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

Abstract

A compound according to one embodiment of the present disclosure is represented by formula (1).　In formula (1), R1 to R4 each independently is an optionally substituted hydrocarbon group.

Description

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

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

[0002] There are known products that utilize compounds that generate gas upon thermal decomposition. One example is optical information recording media. In optical information recording media, recording is achieved by altering the recording layer with laser light. Altering the recording layer typically involves the decomposition of materials within the recording layer, such as light-absorbing dyes and resins. Decomposition of materials results in changes in shape, such as irregularities and holes, which change the light reflectance before and after recording. Therefore, material decomposition is important for recording, and active research is being conducted on the thermal decomposition behavior of recording layers. For example, voids can be formed within the recording layer using materials that generate gas upon thermal decomposition. Forming voids increases the difference in refractive index before and after recording, allowing for the formation of clear recording marks.

[0003] Japanese Patent Application Laid-Open No. 2008-221841

[0004] Shuichi Maeda, "Chemical Dye Chemistry of Organic Optical Recording Materials and Optical Discs," Kyoritsu Shuppan, 2013, pp. 54-60

[0005] There is a need for new compounds that evolve gases upon thermal decomposition.

[0006] The compound according to one embodiment of the present disclosure is represented by the following formula (1): In the formula (1), R 1 From R 4 are each independently a hydrocarbon group which may have a substituent.

[0007] The present disclosure provides novel compounds that evolve gases upon thermal decomposition.

[0008] 1A is a flowchart showing a method for recording information using a recording medium containing a compound according to an embodiment of the present disclosure. FIG. 1B is a flowchart showing a method for reading information using a recording medium containing a compound according to an embodiment of the present disclosure. FIG. 2 is a flowchart showing a method for reading information using a recording medium containing a compound according to an embodiment of the present disclosure. 13 is a graph showing the H-NMR spectrum of compound 2 represented by formula (7). 1 4 is a graph showing the H-NMR spectrum of compound 3 represented by formula (8). 1 5 is a graph showing the H-NMR spectrum of compound 4 represented by formula (9). 1 6 is a graph showing the H-NMR spectrum of compound 5 represented by formula (10). 1 1 is a graph showing a H-NMR spectrum.

[0009] (Findings that Form the Basis of the Present Disclosure) In recent years, in the field of optical information recording media, laser light with a short wavelength has been used to achieve a finer focused spot, in view of the diffraction limit of focused laser light. The Blu-ray (registered trademark) disc standard uses laser light with a central wavelength of 405 nm. During recording, the recording layer absorbs this laser light and releases the absorbed light energy as heat. This heat causes the recording layer to decompose, forming a recording mark. For example, in the case of optical information recording media that use an organic material for the recording layer, the light-absorbing dye absorbs the laser light and generates heat, and this heat causes the light-absorbing dye or the material surrounding the light-absorbing dye to decompose. This results in the formation of a recording mark.

[0010] Patent Document 1 discloses that a compound having a substituent that generates gas upon thermal decomposition is used in the recording layer of an optical information recording medium.

[0011] Non-Patent Document 1 discloses that a decarboxylation reaction is preferable for forming recording marks by gas generation in an optical information recording medium.

[0012] Optical information recording media are required to be capable of high-speed recording. To achieve high-speed recording, it is necessary to form recording marks with short-time laser irradiation. However, as the laser irradiation time becomes shorter, the amount of light absorbed by the recording layer decreases, and the amount of heat generated also decreases. Therefore, high-speed recording requires the property of thermal decomposition at low temperatures.

[0013] As a result of extensive research, the present inventors have newly discovered that a compound represented by the formula (1) described below decomposes at low temperatures while generating gas.

[0014] (Summary of one aspect of the present disclosure) A compound according to a first aspect of the present disclosure is represented by the following formula (1). In the formula (1), R 1 From R 4 are each independently a hydrocarbon group which may have a substituent.

[0015] The compound according to the first aspect can be thermally decomposed to generate carbon dioxide.

[0016] In the second aspect of the present disclosure, for example, in the compound according to the first aspect, the hydrocarbon group may be an alkyl group, an unsaturated hydrocarbon group, or an aryl group.

[0017] The compound according to the second embodiment can generate carbon dioxide upon thermal decomposition.

[0018] In the third aspect of the present disclosure, for example, the compound according to the first aspect may be represented by the following formula (2): In the formula (2), R 5 From R 9 each independently contain at least one atom selected from the group consisting of H, C, N, O, F, P, S, Cl, I and Br.

[0019] According to a third aspect, the compound may be thermally decomposed at temperatures below 150°C, for example.

[0020] In the fourth aspect of the present disclosure, for example, in the compound according to the third aspect, the R 5 From the above R 9 may be, independently of one another, 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.

[0021] In the fifth aspect of the present disclosure, for example, the compound according to the first aspect may be represented by the following formula (3) or (4): In the formula (4), L contains at least one atom selected from the group consisting of C, N, O, P, S, and Si.

[0022] According to the fourth or fifth aspect, the compound may be thermally decomposed, for example, at 150°C or below.

[0023] In the sixth aspect of the present disclosure, for example, the compound according to the first aspect may be represented by the following formula (5):

[0024] The compound according to the sixth aspect of the present disclosure can be thermally decomposed at 150°C or less.

[0025] In the seventh aspect of the present disclosure, for example, the compound according to any one of the first to sixth aspects may be used in a device that utilizes light having a wavelength of 390 nm or more and 420 nm or less.

[0026] The compound according to the seventh aspect of the present disclosure generates gas upon thermal decomposition, and is therefore suitable as a material for devices that utilize light and / or heat.

[0027] A recording medium according to an eighth aspect of the present disclosure includes a compound according to any one of the first to seventh aspects.

[0028] The recording medium according to the eighth aspect makes it possible to record information at high speed.

[0029] An information recording method according to a ninth aspect of the present disclosure includes: preparing a light source that emits light having a wavelength of 390 nm or more and 420 nm or less; and concentrating the light from the light source and irradiating the light onto a recording layer in a recording medium containing a compound according to any one of the first to seventh aspects.

[0030] The information recording method according to the ninth aspect of the present disclosure makes it possible to record information at high speed.

[0031] An information reading method according to a tenth aspect of the present disclosure is, for example, a method for reading information recorded by the recording method according to the ninth aspect, and the reading method includes measuring optical characteristics of a recording layer in the recording medium by irradiating light onto the recording layer, and reading information from the recording layer.

[0032] In an eleventh aspect of the present disclosure, for example, in the information reading method according to the tenth aspect, the optical property may be the intensity of fluorescent light emitted from the recording layer.

[0033] According to the information reading method of the tenth or eleventh aspect, the recording layer on which the information is recorded can be easily identified.

[0034] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments.

[0035] (Embodiment) Compound A of this embodiment is represented by the following formula (1).

[0036] In formula (1), R 1 From R 4 are each independently a hydrocarbon group which may have a substituent.

[0037] The hydrocarbon group is an alkyl group or an unsaturated hydrocarbon group.

[0038] The number of carbon atoms in the alkyl group is not particularly limited and is, for example, 1 or more and 20 or less. From the viewpoint of facilitating the synthesis of compound A, the number of carbon atoms in the alkyl group may be 1 or more and 10 or 1 or more and 5 or less. In some cases, the number of carbon atoms in the alkyl group may be 7 or more. By adjusting the number of carbon atoms in the alkyl group, the solubility of compound A in a solvent or 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 with a group containing at least one atom selected from the group consisting of N, O, P, and S. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a 2-methylbutyl group, a pentyl group, a hexyl group, a 2,3-dimethylhexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, a 2-methoxybutyl group, and a 6-methoxyhexyl group.

[0039] The unsaturated hydrocarbon group contains an unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond. The number of unsaturated bonds contained in the unsaturated hydrocarbon group is, for example, 1 to 5. The number of carbon atoms in the unsaturated hydrocarbon group is not particularly limited and is, for example, 2 to 20, or alternatively 2 to 10, or alternatively 2 to 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 with a group containing at least one atom selected from the group consisting of N, O, P, and S. Examples of unsaturated hydrocarbon groups include a vinyl group, an ethynyl group, and an aryl group.

[0040] Compound A represented by formula (1) can generate carbon dioxide by thermal decomposition. The thermal decomposition temperature of compound A is not particularly limited and may be 150°C or lower. The thermal decomposition temperature of compound A may be, for example, in the range of 100°C or higher and 150°C or lower, or in the range of 115°C or higher and 145°C or lower. By having a thermal decomposition temperature of 100°C or higher, an optical recording medium containing compound A can withstand a heat resistance test at a predetermined temperature.

[0041] When compound A is a 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 then applying the solution to a substrate. The ability to form a thin film by a wet method is advantageous for mass production of products using compound A.

[0042] The thermal decomposition temperature of Compound A can be measured by thermogravimetric analysis. 10 ) is the temperature at which a weight loss of 10 wt % was observed in thermogravimetric analysis.

[0043] 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 (—SO—). The electron-withdrawing property of the sulfonyl group weakens the bond between the carbon atom of the carbonyl group and the sulfur atom of the sulfonyl group. This is thought to contribute to a reduction in the thermal decomposition temperature of compound A.

[0044] In formula (1), R 2 From R 4 is a tertiary carbon atom. Such a structure enables the generation of carbon dioxide during thermal decomposition of the compound represented by formula (1).

[0045] In formula (1), R 2 From R 4 Each of R has a carbon atom bonded to a tertiary carbon atom. At least one of these carbon atoms has a hydrogen atom bonded to it. With this structure, during thermal decomposition of the compound represented by formula (1), the tertiary carbon atom and R 2 From R 4 A typical example of a group with such properties is the BOC group (tert-butoxycarbonyl group).

[0046] Compound A may have a property of being less likely to absorb light in a specific wavelength range. 2 mol -1 ・L・cm -1 In this case, compound A can be used in an optical recording medium that records and reads information using light in that wavelength range, and the optical recording medium can be easily multi-layered. The specific wavelength range is, for example, 390 nm or more and 420 nm or less, and may be, for example, 405 nm.

[0047] Examples of the compound A represented by formula (1) include compounds represented by the following formula (2).

[0048] In formula (2), R 5 From R 9 each independently contain at least one atom selected from the group consisting of H, C, N, O, F, P, S, Cl, I and Br.

[0049] In formula (2), R 5 From R 9may be, independently of one another, a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, an oxygen atom-containing group, a nitrogen atom-containing group, a sulfur atom-containing group, a silicon atom-containing group, a phosphorus atom-containing group, or a boron atom-containing group. The following explanations regarding the nitrogen atom-containing group, the oxygen atom-containing group, the phosphorus atom-containing group, and the sulfur atom-containing group are given in relation to R in formula (1). 1 From R 4 can also be applied to

[0050] Examples of halogen atoms include F, Cl, Br, and I. In this specification, halogen atoms may be referred to as halogen groups.

[0051] The number of carbon atoms in the hydrocarbon group is not particularly limited, and may be, for example, 1 to 20, or may be 1 to 10, or may be 1 to 5. By adjusting the number of carbon atoms in the hydrocarbon group, it is possible to adjust the solubility of compound A in a solvent or a resin composition. The hydrocarbon group may be linear, branched, or cyclic.

[0052] The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0053] Examples of the hydrocarbon group include saturated aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and unsaturated aliphatic hydrocarbon groups. The saturated aliphatic hydrocarbon group may be an alkyl group. Examples of the saturated aliphatic 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, and -(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 the alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, etc. Examples of the aliphatic unsaturated hydrocarbon group include -CH=CH2, -C≡CH, -C≡CCH3, -C(CH3)=CH2, -CH=CHCH3, and -CH2CH=CH2.

[0054] A halogenated hydrocarbon group refers to a group in which at least one hydrogen atom contained in a hydrocarbon group has been substituted with a halogen atom. The halogenated hydrocarbon group may be a group in which all hydrogen atoms contained in the hydrocarbon group have been substituted with halogen atoms. Examples of the halogenated hydrocarbon group include a halogenated alkyl group and a halogenated alkenyl group.

[0055] Examples of halogenated alkyl groups include -CF3, -CH2F, -CH2Br, -CH2Cl, -CH2I, -CH2CF3, etc. Examples of halogenated alkenyl groups include -CH=CHCF3, etc.

[0056] The group containing an oxygen atom is, for example, a substituent having at least one group selected from the group consisting of a hydroxyl group, a carboxyl group, an aldehyde group, an ether group, an acyl group, and an ester group.

[0057] Examples of the substituent having a hydroxyl group include a hydroxyl group itself and a hydrocarbon group having a hydroxyl group. In this substituent, the hydroxyl group can be deprotonated to form -O - Examples of hydrocarbon groups having a hydroxyl group include -CHOH, -CH(OH)CH, -CHCH(OH)CH, and -CHC(OH)(CH).

[0058] Examples of substituents having a carboxyl group include the carboxyl group itself and hydrocarbon groups having a carboxyl group. In this substituent, the carboxyl group is deprotonated to form -CO2 -The hydrocarbon group having a carboxyl group may be in the form of -CH2CH2COOH, -C(COOH)(CH3)2, -CH2CO2 - Examples include:

[0059] Examples of the substituent having an aldehyde group include the aldehyde group itself and hydrocarbon groups having an aldehyde group, such as —CH═CHCHO.

[0060] Examples of the substituent having an ether group include an alkoxy group, a halogenated alkoxy group, an alkenyloxy group, an oxiranyl group, and a hydrocarbon group having at least one of these functional groups. At least one hydrogen atom contained in the alkoxy group may be substituted with a group containing at least one atom selected from the group consisting of N, O, P, and S. Examples of the alkoxy group include 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, and -OCHO. - , —OCH2CH2O - , —O(CH2)3O - Examples of halogenated alkoxy groups include -OCHF2, -OCH2F, and -OCH2Cl. Examples of alkenyloxy groups include -OCH=CH2. Examples of hydrocarbon groups having a functional group such as an alkoxy group include -CHOCH3, -C(OCH3)3, a 2-methoxybutyl group, and a 6-methoxyhexyl group.

[0061] Examples of substituents having an acyl group include the acyl group itself and hydrocarbon groups having an acyl group. Examples of acyl groups include -COCH3. Examples of hydrocarbon groups having an acyl group include -CH=CHCOCH3.

[0062] Examples of substituents having an ester group include alkoxycarbonyl groups, acyloxy groups, and hydrocarbon groups having at least one of these functional groups. Examples of alkoxycarbonyl groups include -COOCH3, -COO(CH2)3CH3, and -COO(CH2)7CH3. Examples of acyloxy groups include -OCOCH3. Examples of hydrocarbon groups having a functional group such as an acyloxy group include -CH2OCOCH3.

[0063] The group containing a nitrogen atom is, for example, a substituent having at least one selected from the group consisting of 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.

[0064] 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 these substituents, the amino group may be protonated. Examples of tertiary amino groups include -N(CH3)2. Examples of hydrocarbon groups having a functional group such as a primary amino group include -CH2NH2, -CH2N(CH3)2, -(CH2)4N(CH3)2, and -CH2CH2NH3. + , -CH2CH2NH(CH3)2 + , -CH2CH2N(CH3)3 + Examples include:

[0065] Examples of the substituent having an imino group include the imino group itself and hydrocarbon groups having an imino group. Examples of the imino group include -N=CCl2.

[0066] Examples of substituents having a cyano group include the cyano group itself and hydrocarbon groups having a cyano group, such as -CHCN and -CH=CHCN.

[0067] Examples of the substituent having an azido group include the azido group itself and a hydrocarbon group having an azido group.

[0068] Examples of substituents having an amide group include the amide group itself and hydrocarbon groups having an amide group. Examples of amide groups include -CONH2, -NHCHO, -NHCOCH3, -NHCOCF3, -NHCOCH2Cl, and -NHCOCH(CH3)2. Examples of hydrocarbon groups having an amide group include -CH2CONH2 and -CH2NHCOCH3.

[0069] Examples of substituents having a carbamate group include the carbamate group itself and hydrocarbon groups having a carbamate group, such as -NHCOOCH3, -NHCOOCH2CH3, and -NHCO2(CH2)3CH3.

[0070] Examples of substituents having a nitro group include the nitro group itself and hydrocarbon groups having a nitro group, such as —C(NO)(CH).

[0071] Examples of the substituent having a cyanamide group include the cyanamide group itself and a hydrocarbon group having a cyanamide group. The cyanamide group is represented by —NHCN.

[0072] 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.

[0073] Examples of the substituent having an oxime group include the oxime group itself and a hydrocarbon group having an oxime group. The oxime group is represented by —CH═NOH.

[0074] The group containing a sulfur atom is, for example, a substituent having at least one selected from the group consisting of a thiol group, a sulfide group, a sulfinyl group, a sulfonyl group, a sulfino group, a sulfonic acid group, an acylthio group, a sulfenamide group, a sulfonamide group, a thioamide group, a thiocarbamide group, and a thiocyano group.

[0075] Examples of the substituent having a thiol group include a thiol group itself and a hydrocarbon group having a thiol group. A thiol group is represented by —SH.

[0076] Examples of substituents having a sulfide group include alkylthio groups, alkyldithio groups, alkenylthio groups, alkynylthio groups, thiacyclopropyl groups, and hydrocarbon groups having at least one of these functional groups. At least one hydrogen atom contained in the alkylthio group may be substituted with a halogen group. Examples of alkylthio groups include -SCH3, -S(CH2)F, -SCH(CH3)2, and -SCH2CH3. Examples of alkyldithio groups include -SSCH3. Examples of alkenylthio groups include -SCH=CH2 and -SCH2CH=CH2. Examples of alkynylthio groups include -SC≡CH. Examples of hydrocarbon groups having a functional group such as an alkylthio group include -CH2SCF3.

[0077] Examples of the substituent having a sulfinyl group include the sulfinyl group itself and hydrocarbon groups having a sulfinyl group. Examples of the sulfinyl group include —SOCH3.

[0078] Examples of substituents having a sulfonyl group include the sulfonyl group itself and hydrocarbon groups having a sulfonyl group. Examples of sulfonyl groups include -SO2CH3. Examples of hydrocarbon groups having a sulfonyl group include -CH2SO2CH3 and -CH2SO2CH2CH3.

[0079] Examples of the substituent having a sulfino group include the sulfino group itself and a hydrocarbon group having a sulfino group. In this substituent, the sulfino group can be deprotonated to form -SO2 - It may be in the state of

[0080] Examples of the substituent having a sulfonic acid group include the sulfonic acid group itself and a hydrocarbon group having a sulfonic acid group. In this substituent, the sulfonic acid group is deprotonated to form -SO3 - It may be in the state of

[0081] Examples of substituents having an acylthio group include the acylthio group itself and hydrocarbon groups having an acylthio group. Examples of the acylthio group include -SCOCH3.

[0082] Examples of the substituent having a sulfenamide group include the sulfenamide group itself and hydrocarbon groups having a sulfenamide group. Examples of the sulfenamide group include —SN(CH3)2.

[0083] Examples of the substituent having a sulfonamide group include the sulfonamide group itself and hydrocarbon groups having a sulfonamide group. Examples of the sulfonamide group include -SO2NH2 and -NHSO2CH3.

[0084] Examples of substituents having a thioamide group include the thioamide group itself and hydrocarbon groups having a thioamide group. Examples of thioamide groups include -NHCSCH3 and -CH2SC(NH2)2. + Examples include:

[0085] Examples of substituents having a thiocarbamide group include the thiocarbamide group itself and hydrocarbon groups having a thiocarbamide group. Examples of the thiocarbamide group include -NHCSNHCH2CH3.

[0086] Examples of substituents having a thiocyano group include the thiocyano group itself and hydrocarbon groups having a thiocyano group, such as —CH2SCN.

[0087] The group containing a silicon atom is, for example, a substituent having at least one group selected from the group consisting of a silyl group and a siloxy group.

[0088] Substituents having a silyl group include the silyl group itself and hydrocarbon groups having a silyl group. Examples of silyl groups include -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, and -Si(CH3)2OSi(CH3)3. Examples of hydrocarbon groups having a silyl group include -(CH2)2Si(CH3)3.

[0089] Examples of the substituent having a siloxy group include the siloxy group itself and hydrocarbon groups having a siloxy group, such as —CH2OSi(CH3)3.

[0090] The group containing a phosphorus atom is, for example, a substituent having at least one group selected from the group consisting of a phosphino group and a phosphoryl group.

[0091] Examples of the substituent having a phosphino group include the phosphino group itself and hydrocarbon groups having a phosphino group, such as -PH2, -P(CH3)2, -P(CH2CH3)2, -P(C(CH3)3)2, and -P(CH(CH3)2)2.

[0092] Examples of substituents having a phosphoryl group include the phosphoryl group itself and hydrocarbon groups having a phosphoryl group, such as —CH2PO(OCH2CH3)2.

[0093] 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 the boronic acid group itself and a hydrocarbon group having a boronic acid group.

[0094] Specific examples of the compound A represented by formula (1) include compounds represented by the following formula (3) or (4).

[0095] In formula (4), L contains at least one atom selected from the group consisting of C, N, O, P, S, and Si.

[0096] Further specific examples of the compound A represented by formula (1) include compounds represented by the following formula (5).

[0097] The compound represented by formula (3), (4) or (5) can be thermally decomposed at, for example, 150° C. or lower.

[0098] There is no particular limitation on the method for synthesizing the compound represented by formula (5). The compound represented by formula (5) can be synthesized, for example, by the following method.

[0099] First, a compound represented by the following formula (6) is prepared: The compound is 4,4'-thiobisbenzenethiol.

[0100] Next, the compound represented by formula (6) is reacted with a compound having a tert-butoxycarbonyl group. The reaction product is then reacted with sodium hypochlorite pentahydrate as an oxidizing agent. This oxidizes the sulfur and converts it to a sulfonyl group, yielding the compound represented by formula (5).

[0101] 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 isobutene upon decomposition. In this specification, a compound that generates a gas upon decomposition is referred to as a gas-generating material.

[0102] Compound A represented by formula (1) can be used, for example, as a component of a gas-generating material. That is, in another aspect, the present disclosure provides a gas-generating material containing compound A represented by formula (1). The gas-generating material contains, for example, compound A as a main component. "Main component" means the component contained in the gas-generating material in the largest amount by weight. The gas-generating material, for example, consists essentially of compound A. "Consisting essentially of..." means excluding other components that alter the essential characteristics of the referenced material. However, the gas-generating material may contain impurities in addition to compound A. The gas-generating material is used in devices or chemical products that require deformation or alteration by heat.

[0103] The gas-generating material functions as a recording mark forming material used in, for example, an optical information recording medium. In particular, the gas-generating material containing Compound A has a low thermal decomposition temperature and generates gas at a low temperature. Therefore, if the gas-generating material containing Compound A is used in an optical information recording medium, recording marks can be formed at high speed.

[0104] 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 serving as the recording layer contains compound A. That is, from another aspect thereof, the present disclosure provides a recording medium containing compound A represented by formula (1).

[0105] The recording layer may further contain, in addition to compound A, a polymer compound that functions as a light-absorbing dye or a binder. 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 and a plurality of dielectric layers may be alternately stacked.

[0106] The light-absorbing dye may be a nonlinear optical material having a nonlinear optical effect. The nonlinear optical effect means that when a substance is irradiated with strong light such as laser light, an optical phenomenon proportional to the square or higher order of the electric field of the irradiated light occurs in the substance. Combining a nonlinear optical material with compound A of the present disclosure makes it possible to form a multi-layer recording layer, improve recording density, and increase recording speed.

[0107] Next, a method for recording information using the above-mentioned recording medium will be described. FIG. 1A is a flowchart illustrating the method for recording information using the above-mentioned recording medium. First, in step S11, a light source emitting light having a wavelength of 390 nm or more and 420 nm or less is prepared. For example, a femtosecond laser such as a titanium sapphire laser can be used as the light source. A pulsed laser having a pulse width of picoseconds to nanoseconds, such as a semiconductor laser, can also be used as the light source. Next, in step S12, the light from the light source is focused using a lens or the like and irradiated onto the recording layer of the recording medium. More specifically, the light from the light source is focused using a lens or the like and irradiated onto the recording region of the recording medium. The NA (numerical aperture) of the lens used for focusing is not particularly limited. As an example, a lens with an NA in the range of 0.8 to 0.9 can be used. The power density near the focus of this light is, for example, 0.1 W / cm. 2 Above 1.0 x 10 20 W / cm 2 The power density near the focal point of this light is 1.0 W / cm 2 or more, and may be 1.0 × 10 2 W / cm 2 or more, and may be 1.0 × 10 5 W / cm 2 In this specification, the recording area means a spot that exists in the recording layer and that can record information when irradiated with light.

[0108] In the recording area irradiated with the light, a physical or chemical change occurs. For example, heat is generated when the light-absorbing dye returns from the transition state to the ground state. This heat causes compound A present in the recording area to decompose and generate gas. This changes the optical properties of the recording area. For example, the intensity of light reflected in the recording area, the reflectance of light in the recording area, the absorbance of light in the recording area, and the refractive index of light in the recording area change. In the recording area irradiated with light, the intensity or wavelength of the fluorescent light emitted from the recording area may also change. This allows information to be recorded in the recording layer, specifically in the recording area (step S13).

[0109] Next, a method for reading information using the above-mentioned recording medium will be described. FIG. 1B is a flowchart illustrating a method for reading information using the above-mentioned recording medium. First, in step S21, light is irradiated onto the recording layer of the recording medium. More specifically, light is irradiated onto the recording area of ​​the recording medium. The light used in step S21 may be the same as or different from the light used to record information on the recording medium. Next, in step S22, the optical characteristics of the recording layer are measured. More specifically, the optical characteristics of the recording area are measured. Examples of optical characteristics include the intensity of light reflected from the area, the reflectance of light in the area, the absorptance of light in the area, the refractive index of light in the area, and the wavelength of fluorescent light emitted from the area. Next, in step S23, information is read from the recording layer, more specifically, the recording area.

[0110] In the information reading method, the recording area where information is recorded can be found by the following method. First, light is irradiated onto a specific area of ​​the recording medium. This light may be the same as or different from the light used to record information on the recording medium. Next, the optical characteristics of the area irradiated with light are measured. Examples of optical characteristics include the intensity of fluorescent light emitted from the area, the intensity of light reflected from the area, the reflectance of light in the area, the absorbance of light in the area, the refractive index of light in the area, and the wavelength of fluorescent light emitted from the area. Whether or not the area irradiated with light is a recording area is determined based on the measured optical characteristics. For example, if the intensity of light reflected from the area is equal to or less than a specific value, the area is determined to be a recording area. On the other hand, if the intensity of the reflected light exceeds a specific value, the area is determined to be not a recording area. Note that the method for determining whether or not the area irradiated with light is a recording area is not limited to the above method. For example, if the intensity of light reflected from the area exceeds a specific value, the area may be determined to be a recording area. Alternatively, if the intensity of light reflected from the area is equal to or less than a specific value, the area may be determined to be a non-recorded area. If the area is determined to be a non-recorded area, the same operation is performed on other areas of the recording medium. This allows the search for a recorded area.

[0111] The information recording and reading methods using the above-mentioned recording medium can be performed, for example, by a known recording device that includes, for example, a light source that irradiates a recording area of ​​the recording medium with light, a measuring device that measures the optical characteristics of the recording area, and a controller that controls the light source and the measuring device.

[0112] The present disclosure will be described in more detail below with reference to examples. Note that the following examples are merely illustrative and the present disclosure is not limited to the following examples.

[0113] [Synthesis of Compound 1] First, 150 mg of 4,4'-thiobisbenzenethiol (manufactured by Tokyo Chemical Industry Co., Ltd.), 290 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 170 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.) as raw materials, 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, and the raw materials were dissolved in the solvent. Next, the resulting 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 the mixture was stirred at room temperature for 48 hours. The resulting reaction solution was purified by silica gel column chromatography to obtain Compound 1 represented by Formula (5). Compound 1 can be synthesized by the following method. 1 The compound was identified by H-NMR. 1 1 is a graph showing the H-NMR spectrum of Compound 1. 1 The H-NMR spectrum was as follows: 1 H-NMR (600MHz, CHLOROFORM-D) δ 7.93 (d, J=8.3Hz, 4H), 7.66 (d, J=8.3Hz, 4H), 1.51 (s, 18H).

[0114] [Synthesis of Compound 2] First, 150 mg of 9,3':6',9''-tert-butylcarbazole (manufactured by Tokyo Chemical Industry Co., Ltd.), 150 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 90 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.) as raw materials, and 60 mL of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a solvent were placed in a 100 mL eggplant-shaped flask, and the raw materials were dissolved in the solvent. Next, the resulting solution was stirred at room temperature using a stirrer for 2 hours. The resulting reaction solution was purified by silica gel column chromatography to obtain Compound 2 represented by Formula (7). Compound 2 can be synthesized by the following method. 1 The compound was identified by H-NMR. 1 1 is a graph showing the H-NMR spectrum of Compound 2. 1 The H-NMR spectrum was as follows: 1H-NMR (600MHz, CHLOROFORM-D) δ 8.60 (d, J=9.0Hz, 2H), 8.15 (d, J=7.6Hz, 6H), 7.71 (dd, J=8.6, 2.4Hz, 2H), 7.40 (d, J=4.8Hz, 8H), 7.30-7.27 (m, 4H), 1.86 (s, 9H).

[0115] [Synthesis of Compound 3] 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.), and 70 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.) as raw materials, and 60 mL of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a solvent were placed in a 100 mL eggplant-shaped flask, and the raw materials were dissolved in the solvent. The resulting reaction solution was purified by silica gel column chromatography to obtain Compound 3 represented by Formula (8). Compound 3 can be synthesized by the following procedure: 1 The compound was identified by H-NMR. 1 1 is a graph showing the H-NMR spectrum of Compound 3. 1 The H-NMR spectrum was as follows: 1 H-NMR (600MHz, CHLOROFORM-D) δ 8.64 (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).

[0116] [Synthesis of Compound 4] 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.), and 270 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.) as raw materials, 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, and the raw materials were dissolved in the solvent. Next, the resulting solution was stirred at room temperature using a stirrer for 2 hours. The resulting reaction solution was purified by silica gel column chromatography to obtain compound 4 represented by formula (9). Compound 4 can be synthesized by the following method: 1 The compound was identified by H-NMR. 1 1 is a graph showing the H-NMR spectrum of Compound 4. 1 The H-NMR spectrum was as follows: 1 H-NMR (600MHz, CHLOROFORM-D) δ 8.05 (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).

[0117] [Synthesis of Compound 5] First, 150 mg of 4,4'-thiobisbenzenethiol (manufactured by Tokyo Chemical Industry Co., Ltd.), 290 mg of di-tert-butyl dicarbonate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 170 mg of 4-dimethylaminopyridine (manufactured by Tokyo Chemical Industry Co., Ltd.) as raw materials, and 60 mg of dichloromethane (manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a solvent were placed in a 100 mL eggplant-shaped flask, and the raw materials were dissolved in the solvent. Next, the resulting solution was stirred at room temperature using a stirrer for 2 hours. The resulting reaction solution was purified by silica gel column chromatography to obtain Compound 5 represented by Formula (10). Compound 5 can be synthesized by the following method: 1 The compound was identified by H-NMR. 1 1 is a graph showing the H-NMR spectrum of Compound 5. 1 The H-NMR spectrum was as follows: 1H-NMR (600MHz, CHLOROFORM-D) δ 7.45 (d, J=8.3Hz, 4H), 7.34 (d, J=8.3Hz, 4H), 1.51 (s, 18H).

[0118]

[0119] <Measurement of Decomposition Temperature> The thermal decomposition temperatures of Compounds 1 to 5 were measured by thermogravimetric analysis. Using a TG apparatus (TG / DTA7200, manufactured by Hitachi High-Tech Science Corporation), the weight loss rate was measured by increasing the temperature at a rate of 10°C / min in the range from 25°C to 500°C under a nitrogen gas 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.

[0120] <Bond Distance and Thermal Decomposition Temperature> Compounds 1 to 5 have a structure represented by the following formula (11). The bond distance between X and C in compounds 1 to 5 was determined by performing a structural optimization calculation using DFT calculation. In detail, first, a structural optimization calculation was performed on the compounds using Gaussian16 (manufactured by Gaussian Corporation), a quantum chemistry calculation program. 6-31++G(d,p) was used as the basis function. CAM-B3LYP was used as the functional. The bond distance and thermal decomposition temperature of each compound are shown in Table 1.

[0121]

[0122] 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 lower the temperature at which the compound can decompose and generate carbon dioxide.

[0123] Next, structural optimization calculations were performed by DFT calculations on compounds 6 to 9, respectively represented by the following formulas (12) to (15), to determine the bond distance between X and C in compounds 6 to 9. In all of compounds 6 to 9, the bond distance between carbon and the sulfonyl group was 1.86 nm or longer. In other words, like compound 1, compounds 6 to 9 can be expected to have thermal decomposition temperatures of 150°C or lower. The bond distances of compounds 6 to 9 are shown in Table 2.

[0124]

[0125] <Preparation of Recording Layer> First, the following materials were mixed by stirring to obtain a uniformly mixed coating liquid. Compounds 1 to 5 were used as the gas-generating material. Poly(9-vinylcarbazole) (manufactured by Aldrich Chemical Co.) was used as the resin. 7-diethylamino-4-methylcoumarin (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the dye. Chlorobenzene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the solvent. The composition ratios of the coating liquids in Example 1 and Comparative Examples 1 to 5 are shown in Table 3.

[0126]

[0127] Next, a thin film serving as a recording layer was formed on a quartz substrate using the coating solution. The quartz substrate had dimensions of 20 mm length, 20 mm width, and 1 mm thickness. The quartz substrate was placed on a spin coater, and 400 μL of the coating solution was dropped onto the quartz substrate and rotated at 3000 rpm for 30 seconds. The quartz substrate was then dried on a hot plate at 80°C for 30 minutes to obtain a resin thin film containing the gas-generating material and the dye.

[0128] <Recording Experiment> Light with a central wavelength of 405 nm, a peak power of 40 mW, and a repetition rate of 1 Hz was irradiated onto a resin thin film through a lens with an NA of 0.85, while varying the pulse width. When the irradiated area under observation with an optical microscope was found to have been altered and a hole formed in the resin thin film, it was determined that a recording mark had been formed, and the pulse width at that time was considered to be the recording pulse width. The recording pulse widths for the resin thin films of Example 1 and Comparative Examples 1 to 5 are shown in Table 4.

[0129]

[0130] As can be seen from Table 1, the recording pulse width in Example 1 was short, while the recording pulse widths in Comparative Examples 1 to 5 were long. This indicates that recording on the resin thin film of Example 1 may be possible at higher speeds than recording on the resin thin films of Comparative Examples 1 to 5. These results suggest that compounds having the structure represented by formula (1) exhibit a low thermal decomposition temperature due to the long bond distance between carbon and the sulfonyl group. During recording, the dye absorbs laser light and generates heat. The generated heat promotes thermal decomposition, forming recording marks. The lower the thermal decomposition temperature, the shorter the time it takes for the dye temperature to rise to that temperature. As a result, compared to compounds with high thermal decomposition temperatures, compounds with low thermal decomposition temperatures enable recording with short recording pulse widths, i.e., with less input energy.

[0131] The compounds of the present disclosure can be used in applications such as optical information recording media, resists, and easily dismantled adhesives. The compounds of the present disclosure can generate gas by thermal decomposition at low temperatures. This allows high-speed recording to be achieved in optical information recording media. According to the present disclosure, a new compound suitable for lowering the temperature at which recording marks are formed in the recording layer of an optical information recording medium to improve recording sensitivity can be provided.

Claims

1. A compound represented by the following formula (3) or (4): 【Chemistry 1】 In the formula (4), L contains at least one atom selected from the group consisting of C, N, O, P, S, and Si.

2. The compound according to claim 1, represented by the following formula (5): 【Chemistry 2】

3. The compound according to claim 1, having a thermal decomposition temperature of 150°C or less.

4. The compound according to claim 1 for use in a device that utilizes light having a wavelength of 390 nm or more and 420 nm or less.

5. A recording medium comprising a compound according to any one of claims 1 to 4.

6. providing a light source that emits light having a wavelength of 390 nm or more and 420 nm or less; The light from the light source is concentrated and irradiated onto a recording layer of a recording medium containing the compound according to any one of claims 1 to 4. (a) how information is recorded;

7. A method for reading information recorded by the recording method according to claim 6, comprising the steps of: The reading method includes: measuring optical characteristics of a recording layer in the recording medium by irradiating the recording layer with light; Reading information from the recording layer; A method of reading information, comprising:

8. The method of claim 7 , wherein the optical characteristic is the intensity of light reflected by the recording layer.

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