Thermal recording material

Abstract

To provide a thermal recording material having superior sensitivity and transparency.SOLUTION: A thermal recording material 1 of the present invention has a structure in which a thermal recording layer 4 is laminated on a substrate 2. The substrate 2 is a transparent film. The thermal recording layer 4 includes color-developer particles having an average particle diameter of less than 0.25 μm and a sensitizer. The sensitizer includes a compound represented by formula (1). (In formula (1), R1 is a hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R1 groups may be the same or different. n represents an integer of 0 to 3, and a plurality of n values may be the same or different).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heat-sensitive recording medium.

Background Art

[0002] A heat-sensitive recording medium develops color through a chemical reaction by heating with a thermal head or the like, and a recorded image can be obtained. It is used not only as a recording medium for facsimiles, automatic ticket vending machines, and scientific measuring instruments, but also widely used as a heat-sensitive recording label for POS systems in retail stores and the like, receipt paper, and the like.

[0003] As described above, heat-sensitive recording media are widely used. For this reason, various performances are required for heat-sensitive recording media. For example, in recent years, in the trend of miniaturization and power saving of recording devices, a performance in which the printed portion can exhibit a sufficiently high color density even with low applied energy, that is, excellent sensitivity, is required.

[0004] As a technique for improving sensitivity, a technique of blending a sensitizer into a heat-sensitive recording layer has been conventionally known. For example, a heat-sensitive recording medium characterized in that at least a fatty acid amide is contained as a sensitizer in the heat-sensitive recording layer and the content of the fatty acid amide in the sensitizer is 60% by mass or more has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Incidentally, in scenarios where a heat-sensitive recording medium is used as a label for food containers such as bento boxes or a film for food packaging, there has been a problem that the contents cannot be visually recognized when an opaque heat-sensitive recording medium is used. In recent years, with the expansion of the usage scenarios of heat-sensitive recording media, the demand for transparency has been increasing, so such problems are being regarded as more important. However, when a sensitizer is blended for the purpose of improving sensitivity, the transparency generally tends to decrease, so it is difficult to achieve both high sensitivity and transparency, and a heat-sensitive recording medium excellent in sensitivity and transparency has not yet been provided.

[0007] Therefore, an object of the present invention is to provide a heat-sensitive recording medium excellent in sensitivity and transparency.

Means for Solving the Problems

[0008] As a result of intensive studies to achieve the above object, the present inventors have found that a heat-sensitive recording layer containing a specific base material, specific developer particles, and a specific sensitizer can produce a heat-sensitive recording medium excellent in sensitivity and transparency. The present invention has been completed based on these findings.

[0009] That is, the present invention is a heat-sensitive recording medium in which a heat-sensitive recording layer is laminated on a base material, the base material is a transparent film, the heat-sensitive recording layer contains developer particles having an average particle diameter of less than 0.25 μm and a sensitizer, the developer particles contain a urea compound, and the sensitizer contains a compound represented by the following formula (1).

Chemical formula

[0010] The compound represented by the above formula (1) is preferably at least one selected from the group consisting of 1,2-bis(phenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, and 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethane.

[0011] The content ratio of the above sensitizer is preferably 1% by mass to 30% by mass with respect to 100% by mass of the total solid content of the above heat-sensitive recording layer.

[0012] The above urea compound is preferably a non-phenolic developer.

[0013] As the above urea compound, it is preferable to contain at least the compound represented by the following formula (2) and / or the compound represented by the following formula (3).

Chemical formula

Chemical formula

[0014] The above heat-sensitive recording medium preferably has a protective layer on the side opposite to the above base material of the above heat-sensitive recording layer.

[0015] The above heat-sensitive recording medium preferably has an anchor layer between the above base material and the above heat-sensitive recording layer.

[0016] The haze of the above heat-sensitive recording medium is preferably 27% or less. [Advantages of the Invention]

[0017] According to the present invention, a heat-sensitive recording medium excellent in sensitivity and transparency can be provided. [Brief Description of the Drawings]

[0018]

Figure 1

[0019] [Heat-Sensitive Recording Medium] The heat-sensitive recording medium of the present invention is a heat-sensitive recording medium in which a heat-sensitive recording layer is laminated on a base material, and the base material is a transparent film. The heat-sensitive recording layer contains developer particles having an average particle diameter of less than 0.25 μm and a sensitizer. Further, the developer particles contain a urea compound, and the sensitizer contains a compound represented by the following formula (1).

[0020] [Chemical Formula] (In formula (1), R 1 is a hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R 1 may be the same or different. n represents an integer of 0 to 3, and a plurality of n may be the same or different.)

[0021] The heat-sensitive recording medium of the present invention may include other layers other than those described above. Examples of the other layers include an anchor layer, a protective layer, a back coat layer, and the like. Further, the protective layer may be a single layer or a multilayer. The anchor layer is a layer provided between the base material and the heat-sensitive recording layer. The protective layer is a layer provided on the surface of the heat-sensitive recording layer opposite to the surface provided with the base material. The back coat layer is a layer provided on the surface of the base material opposite to the surface provided with the heat-sensitive recording layer.

[0022] The thermal recording medium of the present invention preferably includes a protective layer as the other layer. At this time, the thermal recording medium includes a base material, a thermal recording layer, and a protective layer in this order. Further, the thermal recording medium of the present invention more preferably includes a protective layer and an anchor layer as the other layer. At this time, the thermal recording medium includes a base material, an anchor layer, a thermal recording layer, and a protective layer in this order. Further, the protective layer is preferably a multilayer, and more preferably a bilayer. That is, the thermal recording medium of the present invention more preferably includes a bilayer protective layer and an anchor layer as the other layer. At this time, the thermal recording medium includes a base material, an anchor layer, a thermal recording layer, a first protective layer, and a second protective layer in this order.

[0023] Hereinafter, an embodiment of the thermal recording medium of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments.

[0024] FIG. 1 is a schematic cross-sectional view showing an embodiment of the thermal recording medium of the present invention.

[0025] As shown in FIG. 1, the thermal recording medium 1 of the present embodiment includes a sheet-like base material 2, an anchor layer 3, a thermal recording layer 4, and a protective layer 5 in this order, and the protective layer 5 includes a first protective layer 5a and a second protective layer 5b. That is, as shown in FIG. 1, the thermal recording medium 1 of the present embodiment includes a sheet-like base material 2, an anchor layer 3, a thermal recording layer 4, a first protective layer 5a, and a second protective layer 5b in this order. The anchor layer 3 is laminated so as to be in direct contact with the surface of the base material 2, the thermal recording layer 4 is laminated so as to be in direct contact with the surface of the anchor layer 3, the first protective layer 5a is laminated so as to be in direct contact with the surface of the thermal recording layer 4, and the second protective layer 5b is laminated so as to be in direct contact with the surface of the first protective layer 5a.

[0026] (Base material) In this embodiment, the base material 2 is a transparent film and functions as a support for the thermal recording medium 1. Examples of the transparent film include synthetic resin films such as polypropylene films, polyethylene terephthalate films, polystyrene films, and polycarbonate films. The synthetic resin film may be stretched or unstretched. Further, the base material 2 may be single-layered or multi-layered.

[0027] The thickness of the base material 2 is not particularly limited. For example, 5 μm to 150 μm is preferable, and more preferably 10 μm to 100 μm. If the thickness is within the above range, transparency, coatability, and supportability can be more excellent. Further, from the viewpoint of further improving transparency, the haze of the base material 2 is preferably 10% or less, more preferably 5% or less, and still more preferably 3% or less. Here, the haze can be measured by a conventional method. For example, it can be determined by a method in accordance with JIS K 7136:2000.

[0028] (Anchor layer) In this embodiment, the anchor layer 3 functions as a layer for enhancing the adhesion between the base material 2 and the thermal recording layer 4. The anchor layer may not be provided if not necessary, and in that case, the thermal recording layer can be directly laminated on the surface of the base material. The material for forming the anchor layer 3 is not particularly limited. For example, it can be formed using a resin. Further, the anchor layer 3 may contain other components. Examples of the other components include surfactants and preservatives.

[0029] Examples of the resin include acrylic resins such as acrylic resins, styrene-acrylic resins, acrylic-urethane resins, acrylic-amide resins, and vinyl acetate-acrylic resins; maleic acid resins such as maleic acid resins, styrene-maleic acid resins, and olefin-maleic acid resins; styrene butadiene latex (SBR) resins, and the like. These resins may be modified resins modified by known methods. Further, these resins can be used alone or in combination of two or more.

[0030] In this specification, the "acrylic resin" means a resin (acrylic resin) obtained by polymerizing an acrylic monomer, and / or a resin obtained by copolymerizing an acrylic monomer and another monomer (a monomer other than an acrylic monomer copolymerizable with the acrylic monomer). Here, two or more of the above other monomers may be used. Further, when simply described as "acrylic", unless otherwise specified, it means (meth)acrylic acid (salt) and / or (meth)acrylate. Here, "(meth)acrylic acid" means acrylic acid and / or methacrylic acid, and "(meth)acrylic acid (salt)" means (meth)acrylic acid and / or (meth)acrylate salt.

[0031] The salt in the above (meth)acrylate is not particularly limited, and examples thereof include ammonium salts such as ammonia; alkanolamine salts such as triethanolamine, diethanolamine, and monoethanolamine; alkylamine salts such as methylamine salt, ethylamine salt, diethylamine salt, and triethylamine salt; polyamine salts such as diethyleneamine salt and diethylenetriamine salt; alkali metal salts such as lithium, sodium, and potassium; alkaline earth metal salts such as magnesium and calcium; polyvalent metal salts such as zinc and iron. These salts can be used alone or in combination of two or more.

[0032] The composition forming the above resin may be solid, may be an emulsion, or may be a solution. From the viewpoint of excellent handleability and coatability, it is preferably an emulsion or a solution.

[0033] Examples of the above surfactant include sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, alkyl ether sulfate ester salts, acetylene glycol, and alkylene oxide adducts of acetylene glycol. These surfactants can be used alone or in combination of two or more.

[0034] (Thermosensitive recording layer) In this embodiment, the thermosensitive recording layer 4 is a layer that forms a recorded image on the thermosensitive recording medium 1 by developing color through a chemical reaction upon heating by a thermal head or the like. The thermosensitive recording layer 4 contains at least developer particles having an average particle diameter of less than 0.25 μm and a sensitizer. Further, the developer particles contain a urea compound, and the sensitizer contains a compound represented by the above formula (1). The thermosensitive recording layer 4 may further contain other components as necessary. Examples of the other components include dyes, binders, fillers, lubricants, dispersants, preservatives, and the like. In this specification, the "urea compound" means a compound having one or more urea bonds (-NH-C(=O)-NH-) in the molecule.

[0035] In this embodiment, the sensitizer contains at least a compound represented by the following formula (1). Generally, by blending a sensitizer into the thermosensitive recording layer, the sensitivity can be further improved. In this embodiment, by using a specific sensitizer represented by the following formula (1), excellent sensitivity and excellent transparency can be achieved simultaneously. These sensitizers can be used alone or in combination of two or more.

[0036] [Chemical formula] (In formula (1), R 1 is a hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R 1 may be the same or different. n represents an integer from 0 to 3, and a plurality of n may be the same or different.)

[0037] In the above formula (1), R 1 is a hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R 1 may be the same or different. n represents an integer from 0 to 3, and when n is 2 or more, a plurality of n may be the same or different.

[0038] In the above formula (1), a plurality of R 1is directly bonded to the carbon atoms constituting the benzene ring. Also, a plurality of R 1 may have the same or different substitution positions. The substitution position of R 1 is preferably at the 2-position, 3-position, or 4-position, more preferably at the 3-position.

[0039] In the above formula (1), the "hydrocarbon group having 1 to 3 carbon atoms" of the above R 1 includes, for example, a linear alkyl group having 1 to 3 carbon atoms, a branched alkyl group having 1 to 3 carbon atoms, and an alicyclic alkyl group having 3 carbon atoms. Also, a plurality of "hydrocarbon groups having 1 to 3 carbon atoms" may be the same or different.

[0040] Examples of the "linear alkyl group having 1 to 3 carbon atoms, branched alkyl group having 1 to 3 carbon atoms, and alicyclic alkyl group having 3 carbon atoms" include linear, branched, and alicyclic alkyl groups having 1 to 3 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, and a cyclopropyl group.

[0041] In the above formula (1), the above R 1 is preferably a linear alkyl group having 1 to 3 carbon atoms or a branched alkyl group having 1 to 3 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms. Specifically, the above R 1 is preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, etc., and more preferably a methyl group.

[0042] In the above formula (1), the above n is preferably an integer of 0 to 2, more preferably an integer of 0 to 1, and even more preferably 1.

[0043] Specific examples of the compound represented by the above formula (1) include, but are not limited to, the following compounds.

[0044] That is, as the compound represented by the above formula (1), 1,2-bis(phenoxy)ethane, 1,2-bis(2-methylphenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, 1,2-bis(2-ethylphenoxy)ethane, 1,2-bis(3-ethylphenoxy)ethane, 1,2-bis(4-ethylphenoxy)ethane, 1,2-bis(3,4-dimethylphenoxy)ethane, 1,2-bis(2,4-dimethylphenoxy)ethane, 1-phenoxy-2-(2-methylphenoxy)ethane, 1-phenoxy-2-(3-methylphenoxy)ethane, 1-phenoxy-2-(4-methylphenoxy)ethane, 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethane, 1-(2-methylphenoxy)-2-(3-methylphenoxy)ethane, etc. may be mentioned.

[0045] Among them, the compound represented by the above formula (1) is preferably at least one selected from the group consisting of 1,2-bis(phenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, and 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethane; more preferably at least one selected from the group consisting of 1,2-bis(phenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, and 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethane; and even more preferably 1,2-bis(3-methylphenoxy)ethane.

[0046] In this embodiment, the sensitizer may contain the compound represented by the above formula (1) alone or may contain two or more compounds represented by the above formula (1).

[0047] In this embodiment, the sensitizer may contain a sensitizer other than the compound represented by the above formula (1) (other sensitizers) within a range not impairing the effects of the present invention.

[0048] Examples of other sensitizers include known sensitizers such as stearic acid, stearic acid amide, stearic acid anilide, methylol stearic acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide, 1-benzyloxynaphthalene, 2-benzyloxynaphthalene, 2,6-diisopropylnaphthalene, di(p-chlorobenzyl) oxalate, di(p-methylbenzyl) oxalate, dibenzyl oxalate, p-benzylbiphenyl, m-terphenyl, diphenyl sulfone, benzyl p-benzyloxybenzoate, dibenzyl terephthalate, p-toluenesulfonamide, etc.

[0049] In this embodiment, the content ratio of the compound represented by the above formula (1) is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, particularly preferably 95% by mass or more, based on 100% by mass of the total amount of the sensitizers in the heat-sensitive recording layer 4. When the content ratio is 60% by mass or more, the sensitivity and transparency can be further improved. Also, the content ratio of the compound represented by the above formula (1) may be 100% by mass based on 100% by mass of the total amount of the sensitizers in the heat-sensitive recording layer 4.

[0050] In this embodiment, the content ratio of the sensitizer is preferably 0.1% by mass or more, more preferably 1% by mass or more, still more preferably 2% by mass or more, still more preferably 5% by mass or more, particularly preferably 7% by mass or more, based on 100% by mass of the total solid content of the heat-sensitive recording layer 4. When the content ratio is 0.1% by mass or more, the sensitivity can be further improved. Also, the content ratio of the sensitizer is preferably 30% by mass or less, more preferably 25% by mass or less, still more preferably 20% by mass or less, based on 100% by mass of the total solid content of the heat-sensitive recording layer 4. When the content ratio is 30% by mass or less, the transparency can be further improved. Also, the content ratio of the compound represented by the above formula (1) is preferably within the above range based on 100% by mass of the total solid content of the heat-sensitive recording layer 4.

[0051] In the present embodiment, from the viewpoint of further improving transparency, the average particle diameter of the above sensitizer is preferably 5.0 μm or less, more preferably 3.0 μm or less, still more preferably 1.5 μm or less, and particularly preferably 1.0 μm or less. In this specification, the average particle diameter of the above sensitizer is the average particle diameter measured by the laser diffraction / scattering method, specifically, it means the particle diameter (D50, median diameter) at the integrated value of 50% in the particle size distribution measured by the laser diffraction / scattering method. The average particle diameter by the laser diffraction / scattering method can be measured using a laser diffraction / scattering type particle size distribution measuring device (for example, manufactured by Microtrac Bell Co., Ltd., device name: MT3300EX-II).

[0052] In the present embodiment, the average particle diameter of the above developer particles is less than 0.25 μm. From the viewpoint of further improving transparency, the average particle diameter of the above developer particles is preferably 0.24 μm or less, more preferably 0.22 μm or less, still more preferably 0.20 μm or less, and particularly preferably 0.18 μm or less. The lower limit value of the average particle diameter of the above developer particles is not particularly limited, but from the viewpoint of storage stability, for example, it is preferably 0.01 μm or more, more preferably 0.05 μm or more, and still more preferably 0.10 μm or more.

[0053] In this specification, the average particle diameter of the above "developer particles with an average particle diameter of less than 0.25 μm" is the average particle diameter measured by the dynamic light scattering method, specifically, it means the particle diameter (D50, median diameter) at the integrated value of 50% in the particle size distribution measured by the dynamic light scattering method. The average particle diameter by the dynamic light scattering method can be measured using a dynamic light scattering type particle size measuring device (for example, manufactured by Microtrac Bell Co., Ltd., device name: NANOTRAC WAVE II). By measuring with the dynamic light scattering method, the average particle diameter can be obtained more accurately even in the particle diameter range of less than 0.25 μm.

[0054] The average particle diameter of the above color former particles can be adjusted by a conventional method. For example, as described in the item of the production method described below, it can be made into fine particles by grinding using a mill or the like. Further, in the present embodiment, the shape of the above color former particles is not particularly limited, and may be, for example, spherical, ellipsoidal, needle-like, amorphous, or the like.

[0055] From the viewpoint of environmental compatibility, the above color former particles preferably contain a non-phenolic color former. Further, it is more preferable that the above urea compound is a non-phenolic color former. These color formers can be used alone or in combination of two or more.

[0056] The above urea compound is preferably an N, N'-diarylurea derivative having one or more sulfonic acid ester structures (-S(=O)2-O-) in the molecule. Here, the "N, N'-diarylurea derivative" means a compound having an N, N'-diarylurea skeleton. Specifically, the above urea compound preferably contains a compound represented by the following formula (2) and / or a compound represented by the following formula (3).

[0057]

Chemical formula

[0058]

Chemical formula

[0059] The compound represented by the above formula (2) and / or the compound represented by the above formula (3) can be colored by heating, for example, in contact with the dye described later.

[0060] In the above formula (2) and the above formula (3), R 2 is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and a plurality of R 2 may be the same or different. A 1 is a hydrocarbon group having 1 to 4 carbon atoms, and a plurality of A 1 may be the same or different. m represents an integer of 0 to 4, and when m is 2 or more, a plurality of m may be the same or different.

[0061] In the above formula (2), a plurality of R 2 -SO3- is directly bonded to the carbon atom constituting the benzene ring. Also, the substitution positions of a plurality of R 2 -SO3- may be the same substitution position or different substitution positions. The substitution position of R 2 -SO3- is preferably at the 2-position, 3-position, or 4-position, more preferably at the 3-position.

[0062] In the above formula (3), R 2 -SO3- is directly bonded to the carbon atom constituting the benzene ring. The substitution position of R 2 -SO3- is preferably at the 2-position, 3-position, or 4-position, more preferably at the 3-position.

[0063] In the above formula (2) and the above formula (3), among the "hydrocarbon group having 1 to 12 carbon atoms which may have a substituent" of the above R 2 examples of the "hydrocarbon group having 1 to 12 carbon atoms" include a linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 1 to 12 carbon atoms, an alicyclic alkyl group having 3 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and the like. Also, a plurality of "hydrocarbon groups having 1 to 12 carbon atoms which may have a substituent" may be the same or different.

[0064] Examples of the above “linear alkyl group having 1 to 12 carbon atoms, branched alkyl group having 1 to 12 carbon atoms, or alicyclic alkyl group having 3 to 12 carbon atoms” include linear alkyl groups having 1 to 12 carbon atoms, branched alkyl groups having 1 to 12 carbon atoms, or alicyclic alkyl groups having 3 to 12 carbon atoms such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, cyclopentyl group, hexyl group, cyclohexyl group, 2-ethylhexyl group, lauryl group, etc. These alkyl groups may further have substituents described later.

[0065] Examples of the above “aralkyl group having 7 to 12 carbon atoms” include unsubstituted aralkyl groups such as benzyl group, 1-phenylethyl group, 2-phenylethyl group, 3-phenylpropyl group, etc. These aralkyl groups may further have substituents described later. Examples of the “aralkyl group having 7 to 12 carbon atoms and having a substituent” include aralkyl groups having substituents such as p-methylbenzyl group, m-methylbenzyl group, m-ethylbenzyl group, p-ethylbenzyl group, p-i-propylbenzyl group, p-t-butylbenzyl group, p-methoxybenzyl group, m-methoxybenzyl group, o-methoxybenzyl group, m,p-di-methoxybenzyl group, p-ethoxy-m-methoxybenzyl group, p-phenylmethylbenzyl group, p-cumylbenzyl group, p-phenylbenzyl group, o-phenylbenzyl group, m-phenylbenzyl group, p-tolylbenzyl group, m-tolylbenzyl group, o-tolylbenzyl group, p-chlorobenzyl group, etc.

[0066] Examples of the above-mentioned "aryl group having 6 to 12 carbon atoms" include unsubstituted aryl groups such as phenyl group, 1-naphthyl group, 2-naphthyl group, etc. Further, these aryl groups may further have substituents described later. Examples of the "aryl group having 6 to 12 carbon atoms and having a substituent" include aryl groups having substituents such as p-tolyl group, m-tolyl group, o-tolyl group, 2,5-dimethylphenyl group, 2,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,3-dimethylphenyl group, 3,4-dimethylphenyl group, mesitylene group, p-ethylphenyl group, p-i-propylphenyl group, p-t-butylphenyl group, p-methoxyphenyl group, 3,4-dimethoxyphenyl group, p-ethoxyphenyl group, p-chlorophenyl group, t-butylated naphthyl group, etc.

[0067] The above-mentioned "substituent" is not particularly limited. Among the above-mentioned "hydrocarbon group having 1 to 12 carbon atoms which may have a substituent", when the "hydrocarbon group having 1 to 12 carbon atoms" is a "linear alkyl group having 1 to 12 carbon atoms, a branched alkyl group having 1 to 12 carbon atoms", examples of the substituent include halogen atom, alkoxy group, etc. Further, among the above-mentioned "hydrocarbon group having 1 to 12 carbon atoms which may have a substituent", when the "hydrocarbon group having 1 to 12 carbon atoms" is a "cycloalkyl group having 3 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms", examples of the substituent include halogen atom, alkyl group, alkoxy group, aryl group, etc. Among them, the substituent is preferably an alkyl group or an alkoxy group. Here, the number of carbon atoms of the alkyl group and the alkoxy group as the substituent is not particularly limited, but among them, 1 to 6 carbon atoms are preferable, and 1 to 4 carbon atoms are more preferable. The above-mentioned "substituent" may be plural or not. Also, the substitution positions of the plural "substituents" may be the same or different. The substitution position of the above-mentioned "substituent" is preferably any one of the 2-position, 3-position, or 4-position of the aralkyl group or the aryl group, and more preferably the 4-position.

[0068] In the above formula (2) and the above formula (3), the above R 2Among them, an aryl group having 6 to 12 carbon atoms without substitution or having a substituent is preferable. More specifically, the above R 2 is preferably a phenyl group, p-tolyl group, m-tolyl group, o-tolyl group, 2,5-dimethylphenyl group, 2,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,3-dimethylphenyl group, 3,4-dimethylphenyl group, and among them, p-tolyl group is more preferable. When such R 2 is the case, the sensitivity becomes more excellent.

[0069] In the above formula (2) and the above formula (3), the above A 1 is a carbon atom constituting the benzene ring, and can be bonded to a carbon atom to which the above R 2 -SO3- is not bonded. Also, the substitution positions of a plurality of A 1 may be the same substitution position or different. The substitution position of the above A 1 is preferably the 2-position, 3-position, or 4-position.

[0070] In the above formula (2) and the above formula (3), the above m is preferably an integer of 0 to 2, more preferably an integer of 0 to 1, and even more preferably 0.

[0071] Examples of the hydrocarbon group having 1 to 4 carbon atoms of the above A 1 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, and t-butyl group.

[0072] Specific compounds of the compound represented by the above formula (2) of the present embodiment include, for example, the following compounds, but are not limited to these compounds.

[0073] That is, as the compound represented by the above formula (2), N,N'-di-[3-(o-toluenesulfonyloxy)phenyl]urea, N,N'-di-[3-(m-toluenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-toluenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-toluenesulfonyloxy)-4-methyl-phenyl]urea, N,N'-di-[3-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(mesitylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-methyl-phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-ethyl-phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-5-methyl-phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-propyl-phenyl]urea,

[0074] N,N'-Di-[3-(1-naphthalenesulfonyloxy)phenyl]urea, N,N'-di-[3-(2-naphthalenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-ethylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-propylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-isopropylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-t-butylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(m-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(o-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(m,p-dimethoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-ethoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-propoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-butoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-cumylbenzylsulfonyloxy)phenyl]urea, N,N'-di-[3-(p-cumylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(o-phenylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-phenylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0075] N-[3-(Benzenesulfonyloxy)phenyl]-N'-[3-(p-toluenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N'-[3-(m-toluenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N’-[3-(p-xylenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N’-[3-(mesitylenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N’-[3-(1-naphthalenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N’-[3-(2-naphthalenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N’-[3-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N'-[3-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N'-[3-(benzylsulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N'-[3-(ethanesulfonyloxy)phenyl]urea, N-[3-(Benzenesulfonyloxy)phenyl]-N'-[3-(benzenesulfonyloxy)-4-methylphenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N’-[3-(m-toluenesulfonyloxy)phenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N’-[3-(o-toluenesulfonyloxy)phenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[3-(p-toluenesulfonyloxy)-4-methylphenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[3-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N’-[3-(p-methoxybenzenesulfonyloxy)phenyl]urea,N-[3-(p-Toluenesulfonyloxy)phenyl]-N’-[3-(2-naphthalenesulfonyloxy)phenyl]urea,

[0076] N-[3-(p-Toluenesulfonyloxy)phenyl]-N'-[3-(benzylsulfonyloxy)phenyl]urea, N-[3-(p-Toluenesulfonyloxy)phenyl]-N'-[3-(p-methylbenzylsulfonyloxy)phenyl]urea, N-[3-(p-Toluenesulfonyloxy)phenyl]-N'-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea, N-[3-(p-Toluenesulfonyloxy)phenyl]-N'-[3-(methanesulfonyloxy)phenyl]urea, N-[3-(p-Toluenesulfonyloxy)phenyl]-N’-[3-(propanesulfonyloxy)phenyl]urea, N-[3-(p-Toluenesulfonyloxy)phenyl]-N’-[3-(butanesulfonyloxy)phenyl]urea,

[0077] N,N'-Di-[3-(benzylsulfonyloxy)phenyl]urea, N,N'-Di-[3-(benzylsulfonyloxy)-4-methyl-phenyl]urea, N,N'-Di-[3-(phenylethanesulfonyloxy)phenyl]urea, N,N'-Di-[3-(phenylpropanesulfonyloxy)phenyl]urea, N,N'-Di-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea,

[0078] N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea, N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(ethanesulfonyloxy)phenyl]urea, N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea,

[0079] N,N'-Di-[3-(methanesulfonyloxy)phenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-methyl-phenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-ethyl-phenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-5-methyl-phenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4,5-dimethyl-phenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)-4-methyl-phenyl]urea, N,N'-di-[3-(1-propanesulfonyloxy)phenyl]urea, N,N'-di-[3-(2-propanesulfonyloxy)phenyl]urea, N,N'-di-[3-(butanesulfonyloxy)phenyl]urea, N,N'-di-[3-(pentanesulfonyloxy)phenyl]urea, N,N'-di-[3-(hexanesulfonyloxy)phenyl]urea, N,N'-di-[3-(cyclohexanesulfonyloxy)phenyl]urea, N,N'-di-[3-(dodecanesulfonyloxy)phenyl]urea,

[0080] N-[3-(methanesulfonyloxy)phenyl]-N'-[3-(ethanesulfonyloxy)phenyl]urea, N-[3-(ethanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, N-[3-(methanesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea, N-[3-(ethanesulfonyloxy)phenyl]-N'-[3-(cyclohexanesulfonyloxy)phenyl]urea,

[0081] N,N'-Di-[4-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-methyl-phenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-ethyl-phenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-propyl-phenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-t-butyl-phenyl]urea,

[0082] N,N'-Di-[4-(o-toluenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-toluenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-toluenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-toluenesulfonyloxy)-3-methyl-phenyl]urea,

[0083] N,N'-Di-[4-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[4-(mesitylenesulfonyloxy)phenyl]urea,

[0084] N,N'-Di-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N,N'-di-[4-(2-naphthalenesulfonyloxy)phenyl]urea,

[0085] N,N'-Di-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-propylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-isopropylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea,

[0086] N,N'-Di-[4-(p-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(o-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m,p-dimethoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-ethoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-propoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea,

[0087] N,N'-Di-[4-(p-cumylbenzylsulfonyloxy)phenyl]urea, N,N'-di-[4-(p-cumylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(o-phenylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea,

[0088] N,N'-Di-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0089] N-[4-(benzenesulfonyloxy)phenyl]-N'-[4-(p-toluenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N'-[4-(m-toluenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N'-[4-(o-toluenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N'-[4-(p-xylenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N'-[4-(mesitylenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N’-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N’-[4-(2-naphthalenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N’-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N’-[4-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N’-[4-(benzylsulfonyloxy)phenyl]urea, N-[4-(benzenesulfonyloxy)phenyl]-N’-[4-(ethanesulfonyloxy)phenyl]urea, N-[4-(p-toluenesulfonyloxy)phenyl]-N’-[4-(m-toluenesulfonyloxy)phenyl]urea, N-[4-(p-toluenesulfonyloxy)phenyl]-N’-[4-(o-toluenesulfonyloxy)phenyl]urea, N-[4-(p-toluenesulfonyloxy)phenyl]-N'-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[4-(p-toluenesulfonyloxy)phenyl]-N’-[4-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[4-(p-toluenesulfonyloxy)phenyl]-N’-[4-(2-naphthalenesulfonyloxy)phenyl]urea, N-[4-(p-toluenesulfonyloxy)phenyl]-N’-[4-(benzylsulfonyloxy)phenyl]urea,N-[4-(p-Toluenesulfonyloxy)phenyl]-N’-[4-(p-methylbenzylsulfonyloxy)phenyl]urea, N-[4-(p-Toluenesulfonyloxy)phenyl]-N’-[4-(p-methoxybenzylsulfonyloxy)phenyl]urea, N-[4-(p-Toluenesulfonyloxy)phenyl]-N’-[4-(methanesulfonyloxy)phenyl]urea, N-[4-(p-Toluenesulfonyloxy)phenyl]-N’-[4-(propanesulfonyloxy)phenyl]urea, N-[4-(p-Toluenesulfonyloxy)phenyl]-N’-[4-(butanesulfonyloxy)phenyl]urea,

[0090] N,N'-Di-[4-(benzylsulfonyloxy)phenyl]urea, N,N'-Di-[4-(benzylsulfonyloxy)-3-methyl-phenyl]urea, N,N'-Di-[4-(phenylethanesulfonyloxy)phenyl]urea, N,N'-Di-[4-(phenylpropanesulfonyloxy)phenyl]urea, N,N'-Di-[4-(p-methoxybenzylsulfonyloxy)phenyl)urea,

[0091] N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea,

[0092] N,N'-Di-[4-(methanesulfonyloxy)phenyl]urea, N,N'-Di-[4-(methanesulfonyloxy)-3-methyl-phenyl]urea, N,N'-Di-[4-(methanesulfonyloxy)-4-ethyl-phenyl]urea, N,N'-Di-[4-(methanesulfonyloxy)-3-methyl-phenyl]urea, N,N'-Di-[4-(methanesulfonyloxy)-3,5-dimethyl-phenyl]urea, N,N'-Di-[4-(ethanesulfonyloxy)phenyl]urea, N,N'-Di-[4-(ethanesulfonyloxy)-3-methyl-phenyl]urea, N,N'-Di-[4-(1-propanesulfonyloxy)phenyl]urea, N,N'-Di-[4-(2-propanesulfonyloxy)phenyl]urea, N,N'-Di-[4-(butanesulfonyloxy)phenyl]urea, N,N'-Di-[4-(pentanesulfonyloxy)phenyl]urea, N,N’-Di-[4-(hexanesulfonyloxy)phenyl]urea, N,N’-Di-[4-(cyclohexanesulfonyloxy)phenyl]urea, N,N’-Di-[4-(dodecanesulfonyloxy)phenyl]urea,

[0093] N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea,

[0094] N,N'-Di-[2-(benzenesulfonyloxy)phenyl]urea, N,N'-Di-[2-(benzenesulfonyloxy)-4-methyl-phenyl]urea, N,N'-Di-[2-(benzenesulfonyloxy)-4-ethyl-phenyl]urea, N,N'-Di-[2-(benzenesulfonyloxy)-5-methyl-phenyl]urea, N,N'-Di-[2-(benzenesulfonyloxy)-4-propyl-phenyl]urea,

[0095] N,N'-Di-[2-(o-toluenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-toluenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-toluenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-toluenesulfonyloxy)-4-methyl-phenyl]urea,

[0096] N,N'-Di-[2-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[2-(mesitylenesulfonyloxy)phenyl]urea,

[0097] N,N'-Di-[2-(1-naphthalenesulfonyloxy)phenyl]urea, N,N'-di-[2-(2-naphthalenesulfonyloxy)phenyl]urea,

[0098] N,N'-Di-[2-(p-ethylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-propylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-isopropylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-t-butylbenzenesulfonyloxy)phenyl]urea,

[0099] N,N'-Di-[2-(p-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(o-methoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m,p-dimethoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-ethoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-propoxybenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-butoxybenzenesulfonyloxy)phenyl]urea,

[0100] N,N'-Di-[2-(p-cumylbenzylsulfonyloxy)phenyl]urea, N,N'-di-[2-(p-cumylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(o-phenylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-phenylbenzenesulfonyloxy)phenyl]urea,

[0101] N,N'-Di-[2-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0102] N-[2-(Benzenesulfonyloxy)phenyl]-N'-[2-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N'-[2-(m-toluenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N'-[2-(o-toluenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N'-[2-(p-xylenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N'-[2-(mesitylenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N’-[2-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N’-[2-(2-naphthalenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N’-[2-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N’-[2-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N’-[2-(benzylsulfonyloxy)phenyl]urea, N-[2-(Benzenesulfonyloxy)phenyl]-N’-[2-(ethanesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N’-[2-(m-toluenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N’-[2-(o-toluenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[2-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N’-[2-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N’-[2-(2-naphthalenesulfonyloxy)phenyl]urea,

[0103] N-[2-(p-Toluenesulfonyloxy)phenyl]-N'-[2-(benzylsulfonyloxy)phenyl]urea, N-[2-(p-Toluenesulfonyloxy)phenyl]-N'-[2-(p-methylbenzylsulfonyloxy)phenyl]urea, N-[2-(p-Toluenesulfonyloxy)phenyl]-N'-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea, N-[2-(p-Toluenesulfonyloxy)phenyl]-N'-[2-(methanesulfonyloxy)phenyl]urea, N-[2-(p-Toluenesulfonyloxy)phenyl]-N’-[2-(propanesulfonyloxy)phenyl]urea, N-[2-(p-Toluenesulfonyloxy)phenyl]-N’-[2-(butanesulfonyloxy)phenyl]urea,

[0104] N,N'-Di-[2-(benzylsulfonyloxy)phenyl]urea, N,N'-Di-[2-(benzylsulfonyloxy)-4-methyl-phenyl]urea, N,N'-Di-[2-(phenylethanesulfonyloxy)phenyl]urea, N,N'-Di-[2-(phenylpropanesulfonyloxy)phenyl]urea, N,N'-Di-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea, etc.

[0105] N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea,

[0106] N,N'-Di-[2-(methanesulfonyloxy)phenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-methyl-phenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-ethyl-phenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-5-methyl-phenyl]urea, N,N’-di-[2-(methanesulfonyloxy)-4,5-dimethyl-phenyl]urea, N,N’-di-[2-(ethanesulfonyloxy)phenyl]urea, N,N’-di-[2-(ethanesulfonyloxy)-4-methyl-phenyl]urea, N,N'-di-[2-(1-propanesulfonyloxy)phenyl]urea, N,N'-di-[2-(2-propanesulfonyloxy)phenyl]urea, N,N'-di-[2-(butanesulfonyloxy)phenyl]urea, N,N'-di-[2-(pentanesulfonyloxy)phenyl]urea, N,N’-di-[2-(hexanesulfonyloxy)phenyl]urea, N,N’-di-[2-(cyclohexanesulfonyloxy)phenyl]urea, N,N’-di-[2-(dodecanesulfonyloxy)phenyl]urea,

[0107] N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(hexanesulfonyloxy)phenyl]urea,

[0108] N-[3-(benzenesulfonyloxy)phenyl]-N'-[4-(benzenesulfonyloxy)phenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[4'-(p-toluenesulfonyloxy)phenyl]urea, N-[3-(m-toluenesulfonyloxy)phenyl]-·'-[4-(m-toluenesulfonyloxy)phenyl]urea, N-[3-(o-toluenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea,

[0109] N-[3-(p-Xylenesulfonyloxy)phenyl]-N'-[4-(p-xylenesulfonyloxy)phenyl]urea, N-[3-(m-xylenesulfonyloxy)phenyl]-N'-[4-(m-xylenesulfonyloxy)phenyl]urea, N-[3-(mesitylenesulfonyloxy)phenyl]-N'-[4-(mesitylenesulfonyloxy)phenyl]urea,

[0110] N-[3-(1-Naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N-[3-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea,

[0111] N-[3-(p-Ethylbenzenesulfonyloxy)phenyl]-N'-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[3-(p-Propylbenzenesulfonyloxy)phenyl]-N'-[4-(p-propylbenzenesulfonyloxy)phenyl]urea, N-[3-(p-Isopropylbenzenesulfonyloxy)phenyl]-N'-[4-(p-isopropylbenzenesulfonyloxy)phenyl]urea, N-[3-(p-t-Butylbenzenesulfonyloxy)phenyl]-N'-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea,

[0112] N-[3-(p-Methoxybenzenesulfonyloxy)phenyl]-N'-[4-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[3-(m-methoxybenzenesulfonyloxy)phenyl]-N'-[4-(m-methoxybenzenesulfonyloxy)phenyl]urea, N-[3-(o-methoxybenzenesulfonyloxy)phenyl]-N'-[4-(o-methoxybenzenesulfonyloxy)phenyl]urea, N-[3-(m,p-dimethoxybenzenesulfonyloxy)phenyl]-N'-[4-(m,p-dimethoxybenzenesulfonyloxy)phenyl]urea, N-[3-(p-ethoxybenzenesulfonyloxy)phenyl]-N’-[4-(p-ethoxybenzenesulfonyloxy)phenyl]urea, N-[3-(p-propoxybenzenesulfonyloxy)phenyl]-N’-[4-(p-propoxybenzenesulfonyloxy)phenyl]urea, N-[3-(p-butoxybenzenesulfonyloxy)phenyl]-N’-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea,

[0113] N-[3-(p-Cumylbenzylsulfonyloxy)phenyl]-N'-[4-(p-cumylbenzylsulfonyloxy)phenyl]urea, N-[3-(p-cumylbenzenesulfonyloxy)phenyl]-N'-[4-(p-cumylbenzenesulfonyloxy)phenyl]urea, N-[3-(o-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(o-phenylbenzenesulfonyloxy)phenyl]urea, N-[3-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea,

[0114] N-[3-(p-Chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0115] N-[3-(benzenesulfonyloxy)phenyl]-N'-[4-(p-toluenesulfonyloxy)phenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[4-(o-toluenesulfonyloxy)phenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[4-(benzenesulfonyloxy)phenyl]urea, N-[3-(benzenesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea,

[0116] N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea, N-[3-(phenylethanesulfonyloxy)phenyl]-N'-[4-(phenylethanesulfonyloxy)phenyl]urea, N-[3-(phenylpropanesulfonyloxy)phenyl]-N'-[4-(phenylpropanesulfonyloxy)phenyl]urea, N-[3-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[4-(p-methoxybenzylsulfonyloxy)phenyl]urea, etc.

[0117] N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea, N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(p-methylbenzylsulfonyloxy)phenyl]urea,

[0118] N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, N-[3-(ethanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[3-(1-propanesulfonyloxy)phenyl]-N'-[4-(1-propanesulfonyloxy)phenyl]urea, N-[3-(2-propanesulfonyloxy)phenyl]-N'-[4-(2-propanesulfonyloxy)phenyl]urea, N-[3-(butanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea, N-[3-(pentanesulfonyloxy)phenyl]-N'-[4-(pentanesulfonyloxy)phenyl]urea, N-[3-(hexanesulfonyloxy)phenyl]-N'-[4-(hexanesulfonyloxy)phenyl]urea, N-[3-(cyclohexanesulfonyloxy)phenyl]-N'-[4-(cyclohexanesulfonyloxy)phenyl]urea, N-[3-(dodecanesulfonyloxy)phenyl]-N'-[4-(dodecanesulfonyloxy)phenyl]urea,

[0119] N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[3-(methanesulfonyloxy)phenyl]-N'- 4-(butanesulfonyloxy)phenyl]urea,

[0120] N-[2-(benzenesulfonyloxy)phenyl]-N'-[4-(benzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[4-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(m-toluenesulfonyloxy)phenyl]-N'-[4-(m-toluenesulfonyloxy)phenyl]urea, N-[2-(o-toluenesulfonyloxy)phenyl]-N'-[4-(o-toluenesulfonyloxy)phenyl]urea,

[0121] N-[2-(p-Xylenesulfonyloxy)phenyl]-N'-[4-(p-xylenesulfonyloxy)phenyl]urea, N-[2-(m-xylenesulfonyloxy)phenyl]-N'-[4-(m-xylenesulfonyloxy)phenyl]urea, N-[2-(mesitylenesulfonyloxy)phenyl]-N'-[4-(mesitylenesulfonyloxy)phenyl]urea,

[0122] N-[2-(1-Naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[4-(2-naphthalenesulfonyloxy)phenyl]urea,

[0123] N-[2-(p-Ethylbenzenesulfonyloxy)phenyl]-N'-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-Propylbenzenesulfonyloxy)phenyl]-N'-[4-(p-propylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-Isopropylbenzenesulfonyloxy)phenyl]-N'-[4-(p-isopropylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-t-Butylbenzenesulfonyloxy)phenyl]-N'-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea,

[0124] N-[2-(p-Methoxybenzenesulfonyloxy)phenyl]-N'-[4-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(m-methoxybenzenesulfonyloxy)phenyl]-N'-[4-(m-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(o-methoxybenzenesulfonyloxy)phenyl]-N'-[4-(o-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(m,p-dimethoxybenzenesulfonyloxy)phenyl]-N'-[4-(m,p-dimethoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-ethoxybenzenesulfonyloxy)phenyl]-N’-[4-(p-ethoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-propoxybenzenesulfonyloxy)phenyl]-N’-[4-(p-propoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-butoxybenzenesulfonyloxy)phenyl]-N’-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea,

[0125] N-[2-(p-Cumylbenzylsulfonyloxy)phenyl]-N'-[4-(p-cumylbenzylsulfonyloxy)phenyl]urea, N-[2-(p-cumylbenzenesulfonyloxy)phenyl]-N'-[4-(p-cumylbenzenesulfonyloxy)phenyl]urea, N-[2-(o-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(o-phenyl)benzenesulfonyloxy)phenyl]urea, N-[2-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea,

[0126] N-[2-(p-Chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0127] N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(benzenesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[4-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N’-[4-(o-toluenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl-N'-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[4-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[4-[benzenesulfonyloxy]phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N’-[4-(mesitylenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N’-[4-(1-naphthalenesulfonyloxy)phenyl]urea,

[0128] N-[2-(benzylsulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea, N-[2-(phenylethanesulfonyloxy)phenyl]-N'-[4-(phenylethanesulfonyloxy)phenyl]urea, N-[2-(phenylpropanesulfonyloxy)phenyl]-N'-[4-(phenylpropanesulfonyloxy)phenyl]urea, N-[2-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[4-(p-methoxybenzylsulfonyloxy)phenyl]urea,

[0129] N-[2-(Ethanesulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea,

[0130] N-[2-(methanesulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[2-(1-propanesulfonyloxy)phenyl]-N'-[4-(1-propanesulfonyloxy)phenyl]urea, N-[2-(2-propanesulfonyloxy)phenyl]-N'-[4-(2-propanesulfonyloxy)phenyl]urea, N-[2-(butanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea, N-[2-(pentanesulfonyloxy)phenyl]-N’-[4-(pentanesulfonyloxy)phenyl]urea, N-[2-(hexanesulfonyloxy)phenyl]-N’-[4-(hexanesulfonyloxy)phenyl]urea, N-[2-(cyclohexanesulfonyloxy)phenyl]-N’-[4-(cyclohexanesulfonyloxy)phenyl]urea, N-[2-(dodecanesulfonyloxy)phenyl]-N’-[4-(dodecanesulfonyloxy)phenyl]urea,

[0131] N-[2-(methanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea,

[0132] N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(benzenesulfon N-[2-(nitrooxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(m-toluenesulfonyloxy)phenyl]-N'-[3-(m-toluenesulfonyloxy)phenyl]urea, N-[2-(o-toluenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea,

[0133] N-[2-(p-xylenesulfonyloxy)phenyl]-N'-[3-(p-xylenesulfonyloxy)phenyl]urea, N-[2-(m-xylenesulfonyloxy)phenyl]-N'-[3-(m-xylenesulfonyloxy)phenyl]urea, N-[2-(mesitylenesulfonyloxy)phenyl]-N'-[3-(mesitylenesulfonyloxy)phenyl]urea,

[0134] N-[2-(1-naphthalenesulfonyloxy)phenyl]-N'-[3-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea,

[0135] N-[2-(p-ethylbenzenesulfonyloxy)phenyl]-N'-[3-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-propylbenzenesulfonyloxy)phenyl]-N'-[3-(p-propylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-isopropylbenzenesulfonyloxy)phenyl]-N'-[3-(p-isopropylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-t-butylbenzenesulfonyloxy)phenyl]-N'-[3-(p-t-butylbenzenesulfonyloxy)phenyl]urea,

[0136] N-[2-(p-Methoxybenzenesulfonyloxy)phenyl]-N'-[3-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(m-methoxybenzenesulfonyloxy)phenyl]-N'-[3-(m-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(o-methoxybenzenesulfonyloxy)phenyl]-N'-[3-(o-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(m,p-dimethoxybenzenesulfonyloxy)phenyl]-N'-[3-(m,p-dimethoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-ethoxybenzenesulfonyloxy)phenyl]-N'-[3-(p-ethoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-propoxybenzenesulfonyloxy)phenyl]-N'-[3-(p-propoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-butoxybenzenesulfonyloxy)phenyl]-N'-[3-(p-butoxybenzenesulfonyloxy)phenyl]urea,

[0137] N-[2-(p-Cumylbenzylsulfonyloxy)phenyl]-N'-[3-(p-cumylbenzylsulfonyloxy)phenyl]urea, N-[2-(p-cumylbenzenesulfonyloxy)phenyl]-N'-[3-(p-cumylbenzenesulfonyloxy)phenyl]urea, N-[2-(o-phenylbenzenesulfonyloxy)phenyl]-N'-[3-(o-phenylbenzenesulfonyloxy)phenyl]urea, N-[2-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[3-(p-phenylbenzenesulfonyloxy)phenyl]urea,

[0138] N-[2-(p-Chlorobenzenesulfonyloxy)phenyl]-N'-[3-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0139] N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(benzenesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(ethanesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N’-[3-(p-ethylbenzenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N’-[3-(p-methoxybenzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(benzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(mesitylenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(1-naphthalenesulfonyloxy)phenyl]urea,

[0140] N-[2-(benzylsulfonyloxy)phenyl]-N'-[3-(benzylsulfonyloxy)phenyl]urea, N-[2-(phenylethanesulfonyloxy)phenyl]-N'-[3-(phenylethanesulfonyloxy)phenyl]urea, N-[2-(phenylpropanesulfonyloxy)phenyl]-N'-[3-(phenylpropanesulfonyloxy)phenyl]urea, N-[2-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea,

[0141] N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(benzenesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(methanesulfonyloxy)phenyl]urea, N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea,

[0142] N-[2-(methanesulfonyloxy)phenyl]-N'-[3-(methanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(ethanesulfonyloxy)phenyl]urea, N-[2-(1-propanesulfonyloxy)phenyl]-N'-[3-(1-propanesulfonyloxy)phenyl]urea, N-[2-(2-propanesulfonyloxy)phenyl]-N'-[3-(2-propanesulfonyloxy)phenyl]urea, N-[2-(butanesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea, N-[2-(pentanesulfonyloxy)phenyl]-N’-[3-(pentanesulfonyloxy)phenyl]urea, N-[2-(hexanesulfonyloxy)phenyl]-N’-[3-(hexanesulfonyloxy)phenyl]urea, N-[2-(cyclohexanesulfonyloxy)phenyl]-N’-[3-(cyclohexanesulfonyloxy)phenyl]urea, N-[2-(dodecanesulfonyloxy)phenyl]-N’-[3-(dodecanesulfonyloxy)phenyl]urea,

[0143] N-[2-(methanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea, etc. are exemplified. Among them, as the compound represented by the above formula (2), N,N’-di-[3-(p-toluenesulfonyloxy)phenyl]urea is particularly preferred.

[0144] In addition, as specific compounds, the compounds represented by the above formula (3) of the present embodiment include, for example, the following compounds, but are not limited to these compounds.

[0145] That is, as the compounds represented by the above formula (3), 3-[(3-phenylureido)phenyl]-4-methylbenzenesulfonate, 4-[(3-phenylureido)phenyl]-4-methylbenzenesulfonate, 2-[(3-phenylureido)phenyl]-4-methylbenzenesulfonate, 3-[(3-phenylureido)phenyl]-2-methylbenzenesulfonate, 4-[(3-phenylureido)phenyl]-2-methylbenzenesulfonate, 2-[(3-phenylureido)phenyl]-2-methylbenzenesulfonate, 3-[(3-phenylureido)phenyl]-3-methylbenzenesulfonate, 4-[(3-phenylureido)phenyl]-3-methylbenzenesulfonate, 2-[(3-phenylureido)phenyl]-3-methylbenzenesulfonate, 3-[(3-phenylureido)phenyl]-benzenesulfonate, 4-[(3-phenylureido)phenyl]-benzenesulfonate, 2-[(3-phenylureido)phenyl]-benzenesulfonate,

[0146] 3-[3-(4-Methylphenylureido)]phenyl-4-methylbenzenesulfonate, 4-[3-(4-methylphenylureido)]phenyl-4-methylbenzenesulfonate, 2-[3-(4-methylphenylureido)]phenyl-4-methylbenzenesulfonate, 3-[3-(4-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 4-[3-(4-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 2-[3-(4-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 3-[3-(4-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 4-[3-(4-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 2-[3-(4-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 3-[3-(4-methylphenylureido)]phenyl-benzenesulfonate, 4-[3-(4-methylphenylureido)]phenyl-benzenesulfonate, 2-[3-(4-methylphenylureido)]phenyl-benzenesulfonate,

[0147] 3-[3-(2-Methylphenylureido)]phenyl-4-methylbenzenesulfonate, 4-[3-(2-methylphenylureido)]phenyl-4-methylbenzenesulfonate, 2-[3-(2-methylphenylureido)]phenyl-4-methylbenzenesulfonate, 3-[3-(2-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 4-[3-(2-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 2-[3-(2-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 3-[3-(2-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 4-[3-(2-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 2-[3-(2-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 3-[3-(2-methylphenylureido)]phenyl-benzenesulfonate, 4-[3-(2-methylphenylureido)]phenyl-benzenesulfonate, 2-[3-(2-methylphenylureido)]phenyl-benzenesulfonate,

[0148] 3-[3-(3-Methylphenylureido)]phenyl-4-methylbenzenesulfonate, 4-[3-(3-methylphenylureido)]phenyl-4-methylbenzenesulfonate, 2-[3-(3-methylphenylureido)]phenyl-4-methylbenzenesulfonate, 3-[3-(3-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 4-[3-(3-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 2-[3-(3-methylphenylureido)]phenyl-2-methylbenzenesulfonate, 3-[3-(3-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 4-[3-(3-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 2-[3-(3-methylphenylureido)]phenyl-3-methylbenzenesulfonate, 3-[3-(3-methylphenylureido)]phenyl-benzenesulfonate, 4-[3-(3-methylphenylureido)]phenyl-benzenesulfonate, 2-[3-(3-methylphenylureido)]phenyl-benzenesulfonate,

[0149] 3-(3-Phenylureido)phenyl-4-propyloxybenzenesulfonate, 4-(3-phenylureido)phenyl-4-propyloxybenzenesulfonate, 2-(3-phenylureido)phenyl-4-propyloxybenzenesulfonate, 3-(3-phenylureido)phenyl-4-phenyloxybenzenesulfonate, 4-(3-phenylureido)phenyl-4-phenyloxybenzenesulfonate, 2-(3-phenylureido)phenyl-4-phenyloxybenzenesulfonate and the like can be mentioned. Among them, as the compound represented by the above formula (3), 3-[(3-phenylureido)phenyl]-4-methylbenzenesulfonate is particularly preferable.

[0150] In the present embodiment, the color developer particles may contain a urea compound alone or may contain two or more urea compounds. Further, the color developer particles may contain the compound represented by the above formula (2) alone or may contain two or more compounds represented by the above formula (2). Similarly, the color developer particles may contain the compound represented by the above formula (3) alone or may contain two or more compounds represented by the above formula (3). Further, the color developer particles may contain both the compound represented by the above formula (2) and the compound represented by the above formula (3).

[0151] In the present embodiment, the color developer particles may contain a color developer other than the compound represented by the above formula (2) and / or the compound represented by the above formula (3) (other color developers) within a range not impairing the effects of the present invention.

[0152] Examples of other color developers include known non-phenol color developers such as N-3-[(p-toluenesulfonyl)oxy]phenyl-N'-(p-toluenesulfonyl)-urea (trade name: PF-201), N-[2-(3-phenylureido)phenyl]-benzenesulfonamide (trade name: NKK-1304), and known color developers such as 4,4'-isopropylidenediphenol (BPA), 4,4'-dihydroxydiphenylsulfone (BPS), 4-allyloxy-4'-hydroxydiphenylsulfone (trade name: BPS-MAE), 4-allyloxy-4'-hydroxy-diphenylsulfone (trade name: TGSA), 4-hydroxy-4'-isopropoxysulfone (trade name: D-8), N-(m-tolylaminocarbonyl)-methionine, N-(m-tolylaminocarbonyl)-phenylalanine, and N-(phenylaminocarbonyl)-phenylalanine.

[0153] Furthermore, as other color developers, for example, 1,1-bis(p-hydroxyphenyl)cyclohexane, 1,1-bis(p-hydroxyphenyl)propane, 2,2-bis(p-hydroxyphenyl)propane, 2,2-bis(p-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 2,2'-methylenebis(4-chlorophenol), 2,2-bis(4-hydroxyphenyl)-4-methylpentane, poly(4-hydroxybenzoic acid), benzyl 4-hydroxybenzoate, 2,4-bis(phenylsulfonyl)phenol, α-{4-[(4-hydroxyphenyl)sulfonyl]phenyl}-ω-hydroxy poly(degree of polymerization n = 1 to 7)(oxyethylene oxyethylene oxy-p-phenylene sulfonyl-p-phenylene), 3,5-bis(α-methylbenzyl)salicylic acid, zinc bis[4-(n-octyloxycarbonylamino)salicylate], 4,4'-bis(p-tolylsulfonylaminocarbonylamino)diphenylmethane, 4-hydroxybenzenesulfonanilide, N-(2-hydroxyphenyl)-2-[(4-hydroxyphenyl)thio]acetamide, N-(4-hydroxyphenyl)-2-[(4-hydroxyphenyl)thio]acetamide, 4-[[4-[4-[4-[[4-(1-methylethoxy)phenyl]sulfonylphenoxy]butoxy]phenyl]sulfonyl]phenol, 4-tert-butylphenol·formaldehyde polycondensate, etc. may be mentioned.

[0154] In this embodiment, the color developer particles may further contain other components in addition to the urea compound. Examples of the other components include dispersants. By the color developer particles containing a dispersant or the like, the adjustment of the average particle diameter can be made easier. Examples of the dispersant include the same ones as those described later.

[0155] In this embodiment, the content ratio of the urea compound is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more with respect to 100% by mass of the total amount of the developer particles in the heat-sensitive recording layer 4. When the content ratio is 50% by mass or more, the sensitivity can be further improved. Also, the total content ratio of the compound represented by the above formula (2) and / or the compound represented by the above formula (3) is preferably within the above range with respect to 100% by mass of the total amount of the developer particles in the heat-sensitive recording layer 4.

[0156] In this embodiment, the content ratio of the developer particles is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4. When the content ratio is 10% by mass or more, the sensitivity can be further improved. Also, the content ratio of the developer particles is preferably 50% by mass or less, more preferably 45% by mass or less, still more preferably 40% by mass or less with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4. Also, the content ratio of the total amount of the developer is preferably within the above range with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4.

[0157] In this embodiment, the mass of the sensitizer with respect to 100 parts by mass of the developer particles is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and particularly preferably 15 parts by mass or more. When it is the above mass, the sensitivity can be further improved. Also, the mass of the sensitizer with respect to 100 parts by mass of the developer particles is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 60 parts by mass or less. When it is the above mass, the transparency can be further improved.

[0158] In this embodiment, the urea compound contained in the developer particles is N,N'-di-[3-(p-toluenesulfonyloxy)phenyl]urea and / or 3-[(3-phenylureido)phenyl]-4-methylbenzenesulfonate, and further, the compound represented by the above formula (1) contained in the sensitizer is preferably 1,2-bis(3-methylphenoxy)ethane. By using such a combination, particularly excellent sensitivity and transparency can be achieved.

[0159] In this embodiment, it is preferable that the heat-sensitive recording layer 4 contains the above dye. The above dye is a component that develops color by heating. For example, a chemical reaction proceeds by heating with a thermal head or the like, thereby developing color, and it is a component for forming a recorded image on the heat-sensitive recording body 1 of this embodiment. The above dye is not particularly limited, and known dyes generally used can be used. Examples of the above dye include 3-(N-isobutyl-N-ethyl)amino-6-methyl-7-anilinofluoran, 3-(N-isopentyl-N-ethyl)amino-6-methyl-7-o-chloroanilinofluoran, 3-(N-methyl-N-p-toluidino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-p-toluidino)-6-methyl-7-anilinofluoran, 3-(N-ethyl-N-isopentyl)amino-6-methyl-7-anilinofluoran, 3-(N-ethoxypropyl-N-ethyl)amino-6-methyl-7-anilinofluoran, 3-(N-cyclohexyl-N-methyl)amino-6-methyl-7-anilinofluoran, 3-(N-methyl-N-n-propyl)amino-6-methyl-7-anilinofluoran, 3-dibutylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-p-toluidinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-8-methylfluoran, 3-diethylamino-7-(m-trifluoromethylanilino)fluoran, 3-diethylamino-7-(o-chloroanilino)fluoran, 3-diethylamino-7-chlorofluoran, 3-dibutylamino-6-methyl-7-bromofluoran, 3-dibutylamino-7-(o-chloroanilino)fluoran, 3-dipentylamino-6-methyl-7-anilinofluoran, 3-dimethylamino-5-methyl-7-methylfluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, crystal violet lactone, and the like. These dyes can be used alone or in combination of two or more.

[0160] The average particle diameter of the above dye is preferably 0.1 μm to 1.0 μm. Since the dye melts and reacts, as the average particle diameter increases, the reaction becomes sluggish and the sensitivity characteristics decrease. On the other hand, as the average particle diameter decreases, the risk of unexpected color development due to heat or the like during drying of the paint increases. In this embodiment, by adjusting the average particle diameter of the dye within the above range, the sensitivity characteristics and color development temperature of the dye can be appropriately adjusted. In this specification, the average particle diameter of the above dye means the particle diameter (D50, median diameter) at the integrated value of 50% in the particle size distribution measured by the laser diffraction / scattering method. The average particle diameter by the laser diffraction / scattering method can be measured using a laser diffraction / scattering type particle size distribution measuring device (for example, manufactured by Microtrac Bell Co., Ltd., device name: MT3300EX-II).

[0161] In this embodiment, the content ratio of the above dye is preferably 5% by mass or more, more preferably 10% by mass or more, and still more preferably 15% by mass or more with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4. Also, the content ratio of the above dye is preferably 40% by mass or less, more preferably 30% by mass or less with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4.

[0162] The above binder includes, for example, acrylic resins such as acrylic resin, styrene-acrylic resin, acrylic-urethane resin, acrylic-amide resin, vinyl acetate-acrylic resin; maleic acid resins such as maleic acid resin, styrene-maleic acid resin, olefin-maleic acid resin; resins such as styrene butadiene latex (SBR) resin. These resins may be modified resins modified by known methods. In addition, starch, casein, gelatin, polyamide, polyacrylamide, modified polyacrylamide, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl acetate, isobutylene-maleic anhydride copolymer, diisobutylene-maleic anhydride copolymer, vinyl acetate-maleic anhydride copolymer, methyl vinyl-maleic anhydride copolymer, isopropylene-maleic anhydride copolymer, styrene-butadiene copolymer, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, polyurethane, polystyrene, polyvinyl pyrrolidone, acrylonitrile, methyl vinyl ether, etc. may be mentioned. These binders can be used alone or in combination of two or more.

[0163] In this embodiment, the content ratio of the above binder is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, and particularly preferably 25% by mass or more with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4. Also, the content ratio of the above binder is preferably 60% by mass or less, more preferably 50% by mass or less with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4.

[0164] The above lubricants include, for example, hydrocarbon waxes such as paraffin wax, polyethylene wax, polystyrene wax; ester waxes such as carnauba wax; oils such as silicone oil, whale oil; fatty acids such as oleic acid; metal soaps such as zinc stearate. These lubricants can be used alone or in combination of two or more.

[0165] In this embodiment, the content ratio of the lubricant is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1% by mass or more with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4. Also, the content ratio of the lubricant is preferably 10% by mass or less, more preferably 5% by mass or less with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4.

[0166] Examples of the dispersant include anionic surfactants such as sodium dialkyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, and alkyl ether sulfate salts; nonionic surfactants such as acetylene glycol and alkylene oxide adducts of acetylene glycol; polyvinyl alcohols such as fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, and sulfonic acid-modified polyvinyl alcohol; styrene-acrylic copolymers and the like. These dispersants can be used alone or in combination of two or more.

[0167] Examples of the filler include inorganic fillers such as aluminum hydroxide, magnesium hydroxide, aluminum oxide, magnesium oxide, aluminum silicate, calcium carbonate, magnesium carbonate, titanium oxide, barium sulfate, silica gel, activated clay, talc, clay, kaolin, calcined kaolin, diatomaceous earth, white carbon, zinc oxide, silicon oxide, silica, and colloidal silica; and organic fillers such as styrene-acrylic resin particles, polystyrene resin particles, urea-formalin resin particles, and polyolefin resin particles. These fillers can be used alone or in combination of two or more.

[0168] In this embodiment, the content ratio of the filler is preferably 0.1% by mass or more, more preferably 1% by mass or more, and still more preferably 5% by mass or more with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4. Also, the content ratio of the filler is preferably 30% by mass or less, more preferably 20% by mass or less with respect to 100% by mass of the total solid content of the heat-sensitive recording layer 4.

[0169] As the coating amount (dry mass) of the above-described heat-sensitive recording layer 4, for example, 0.3 g / m 2 ~10 g / m 2 is preferable, and more preferably 2.5 g / m 2 ~6.5 g / m 2 .

[0170] When the coating amount of the heat-sensitive recording layer 4 in the present embodiment is within the above range, it is preferable from the viewpoint that the color developability of the obtained heat-sensitive recording medium 1 is more excellent.

[0171] (Protective layer) The protective layer 5 of the present embodiment includes a first protective layer 5a and a second protective layer 5b.

[0172] In the present embodiment, the first protective layer 5a functions as a layer that penetrates the irregularities on the surface of the heat-sensitive recording layer 4 to fill the voids and forms a smooth first protective layer 5a, thereby suppressing the irregular reflection of light and further improving the transparency. It also functions as a layer that further improves the barrier properties (such as water resistance, oil resistance, chemical resistance, plasticizer resistance, etc.) of the heat-sensitive recording medium 1. The first protective layer 5a may not be provided if not necessary. The material for forming the first protective layer 5a is not particularly limited, and for example, it can be formed using a resin. Further, the first protective layer 5a may contain other components. Examples of the other components in the first protective layer 5a include crosslinking agents, surfactants, preservatives, and the like.

[0173] The resin may be, for example, a resin having a water-soluble portion or a resin not having a water-soluble portion. These resins may be modified resins modified by known methods. Further, these resins can be used alone or in combination of two or more.

[0174] From the viewpoint of further improving the transparency of the heat-sensitive recording body 1, the first protective layer 5a of the present embodiment preferably contains a resin having a water-soluble portion. Examples of the resin having a water-soluble portion include resins having a hydroxy group as a hydrophilic structural unit (hydroxy group-containing resins), resins having a carboxy group as a hydrophilic structural unit (carboxy group-containing resins), and the like. In the present specification, the carboxy group in the "carboxy group-containing resin" may be a free carboxy group or an acid anhydride group (specifically, a dicarboxylic acid anhydride group). Further, the acid anhydride group may be partially ring-opened to form a carboxy group. In the carboxy group-containing resin, part or all of the carboxy groups may be neutralized with an alkali.

[0175] Examples of the hydroxy group-containing resin include polyvinyl alcohol (PVA)-based resins such as fully saponified polyvinyl alcohol resin and partially saponified polyvinyl alcohol resin.

[0176] Examples of the carboxy group-containing resin include acrylic resins such as acrylic resin, styrene-acrylic resin, acrylic-urethane resin, acrylic-amide resin, and vinyl acetate-acrylic resin; maleic acid resins such as maleic acid resin, styrene-maleic acid resin, and olefin-maleic acid resin.

[0177] The carboxy group-containing resin is preferably at least one selected from the group consisting of acrylic resins and maleic acid resins, more preferably an acrylic resin. As the acrylic resin, at least one selected from the group consisting of acrylic resin, styrene-acrylic resin, acrylic-urethane resin, acrylic-amide resin, and vinyl acetate-acrylic resin is preferable, at least one selected from the group consisting of acrylic resin, styrene-acrylic resin, and acrylic-urethane resin is more preferable, and at least one selected from the group consisting of acrylic resin and styrene-acrylic resin is even more preferable.

[0178] Also, from the viewpoint of further improving the storage stability of the heat-sensitive recording material 1, the first protective layer 5a of the present embodiment preferably contains a core-shell type resin. In the present specification, the "core-shell type resin" means a resin having a structure in which hydrophobic core particles are coated with a water-soluble shell polymer, that is, a core-shell structure.

[0179] The above core-shell type resin is not particularly limited. For example, a carboxyl group-containing resin having a core-shell structure (core-shell type carboxyl group-containing resin) is preferable. Here, it is considered that the above core-shell type carboxyl group-containing resin contains a carboxyl group in at least the structure of the water-soluble shell polymer. Generally, a core-shell type resin is a resin obtained by forming hydrophobic core particles and a water-soluble shell polymer by a multi-step polymerization reaction, and each resin forming the core particles and the shell polymer includes the same resins as those described above. Therefore, all descriptions of the above resins can be incorporated by reference for the resins in the core-shell type resin.

[0180] Specifically, the above core-shell type carboxyl group-containing resin is preferably at least one selected from the group consisting of a core-shell type acrylic resin and a core-shell type maleic acid resin, and more preferably a core-shell type acrylic resin. The above core-shell type acrylic resin is preferably at least one selected from the group consisting of a core-shell type acrylic resin, a core-shell type styrene-acrylic resin, a core-shell type acrylic-urethane resin, a core-shell type acrylic-amide resin, and a core-shell type vinyl acetate-acrylic resin, more preferably at least one selected from the group consisting of a core-shell type acrylic resin, a core-shell type styrene-acrylic resin, and a core-shell type acrylic-urethane resin, and still more preferably at least one selected from the group consisting of a core-shell type acrylic resin and a core-shell type styrene-acrylic resin. The above core-shell type acrylic resin can include, for example, resins commercially available under the name of Barrier Star (manufactured by Mitsui Chemicals, Inc.).

[0181] In addition, examples of the above resin include SBR resin.

[0182] In this embodiment, the content ratio of the above resin is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, particularly preferably 99% by mass or more, based on 100% by mass of the total solid content of the first protective layer 5a. When the content ratio is 70% by mass or more, the transparency is further improved.

[0183] In this embodiment, the content ratio of the above core-shell type resin is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, particularly preferably 99% by mass or more, based on 100% by mass of the total amount of the resin in the first protective layer 5a. Further, the content ratio of the above core-shell type resin may be 100% by mass based on 100% by mass of the total amount of the resin in the first protective layer 5a. When the content ratio is 70% by mass or more, the storage stability of the heat-sensitive recording body 1 can be further improved.

[0184] Examples of the above crosslinking agent include inorganic crosslinking agents such as zirconium carbonate; organic crosslinking agents such as cationic crosslinking agents and non-cationic crosslinking agents. Examples of the above cationic crosslinking agent include epichlorohydrin-based resins such as polyamide epichlorohydrin resin, polyamine epichlorohydrin resin, and polyamide polyamine epichlorohydrin resin. Examples of the above non-cationic crosslinking agent include oxazoline-based compounds such as oxazoline group-containing polymers. These crosslinking agents can be used alone or in combination of two or more.

[0185] In this embodiment, the content ratio of the above other components is preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, still more preferably 5% by mass or less, particularly preferably 1% by mass or less, based on 100% by mass of the total solid content of the first protective layer 5a. When the content ratio is 30% by mass or less, the transparency can be further improved.

[0186] The coating amount (dry mass) of the above-described first protective layer 5a is, for example, 0.3 g / m 2 ~5.0 g / m 2 is preferable, and more preferably 0.5 g / m 2 ~5.0 g / m 2 .

[0187] When the coating amount of the first protective layer 5a in the present embodiment is within the above range, it is preferable from the viewpoint that the transparency, barrier property, etc. of the obtained thermal recording medium 1 are more excellent.

[0188] In the present embodiment, the second protective layer 5b functions as a layer that further improves the color development property of the thermal recording layer 4 by improving the matching property of the thermal recording medium 1 with respect to the thermal head. The second protective layer may not be provided if not necessary. The material for forming the second protective layer 5b is not particularly limited, and for example, it can be formed using a binder, a crosslinking agent, a filler, a lubricant, etc. Further, the second protective layer 5b may contain other components. Examples of the other components in the second protective layer 5b include a surfactant, a preservative, etc.

[0189] As the above binder, for example, the same resins as those exemplified in the description of the first protective layer 5a can be used as the binder. These binders can be used alone or in combination of two or more.

[0190] At least one selected from the group consisting of an acrylic resin and a maleic acid resin is preferable as the binder, and an acrylic resin is more preferable. As the acrylic resin, at least one selected from the group consisting of an acrylic resin, a styrene-acrylic resin, an acrylic-urethane resin, an acrylic-amide resin, and a vinyl acetate-acrylic resin is preferable, at least one selected from the group consisting of an acrylic resin, a styrene-acrylic resin, and an acrylic-urethane resin is more preferable, and at least one selected from the group consisting of an acrylic resin and a styrene-acrylic resin is even more preferable.

[0191] In this embodiment, the content ratio of the above binder is preferably 10% by mass or more, more preferably 20% by mass or more, based on 100% by mass of the total solid content of the second protective layer 5b. Further, the content ratio of the above binder is preferably 70% by mass or less, more preferably 60% by mass or less, based on 100% by mass of the total solid content of the second protective layer 5b.

[0192] Examples of the above crosslinking agent include the same ones as those exemplified in the description of the first protective layer 5a. These crosslinking agents can be used alone or in combination of two or more.

[0193] Examples of the above filler include silica, colloidal silica, calcium carbonate, polymethyl methacrylate (PMMA), polystyrene (PS), and the like. Note that the average particle diameter of these fillers is preferably 1.0 μm or less. These fillers can be used alone or in combination of two or more.

[0194] In this embodiment, the content ratio of the above filler is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass or more, based on 100% by mass of the total solid content of the second protective layer 5b. Further, the content ratio of the above filler based on 100% by mass of the total solid content of the second protective layer 5b is preferably 70% by mass or less, more preferably 60% by mass or less.

[0195] Examples of the above lubricant include the same ones as those exemplified in the description of the heat-sensitive recording layer 4. These lubricants can be used alone or in combination of two or more.

[0196] In this embodiment, the content ratio of the above other components is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, based on 100% by mass of the total solid content of the second protective layer 5b.

[0197] Examples of the coating amount (dry mass) of the second protective layer 5b include 0.3 g / m 2 ~5.0 g / m2 is preferable, more preferably 0.5 g / m 2 ~5.0 g / m 2 .

[0198] When the coating amount of the second protective layer 5b in the present embodiment is within the above range, it is preferable from the viewpoint that the color developability and the like of the obtained heat-sensitive recording medium 1 are more excellent.

[0199] The haze of the heat-sensitive recording medium 1 of the present embodiment is preferably 27% or less, more preferably 25% or less, and still more preferably 23% or less when measured by the method described in the examples. Further, the haze of the laminate in which the base material 2, the anchor layer 3, the heat-sensitive recording layer 4, and the first protective layer 5a of the present embodiment are laminated in this order is preferably 24% or less, more preferably 22% or less, and still more preferably 20% or less when measured by the method described in the examples. When the above haze is within the above range, the transparency as the heat-sensitive recording medium 1 becomes more excellent.

[0200] The dynamic sensitivity of the heat-sensitive recording medium 1 of the present embodiment is preferably such that the optical density is 0.5 or more, more preferably 0.6 or more, still more preferably 0.7 or more, and particularly preferably 0.8 or more when the applied energy is 0.20 mJ / dot and measured by the method described in the examples. Further, the dynamic sensitivity of the heat-sensitive recording medium 1 of the present embodiment is preferably such that the optical density is 1.0 or more, more preferably 1.2 or more, still more preferably 1.3 or more, and particularly preferably 1.4 or more when the applied energy is 0.24 mJ / dot and measured by the method described in the examples. When the above optical density is within the above range, the sensitivity as the heat-sensitive recording medium 1 becomes more excellent.

[0201] [Method for manufacturing a heat-sensitive recording medium] The method for manufacturing the heat-sensitive recording medium of the present invention is not particularly limited, and known or commonly used methods can be applied. For example, a coating material for a heat-sensitive recording layer can be prepared by dispersing the components contained in the heat-sensitive recording layer in a solvent such as water. Next, the coating material for the heat-sensitive recording layer is applied to the surface of the base material and dried to form a heat-sensitive recording layer.

[0202] (Preparation process) The coating material for the heat-sensitive recording layer of the present embodiment may be prepared by previously dispersing all the materials in the same solvent. Alternatively, a dye and a developer that react with each other may be prepared as separate dispersions and then mixed to obtain the coating material for the heat-sensitive recording layer. At this time, other components may be added to either the dispersion containing the dye or the dispersion containing the developer, or to both. Examples of the method for preparing the coating material for the heat-sensitive recording layer include crushing treatment using stirring, ultrasonic treatment, ball mill, bead mill, sand mill, high-pressure homogenizer, etc. These methods can be used alone or in combination of two or more kinds.

[0203] As the developer particles used in the present embodiment, commercially available ones may be used as they are, or they may be used after being previously micronized. The method for micronizing the developer particles is not particularly limited, and known or commonly used methods can be applied. For example, the developer particles and a known dispersant are mixed, a solvent such as water is added, and then pulverized by using a mill such as a ball mill, bead mill, sand mill, etc. according to a conventional method to be micronized.

[0204] (Coating process) Examples of the method for coating the coating material for the heat-sensitive recording layer obtained above include a method of directly coating on a substrate, and a method of coating on a release liner or the like and then transferring it to the substrate. Examples of the coating method include air knife coating, bar blade coating, pure blade coating, rod blade coating, short dwell coating, curtain coating, die coating, gravure coating, etc. Also, manual coating using a wire bar may be used. These methods can be used alone or in combination of two or more kinds.

[0205] (Drying process) As a method for drying the coating material for the heat-sensitive recording layer applied above, for example, heat drying, normal temperature drying, vacuum drying, etc. can be mentioned. These methods can be used alone or in combination of two or more. The heat-sensitive recording layer 4 can be formed by these methods.

[0206] When the heat-sensitive recording medium of the present invention includes a substrate and other layers other than the heat-sensitive recording layer, as a method for forming the other layers, the above content can be incorporated. For example, as shown in FIG. 1, as a manufacturing method of the heat-sensitive recording medium 1 including the substrate 2, the anchor layer 3, the heat-sensitive recording layer 4, the first protective layer 5a, and the second protective layer 5b in this order, an anchor layer coating material is applied on the substrate 2 and dried to form the anchor layer 3, and further, the heat-sensitive recording layer 4 is formed on the anchor layer 3 by any of the methods described above. Then, a first protective layer coating material is applied on the heat-sensitive recording layer 4 and dried to form the first protective layer 5a, and then a second protective layer coating material is applied on the first protective layer 5a and dried to form the second protective layer 5b, whereby the heat-sensitive recording medium 1 can be obtained. The anchor layer coating material, the first protective layer coating material, and the second protective layer coating material may be prepared by preparing the coating material for each layer. For example, all the materials contained in the layer may be dispersed in the same solvent in advance for preparation, or when they contain components that react with each other, each material may be prepared as a separate dispersion and then the two may be mixed and prepared. The above preparation method, coating method, and drying method are not particularly limited, and the methods listed above can be used.

[0207] In the manufacturing method of the heat-sensitive recording medium of the present invention, each layer may be simultaneously coated in multiple layers by, for example, a curtain coater or the like, or may be formed individually and sequentially. Also, some layers may be simultaneously coated and some layers may be individually and sequentially formed.

Examples

[0208] Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited by these examples and is limited only by the description in the claims.

[0209] A thermal recording medium with an anchor layer, a thermal recording layer, a first protective layer, and a second protective layer laminated in this order on a base material was produced by the following steps and evaluated using each of the tests described later. (Example 1) (Production of Thermal Recording Medium) <Anchor Layer> Using water as a solvent, an acrylic emulsion with a solid content concentration of 38% by mass was applied and dried on the surface of a transparent film (material: biaxially stretched polypropylene, thickness: 40 μm, haze: 2.1%) as a base material by a conventional method to form an anchor layer with a coating amount of 1.0 g / m 2 (dry mass).

[0210] <Thermal Recording Layer> As a dye, 3 - dibutylamino - 6 - methyl - 7 - anilinofluoran (trade name: ODB - 2, average particle diameter: 0.22 μm) at 20.0% by mass, color developer particle 1 at 31.0% by mass, as sensitizer 1, 1,2 - bis(3 - methylphenoxy)ethane (manufactured by Mitsuho Co., Ltd., trade name: KS - 232 - S, average particle diameter: 1.2 μm) at 5.0% by mass, as a binder, styrene - butadiene latex at 32.5% by mass, as a filler, kaolin (made into a dispersion with a solid content concentration of 43% by dispersing in a styrene - acrylic oligomer) at 10.0% by mass, as a lubricant, polystyrene wax at 2% by mass, and water as a solvent were used to prepare a coating liquid for the thermal recording layer (solid content concentration 23% by mass) by a conventional method. Then, the obtained coating liquid for the thermal recording layer was applied and dried on the surface of the above - mentioned anchor layer by a conventional method to form a thermal recording layer with a coating amount of 4.3 g / m 2 (dry mass). Note that the numerical values of each of the above - mentioned compounding materials (excluding water) indicate the mass at the time of drying.

[0211] The above colorant particles 1 were prepared by mixing the colorant particles 2 described below and a styrene-acrylic copolymer as a dispersant at a mass ratio of 85:15, adding water, and then pulverizing using a sand mill by a conventional method so that the average particle diameter became 0.17 μm. The average particle diameter of the above colorant particles 1 is the median diameter measured by a dynamic light scattering particle size measuring device (manufactured by Microtrac Bell Co., Ltd., device name: NANOTRAC WAVE II). The numerical values of the above respective compounding materials (excluding water) indicate the mass ratio during drying.

[0212] <First protective layer> Using water as a solvent, a core-shell type acrylic emulsion with a solid content concentration of 35% by mass was coated on the surface of the above heat-sensitive recording layer by a conventional method and dried, whereby a first protective layer with a coating amount of 1.6 g / m 2 (dry mass) was formed.

[0213] <Second protective layer> As a binder, 42% by mass of an acrylic emulsion with a solid content concentration of 20% by mass, as a crosslinking agent, 5% by mass of ammonium zirconium carbonate, as a lubricant, 10.5% by mass of polystyrene wax, as a lubricant, 3.5% by mass of zinc stearate, as a filler, 39% by mass of silica (silicon dioxide), and water as a solvent were contained in a coating liquid for the second protective layer (solid content concentration: 14% by mass). By preparing the coating liquid for the second protective layer by a conventional method and then coating and drying the obtained coating liquid for the second protective layer on the surface of the above first protective layer by a conventional method, a second protective layer with a coating amount of 1.5 g / m 2 (dry mass) was formed. The numerical values of the above respective compounding materials (excluding water) indicate the mass during drying.

[0214] (Examples 2 to 9, Comparative Examples 1 to 7) In the production process of the heat-sensitive recording layer, a heat-sensitive recording medium was produced in the same manner as in Example 1, except that each compounding material was added in the mass ratio shown in Table 1 or Table 2. Note that the numerical values for each compounding material of the heat-sensitive recording layer shown in Table 1 or Table 2 all represent the mass ratio when dry. Also, "developer particles 2" shown in Table 1 is N,N'-di-[3-(p-toluenesulfonyloxy)phenyl]urea (manufactured by Mitsuho Co., Ltd., trade name: S-176, average particle diameter: 0.25 μm), and "sensitizer 2" is stearic acid amide (manufactured by Chukyo Yushi Co., Ltd., trade name: L-271, average particle diameter: 0.4 μm).

[0215] "Developer particles 4" shown in Table 2 is 3-[(3-phenylureido)phenyl]-4-methylbenzenesulfonate (manufactured by Nippon Kayaku Co., Ltd., trade name: TGMD, average particle diameter: 0.25 μm). "Developer particles 3" is a mixture of the above developer particles 4 and a styrene-acrylic copolymer as a dispersant in a mass ratio of 85:15, water was added, and then it was pulverized using a sand mill by a conventional method so that the average particle diameter became 0.17 μm. Note that the average particle diameter of the above developer particles 3 is the median diameter measured by a dynamic light scattering type particle diameter measuring device (manufactured by Microtrac Bell Co., Ltd., device name: NANOTRAC WAVE II). Note that the numerical values of the above each compounding material (excluding water) represent the mass ratio when dry.

[0216] Among the compounding materials used in the examples and comparative examples, the average particle diameters of the compounding materials other than "developer particles 1 and developer particles 3", that is, the dye, sensitizer 1, sensitizer 2, developer particles 2, and developer particles 4, are the median diameters measured by a laser diffraction / scattering type particle diameter distribution measuring device (manufactured by Microtrac Bell Co., Ltd., device name: MT3300EX-II).

[0217] [Evaluation] The following evaluations were performed on the heat-sensitive recording media obtained in the examples and comparative examples, as well as on the laminates formed up to the heat-sensitive recording layer obtained in the production process of the heat-sensitive recording medium and the laminates formed up to the first protective layer. The results are shown in Table 1 or Table 2.

[0218] (1) Haze Using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., model name: NDH7000), the haze of the thermal recording medium, the laminate formed up to the thermal recording layer, and the laminate formed up to the first protective layer was measured according to the method specified in JIS K 7136:2000. When measuring, in the case of the laminate formed up to the thermal recording layer, the sample was placed so that the measuring light was incident from the direction in which the thermal recording layer was located on the surface; in the case of the laminate formed up to the first protective layer, the sample was placed so that the measuring light was incident from the direction in which the first protective layer was located on the surface; and in the case of the thermal recording medium, the sample was placed so that the measuring light was incident from the direction in which the second protective layer was located on the surface. The haze of the laminate formed up to the thermal recording layer is denoted as H1, the haze of the laminate formed up to the first protective layer is denoted as H2, and the haze of the thermal recording medium is denoted as H3, which are shown in Table 1 or Table 2.

[0219] (2) Kinetic sensitivity For the thermal recording medium, using a thermal paper printing test apparatus (manufactured by Okura Engineering Co., Ltd., model name: Pulse Simulator TH-M2 / PP), the printing speed was set to 50 mm / sec, the applied voltage was 17.0 V, the head resistance value was 870 Ω, and the pulse width was 0.488 to 1.394 ms. Printing was performed with an applied energy of 0.20 mJ / dot or 0.24 mJ / dot, and the optical density (OD value) under each applied energy condition was measured using a spectrophotometer (manufactured by X-rite, model name: eXact).

[0220] [Table 1]

[0221] [Table 2]

[0222] Table 1 shows the results when N,N'-di-[3-(p-toluenesulfonyloxy)phenyl]urea is used as the color former. As in Comparative Example 1, when the average particle diameter of the color former particles was 0.25 μm and no sensitizer was added, the haze values were low (H2 = 21.89%, H3 = 26.89%), and the transparency was good, but the kinetic sensitivity was also low (0.46 at 0.20 mj / dot and 0.98 at 0.20 mj / dot), resulting in inferior sensitivity. In Comparative Example 2, where sensitizer 1 was further added compared to Comparative Example 1, the kinetic sensitivity improved and the sensitivity was good, but the haze also increased, resulting in inferior transparency. Also, in Comparative Example 3, where sensitizer 1 was replaced with sensitizer 2 compared to Comparative Example 2, the sensitivity was good, but the haze increased significantly, resulting in greatly inferior transparency. In addition, in Comparative Example 4, where color former particles finer than those in Comparative Example 3 were used, although there was a tendency for the haze to decrease, the transparency was inferior to that of Comparative Example 1, and satisfactory transparency could not be achieved.

[0223] On the other hand, for Examples 1 to 5 in which the average particle diameter of the color former particles was micronized to 0.17 μm and sensitizer 1 was added as the sensitizer, it was confirmed that all of them had lower haze and higher kinetic sensitivity than Comparative Example 1, and good transparency and sensitivity could be achieved. Here, when comparing Example 3 and Comparative Example 4, which have the same composition except for the type of sensitizer, the result was that Example 3 had lower haze and higher kinetic sensitivity than Comparative Example 4. Since the average particle diameter of sensitizer 1 used in Example 3 was 1.2 μm and the average particle diameter of sensitizer 2 used in Comparative Example 4 was 0.4 μm, it can be seen that sensitizer 1 was able to achieve better transparency despite having a larger average particle diameter than sensitizer 2. From such results, it was confirmed that by using sensitizer 1, better transparency and sensitivity can be achieved simultaneously.

[0224] Table 2 shows the results when 3-[(3-phenylureido)phenyl]-4-methylbenzenesulfonate is used as the color former. As in Comparative Example 5, when the average particle diameter of the color former particles was 0.25 μm and no sensitizer was added, the haze was at low values (H2 = 23.68%, H3 = 26.11%), and the transparency was good, but the dynamic sensitivity was also at low values (0.41 at 0.20 mj / dot and 0.96 at 0.20 mj / dot), resulting in inferior sensitivity. In Comparative Example 6, where sensitizer 1 was further added to Comparative Example 5, the dynamic sensitivity improved and the sensitivity was good, but the haze also increased, resulting in inferior transparency. Also, in Comparative Example 7, where color former particles finer than those in Comparative Example 5 were used, the haze decreased and good transparency was achieved, but the dynamic sensitivity was low and satisfactory sensitivity could not be achieved.

[0225] On the other hand, for Examples 6 to 9 in which the average particle diameter of the color former particles was made finer to 0.17 μm and sensitizer 1 was added as the sensitizer, it was confirmed that in all cases, the transparency was equal to or better than that of Comparative Example 5, and the dynamic sensitivity was higher than that of Comparative Example 5, achieving good transparency and sensitivity. Here, when Example 6 and Comparative Example 6 are compared, although the blending ratio of sensitizer 1 in Example 6 was a very small amount, 1 / 5, compared to Comparative Example 6, the dynamic sensitivity was the same. The reason for this is not clear, but it is presumed that due to the finer color former particles, the color former and the sensitizer react more easily, resulting in improved color development efficiency.

[0226] As a summary above, the configuration of the present invention and its variations are appended below. [Appendix 1] A heat-sensitive recording body in which a heat-sensitive recording layer is laminated on a base material, the base material is a transparent film, the heat-sensitive recording layer contains color former particles having an average particle diameter of less than 0.25 μm and a sensitizer, the color former particles contain a urea compound, and the sensitizer contains a compound represented by the above formula (1). [Supplementary Note 2] The compound represented by the formula (1) is at least one selected from the group consisting of 1,2-bis(phenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, and 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethane. The heat-sensitive recording material according to Supplementary Note 1. [Supplementary Note 3] The content ratio of the sensitizer is 1% by mass to 30% by mass with respect to 100% by mass of the total solid content of the heat-sensitive recording layer. The heat-sensitive recording material according to Supplementary Note 1 or 2. [Supplementary Note 4] The urea compound is a non-phenolic developer. The heat-sensitive recording material according to any one of Supplementary Notes 1 to 3. [Supplementary Note 5] The heat-sensitive recording material according to any one of Supplementary Notes 1 to 4, including at least the compound represented by the above formula (2) and / or the compound represented by the above formula (3) as the urea compound. [Supplementary Note 6] The heat-sensitive recording material according to any one of Supplementary Notes 1 to 5, comprising a protective layer on the side opposite to the base material of the heat-sensitive recording layer. [Supplementary Note 7] The protective layer contains a resin, and the content ratio of the resin is 70% by mass or more with respect to 100% by mass of the total solid content of the protective layer. The heat-sensitive recording material according to any one of Supplementary Notes 1 to 6. [Supplementary Note 8] The heat-sensitive recording material according to any one of Supplementary Notes 1 to 7, comprising an anchor layer between the base material and the heat-sensitive recording layer. [Supplementary Note 9] The heat-sensitive recording material according to any one of Supplementary Notes 1 to 8, having a haze of 27% or less.

Explanation of Symbols

[0227] 1 Heat-sensitive recording material 2 Base material 3 Anchor layer 4 Heat-sensitive recording layer 5a First protective layer 5b Second protective layer 5 Protective layer

Claims

1. A thermal recording medium having a thermal recording layer laminated on a substrate, wherein the substrate is a transparent film, the thermal recording layer contains developer particles having an average particle diameter of less than 0.25 μm and a sensitizer, the developer particles contain a urea compound, the sensitizer contains a compound represented by the following formula (1), a thermal recording medium. 【Chemical 1】 (In formula (1), R 1 is a hydrocarbon group having 1 to 3 carbon atoms, and a plurality of R 1 may be the same or different. n represents an integer of 0 to 3, and a plurality of n may be the same or different.)

2. The compound represented by the formula (1) is at least one selected from the group consisting of 1,2-bis(phenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, and 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethane, the thermal recording medium according to Claim 1.

3. The content ratio of the sensitizer is 1% by mass to 30% by mass based on 100% by mass of the total solid content of the thermal recording layer, the thermal recording medium according to Claim 1 or 2.

4. The urea compound is a non-phenolic developer, the thermal recording medium according to Claim 1 or 2.

5. The thermal recording medium according to Claim 1 or 2, containing at least a compound represented by the following formula (2) and / or a compound represented by the following formula (3) as the urea compound. 【Chemical 2】 (In formula (2), R 2 is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and a plurality of R 2 may be the same or different. A 1 is a hydrocarbon group having 1 to 4 carbon atoms, and a plurality of A 1 may be the same or different. m represents an integer of 0 to 4, and a plurality of m may be the same or different.) [Chemical Formula 3] (Each symbol in formula (3) is the same as in formula (2).)

6. The thermal recording medium according to Claim 1 or 2, having a protective layer on the side opposite to the substrate of the thermal recording layer.

7. The thermal recording medium according to Claim 1 or 2, having an anchor layer between the substrate and the thermal recording layer.

8. The thermal recording medium according to Claim 1 or 2, having a haze of 27% or less.

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