high speed.

[0143] The recording medium includes, for example, a thin film called a recording layer. In the recording medium, information is recorded in the recording layer. As an example, the thin film as the recording layer contains compound A. That is, the present disclosure provides a recording medium containing compound A represented by formula (1) from another aspect.

[0144] The recording layer may further include a polymer compound that functions as a light absorbing pigment or an adhesive in addition to the compound A. The recording medium may also include a dielectric layer in addition to the recording layer. The recording medium may include, for example, a plurality of recording layers and a plurality of dielectric layers. In the recording medium, a plurality of recording layers may be alternately stacked with a plurality of dielectric layers.

[0145] The light absorbing pigment may be a nonlinear optical material having a nonlinear optical (Non-Linear Optical) effect. The so-called nonlinear optical effect means an optical phenomenon that occurs in a substance in a manner proportional to the square of the electric field of the irradiated light or a higher order than the square when a strong light such as a laser is irradiated on the substance. By combining a nonlinear optical material with the compound A of the present disclosure, it is possible to achieve multilayering of the recording layer, an increase in recording density, and an increase in recording speed.

[0146] Next, a method of recording information using the above-mentioned recording medium will be described. Figure 1A This is a flowchart related to a method for recording information using the above-mentioned recording medium. First, in step S11, a light source that emits light with a wavelength of more than 390nm and less than 420nm is prepared. As the light source, for example, a femtosecond laser such as a titanium sapphire laser can be used. As the light source, a pulsed laser with a pulse width of picoseconds to nanoseconds such as a semiconductor laser can be used. Secondly, in step S12, the light from the light source is focused by a lens or the like, and irradiated onto the recording layer in the recording medium. Specifically, the light from the light source is focused by a lens or the like, and irradiated onto the recording area in the recording medium. There is no particular restriction on the NA (numerical aperture) of the lens used for light focusing. As an example, a lens with an NA in the range of more than 0.8 and less than 0.9 can be used. The power density near the focus of the light is, for example, 0.1W / cm 2 Above and 1.0×10 20 W / cm 2 The power density near the focal point of the light can be 1.0 W / cm 2 Above, can be 1.0×10 2 W / cm 2 Above, can be 1.0×10 5 W / cm 2 In this specification, the recording area refers to a site existing in the recording layer and capable of recording information by irradiating light.

[0147] In the above-mentioned recording area irradiated with light, physical changes or chemical changes occur. For example, heat is generated when the light absorbing pigment returns to the ground state from the transition state. Due to this heat, the compound A present in the recording area decomposes and produces gas. As a result, the optical properties of the recording area change. For example, the intensity of the light reflected in the recording area, the reflectivity of the light in the recording area, the absorptivity of the light in the recording area, the refractive index of the light in the recording area, etc. change. In the recording area irradiated with light, the intensity of the fluorescent light radiated from the recording area or the wavelength of the fluorescent light sometimes also changes. As a result, information can be recorded in the recording layer, specifically in the recording area (step S13).

[0148] Next, a method of reading information using the above-mentioned recording medium will be described. Figure 1B This is a flowchart related to a method for reading information using the above-mentioned recording medium. First, in step S21, the recording layer in the recording medium is irradiated with light. Specifically, the recording area in the recording medium is irradiated with light. The light used in step S21 may be the same as or different from the light used to record information in the recording medium. Next, in step S22, the optical properties of the recording layer are measured. Specifically, the optical properties of the recording area are measured. As optical properties, for example, the intensity of light reflected in the area, the reflectivity of light in the area, the absorptivity of light in the area, the refractive index of light in the area, the wavelength of fluorescent light emitted from the area, etc. can be listed. Next, in step S23, information is read from the recording layer, specifically, from the recording area.

[0149] In the information reading method, the recording area where the information is recorded can be found by the following method. First, light is irradiated to a specific area of ​​the recording medium. The light may be the same as or different from the light used to record the information on the recording medium. Next, the optical characteristics of the area irradiated with light are measured. As optical characteristics, for example, the intensity of the fluorescent light emitted in the area, the intensity of the light reflected in the area, the reflectivity of the light in the area, the absorptivity of the light in the area, the refractive index of the light in the area, the wavelength of the fluorescent light irradiated from the area, etc. can be listed. Based on the measured optical characteristics, it is determined whether the area irradiated with light is a recording area. For example, when the intensity of the light reflected in the area is below a specific value, it is determined that the area is a recording area. On the other hand, when the intensity of the reflected light is higher than a specific value, it is determined that the area is not a recording area. Furthermore, the method for determining whether the area irradiated with light is a recording area is not limited to the above method. For example, when the intensity of the light reflected in the area is greater than a specific value, it can be determined that the area is a recording area. In addition, when the intensity of the light reflected in the area is below a specific value, it can be determined that the area is not a recording area. When it is determined that the area is not a recording area, the same operation is performed on other areas of the recording medium. In this way, the recording area can be found.

[0150] The information recording method and reading method using the above-mentioned recording medium can be performed by using a known recording device, for example. The recording device includes a light source for irradiating light to a recording area in the recording medium, a measuring device for measuring optical characteristics of the recording area, and a controller for controlling the light source and the measuring device.

[0151] Example

[0152] The present disclosure will be described in more detail below using examples. Note that the following examples are just examples, and the present disclosure is not limited to the following examples.

[0153] [Synthesis of Compound 1]

[0154] First, 150 mg of 4,4'-thiobisthiophenol (manufactured by Tokyo Chemical Industry Co., Ltd.), 290 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 170 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 mL of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a solvent were placed in a 100-mL eggplant flask to dissolve the raw materials in the solvent. Next, the obtained solution was stirred at room temperature for 2 hours using a stirrer. Next, 650 mg of sodium hypochlorite pentahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the solution and stirred at room temperature for 48 hours. The obtained reaction solution was purified by silica gel column chromatography to obtain compound 1 represented by formula (5). Compound 1 was purified by1 Identification by H-NMR. Figure 2 is the 1 H-NMR spectrum of compound 1 1 The H-NMR spectrum is as follows.

[0155] 1 H-NMR (600 MHz, chloroform-D) δ7.93 (d, J=8.3 Hz, 4H), 7.66 (d, J=8.3 Hz, 4H), 1.51 (s, 18H).

[0156] [Synthesis of Compound 2]

[0157] First, 150 mg of 9,3':6',9"-tricarbazole (manufactured by Tokyo Chemical Industry Co., Ltd.), 150 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 90 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 mL of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a solvent were placed in a 100 mL eggplant flask to dissolve the raw materials in the solvent. Next, the obtained solution was stirred at room temperature for 2 hours using a stirrer. The obtained reaction solution was purified by silica gel column chromatography to obtain compound 2 represented by formula (7). Compound 2 was purified by 1 Identification by H-NMR. Figure 3 To represent compound 2 1 H-NMR spectrum of compound 2 1 The H-NMR spectrum is as follows.

[0158] 1 H-NMR (600MHz, chloroform-D) δ8.60(d,J=9.0Hz,2H),8.15(d,J=7.6Hz,6H),7.71(d d,J=8.6,2.4Hz,2H),7.40(d,J=4.8Hz,8H),7.30-7.27(m,4H),1.86(s,9H).

[0159] [Synthesis of Compound 3]

[0160] First, 150 mg of 2,4,6-tris(4-butoxy-2-hydroxyphenyl)-1,3,5-triazine (manufactured by Tokyo Chemical Industry Co., Ltd.), 130 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 70 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 mL of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a solvent were placed in a 100 mL eggplant flask, and the raw materials were dissolved in the solvent. The obtained reaction solution was purified by silica gel column chromatography to obtain compound 3 represented by formula (8). Compound 3 was purified by1 Identification by H-NMR. Figure 4 To represent compound 3 1 H-NMR spectrum of compound 3 1 The H-NMR spectrum is as follows.

[0161] 1 H-NMR (600MHz, chloroform-D) δ8.64(d,J=9.0Hz,3H),6.93(dd,J=9.0,2.8Hz,3H),6.77(d,J=2.8Hz,3H),4.04( t,J=6.5Hz,6H),1.83-1.78(m,6H),1.52(td,J=15.0,7.3Hz,6H),1.28(s,27H),1.00(t,J=7.6Hz,9H).

[0162] [Synthesis of Compound 4]

[0163] First, 150 mg of methyl 4-aminobenzoate (manufactured by Tokyo Chemical Industry Co., Ltd.), 480 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 270 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 mL of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a solvent were placed in a 100 mL eggplant-shaped flask to dissolve the raw materials in the solvent. Next, the obtained solution was stirred at room temperature for 2 hours using a stirrer. The obtained reaction solution was purified by silica gel column chromatography to obtain compound 4 represented by formula (9). Compound 4 was purified by 1 Identification by H-NMR. Figure 5 To represent compound 4 1 H-NMR spectrum of compound 4 1 The H-NMR spectrum is as follows.

[0164] 1 H-NMR (600 MHz, chloroform-D) δ8.05 (d, J=9.0 Hz, 2H), 7.34 (d, J=8.3 Hz, 2H), 3.92 (s, 3H), 1.61 (s, 1H), 1.44 (s, 9H).

[0165] [Synthesis of Compound 5]

[0166] First, 150 mg of 4,4'-thiobisthiophenol (manufactured by Tokyo Chemical Industry Co., Ltd.), 290 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), 170 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 mg of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a solvent were placed in a 100 mL eggplant-shaped flask to dissolve the raw materials in the solvent. Next, the obtained solution was stirred at room temperature for 2 hours using a stirrer. The obtained reaction solution was purified by silica gel column chromatography to obtain compound 5 represented by formula (10). Compound 5 was purified by 1 Identification by H-NMR. Figure 6 To represent compound 5 1 H-NMR spectrum of compound 5 1 The H-NMR spectrum is as follows.

[0167] 1 H-NMR (600 MHz, chloroform-D) δ7.45 (d, J = 8.3 Hz, 4H), 7.34 (d, J = 8.3 Hz, 4H), 1.51 (s, 18H).

[0168] [Chemical formula number 11]

[0169]

[0170] [Chemical formula number 12]

[0171]

[0172] [Chemical formula number 13]

[0173]

[0174] [Chemical formula number 14]

[0175]

[0176] <Determination of decomposition temperature>

[0177] The thermal decomposition temperatures of compounds 1 to 5 were measured by thermogravimetric analysis. A TG apparatus (TG / DTA7200 manufactured by Hitachi High-Tech Science Co., Ltd.) was used to measure the weight loss rate by increasing the temperature at 10°C / min in the range of 25°C to 500°C under a nitrogen flow at a flow rate of 60 mL / min. The temperature at which the weight loss rate reached 10% of the initial weight was regarded as the thermal decomposition temperature.

[0178] <Bond distance and thermal decomposition temperature>

[0179] Compounds 1 to 5 have a structure represented by the following formula (11). The structural optimization calculation was performed by DFT calculation to obtain the bond distance between X and C in compounds 1 to 5. Specifically, first, a quantum chemical calculation program, Gaussian16 (manufactured by Gaussian Corporation), was used to perform structural optimization calculations for the compounds. As a basis function, 6-31++G(d, p) was used. As a universal function, CAM-B3LYP was used. The bond distances and thermal decomposition temperatures in each compound are shown in Table 1.

[0180] [Chemical formula number 15]

[0181]

[0182] Table 1

[0183]

[0184] As can be seen from Table 1, the longer the bond distance between X and C, the lower the thermal decomposition temperature of the compound. In other words, the longer the bond distance between X and C, the more likely the compound is to decompose at a lower temperature to generate carbon dioxide.

[0185] Next, for compounds 6 to 9 represented by the following formulas (12) to (15), structural optimization calculations were performed by DFT calculations to determine the bond distances between X and C in compounds 6 to 9. In compounds 6 to 9, the bond distances between carbon and the sulfonyl group were all 1.86 nm or more. That is, similarly to compound 1, compounds 6 to 9 can be expected to have thermal decomposition temperatures of 150° C. or less. The bond distances of compounds 6 to 9 are shown in Table 2.

[0186] [Chemical formula number 16]

[0187]

[0188] [Chemical formula number 17]

[0189]

[0190] [Chemical formula number 18]

[0191]

[0192] [Chemical formula number 19]

[0193]

[0194] Table 2

[0195]

[0196] <Production of recording layer>

[0197] First, the following materials were mixed by stirring to obtain a uniformly mixed coating solution. As gas generating materials, compounds 1 to 5 were used. As resins, poly (9-vinyl carbazole) (manufactured by Aldrich) was used. As pigments, 7-diethylamino-4-methylcoumarin (manufactured by Tokyo Chemical Industry Co., Ltd.) was used. As solvents, chlorobenzene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used. The composition ratios of the coating solutions of Example 1 and Comparative Examples 1 to 5 are shown in Table 3.

[0198] Table 3

[0199]

[0200] Next, a thin film as a recording layer was formed on a quartz substrate using a coating liquid. The size of the quartz substrate was 20 mm in length, 20 mm in width, and 1 mm in thickness. The quartz substrate was placed on a spin coater, 400 μL of the coating liquid was dripped onto the quartz substrate, and the substrate was rotated at a speed of 3000 rpm for 30 seconds. Then, the quartz substrate was dried on a hot plate at 80° C. for 30 minutes, thereby obtaining a resin film containing a gas generating material and a pigment.

[0201] <Recording experiment>

[0202] Light with a central wavelength of 405 nm, a peak power of 40 mW, and a repetition frequency of 1 Hz was passed through a lens of NA 0.85, and irradiated onto the resin film while changing the pulse width. When the light irradiated portion was deteriorated under observation with an optical microscope and a hole was formed in the resin film, it was determined that a recording mark was formed, and the pulse width at this time was regarded as the recording pulse width. The recording pulse widths in the resin films of Example 1 and Comparative Examples 1 to 5 are shown in Table 4.

[0203] Table 4

[0204] Recording pulse width Example 1 40ns Comparative Example 1 70ns Comparative Example 2 70ns Comparative Example 3 65ns Comparative Example 4 65ns Comparative Example 5 170ns

[0205] As can be seen from Table 1, the recording pulse width of Example 1 is short, while the recording pulse widths of Comparative Examples 1 to 5 are long. That is, the recording on the resin film of Example 1 shows the possibility of recording at high speed compared with the recording on the resin film of Comparative Examples 1 to 5. As can be seen from the results, the compound having the structure represented by formula (1) shows a low thermal decomposition temperature due to the long bond distance between the carbon and the sulfonyl group. During recording, the pigment absorbs the laser and generates heat. The generated heat is used for thermal decomposition to form a recording mark. The lower the thermal decomposition temperature, the shorter the time it takes for the temperature of the pigment to rise to the thermal decomposition temperature. As a result, compared with compounds having a high thermal decomposition temperature, compounds having a low thermal decomposition temperature can be recorded under a short recording pulse width, i.e., a smaller introduction energy.

[0206] Industrial Applicability

[0207] The compounds disclosed herein can be used in applications such as optical information recording media, resists, and easily disintegrable adhesives. The compounds disclosed herein can generate gas by thermal decomposition at low temperatures. Therefore, high-speed recording can be achieved in optical information recording media. In the present disclosure, a novel compound suitable for the low temperature of the formation temperature of recording marks in order to improve recording sensitivity in the recording layer of an optical information recording medium can be provided.

Claims

1. A compound represented by the following formula (1): [Chemical formula number 1] In the formula (1), R 1 To R 4 Each of them is independently a hydrocarbon group which may have a substituent.

2. The compound according to claim 1, wherein The hydrocarbon group is an alkyl group or an unsaturated hydrocarbon group.

3. The compound according to claim 1, which is represented by the following formula (2): [Chemical formula number 2] In the formula (2), R 5 To R 9 Each of the above-mentioned atoms independently contains at least one atom selected from the group consisting of H, C, N, O, F, P, S, Cl, I and Br.

4. The compound according to claim 3, wherein The R 5 To the R 9 Each of them is independently a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, a group containing an oxygen atom, a group containing a nitrogen atom, a group containing a sulfur atom, a group containing a silicon atom, a group containing a phosphorus atom, or a group containing a boron atom.

5. The compound according to claim 1, which is represented by the following formula (3) or (4): [Chemical formula number 3] In the formula (4), L includes at least one atom selected from C, N, O, P, S and Si.

6. The compound according to claim 1, which is represented by the following formula (5): [Chemical formula number 4] The compound according to claim 1 , which has a thermal decomposition temperature of 150° C. or less. 8 . The compound according to claim 1 , which is used for a device utilizing light having a wavelength of 390 nm or more and 420 nm or less. 9 . A recording medium comprising the compound according to claim 1 .

10. A method for recording information, comprising: preparing a light source that emits light having a wavelength of 390 nm or more and 420 nm or less; and collecting the light from the light source and irradiating the light to a recording layer in a recording medium comprising the compound according to any one of claims 1 to 8.

11. A method for reading information, which is a method for reading information recorded by the recording method according to claim 10, the reading method comprising: measuring optical properties of the recording layer by irradiating the recording layer in the recording medium with light; and reading information from the recording layer.

12. The reading method according to claim 11, wherein: The optical characteristic is the intensity of light reflected by the recording layer.

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