Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C381/00—Compounds containing carbon and sulfur and having functional groups not covered by groups C07C301/00 - C07C337/00
  • C07C381/14—Compounds containing a carbon atom having four bonds to hetero atoms with a double bond to one hetero atom and at least one bond to a sulfur atom further doubly-bound to oxygen atoms
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
  • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
  • G11B7/2403—Layers; Shape, structure or physical properties thereof
  • G11B7/24035—Recording layers

Definitions

• the present disclosure relates to a compound, a recording medium, a method for recording information, and a method for reading information.
• optical information storage media In optical information recording media, recording is performed by changing the quality of the recording layer with laser light. Altering the recording layer typically means that materials within the recording layer, such as light-absorbing dyes and resins, decompose. When the material decomposes, its shape changes, such as unevenness and holes, and the light reflectance changes before and after recording. Therefore, decomposition of the material is important for recording, and research on the thermal decomposition behavior of recording layers is actively underway. For example, voids can be formed in the recording layer using a material that generates gas upon thermal decomposition. By forming the void, the difference in refractive index before and after recording increases. Thereby, clear recording marks can be formed.
• R 1 to R 4 are each independently a hydrocarbon group which may have a substituent.
• the present disclosure provides novel compounds that generate gas upon thermal decomposition.
• FIG. 1A is a flowchart regarding 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 regarding a method for reading information using a recording medium containing a compound according to an embodiment of the present disclosure.
• FIG. 2 is a graph showing the 1 H-NMR spectrum of compound 1 represented by formula (5).
• FIG. 3 is a graph showing the 1 H-NMR spectrum of compound 2 represented by formula (7).
• FIG. 4 is a graph showing the 1 H-NMR spectrum of compound 3 represented by formula (8).
• FIG. 5 is a graph showing the 1 H-NMR spectrum of compound 4 represented by formula (9).
• FIG. 6 is a graph showing the 1 H-NMR spectrum of compound 5 represented by formula (10).
• Patent Document 1 discloses the use of a compound having a substituent that generates gas upon thermal decomposition in the recording layer of an optical information recording medium.
• Non-Patent Document 1 discloses that a decarboxylation reaction is preferable for forming recording marks by gas generation on an optical information recording medium.
• high-speed recording is required for optical information recording media.
• it is necessary to form recording marks with short-time laser irradiation.
• the laser irradiation time becomes shorter, the amount of light absorbed by the recording layer decreases and the amount of heat generated decreases. Therefore, high-speed recording requires the ability to thermally decompose at low temperatures.
• R 1 to R 4 are each independently a hydrocarbon group which may have a substituent.
• the compound according to the first aspect can be thermally decomposed to generate carbon dioxide.
• the hydrocarbon group may be an alkyl group, an unsaturated hydrocarbon group, or an aryl group.
• the compound according to the second aspect can be thermally decomposed to generate carbon dioxide.
• the compound according to the first aspect may be represented by the following formula (2).
• R 5 to 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. .
• the compound can be thermally decomposed at, for example, 150° C. or lower.
• R 5 to R 9 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group, a halogenated hydrocarbon group, or 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.
• the compound according to the first aspect may be represented by the following formula (3) or (4).
• L includes at least one atom selected from the group consisting of C, N, O, P, S, and Si.
• the compound can be thermally decomposed at, for example, 150° C. or lower.
• the compound according to the first aspect may be represented by the following formula (5).
• the compound according to the sixth aspect of the present disclosure can be thermally decomposed at 150°C or lower.
• the compound according to any one of the first to sixth aspects may be used in a device that uses light having a wavelength of 390 nm or more and 420 nm or less.
• the compound according to the seventh aspect of the present disclosure is suitable as a material for a device that uses light and/or heat because it thermally decomposes to generate gas.
• the recording medium according to the eighth aspect of the present disclosure includes: The compound according to any one of the first to seventh aspects is included.
• the recording medium according to the eighth aspect allows information to be recorded at high speed.
• the information recording method includes: Prepare a light source that emits light having a wavelength of 390 nm or more and 420 nm or less, condensing the light from the light source and irradiating it onto a recording layer in a recording medium containing the compound according to any one of the first to seventh aspects; Including.
• the information recording method enables information to be recorded at high speed.
• the method for reading information according to the tenth aspect of the present disclosure is, for example, a method for reading information recorded by the recording method according to the ninth aspect, comprising:
• the reading method is Measuring the optical properties of the recording layer by irradiating the recording layer in the recording medium with light, reading information from the recording layer; Including.
• the optical property may be the intensity of fluorescent light emitted from the recording layer.
• the information reading method it is possible to easily identify the recording layer on which information is recorded.
• R 1 to R 4 are each independently a hydrocarbon group which may have a substituent.
• the hydrocarbon group is an alkyl group or an unsaturated hydrocarbon group.
• the number of carbon atoms in the alkyl group is not particularly limited, and is, for example, 1 or more and 20 or less.
• the number of carbon atoms in the alkyl group may be 1 or more and 10 or less, or 1 or more and 5 or less, from the viewpoint that compound A can be easily synthesized.
• the alkyl group may have 7 or more carbon atoms. 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.
• alkyl groups include methyl, ethyl, propyl, butyl, 2-methylbutyl, pentyl, hexyl, 2,3-dimethylhexyl, heptyl, octyl, nonyl, decyl, and undecyl groups.
• dodecyl group dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, 2-methoxybutyl group, 6-methoxyhexyl group, and the like.
• the unsaturated hydrocarbon group includes 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, 1 or more and 5 or less.
• the number of carbon atoms in the unsaturated hydrocarbon group is not particularly limited, and may be, for example, 2 or more and 20 or less, 2 or more and 10 or less, or 2 or more and 5 or less.
• 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 the unsaturated hydrocarbon group include a vinyl group, an ethynyl group, and an aryl group.
• Compound A represented by formula (1) can be thermally decomposed to generate carbon dioxide.
• 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 more and 150°C or less, or may be in the range of 115°C or more and 145°C or less. Since the thermal decomposition temperature is 100° C. or higher, the optical recording medium containing Compound A can withstand a heat resistance test at a predetermined temperature.
• 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 by a wet method is advantageous for mass production of products to which Compound A is applied.
• the thermal decomposition temperature of Compound A can be measured by thermogravimetric analysis.
• the 10 wt% pyrolysis temperature (Td 10 ) is the temperature at which a weight loss of 10 wt% is observed in thermogravimetric analysis.
• the atom adjacent to the carbon of the carbonyl group is a sulfur atom (S).
• the atom adjacent to the carbon of the carbonyl group is a sulfur atom (S)
• the sulfur atom constitutes a sulfonyl group (--SO 2 --).
• the bond between the carbon atom of the carbonyl group and the sulfur atom of the sulfonyl group is weakened by the electron-withdrawing property of the sulfonyl group. This is considered to contribute to lowering the thermal decomposition temperature of Compound A.
• the carbon to which R 2 to R 4 are bonded is a tertiary carbon atom.
• Such a structure allows carbon dioxide to be generated during thermal decomposition of the compound represented by formula (1).
• R 2 to R 4 each have a carbon atom bonded to a tertiary carbon atom.
• a hydrogen atom is bonded to at least one of those carbon atoms.
• a tertiary carbon atom and an alkene derived from R 2 to R 4 can be generated together with carbon dioxide.
• a typical example of a group having such properties is the BOC group (tert-butoxycarbonyl group).
• Compound A may have the property of being difficult to absorb light in a specific wavelength range.
• the molar extinction coefficient ⁇ of compound A for light in a specific wavelength range may be smaller than 1 ⁇ 10 2 mol ⁇ 1 ⁇ L ⁇ cm ⁇ 1 .
• compound A can be used in an optical recording medium in which information is recorded and read using light in the wavelength range, and the optical recording medium can be multilayered.
• the specific wavelength range is, for example, from 390 nm to 420 nm, and may be, for example, 405 nm.
• Compound A represented by formula (1) includes a compound represented by formula (2) below.
• R 5 to 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.
• R 5 to R 9 independently include 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, and a sulfur atom. It may be a group containing a silicon atom, a group containing a phosphorus atom, or a group containing a boron atom.
• a group containing a nitrogen atom, a group containing an oxygen atom, a group containing a phosphorus atom, and a group containing a sulfur atom can also be applied to R 1 to R 4 in formula (1).
• halogen atom examples include F, Cl, Br, I, and the like.
• a halogen atom may be referred to as a halogen group.
• the number of carbon atoms in the hydrocarbon group is not particularly limited, and is, for example, 1 or more and 20 or less, may be 1 or more and 10 or less, or may be 1 or more and 5 or less.
• the hydrocarbon group may be linear, branched, or cyclic.
• the hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.
• hydrocarbon group examples include an aliphatic saturated hydrocarbon group, an alicyclic hydrocarbon group, and an aliphatic unsaturated hydrocarbon group.
• the aliphatic saturated hydrocarbon group may be an alkyl group.
• Examples of aliphatic saturated hydrocarbon groups include -CH 3 , -CH 2 CH 3 , -CH 2 CH 2 CH 3 , -CH(CH 3 ) 2 , -CH(CH 3 )CH 2 CH 3 , -C(CH 3 ) 3 , -CH2CH ( CH3 ) 2 , -( CH2 ) 3CH3 , -( CH2 ) 4CH3 , -C( CH2CH3 ) ( CH3 ) 2 , -CH2C (CH 3 ) 3 , -(CH 2 ) 5 CH 3 , -(CH 2 ) 6 CH 3 , -(CH 2 ) 7 CH 3 , -(CH 2 ) 8 CH 3 , -(CH 2 ) 9 CH
• Examples of the alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and an adamantyl group.
• a halogenated hydrocarbon group means a group in which at least one hydrogen atom contained in the hydrocarbon group is substituted with a halogen atom.
• the halogenated hydrocarbon group may be a group in which all hydrogen atoms contained in the hydrocarbon group are substituted with halogen atoms.
• Examples of the halogenated hydrocarbon group include a halogenated alkyl group and a halogenated alkenyl group.
• halogenated alkyl group examples include -CF 3 , -CH 2 F, -CH 2 Br, -CH 2 Cl, -CH 2 I, -CH 2 CF 3 and the like.
• the group containing an oxygen atom is, for example, a substituent having at least one 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.
• 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 may be deprotonated to be in the -O - state.
• Examples of the hydrocarbon group having a hydroxyl group include -CH 2 OH, -CH(OH)CH 3 , -CH 2 CH(OH)CH 3 and -CH 2 C(OH)(CH 3 ) 2 .
• Examples of the substituent having a carboxyl group include the carboxyl group itself and a hydrocarbon group having a carboxyl group. In this substituent, the carboxyl group may be deprotonated to be in the -CO 2 - state.
• Examples of the hydrocarbon group having a carboxyl group include -CH 2 CH 2 COOH, -C(COOH)(CH 3 ) 2 and -CH 2 CO 2 - .
• Examples of the substituent having an aldehyde group include the aldehyde group itself and a hydrocarbon group having an aldehyde group.
• 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.
• alkoxy groups include methoxy, ethoxy, 2-methoxyethoxy, butoxy, 2-methylbutoxy, 2-methoxybutoxy, 4-ethylthiobutoxy, pentyloxy, hexyloxy, and heptyloxy groups.
• halogenated alkoxy group examples include -OCHF 2 , -OCH 2 F, and -OCH 2 Cl.
• hydrocarbon group having a functional group such as an alkoxy group include -CH 2 OCH 3 , -C(OCH 3 ) 3 , 2-methoxybutyl group, and 6-methoxyhexyl group.
• Examples of the substituent having an acyl group include the acyl group itself and a hydrocarbon group having an acyl group.
• Examples of the acyl group include -COCH 3 and the like.
• Examples of the substituent having an ester group include an alkoxycarbonyl group, an acyloxy group, and a hydrocarbon group having at least one of these functional groups.
• Examples of the alkoxycarbonyl group include -COOCH 3 , -COO(CH 2 ) 3 CH 3 and -COO(CH 2 ) 7 CH 3 .
• Examples of the acyloxy group include -OCOCH 3 and the like.
• the hydrocarbon group having a functional group such as an acyloxy group include -CH 2 OCOCH 3 and the like.
• the nitrogen atom-containing group is, for example, a substituent having at least one member selected from the group consisting of an amino group, an imino group, a cyano group, an azide group, an amide group, a carbamate group, a nitro group, a cyanamide group, an isocyanate group, and an oxime group. It is the basis.
• substituent having an amino group examples include a primary amino group, a secondary amino group, a tertiary amino group, a quaternary amino group, and a hydrocarbon group having at least one of these functional groups. .
• the amino group may be protonated.
• the tertiary amino group examples include -N(CH 3 ) 2 and the like.
• Hydrocarbon groups having functional groups such as primary amino groups include -CH 2 NH 2 , -CH 2 N(CH 3 ) 2 , -(CH 2 ) 4 N(CH 3 ) 2 , -CH 2 CH 2 Examples include NH 3 + , -CH 2 CH 2 NH(CH 3 ) 2 + , -CH 2 CH 2 N(CH 3 ) 3 + and the like.
• Examples of the substituent having an imino group include the imino group itself and a hydrocarbon group having an imino group.
• Examples of the substituent having a cyano group include the cyano group itself and a hydrocarbon group having a cyano group.
• Examples of the substituent having an azide group include the azide group itself and a hydrocarbon group having an azide group.
• Examples of the substituent having an amide group include the amide group itself and a hydrocarbon group having an amide group.
• Examples of the amide group include -CONH 2 , -NHCHO, -NHCOCH 3 , -NHCOCF 3 , -NHCOCH 2 Cl, -NHCOCH(CH 3 ) 2 and the like.
• Examples of the hydrocarbon group having an amide group include -CH 2 CONH 2 and -CH 2 NHCOCH 3 .
• Examples of the substituent having a carbamate group include the carbamate group itself and a hydrocarbon group having a carbamate group.
• Examples of the carbamate group include -NHCOOCH 3 , -NHCOOCH 2 CH 3 , -NHCO 2 (CH 2 ) 3 CH 3 and the like.
• 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(NO 2 )(CH 3 ) 2 and the like.
• 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.
• Examples of the substituent having an isocyanate group include the isocyanate group itself and a hydrocarbon group having an isocyanate group.
• Examples of the substituent having an oxime group include the oxime group itself and a hydrocarbon group having an oxime group.
• Groups containing a sulfur atom include, for example, 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. It is a substituent having at least one member selected from the group consisting of:
• Examples of the substituent having a thiol group include the thiol group itself and a hydrocarbon group having a thiol group.
• the thiol group is represented by -SH.
• Examples of the substituent having a sulfide group include an alkylthio group, an alkyldithio group, an alkenylthio group, an alkynylthio group, a thiacyclopropyl group, and a hydrocarbon group 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 the alkylthio group include -SCH 3 , -S(CH 2 )F, -SCH(CH 3 ) 2 and -SCH 2 CH 3 .
• Examples of the alkyldithio group include -SSCH 3 and the like.
• alkynylthio group examples include -SC ⁇ CH and the like.
• hydrocarbon group having a functional group such as an alkylthio group examples include -CH 2 SCF 3 and the like.
• Examples of the substituent having a sulfinyl group include the sulfinyl group itself and a hydrocarbon group having a sulfinyl group.
• Examples of the sulfinyl group include -SOCH 3 and the like.
• Examples of the substituent having a sulfonyl group include the sulfonyl group itself and a hydrocarbon group having a sulfonyl group.
• Examples of the sulfonyl group include -SO 2 CH 3 and the like.
• Examples of the hydrocarbon group having a sulfonyl group include -CH 2 SO 2 CH 3 and -CH 2 SO 2 CH 2 CH 3 .
• substituent having a sulfino group examples include the sulfino group itself and a hydrocarbon group having a sulfino group.
• the sulfino group may be deprotonated to form -SO 2 - .
• substituent having a sulfonic acid group examples include the sulfonic acid group itself and a hydrocarbon group having a sulfonic acid group.
• the sulfonic acid group may be deprotonated to form -SO 3 - .
• Examples of the substituent having an acylthio group include the acylthio group itself and a hydrocarbon group having an acylthio group.
• Examples of the acylthio group include -SCOCH 3 and the like.
• 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(CH 3 ) 2 and the like.
• 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 -SO 2 NH 2 and -NHSO 2 CH 3 .
• Examples of the substituent having a thioamide group include the thioamide group itself and a hydrocarbon group having a thioamide group.
• Examples of the thioamide group include -NHCSCH 3 and the like.
• Examples of the hydrocarbon group having a thioamide group include -CH 2 SC(NH 2 ) 2 + and the like.
• Examples of the substituent having a thiocarbamide group include the thiocarbamide group itself and a hydrocarbon group having a thiocarbamide group.
• Examples of the thiocarbamide group include -NHCSNHCH 2 CH 3 and the like.
• Examples of the substituent having a thiocyano group include the thiocyano group itself and a hydrocarbon group having a thiocyano group.
• Examples of the hydrocarbon group having a thiocyano group include -CH 2 SCN and the like.
• the group containing a silicon atom is, for example, a substituent having at least one selected from the group consisting of a silyl group and a siloxy group.
• Examples of the substituent having a silyl group include the silyl group itself and a hydrocarbon group having a silyl group.
• Silyl groups include -Si(CH 3 ) 3 , -SiH(CH 3 ) 2 , -Si(OCH 3 ) 3 , -Si(OCH 2 CH 3 ) 3 , -SiCH 3 (OCH 3 ) 2 , -Si (CH 3 ) 2 OCH 3 , -Si(N(CH 3 ) 2 ) 3 , -SiF(CH 3 ) 2 , -Si(OSi(CH 3 ) 3 ) 3 , -Si(CH 3 ) 2 OSi(CH 3 ) 3 etc.
• Examples of the hydrocarbon group having a silyl group include -(CH 2 ) 2 Si(CH 3 ) 3 and the like.
• Examples of the substituent having a siloxy group include the siloxy group itself and a hydrocarbon group having a siloxy group.
• Examples of the hydrocarbon group having a siloxy group include -CH 2 OSi(CH 3 ) 3 and the like.
• the group containing a phosphorus atom is, for example, a substituent having at least one selected from the group consisting of a phosphino group and a phosphoryl group.
• Examples of the substituent having a phosphino group include the phosphino group itself and a hydrocarbon group having a phosphino group.
• Phosphino groups include -PH 2 , -P(CH 3 ) 2 , -P(CH 2 CH 3 ) 2 , -P(C(CH 3 ) 3 ) 2 , -P(CH(CH 3 ) 2 ) 2 Examples include.
• Examples of the substituent having a phosphoryl group include the phosphoryl group itself and a hydrocarbon group having a phosphoryl group.
• Examples of the hydrocarbon group having a phosphoryl group include -CH 2 PO(OCH 2 CH 3 ) 2 and the like.
• the group containing a boron atom is, for example, a substituent having a boronic acid group.
• substituent having a boronic acid group include the boronic acid group itself and a hydrocarbon group having a boronic acid group.
• compound A represented by formula (1) include compounds represented by formula (3) or formula (4) below.
• L includes at least one atom selected from the group consisting of C, N, O, P, S, and Si.
• the compound represented by formula (3), (4) or (5) can be thermally decomposed at, for example, 150°C or lower.
• 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.
• the compound is 4,4'-thiobisbenzenethiol.
• 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.
• sulfur is oxidized and changed into a sulfonyl group, yielding a compound represented by formula (5).
• 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.
• Compounds that generate gas upon decomposition are referred to herein as gas-generating materials.
• Compound A represented by formula (1) can be used, for example, as a component of a gas generating material. That is, from another aspect, the present disclosure provides a gas generating material containing compound A represented by formula (1).
• the gas generating material contains Compound A as a main component, for example. "Main component” means the component contained in the gas generating material in the largest amount by weight.
• the gas generating material consists essentially of Compound A, for example. "Substantially consisting of” means to exclude other ingredients that alter the essential characteristics of the material referred to. However, the gas generating material may contain impurities in addition to compound A. Gas-generating materials are used in devices or chemical products that require deformation or alteration by heat.
• the gas generating material functions, for example, as a recording mark forming material used in optical information recording media.
• the gas generating material containing Compound A has a low thermal decomposition temperature and generates gas at low temperatures. Therefore, if a gas generating material containing Compound A is used in an optical information recording medium, recording marks can be formed at high speed.
• the recording medium includes, for example, a thin film called a recording layer.
• a recording medium information is recorded on a recording layer.
• a thin film as a recording layer contains compound A. That is, from another aspect, the present disclosure provides a recording medium containing compound A represented by formula (1).
• the recording layer may further contain a polymer compound that functions as a light-absorbing dye or a binder.
• the recording medium may include a dielectric layer in addition to the recording layer.
• the recording medium includes, for example, multiple recording layers and multiple dielectric layers. In the recording medium, a plurality of recording layers and a plurality of dielectric layers may be alternately stacked.
• the light-absorbing dye may be a non-linear optical material that has a non-linear optical effect.
• a nonlinear optical effect means that when a substance is irradiated with intense light such as a laser beam, an optical phenomenon proportional to the square or higher order of the electric field of the irradiated light occurs in the substance.
• FIG. 1A is a flowchart regarding a method for recording information using the above recording medium.
• a light source that emits light having a wavelength of 390 nm or more and 420 nm or less is prepared.
• a light source for example, a femtosecond laser such as a titanium sapphire laser can be used.
• a pulsed laser such as a semiconductor laser having a pulse width of picoseconds to nanoseconds may be used.
• step S12 the light from the light source is focused by a lens or the like and irradiated onto the recording layer of the recording medium.
• light from a light source is focused by a lens or the like and irradiated onto a recording area on a recording medium.
• the NA (numerical aperture) of the lens used for condensing light is not particularly limited.
• a lens having an NA of 0.8 or more and 0.9 or less may be used.
• the power density of this light near the focal point is, for example, 0.1 W/cm 2 or more and 1.0 ⁇ 10 20 W/cm 2 or less.
• the power density near the focal point of this light may be 1.0 W/cm 2 or more, 1.0 ⁇ 10 2 W/cm 2 or more, or 1.0 ⁇ 10 5 W/cm It may be 2 or more.
• the recording area refers to a spot that exists in the recording layer and can record information by being irradiated with light.
• a physical or chemical change occurs in the recording area irradiated with the above light. For example, heat is generated when a light-absorbing dye returns from a transition state to its ground state. This heat decomposes Compound A present in the recording area and generates gas. This changes the optical characteristics of the recording area. For example, the intensity of light reflected in the recording area, the reflectance of light in the recording area, the absorption rate of light in the recording area, the refractive index of light in the recording area, etc. change. In the recording area irradiated with light, the intensity of the fluorescent light emitted from the recording area or the wavelength of the fluorescent light may change. Thereby, information can be recorded in the recording layer, specifically in the recording area (step S13).
• FIG. 1B is a flowchart regarding a method for reading information using the above recording medium.
• a recording layer in a recording medium is irradiated with light. Specifically, light is irradiated onto a recording area on a 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.
• the optical properties of the recording layer are measured. Specifically, the optical characteristics of the recording area are measured.
• Optical properties include, for example, the intensity of light reflected in the region, the reflectance of light in the region, the absorption rate of light in the region, the refractive index of light in the region, and the fluorescence emitted from the region. Examples include the wavelength of light.
• step S23 information is read from the recording layer, specifically from the recording area.
• the recording area where information is recorded can be found by the following method.
• the optical characteristics of the area irradiated with light are measured. Optical properties include, for example, the intensity of fluorescent light emitted from the region, the intensity of light reflected in the region, the reflectance of light in the region, the absorption rate of light in the region, and the intensity of light reflected in the region. Examples include the refractive index of light and the wavelength of fluorescent light emitted from the region. Based on the measured optical characteristics, it is determined whether the area irradiated with light is a recording area.
• the method for determining whether the area irradiated with light is a recording area is not limited to the above method. For example, it may be determined that the area is a recording area when the intensity of the light reflected on the area exceeds a specific value. Alternatively, it may be determined that the area is not a recording area if the intensity of the light reflected by the area is below a specific value. If it is determined that the area is not a recording area, similar operations are performed on other areas of the recording medium. This makes it possible to search for a recording area.
• the method for recording and reading information using the above recording medium can be performed by, for example, a known recording device.
• the recording device includes, for example, a light source that irradiates a recording area on a recording medium with light, a measuring device that measures optical characteristics of the recording area, and a controller that controls the light source and the measuring device.
• FIG. 2 is a graph showing the 1 H-NMR spectrum of Compound 1.
• FIG. 3 is a graph showing the 1 H-NMR spectrum of Compound 2.
• FIG. 4 is a graph showing the 1 H-NMR spectrum of Compound 3.
• the 1 H-NMR spectrum of compound 3 was as follows.
• FIG. 5 is a graph showing the 1 H-NMR spectrum of Compound 4.
• FIG. 6 is a graph showing the 1 H-NMR spectrum of Compound 5.
• the thermal decomposition temperatures of compounds 1 to 5 were determined by thermogravimetric analysis. Using a TG device (manufactured by Hitachi High-Tech Science, TG/DTA7200), 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 stream 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.
• Compounds 1 to 5 have a structure represented by the following formula (11).
• the bond distances between X and C in compounds 1 to 5 were determined by performing structure optimization calculations using DFT calculations. Specifically, first, a structure optimization calculation was performed on the compound using Gaussian 16 (manufactured by Gaussian), which is a quantum chemical calculation program. 6-31++G(d,p) was used as the basis function. CAM-B3LYP was used as the functional. Table 1 shows the bond distance and thermal decomposition temperature for each compound.
• a thin film as a recording layer was formed on the quartz substrate using a coating solution.
• the dimensions of the quartz substrate were 20 mm long, 20 mm wide, and 1 mm thick.
• the quartz substrate was placed in a spin coater, 400 ⁇ L of the coating liquid was dropped onto the quartz substrate, and the spin coater was rotated at a rotational speed of 3000 rpm for 30 seconds. Thereafter, the quartz substrate was 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.
• the recording pulse width of Example 1 was short, and the recording pulse width of Comparative Examples 1 to 5 was long.
• the compound having the structure represented by formula (1) exhibits a low thermal decomposition temperature because the bond distance between carbon and the sulfonyl group is long.
• the dye absorbs laser light and generates heat. The generated heat causes thermal decomposition to proceed and recording marks are formed.
• the lower the pyrolysis temperature the shorter the time it takes for the temperature of the dye to rise to that pyrolysis temperature.
• a compound whose thermal decomposition temperature is low can be recorded with a shorter recording pulse width, that is, with a smaller introduced energy.
• the compound of the present disclosure can be used for 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. Therefore, high-speed recording can be realized in the optical information recording medium. According to the present disclosure, it is possible to provide a new compound suitable for lowering the temperature at which recording marks are formed in order to improve recording sensitivity in the recording layer of an optical information recording medium.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Optical Record Carriers And Manufacture Thereof (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=88919046

Family Applications (1)

Country Status (3)

Citations (5)

• 2023
  • 2023-03-27 WO PCT/JP2023/012101 patent/WO2023228544A1/ja not_active Ceased
  • 2023-03-27 JP JP2024522936A patent/JPWO2023228544A1/ja active Pending
  • 2023-03-27 CN CN202380039970.XA patent/CN119173503A/zh active Pending

Patent Citations (5)

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events