Thermal recording layer, thermal recording medium, thermal recording layer forming solution, method for manufacturing a thermal recording medium, and image recording method

Abstract

To provide a thermosensitive recording medium that can form an image of high concentration and has all of hot water resistance, water resistance, ethanol resistance, temperature and humidity resistance, wet abrasion resistance, and heat resistance.SOLUTION: A thermosensitive recording medium includes a support and a thermosensitive recording layer disposed on the support. The thermosensitive recording layer includes a compound represented by the general formula (1) in the figure and a styrene-acrylic resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention Thermal recording layer, Thermal recording media Thermal recording layer forming liquid, thermal recording medium Manufacturing method, and Regarding image recording methods. [Background technology]

[0002] Thermal recording methods using thermal recording media have several advantages over other recording methods. They do not require development and fixing processes, can be recorded quickly using relatively simple equipment, and are inexpensive. For these reasons, they are rapidly gaining popularity in the food industry, particularly in areas where image reliability is crucial, such as for bento boxes and prepared foods.

[0003] In the food sector, thermal recording media are increasingly being used for labels on PET bottles and fresh foods, and are expected to be exposed to water and hot water. If the image portion of the thermal recording media comes into contact with water or hot water, the contacted image portion may fade. Fading may occur in particular at temperatures such as hot drinks in vending machines (e.g., 60°C for several hours), hot water from a tap (e.g., 60°C for several minutes), and the hot water cycle temperature of washing machines (40°C to 60°C for several hours). Furthermore, in packaging films for various containers such as PET bottles for soft drinks, metal cans for canned coffee, bottles for beverages, pharmaceuticals, and beer, as well as packaging labels in the POS sector for fresh foods, bento boxes, and prepared foods, it is required that, in addition to the above-mentioned resistance to hot water and water, the film also possesses resistance to ethanol, temperature and humidity, water abrasion, and heat.

[0004] Therefore, for example, in order to improve the water resistance of the image area, it has been proposed to include polyvinyl alcohol and polyamide epichlorohydrin resin in the thermal recording layer, to use hydrophobic resin emulsions such as vinyl acetate emulsion, acrylic emulsion, and SBR latex as binders for the thermal recording layer, or to use non-phenolic color developers that do not contain phenolic compounds as color developers for the thermal recording layer (see, for example, Patent Document 1). [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a thermal recording medium that possesses all of the following properties: resistance to hot water, water, ethanol, temperature and humidity, water abrasion resistance, and heat resistance, while also being able to produce high-density images. [Means for solving the problem]

[0006] The present invention is a means for solving the aforementioned problems. Thermal recording layer teeth, Thermal recording layer contained in thermal recording medium And, The following general formula (3) It contains a compound represented by and a styrene-acrylic resin. [ka] However, in the general formula (3) above, R represents an alkyl group and n represents an integer from 0 to 3. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a thermal recording medium that possesses all of the following properties: resistance to hot water, water, ethanol, temperature and humidity, water abrasion resistance, and heat resistance, while also being able to produce high-density images. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a thermal recording medium according to the first embodiment. [Figure 2]FIG. 2 is a schematic cross-sectional view showing an example of a thermal recording medium according to the second embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an example of a thermal recording medium according to the third embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of a thermal recording medium according to the fourth embodiment. [Figure 5] FIG. 5 is a schematic cross-sectional view showing an example of a thermal recording medium according to the fifth embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view showing an example of a thermal recording medium according to the sixth embodiment. [Figure 7] FIG. 7 is a schematic cross-sectional view showing an example of a thermal recording medium according to the seventh embodiment. [Figure 8] FIG. 8 is a schematic cross-sectional view showing an example of a thermal recording medium according to the eighth embodiment. [Figure 9] FIG. 9 is a schematic view showing an example of an image recording apparatus used in the image recording method of the present invention. [Figure 10] FIG. 10 is a schematic view showing another example of an image recording apparatus used in the image recording method of the present invention. [Figure 11] FIG. 11 is a diagram for explaining the arrangement state of a laser array of an image recording apparatus used in the image recording method of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] (Thermal Recording Medium) The thermal recording medium of the present invention is a thermal recording medium having a support and a thermal recording layer on the support, wherein the thermal recording layer contains a compound represented by the following general formula (1) and a styrene-acrylic resin, and further has other layers as required.

[0010]

Chemical formula

[0011] Conventional techniques can maintain water resistance to water at room temperature (25°C) by using specific non-phenolic color developers, but there is a problem that the image fades when exposed to hot water (60°C or higher).

[0012] In the present invention, a thermal recording medium having a support and a thermal recording layer on the support, wherein the thermal recording layer contains a compound represented by the above general formula (1) and a styrene-acrylic resin, thereby possessing resistance to hot water, water, ethanol, temperature and humidity, water abrasion, and heat, and also enabling the acquisition of high-density images.

[0013] <Thermal recording layer> The thermal recording layer preferably contains the compound represented by the above general formula (1) and a styrene-acrylic resin, and also contains a leuco dye and a photothermal conversion material, and may further contain other components as needed.

[0014] <<Compounds represented by general formula (1)>> The compound represented by the above general formula (1) is a non-phenolic color developer, meaning it does not have a phenol skeleton. Because it contains a non-phenolic color developer, it eliminates the need to include phenolic color developers, which may be endocrine disruptors, thus offering advantages in terms of environmental impact.

[0015] In the above general formulas (1) and (2), R2 is a linear, branched, or alicyclic alkyl group having 1 to 12 carbon atoms, an unsubstituted or 1 to 12 carbon atom alkyl group, a 1 to 12 carbon atom alkoxy group, a 6 to 12 carbon atom aryl group, or a 7 to 12 carbon atom substituted with a halogen atom or a 6 to 12 carbon atom aryl group. Multiple R2s may be the same or different. A1 represents a hydrogen atom or a 1 to 4 carbon atom alkyl group. Multiple A1s may be the same or different.

[0016] In the above general formula (3), R represents an alkyl group, and n represents an integer from 0 to 3. The number of carbon atoms in the alkyl group R may be 1 to 12, 1 to 8, or 1 to 4.

[0017] In the above general formula (1), the substitution positions of the multiple R2-SO3- atoms may be the same or different. Preferably, the 3rd, 4th, or 5th position is preferred, but the 3rd position is more preferred.

[0018] Examples of linear, branched, or alicyclic alkyl groups having 1 to 12 carbon atoms in R2 include methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, cyclopentyl, hexyl, cyclohexyl, 2-ethylhexyl, and lauryl groups.

[0019] Examples of aralkyl groups include unsubstituted or substituted aralkyl groups such as benzyl group, 1-phenylethyl group, 2-phenylethyl group, 3-phenylpropyl group, p-methylbenzyl group, m-methylbenzyl group, m-ethylbenzyl group, p-ethylbenzyl group, pi-propylbenzyl group, pt-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, and p-chlorobenzyl group.

[0020] Examples of aryl groups include unsubstituted or substituted aryl groups such as alkyl groups, alkoxy groups, aralkyl groups, aryl groups, or halogen atoms, such as phenyl groups, p-tolyl groups, m-tolyl groups, o-tolyl groups, 2,5-dimethylphenyl groups, 2,4-dimethylphenyl groups, 3,5-dimethylphenyl groups, 2,3-dimethylphenyl groups, 3,4-dimethylphenyl groups, mesitylene groups, p-ethylphenyl groups, pi-propylphenyl groups, pt-butylphenyl groups, p-methoxyphenyl groups, 3,4-dimethoxyphenyl groups, p-ethoxyphenyl groups, p-chlorophenyl groups, 1-naphthyl groups, 2-naphthyl groups, and t-butylated naphthyl groups.

[0021] The substitution positions of multiple A1 molecules may be the same or different. Preferably, the 3rd, 4th, and 5th positions are preferred. A1 is an alkyl group such as a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, or t-butyl group.

[0022] Specific examples of compounds represented by the above general formulas (1) to (3) include the following compounds, but the invention is not limited to these compounds, and two or more compounds may be used in combination as color developers.

[0023] Furthermore, by using it in combination with existing color developers, such as known non-phenol color developers like N-3-[(p-toluenesulfonyl)oxy]phenyl-N'-(p-toluenesulfonyl)-urea and N-[2-(3-phenylureido)phenyl]-benzenesulfonamide, and known color developers like 4,4'-isopropylidenediphenol (BPA), 4,4'-dihydroxydiphenylsulfone (BPS), 4-allyloxy-4'-hydroxydiphenylsulfone, 4-allyloxy-4'-hydroxy-diphenylsulfone, 4-hydroxy-4'-isopropoxysulfone, N-(m-tolylaminocarbonyl)-methionine, N-(m-tolylaminocarbonyl)-phenylalanine, and N-(phenylaminocarbonyl)-phenylalanine, it becomes possible to further improve the shelf life, which is a problem with these known color developers.

[0024] Compounds represented by the above general formulas (1) to (3) include N,N'-di-[3-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-propylphenyl]urea,

[0025] 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-methylphenyl]urea, N,N'-di-[3-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(mesitylenesulfonyloxy) [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-(pt-butylbenzenesulfonyloxy)phenyl 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,

[0026] 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] [Nyl]-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-methoxy] [Benzenesulfonyloxy)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,

[0027] 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,

[0028] N,N'-di-[3-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[3-(benzylsulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[3-(phenylpropanesulfonyloxy)phenyl]urea, N,N'-di-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea,

[0029] 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,

[0030] N,N'-di-[3-(methanesulfonyloxy)phenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4,5-dimethylphenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)-4 -methylphenyl]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,

[0031] 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,

[0032] N,N'-di-[4-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-ethylphenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-propylphenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-t-butylphenyl]urea,

[0033] 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-methylphenyl]urea,

[0034] N,N'-di-[4-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[4-(mesitylenesulfonyloxy)phenyl]urea,

[0035] N,N'-di-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N,N'-di-[4-(2-naphthalenesulfonyloxy)phenyl]urea,

[0036] 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-(pt-butylbenzenesulfonyloxy)phenyl]urea,

[0037] 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,

[0038] 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,

[0039] N,N'-di-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0040] 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]urea [Ensulfonyloxy)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,

[0041] 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,

[0042] N,N'-di-[4-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[4-(benzylsulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[4-(phenylpropanesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-methoxybenzylsulfonyloxy)phenyl)urea,

[0043] N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea,

[0044] N,N'-di-[4-(methanesulfonyloxy)phenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3,5-dimethylphenyl]urea, N,N'-di-[4-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[4-(ethanesulfonyloxy)-3 -methylphenyl]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,

[0045] N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea,

[0046] N,N'-di-[2-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-4-propylphenyl]urea,

[0047] 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-methylphenyl]urea,

[0048] N,N'-di-[2-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[2-(mesitylenesulfonyloxy)phenyl]urea,

[0049] N,N'-di-[2-(1-naphthalenesulfonyloxy)phenyl]urea, N,N'-di-[2-(2-naphthalenesulfonyloxy)phenyl]urea,

[0050] 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-(pt-butylbenzenesulfonyloxy)phenyl]urea,

[0051] 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,

[0052] 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,

[0053] N,N'-di-[2-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0054] 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]urea [Ensulfonyloxy)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,

[0055] 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,

[0056] N,N'-di-[2-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[2-(benzylsulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[2-(phenylpropanesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea,

[0057] N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea,

[0058] N,N'-di-[2-(methanesulfonyloxy)phenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4,5-dimethylphenyl]urea, N,N'-di-[2-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[2-(ethanesulfonyloxy)-4 -methylphenyl]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,

[0059] N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(hexanesulfonyloxy)phenyl]urea,

[0060] 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]-N'-[4-(m-toluenesulfonyloxy)phenyl]urea, N-[3-(o-toluenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea,

[0061] 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,

[0062] N-[3-(1-naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N-[3-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea,

[0063] 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-(pt-butylbenzenesulfonyloxy)phenyl]-N'-[4-(pt-butylbenzenesulfonyloxy)phenyl]urea,

[0064] 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,

[0065] 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,

[0066] N-[3-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0067] 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,

[0068] 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,

[0069] N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea, N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(p-methylbenzylsulfonyloxy)phenyl]urea,

[0070] 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,

[0071] N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea,

[0072] 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,

[0073] 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,

[0074] N-[2-(1-naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[4-(2-naphthalenesulfonyloxy)phenyl]urea,

[0075] 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-(pt-butylbenzenesulfonyloxy)phenyl]-N'-[4-(pt-butylbenzenesulfonyloxy)phenyl]urea,

[0076] 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,

[0077] 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)benzenesulfonyloxyenyl]urea, N-[2-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea,

[0078] N-[2-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0079] 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,

[0080] 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,

[0081] 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,

[0082] 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,

[0083] 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,

[0084] N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(benzenesulfonyloxy)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,

[0085] 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-(cyylenesulfonyloxy)phenyl]urea,

[0086] N-[2-(1-naphthalenesulfonyloxy)phenyl]-N'-[3-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea,

[0087] 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-(pt-butylbenzenesulfonyloxy)phenyl]-N'-[3-(pt-butylbenzenesulfonyloxy)phenyl]urea,

[0088] 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,

[0089] 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,

[0090] N-[2-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[3-(p-chlorobenzenesulfonyloxy)phenyl]urea,

[0091] 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]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,

[0092] 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,

[0093] N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[3-(methanesulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea,

[0094] 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,

[0095] Examples include N-[2-(methanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, and N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea.

[0096] <Method for producing compounds represented by general formula (1)> The compound represented by the above general formula (1) can be synthesized by reacting the compound represented by the following general formula (4) with the aromatic amine compound represented by the following general formula (5). Furthermore, the compound represented by the above general formula (1) can be synthesized by reacting the compound represented by the following general formula (6) with the aromatic amine compound represented by the following general formula (7).

[0097] [ka]

[0098] [ka]

[0099] However, in the general formulas (4) and (5) above, R1 represents an alkyl group or an aryl group. A1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Multiple A1s may be the same or different. R2 is a linear, branched, or alicyclic alkyl group having 1 to 12 carbon atoms, an unsubstituted or 1 to 12 carbon atom alkyl group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 12 carbon atoms substituted with a halogen atom, or an aryl group having 6 to 12 carbon atoms.

[0100] [ka]

[0101] [ka] However, in the general formulas (6) and (7) above, R1 represents an alkyl group or an aryl group, R represents an alkyl group, and n represents an integer from 0 to 3.

[0102] For example, it can be synthesized by the following method. [Process 1] 3-[(R) n-PhSO3]-Ph-NH2 / deoxidizer+XCOOR1→ 3-[(R) n -PhSO3]-Ph-NHCOOR1+HX·Deoxidizing agent [Process 2] 3-[(R) n -PhSO3]-Ph-NHCOOR1+3-[(R) n -PhSO3]-Ph-NH2 / base →3-{[(R) n -PhSO3]-Ph-NH2=CO+R1OH However, in the above formula, R1 represents an alkyl group or an aryl group, R represents an alkyl group, Ph represents a phenyl group, and n represents an integer from 0 to 3.

[0103] In step 1 of the above synthesis method, XCOOR1 is a halogenated carbonate ester or diester carbonate, where X is chlor, brome, OMe, OEt, OPro, or OPh, and R1 is a Me group, Et group, Pro group, or Ph group. The Me group represents a methyl group, the Et group represents an ethyl group, the Pro group represents a propyl group, and pH represents a phenyl group. Monochloromethyl carbonate, monochloroethyl carbonate, monochlorophenyl carbonate, diethyl carbonate, and diphenyl carbonate are particularly preferred.

[0104] The alkyl groups of R1 and R are the same as the alkyl group of R described above.

[0105] Organic bases and inorganic bases are used as deoxidizing agents and bases in the reaction. Examples of inorganic bases include LiOH, NaOH, KOH, NaHCO3, KHCO3, Na2CO3, K2CO3, MeONa, and EtONa. Examples of organic bases include trimethylamine, triethylamine, tributylamine, pyridine, N,N-dimethylpyridine, and 1,8-diazabicyclo[5,4,0]undecane-7-ene (DBU). Preferably, K2CO3, triethylamine, pyridine, N,N-dimethylpyridine, and 1,8-diazabicyclo[5,4,0]undecane-7-ene (DBU) are used.

[0106] 3-[(R) n -PhSO3]-Ph-NH2 can also be synthesized by directly O-sulfonyling 3-hydroxyaniline, and can also be easily obtained by O-sulfonyling a nitrophenol compound and then reducing the nitro group.

[0107] 3-[(R) n Examples of the -PhSO3]-Ph-NH2 include 3-benzenesulfonyloxyaniline, 3-(p-toluene)sulfonyloxyaniline, 3-(m-toluene)sulfonyloxyaniline, 3-(o-toluene)sulfonyloxyaniline, 3-(p-xylene)sulfonyloxyaniline, and 3-mesitylenesulfonyloxyaniline. Preferably, it is 3-benzenesulfonyloxyaniline or 3-(p-toluene)sulfonyloxyaniline.

[0108] Generally, aprotic solvents can be used as reaction solvents, and the reaction is carried out at a temperature of 0°C to 180°C. In the present invention, the reaction temperature is, for example, in the range of 0°C to 180°C, but preferably 10°C to 100°C, and the solvent and reaction temperature are preferably selected according to the boiling point of the solvent and the stability of the reaction product.

[0109] Examples of aprotic solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylene; halogenated hydrocarbons such as dichloromethane, chloroform, dichloroethane, and chlorobenzene; acetate esters such as ethyl acetate, propyl acetate, butyl acetate, phenyl acetate, and benzyl acetate; ether compounds such as diethyl ether, dimethoxyethane, diethoxyethane, diethylene glycol dimethyl ether, dioxane, tetrahydrofuran, and anisole; ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and acetonitrile, dimethyl sulfamide, dimethyl sulfoxide, and dimethylimidazolidinedione.

[0110] In step 2, the 3-[(R) obtained in step 1 n-PhSO3]-Ph-NHCOOR and 3-[(R) n -PhSO3]-Ph-NH2 is carried out by reacting in the presence of a base. The base, reaction solvent, and reaction temperature used in Step 2 can use the above reaction conditions used in Step 1.

[0111] Also, in order to simplify the reaction operation, it is also possible to simultaneously proceed with Step 1 and Step 2 by using 2 equivalents or more of 3-[(R) n -PhSO3]-Ph-NH2.

[0112] In order to introduce a urea group, various urea group introduction methods have been proposed. For example, methods for forming a urea group from the introduction of carbon monoxide using a metal catalyst such as palladium or molybdenum or carbonylbisimidazole have been proposed, but the catalysts and reagents are expensive, the operations are complicated, and they are not necessarily industrial.

[0113] The N,N'-diphenylurea derivative represented by the above general formulas (1) to (3) can also be synthesized by reacting dihydroxydiphenylurea represented by the following general formula (8) with a sulfonating agent represented by the following general formula (9) in the presence of an aprotic solvent. In particular, when synthesizing a symmetric compound, the above production method of O-sulfonylation after synthesizing dihydroxydiphenylurea is the most versatile and economical.

[0114]

Chemical formula

[0115]

Chemical formula

[0116] In addition, the above manufacturing method offers industrial advantages, such as enabling the dihydroxydiphenylurea production process to be carried out in a smooth slurry state by selecting the reaction solvent, and allowing the subsequent reaction to be carried out continuously without isolating the dihydroxydiphenylurea.

[0117] The N,N'-diphenylurea derivatives represented by the above general formulas (1) to (3) can also be synthesized by reacting urea with an aminophenol compound represented by the following general formula (8-1) in the presence of an aprotic solvent, and then reacting it with a sulfonating agent represented by the above general formula (9). By reacting urea with an aminophenol compound represented by general formula (8-1) in the presence of an aprotic solvent, the production process of dihydroxydiphenylurea proceeds smoothly, and the reaction can be carried out in a slurry state. Furthermore, it becomes possible to proceed continuously to the step of reacting with the sulfonating agent represented by general formula (9) without isolating dihydroxydiphenylurea.

[0118] [ka] However, in the general formula (8-1) above, A1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0119] The reaction to synthesize dihydroxydiphenylurea from aminophenol and urea is carried out in an aprotic solvent at a reaction temperature of 80°C to 200°C, preferably 125°C to 180°C.

[0120] Examples of aminophenols include 2-aminophenol, 3-aminophenol, 4-aminophenol, 2-amino-5-methylphenol, 2-amino-4-methylphenol, 2-amino-6-methylphenol, 2-amino-4,5-dimethylphenol, 2-methyl-5-aminophenol, 3-methyl-5-aminophenol, 2,3-dimethyl-5-aminophenol, 2,4-dimethyl-5-aminophenol, 2,6-dimethyl-5-aminophenol, 3,4-dimethyl-5-aminophenol, 2-methyl-4-aminophenol, 3-methyl-4-aminophenol, and 2,6-dimethyl-4-aminophenol.

[0121] Examples of aprotic solvents include hydrocarbons such as tetralin, benzene, toluene, xylene, and mesitylene; halogenated hydrocarbons such as trichloroethylene, chlorobenzene, and dichlorobenzene; acetate esters such as ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, isoamyl acetate, amyl acetate, hexyl acetate, phenyl acetate, and benzyl acetate; ether compounds such as diethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, dioxane, tetrahydrofuran, and anisole; ketone compounds such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, acetophenone, and benzophenone; tertiary amines such as tributylamine, pyridine, dimethylpyridine, and diazabicycloundecene; and aprotic polar solvents such as acetonitrile, benzonitrile, dimethylformamide, dimethyl sulfoxide, dimethylimidazolidine, and dimethylacetamide. Two or more of these solvents may also be used in combination.

[0122] Preferred solvents are aprotic, water-insoluble solvents exhibiting a boiling point of 110°C or higher, with acetic acid esters exhibiting a boiling point of butyl acetate or higher, and aromatic hydrocarbons such as toluene and xylene being particularly preferred. Methods for processing the reaction after it has finished include (1) isolating dihydroxydiphenylurea by cooling and filtering the reaction solution and using it for the next reaction, and (2) cooling the reaction solution to the temperature of the next reaction and using it as is for the next reaction without isolating dihydroxydiphenylurea.

[0123] Next, the O-sulfonation reaction of dihydroxydiphenylurea can be carried out by adding the sulfonating agent dropwise to a reaction solution consisting of dihydroxydiphenylurea, a deoxidizing agent, and an aprotic solvent, or by adding the deoxidizing agent dropwise to a reaction solution consisting of dihydroxydiphenylurea, a sulfonating agent, and an aprotic solvent. The O-sulfonation reaction is carried out at a temperature in the range of 0°C to 200°C in the presence of a deoxidizing agent, but is preferably carried out at 10°C to 150°C.

[0124] O-sulfonation is carried out using halogenated sulfonylic acids, and as halogenated sulfonylic acids, sulfonylic chlorides are preferred. Examples include ethanesulfonyl chloride, n-propanesulfonyl chloride, i-propanesulfonyl chloride, butanesulfonyl chloride, benzylsulfonyl chloride, benzenesulfonyl chloride, p-toluenesulfonyl chloride, o-toluenesulfonyl chloride, p-xylenesulfonyl chloride, mesitylenesulfonyl chloride, p-ethylbenzenesulfonyl chloride, p-methoxybenzenesulfonyl chloride, p-chlorobenzenesulfonyl chloride, 1-naphthalenesulfonyl chloride, and 2-naphthalenesulfonyl chloride.

[0125] Examples of deoxidizing agents include organic bases such as trimethylamine, triethylamine, tributylamine, pyridine, and dimethylaminopyridine; inorganic bases such as lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, potassium bicarbonate, sodium bicarbonate, sodium carbonate, potassium carbonate, and calcium carbonate; and bases such as sodium hydride, sodium methoxide, and sodium ethoxide.

[0126] The solvent used in the O-sulfonation step of dihydroxydiphenylurea is an aprotic solvent, and in particular, acetic acid esters such as butyl acetate, isoamyl acetate, amyl acetate, and hexyl acetate, which are used in the preceding step, and aromatic hydrocarbons such as toluene, xylene, and mesitylene are especially preferred. As the reaction solvent, the solvent used in the preceding step may be used alone, as a mixture of two or more solvents, or as a two-phase solvent system of water and an aprotic solvent that does not contain water.

[0127] When carrying out the reaction, the solvent and reaction temperature are preferably selected based on the reaction method, taking into consideration the boiling point of the solvent, the physical properties of the sulfonating agent, and the stability of the reaction product. After the reaction is complete, water is added to the reaction solution to wash away any deoxidizing agents or other contaminants. Furthermore, if high purity is required, crystal washing and recrystallization operations may be performed using aromatic hydrocarbons such as benzene and toluene, acetate esters such as ethyl acetate and isoamyl acetate, and alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol.

[0128] There are no particular restrictions on the content of the color developer, and it can be appropriately selected depending on the purpose, but it is preferably 1 to 20 parts by mass, and more preferably 2 to 10 parts by mass, per 1 part by mass of leuco dye.

[0129] <<Leuco dyes>> There are no particular restrictions on the leuco dyes, and they can be appropriately selected from those used in thermal recording media depending on the purpose. For example, leuco compounds of dyes such as triphenylmethane, fluorane, phenothiazine, auramine, spiropyran, and indolinophthalide are preferred.

[0130] There are no particular restrictions on the leuco dyes mentioned above, and they can be appropriately selected depending on the purpose. For example, 3,3-bis(p-dimethylaminophenyl)-phthalide, 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis(p-dimethylaminophenyl)-6-diethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)-6-chlorphthalide, 3,3-bis(p-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlorofluorane, 3-dimethylamino-5,7-dimethylfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-(Np-tolyl-N-e (Tylamino)-6-methyl-7-anilinofluorane, 2-{N-(3'-trifluoromethylphenyl)amino}-6-diethylaminofluorane, 2-{3,6-bis(diethylamino)-9-(o-chloranilino)xanthybenzoate lactam}, 3-diethylamino-6-methyl-7-(m-trichloromethylanilino)fluorane, 3-diethylamino-7-(o-chloranilino)fluorane, 3- Pyrrolidino-6-methyl-7-anilinofluorane, 3-di-n-butylamino-7-o-chloranilino)fluorane, 3-N-methyl-N,n-amylamino-6-methyl-7-anilinofluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-(N,N-diethylamino)-5-methyl-7-(N,N-Dibenzylamino)Fluorane, Benzoylleucomethylene Blue, 6'-Chloro-8'-Methoxy-Benzindolino-Spiropyran, 6'-Bromo-3'-Methoxy-Benzindolino-Spiropyran, 3-(2'-Hydroxy-4'-Dimethylaminophenyl)-3-(2'-Methoxy-5'-Chlorphenyl)Phthalide, 3-(2'-Hydroxy-4'-Dimethylaminophenyl)-3-(2'-Methoxy-5'-Nitrophenyl)Phthalide, 3-(2'-Hydroxy-4'-Diethylaminophenyl)-3-(2'-Methoxy-5'-Methyl Phenyl)phthalide, 3-(2'-methoxy-4'-dimethylaminophenyl)-3-(2'-hydroxy-4'-chlor-5'-methylphenyl)phthalide, 3-(N-ethyl-N-tetrahydrofurfuryl)amino-6-methyl-7-anilinofluorane, 3-N-ethyl-N-(2-ethoxypropyl)amino-6-methyl-7-anilinofluorane, 3-N-methyl-N-isobutyl-6-methyl-7-anilinofluorane, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoro Methylanilinofluorane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluorane, 3-diethylamino-5-chlor-7-(α-phenylethylamino)fluorane, 3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluorane, 3-diethylamino-7-(o-methoxycarbonylphenylamino)fluorane, 3-diethylamino-5-methyl-7-(α-phenylethylamino)fluorane, 3 -Diethylamino-7-piperidinofluorane, 2-chloro-3-(N-methyltoluidino)-7-(pn-butylanilino)fluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3,6-bis(dimethylamino)fluorenspiro(9,3')-6'-dimethylaminophthalide, 3-(N-benzyl-N-cyclohexylamino)-5,6-benzo-7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-chlor-7-anilinofluorane, 3-diethylamino-6-methyl-7-mesitidino-4',5'-Benzofluorane, 3-N-methyl-N-isopropyl-6-methyl-7-anilinofluorane, 3-N-ethyl-N-isoamyl-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-(2',4'-dimethylanilino)fluorane, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7 -(N-benzyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluorane, 3-diethylamino-5-chlor-(α-phenylethylamino)fluorane, 3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluorane, 3-diethylamino-7-(o-methoxycarbonylphenylamino)fluorane, 3-diethylamino-5-methyl-7-(α-phenylethylamino) Diethylamino)fluorane, 3-diethylamino-7-piberidinofluorane, 2-chloro-3-(N-methyltoluidino)-7-(pN-butylanilino)fluorane, 3,6-bis(dimethylamino)fluorenspiro(9,3')-6'-dimethylaminophthalide, 3-(N-benzyl-N-cyclohexylamino)-5,6-benzo-7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-chlor-7-anilinofluorane, 3 -N-ethyl-N-(-2-ethoxypropyl)amino-6-methyl-7-anilinofluorane, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-mesitidino-4',5'-benzofluorane, 3-p-dimethylaminophenyl)-3-{1,1-bis(p-dimethylaminophenyl)ethylene-2-yl}phthalide, 3-(p-dimethylaminophenyl)-3-{1,1-Bis(p-dimethylaminophenyl)ethylene-2-yl}-6-dimethylaminophthalide, 3-(p-dimethylaminophenyl)-3-(1-p-dimethylaminophenyl-1-phenylethylene-2-yl)phthalide, 2-ortho-chloroanilino-6-diethylaminofluorane, 2-anilino-3-methyl-6-diethylaminofluorane, 2-anilino-3-methyl-6-(N-ethyl-Np-tolyl)aminofluorane, 3-N-cyclohexyl-N-methylamino-6-methyl-7-anilinofluorane, 3-(p-dimethylaminophenyl)-3-(1-p-dimethylaminophenyl-1-p-chlorophenylethylene-2-yl)-6-dimethylaminophthalide, 3-(4'-dimethylamino-2'-methoxy)-3-(1"-p-dimethylaminophenyl-1"-p-chlorophenyl-1",3"-butadiene-4"-yl) Benzophthalide, 3-(4'-dimethylamino-2'-benzyloxy)-3-(1"-p-dimethylaminophenyl-1"-phenyl-1",3"-butadiene-4"-yl)benzophthalide, 3-dimethylamino-6-dimethylamino-fluoren-9-spiro-3'-(6'-dimethylamino)phthalide, 3,3-bis(2-(p-dimethylaminophenyl)-2-p-methoxyphenyl)ethenyl)-4,5,6,7-the Examples include trachlorophthalides, 3-bis{1,1-bis(4-pyrrolidinophenyl)ethylene-2-yl}-5,6-dichloro-4,7-dibromophthalides, bis(p-dimethylaminostyryl)-1-naphthalenesulfonylmethane, bis(p-dimethylaminostyryl)-1-p-tolylsulfonylmethane, and 6'-(diethylamino)-2'-(2-fluoroanilino)spiro[phthalide-3,9'-xanthene]. These may be used individually or in combination of two or more.

[0131] There are no particular restrictions on the content of the electron-donating compound, and it can be appropriately selected depending on the purpose, but it is preferably 5% by mass or more and 40% by mass or less, and more preferably 10% by mass or more and 30% by mass or less, relative to the total amount of the thermal recording layer.

[0132] <<Styrene-acrylic resin>> The styrene-acrylic resin may be synthesized as appropriate or a commercially available product may be used. The synthesis method may include, for example, emulsion polymerization, dispersion polymerization, suspension polymerization, pulverization, or solution / bulk polymerization, followed by post-emulsification. Examples of the aforementioned commercially available products include product names: PDX-7357, PDX-7616A, PDX-7732, PDX-7741, PDX-7787, PDX-7734, PDX-7777, PDX-7615, HPD-71, HPD-196 (all manufactured by BASF), product names: EK-15, EK-61 (both manufactured by Saiden Chemical Co., Ltd.), and product names: A-2092, XK-110 (both manufactured by DSM Coating Resins).

[0133] The styrene-acrylic resin is preferably a resin emulsion. A resin emulsion refers to a state in which resin particles are dispersed in an aqueous medium or the like, regardless of whether the resin particles are solid or liquid. The aqueous medium refers to one that contains water or a hydrophilic solvent as a component.

[0134] Methods for dispersing the aforementioned resin particles in an aqueous medium include forced emulsification using a dispersant and self-emulsification using a resin having anionic groups. In the case of forced emulsification, dispersant may remain in the image formed by the ink, potentially reducing the image's intensity; therefore, it is preferable to use self-emulsification.

[0135] There are no particular restrictions on the content of the styrene-acrylic resin, and it can be appropriately selected depending on the purpose, but it is preferably 1.0% by mass or more and 50.0% by mass or less, more preferably 10.0% by mass or more and 50.0% by mass or less, and even more preferably 20.0% by mass or more and 40.0% by mass or less, relative to the entire thermal recording layer.

[0136] Other resins besides the styrene-acrylic resin may be added as needed. Examples of these other resins include polyvinyl alcohol resin, starch or its derivatives; cellulose derivatives such as hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose; water-soluble polymers such as sodium polyacrylate, polyvinylpyrrolidone, acrylamide-acrylic acid ester copolymer, acrylamide-acrylic acid ester-methacrylic acid terpolymer, styrene-maleic anhydride copolymer alkali salt, isobutylene-maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, and casein; emulsions such as polyvinyl acetate resin, polyurethane resin, polyacrylic acid, polyacrylic acid ester, vinyl chloride-vinyl acetate copolymer, polybutyl methacrylate, and ethylene-vinyl acetate copolymer; and latexes such as styrene-butadiene copolymer and styrene-butadiene-acrylic copolymer. These may be used individually or in combination of two or more. If the above-mentioned other resins are included, the content of the above-mentioned other resins is preferably 100 parts by mass or less per 100 parts by mass of the styrene-acrylic resin, and more preferably 50 parts by mass or less, from the viewpoint of resistance to hot water.

[0137] <<Photothermal Conversion Materials>> The aforementioned photothermal conversion materials are materials that absorb laser light and convert it into heat, and can be broadly classified into inorganic materials and organic materials. Examples of the inorganic material include carbon black, metal borides, and particles of at least one of metal oxides such as Ge, Bi, In, Te, Se, and Cr. Among these, materials that have high absorption of light in the near-infrared wavelength region and low absorption of light in the visible wavelength region are preferred, and metal borides and metal oxides are more preferred. Examples of the metal borides and metal oxides include at least one selected from hexaboride, tungsten oxide compounds, antimony tin oxide (ATO), indium tin oxide (ITO), and zinc antimonate. Examples of the aforementioned hexaborides include LaB6, CeB6, PrB6, NdB6, GdB6, TbB6, DyB6, HoB6, YB6, SmB6, EuB6, ErB6, TmB6, YbB6, LuB6, SrB6, CaB6, and (La,Ce)B6. The tungsten oxide compound may be, for example, fine particles of tungsten oxide represented by the general formula: WyOz (where W is tungsten, O is oxygen, 2.2 ≤ z / y ≤ 2.999), as described in International Publication No. 2005 / 037932, Japanese Patent Publication No. 2005-187323, etc., or by the general formula: MxWyOz (where M is H, He, alkali metals, alkaline earth metals, rare earth elements, Mg, Zr, Cr, Mn, Fe, Examples include fine particles of composite tungsten oxide (where W is tungsten, O is oxygen, and 0.001≦x / y≦1, 2.2≦z / y≦3.0), which are represented by one or more elements selected from Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I, where W is tungsten, O is oxygen, and 0.001≦x / y≦1, 2.2≦z / y≦3.0). Among these, cesium-containing tungsten oxide is particularly preferred due to its large absorption in the near-infrared region and small absorption in the visible region. Furthermore, among antimony tin oxide (ATO), indium tin oxide (ITO), and zinc antimonate, ITO is particularly preferred because it has high absorption in the near-infrared region and low absorption in the visible region. These are formed in layers by vacuum deposition or by bonding particulate materials with resin or the like. As the aforementioned organic material, various dyes can be used as appropriate depending on the wavelength of light to be absorbed. However, when a semiconductor laser is used as the light source, near-infrared absorbing dyes having an absorption peak around 600 nm to 1,200 nm are used. Specifically, examples include cyanine dyes, quinone dyes, quinoline derivatives of indonaphthol, phenylenediamine nickel complexes, and phthalocyanine dyes. The aforementioned light and heat conversion materials may be used individually or in combination of two or more types. The aforementioned photothermal conversion material may be incorporated into the thermal recording layer or into a layer other than the thermal recording layer. When incorporated into a layer other than the thermal recording layer, it is preferable to provide the photothermal conversion layer adjacent to the thermal recording layer. The content of the photothermal conversion material is preferably 0.1% by mass or more and 10% by mass or less, and more preferably 0.3% by mass or more and 5% by mass or less, relative to the thermal recording layer.

[0138] <<Other ingredients>> Examples of the other components mentioned above include auxiliary additives, thermofusible substances, lubricants, fillers, ultraviolet absorbers, antioxidants, sensitizers, light stabilizers, and crosslinking agents.

[0139] As the auxiliary additives, for example, various hindered phenol compounds or hindered amine compounds that are electron-accepting but have relatively low color-developing ability may be added. Examples of the aforementioned auxiliary additives include 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(6-tert-butyl-2-methylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1,3-tris(2-methyl-4-hydroxy-5-cyclohexylphenyl)butane, and 4,4'-thiobis(6-tert-butyl-2-methylphenyl). Examples include thiobisphenol, tetrabromobisphenol A, tetrabromobisphenol S, 4,4'-thiobis(2-methylphenol), 4,4'-thiobis(2-chlorophenol), tetrakis(1,2,2,6,6-pentamethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, and tetrakis(1,2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate. These may be used individually or in combination of two or more.

[0140] -Thermofusible substance- Examples of the aforementioned heat-fusible substances include fatty acids such as stearic acid and behenic acid; fatty acid amides such as stearamide and palmitamide; fatty acid metal salts such as zinc stearate, aluminum stearate, calcium stearate, zinc palmitate, and zinc behenate; p-benzyl biphenyl, terphenyl, triphenylmethane, benzyl p-benzyloxybenzoate, benzyl β-benzyloxynaphthalene, phenyl β-naphthoate, and 1-hydroxy-2-naphthoate. Phenyl acid, methyl 1-hydroxy-2-naphthoate, diphenyl carbonate, glycol carbonate, dibenzyl terephthalate, dimethyl terephthalate, 1,4-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-dibendyloxynaphthalene, 1,2-diphenoxyethane, 1,2-bis(3-methylphenoxy)ethane, 1,2-bis(4-methylphenoxy)ethane, 1,4-diphenoxy-2-butene, 1,2-bis(4-methoxyphenoxy Luthio)ethane, dibenzoylmethane, 1,4-diphenylthiobutane, 1,4-diphenylthio-2-butene, 1,3-bis(2-vinyloxyethoxy)benzene, 1,4-bis(2-vinyloxyethoxy)benzene, p-(2-vinyloxyethoxy)biphenyl, p-aryloxybiphenyl, p-propagyloxybiphenyl, dibenzoyloxymethane, dibenzoyloxypropane, dibenzyl disulfide, 1,1-diphenylethanol, 1, Examples include 1-diphenylpropanol, p-benzyloxybenzyl alcohol, 1,3-phenoxy-2-propanol, N-octadecylcarbamoyl-p-methoxycarbonylbenzene, N-octadecylcarbamoylbenzene, 1,2-bis(4-methoxyphenoxy)propane, 1,5-bis(4-methoxyphenoxy)-3-oxapentane, dibenzyl oxalate, bis(4-methylbenzyl oxalate), and bis(4-chlorobenzyl oxalate. These may be used individually or in combination of two or more.

[0141] - Lubricant - Examples of the lubricants include higher fatty acids or their metal salts, higher fatty acid amides, higher fatty acid esters, animal waxes, vegetable waxes, mineral waxes, petroleum-based waxes, and synthetic waxes. These may be used individually or in combination of two or more.

[0142] -Filler- Examples of fillers include inorganic fine powders such as calcium carbonate, silica, zinc oxide, titanium oxide, zirconium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, kaolin, talc, surface-treated calcium, and surface-treated silica; and organic fine powders such as urea-formaldehyde resin, styrene-methacrylic acid copolymer, polystyrene resin, and vinylidene chloride resin. These may be used individually or in combination of two or more. There are no particular restrictions on the content of the filler, and it can be appropriately selected depending on the purpose, but it is preferably 0.4 parts by mass or less, and more preferably 0.2 parts by mass or less, per 1 part by mass of the binder resin.

[0143] -Crosslinking agent- The crosslinking agent is not particularly limited and can be appropriately selected depending on the purpose. Examples include glyoxal derivatives, methylol derivatives, epichlorohydrin, polyamide epichlorohydrin, epoxy compounds, aziridine compounds, hydrazine, hydrazide derivatives, oxazoline derivatives, and carbodiimide derivatives. These may be used individually or in combination of two or more.

[0144] - UV absorber - There are no particular restrictions on the UV absorber, and it can be appropriately selected depending on the purpose. Examples include salicylic acid-based UV absorbers, benzophenone-based UV absorbers, and benzotriazole-based UV absorbers. Examples of the UV absorbers include phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis(2-methoxy-4-hydroxy-5-benzoylphenyl)methane, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'- Examples include di-tert-butylphenyl)chlorobenzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-{2'-hydroxy-3'-(3",4",5",6"-tetrahydrophthalimidomethyl)-5'-methylphenyl}benzotriazole, 2,2'-methylenebis{4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-yl)phenol}, 2-(2'-hydroxy-5'-methacryloxyphenyl)-2H-benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, and 2-(5-methyl-2-hydroxyphenyl)benzotriazole. These can be used individually or in combination of two or more.

[0145] <Support> The support has no particular limitations on its shape, structure, size, material, etc., and can be appropriately selected according to the purpose. Examples of the shape include a flat plate or a sheet. The structure may be a single-layer structure or a laminated structure. The size can be appropriately selected according to the size of the thermal recording medium, etc.

[0146] As the support material, for example, in addition to ordinary paper, synthetic paper, or plastic films such as polyethylene, transparent polyethylene terephthalate, polypropylene, or polyvinyl chloride can be used. When using these plastic films, surface treatments such as matte treatment or corona treatment may be applied to the surface of the support material to improve the adhesion of the coating liquid. Among these, biaxially oriented polyethylene terephthalate sheets are preferred because they are excellent in terms of strength, heat resistance, and dimensional stability. Furthermore, white opaque films or foamed sheets obtained by adding white raw materials or fillers to these materials can also be used. Laminates of the above materials can also be used, and typical examples include laminates of cellulose fibers and synthetic paper, cellulose fibers and plastic film, or plastic film and synthetic paper. The support being a transparent film is preferable in applications in the POS field, such as for fresh food, bento boxes, and prepared foods, because it allows the contents to be visually inspected. Here, transparency refers to a haze (turbidity) of 10% or less, which is an indicator of the transparency of the film. While this is not particularly problematic, a haze of 5% or less is more preferable to achieve the objectives of the present invention. The average thickness of the support can be arbitrarily selected as needed, but from the viewpoint of transparency and ease of processing, it is preferably 3 μm to 500 μm, and more preferably 10 μm to 100 μm. If the average thickness of the support is less than 3 μm, the strength will be insufficient, and if it exceeds 500 μm, the transparency will decrease and the rigidity will become too high, resulting in poor processability.

[0147] <Protective layer> The protective layer contains a binder resin and a crosslinking agent, and may further contain other components as needed. The protective layer is preferably located on the thermal recording layer.

[0148] There are no particular restrictions on the binder resin, and it can be appropriately selected depending on the purpose. Examples include acrylic resins, polyvinyl alcohol resins, starch or its derivatives; cellulose derivatives such as hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose; water-soluble polymers such as sodium polyacrylate, polyvinylpyrrolidone, acrylamide-acrylic ester copolymer, styrene-acrylic copolymer, acrylamide-acrylic ester-methacrylic acid ternary copolymer, styrene-maleic anhydride copolymer alkali salt, isobutylene-maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, and casein; emulsions such as polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic ester, vinyl chloride-vinyl acetate copolymer, polybutyl methacrylate, and ethylene-vinyl acetate copolymer; and latexes such as styrene-butadiene copolymer and styrene-butadiene-acrylic copolymer. These may be used individually or in combination of two or more.

[0149] The crosslinking agent is not particularly limited and can be appropriately selected depending on the purpose. Examples include glyoxal derivatives, methylol derivatives, epichlorohydrin, polyamide epichlorohydrin, epoxy compounds, aziridine compounds, hydrazine, hydrazide derivatives, oxazoline derivatives, and carbodiimide derivatives. These may be used individually or in combination of two or more.

[0150] Furthermore, it is preferable to include a pigment (filler) in the protective layer as needed. Examples of pigments used in the protective layer include inorganic pigments such as zinc oxide, calcium carbonate, barium sulfate, titanium dioxide, lithopone, talc, pyrophyllite, kaolin, aluminum hydroxide, and calcined kaolin, as well as organic pigments such as cross-linked polystyrene resin, urea resin, silicone resin, cross-linked polymethyl methacrylate resin, and melamine-formaldehyde resin. In addition to the resin, water-resistant agent, and pigment mentioned above, the protective layer may also contain conventionally used auxiliary additives, such as surfactants, thermofusible substances, lubricants, and pressure-induced color inhibitors.

[0151] The protective layer is not particularly limited and can be formed by generally known methods. The average thickness of the protective layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 μm or more and 5 μm or less, and more preferably 1 μm or more and 3 μm or less.

[0152] <Print layer> The aforementioned printing layer is made up of various colors, materials, and thicknesses, with ink or the like printed on it, and forms the background of the image printed on the thermal recording layer. By providing a printing layer, it is possible to include the product name, manufacturer name, ingredient list, etc., before product packaging, and to give the product an excellent design. Preferably, the printed layer is located on the thermal recording layer, between the support and the thermal recording layer, or on the side of the support opposite to the thermal recording layer.

[0153] The printing layer contains a colorant, a binder resin, and a solvent, and further contains other components as needed. There are no particular restrictions on the aforementioned coloring material; it can be appropriately selected according to the purpose, and pigments or dyes can be used.

[0154] The binder resin and other components can be the same as those used for the thermal recording layer.

[0155] The printed layer is formed by gravure printing, flexographic printing, offset printing, UV printing, inkjet printing, etc.

[0156] There are no particular restrictions on the average thickness of the printed layer, and it can be appropriately selected depending on the purpose, but it is preferably 0.05 μm or more and 4 μm or less, and more preferably 0.1 μm or more and 2 μm or less.

[0157] <Other layers> The aforementioned other layers are not particularly limited and can be selected as appropriate depending on the purpose, but examples include a back layer, under layer, and heat seal layer.

[0158] -Back layer- The back layer can be provided on the side of the support that does not have a thermal recording layer, if necessary. The back layer contains a filler and a binder resin, and optionally contains other components such as a lubricant and a coloring pigment. For example, inorganic fillers or organic fillers can be used as the filler. Examples of the inorganic fillers include carbonates, silicates, metal oxides, and sulfate compounds. Examples of the organic fillers include silicone resin, cellulose, epoxy resin, nylon resin, phenolic resin, polyurethane resin, urea resin, melamine resin, polyester resin, polycarbonate resin, styrene resin, acrylic resin, polyethylene resin, formaldehyde resin, and polymethyl methacrylate resin. There are no particular restrictions on the binder resin, and it can be appropriately selected depending on the purpose. For example, the same type of binder resin as that used for the thermal recording layer can be used. The average thickness of the back layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 μm or more and 20 μm or less, and more preferably 0.3 μm or more and 10 μm or less.

[0159] -Underclass- The underlayer is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that it contains a binder resin and thermoplastic hollow resin particles, and further contains other components as needed.

[0160] The aforementioned thermoplastic hollow resin particles are microscopic hollow particles that have a thermoplastic resin shell and contain air or other gases inside, and are already in a foamed state.

[0161] There are no particular restrictions on the average particle size (outer diameter) of the thermoplastic hollow resin particles, and they can be appropriately selected depending on the purpose, but a size of 0.2 μm or more and 20 μm or less is preferred, and a size of 2 μm or more and 5 μm or less is more preferred. If the average particle size is smaller than 0.2 μm, it becomes technically difficult to create a hollow structure, and the undercoat layer's role becomes insufficient. On the other hand, if the average particle size is larger than 20 μm, the smoothness of the surface after coating and drying decreases, resulting in uneven coating of the thermal recording layer. To achieve uniformity, it becomes necessary to apply more thermal recording layer forming solution than required.

[0162] There are no particular restrictions on the hollowness of the thermoplastic hollow resin particles, and they can be appropriately selected depending on the purpose, but 50% to 95% is preferred, and 80% to 95% is more preferred. If the hollow ratio is less than 30%, the thermal insulation is insufficient, causing thermal energy from the thermal head to be released outside the thermal recording medium through the support, resulting in an insufficient improvement in sensitivity. The hollow ratio referred to here is the ratio of the outer diameter to the inner diameter (diameter of the hollow part) of the hollow particle, and is expressed by the following formula. Hollowness (%) = (Inner diameter of hollow particle / Outer diameter of hollow particle) × 100

[0163] As mentioned above, the thermoplastic hollow resin particles have a thermoplastic resin as a shell. However, there are no particular restrictions on the thermoplastic resin, and it can be appropriately selected depending on the purpose. Examples include styrene-acrylic resin, polystyrene resin, acrylic resin, polyethylene resin, polypropylene resin, polyacetal resin, chlorinated polyether resin, polyvinyl chloride resin, and copolymer resin mainly composed of vinylidene chloride and acrylonitrile. Among these, styrene-acrylic resin and copolymer resin mainly composed of vinylidene chloride and acrylonitrile are preferred because they have a high hollowness ratio, small variation in particle size, and are suitable for blade coating.

[0164] There are no particular restrictions on the amount of the aforementioned hollow plastic particles that can be applied, and they can be appropriately selected depending on the purpose. However, in order to maintain sensitivity and uniformity of application, the amount applied to the support is 1 m 2 1g to 3g is needed per unit. 1g / m 2 If it is less than 3g / m, sufficient sensitivity cannot be obtained, and 2 Beyond a certain point, a decrease in the bonding strength of the layers occurs.

[0165] -Heat seal layer- The heat-seal layer is formed by laminating LDPE (low-density polyethylene) films used as sealants, and can be welded together by heating the heat-seal layers in close contact with each other. This property allows for the sealing, or heat-sealing, of a bag-shaped packaging sheet by heating it in a similar manner. Therefore, the heat-seal layer can be formed using any material that possesses the property of being heat-sealable, i.e., heat-sealable, and is not limited to LDPE. Suitable materials for heat sealing include films such as HDPE (high-density polyethylene), CPP (unoriented polypropylene), OPP (biaxially oriented polypropylene), and EVA (ethylene-vinyl acetate copolymer). However, polyolefin resins such as polyethylene and polypropylene; vinyl acetate resins such as ethylene-vinyl acetate copolymer (olefin-vinyl acetate copolymer, etc.); and acrylic resins such as ethylene-(meth)acrylic acid copolymer and ionomer [olefin-(meth)acrylic acid copolymer, or its metal crosslinked product, etc.] may also be used. Alternatively, known heat-sealable adhesives may be used for formation. It is preferable to use a material that becomes transparent after formation, as the packaged contents will be visible. The average thickness of the heat seal layer is preferably 5 μm to 50 μm, and more preferably 10 μm to 30 μm, from the viewpoint of transparency and seal strength.

[0166] (Thermal recording layer forming liquid) The thermal recording layer forming liquid of the present invention contains a compound represented by any of the above general formulas (1) to (3), a styrene-acrylic resin, and a solvent, preferably containing a leuco dye, and further optionally containing other components. The leuco dye, the compound represented by any of the above general formulas (1) to (3), the styrene-acrylic resin, and other components can be the same as those used for the thermal recording layer.

[0167] Examples of the aforementioned solvents include water, aromatic solvents, ester solvents, ketone solvents, alcohol solvents, aliphatic hydrocarbons, glycol solvents, and petroleum-based solvents containing 1% or less aromatic components, mainly composed of paraffin or naphthenes. These may be used individually or in combination of two or more. Examples of the aromatic solvent include benzene, toluene, and xylene. Examples of the ester solvent include methyl acetate, ethyl acetate, and isopropyl acetate. Examples of the ketone solvent include acetone and methyl ethyl ketone. Examples of the alcohol solvent include methanol, ethanol, isopropyl alcohol, and n-propyl alcohol. Examples of the aliphatic hydrocarbons include n-hexane, n-heptane, and cyclohexane. Examples of the glycol solvent include ethylene glycol and diethylene glycol.

[0168] The thermal recording layer forming liquid of the present invention can be prepared by grinding and dispersing a leuco dye, a compound represented by any of the above general formulas (1) to (3), a styrene-acrylic resin, and the other components using a disperser such as a ball mill, attritor, or sand mill until the dispersed particle size is 0.1 μm or more and 3 μm or less, and then mixing it with other components as needed.

[0169] (Method of manufacturing a thermal recording medium) The method for manufacturing a thermal recording medium of the present invention includes a thermal recording layer formation step of applying the thermal recording layer forming solution of the present invention onto a support to form a thermal recording layer, and further includes other steps as necessary.

[0170] There are no particular restrictions on the application method, and it can be appropriately selected according to the purpose. Examples include the blade coating method, gravure coating method, gravure offset coating method, bar coating method, roll coating method, knife coating method, air knife coating method, comma coating method, U-comma coating method, AKKU coating method, smoothing coating method, microgravure coating method, reverse roll coating method, 4- to 5-roll coating method, dip coating method, curtain coating method, slide coating method, die coating method, etc.

[0171] The amount of the thermal recording layer forming liquid that adheres after drying is not particularly limited and can be appropriately selected depending on the purpose, but is 1 g / m². 2 More than 20g / m 2 The following is preferable: 2 g / m 2 More than 10g / m 2 The following are preferable.

[0172] There are no particular limitations on the form of the thermal recording medium of the present invention, and can be appropriately selected according to the purpose. For example, it may be used as a label as is, or a layer for printing information such as characters, marks, pictures, barcodes, or two-dimensional codes such as QR codes (registered trademarks) may be provided on the protective layer or support. Alternatively, an adhesive layer may be provided on the side of the support opposite to the side on which the thermal recording layer is provided. Furthermore, there are no particular restrictions on the shape of the thermal recording medium of the present invention, and it can be appropriately selected depending on the purpose. Examples include label shape, sheet shape, roll shape, etc.

[0173] <Application> The thermal recording medium of the present invention can be used in a wide range of applications, such as packaging films for various containers including PET bottles for soft drinks, metal cans for canned coffee, bottles for beverages, pharmaceuticals, beer, etc., and packaging labels in the POS field for fresh foods, bento boxes, and prepared foods.

[0174] Herein, embodiments of the thermal recording medium of the present invention will be described with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and redundant descriptions may be omitted. Furthermore, the number, position, shape, etc. of the following components are not limited to this embodiment, and can be set to a number, position, shape, etc. that is preferable for carrying out the present invention.

[0175] <First Embodiment> Figure 1 is a schematic cross-sectional view showing an example of a thermal recording medium according to the first embodiment. The thermal recording medium of this first embodiment has a thermal recording layer 2 on a support 1.

[0176] <Second Embodiment> Figure 2 is a schematic cross-sectional view showing an example of a thermal recording medium according to the second embodiment. The thermal recording medium of this second embodiment has a thermal recording layer 2 and a protective layer 3 on a support 1 in that order.

[0177] <Third Embodiment> Figure 3 is a schematic cross-sectional view showing an example of a thermal recording medium according to the third embodiment. The thermal recording medium of this third embodiment has a printed layer 4 and a thermal recording layer 2 on a support 1 in that order.

[0178] <Fourth Embodiment> Figure 4 is a schematic cross-sectional view showing an example of a thermal recording medium according to the fourth embodiment. This thermal recording medium of the third embodiment has a printing layer 4, a thermal recording layer 2, and a protective layer 3 on a support 1 in that order.

[0179] <Fifth Embodiment> Figure 5 is a schematic cross-sectional view showing an example of a thermal recording medium according to the fifth embodiment. The thermal recording medium of this fifth embodiment has a thermal recording layer 2 on a support 1, and a printing layer 4 on the side of the support 1 that does not have the thermal recording layer.

[0180] <Sixth Embodiment> Figure 6 is a schematic cross-sectional view showing an example of a thermal recording medium according to the sixth embodiment. This thermal recording medium of the sixth embodiment has a thermal recording layer 2 and a protective layer 3 in that order on a support 1, and a printing layer 4 on the side of the support 1 that does not have the thermal recording layer.

[0181] <Seventh Embodiment> Figure 7 is a schematic cross-sectional view showing an example of a thermal recording medium according to the seventh embodiment. The thermal recording medium of this seventh embodiment has a thermal recording layer 2 and a printing layer 4 on a support 1 in that order.

[0182] <Eighth Embodiment> Figure 8 is a schematic cross-sectional view showing an example of a thermal recording medium according to the eighth embodiment. The thermal recording medium of this eighth embodiment has a thermal recording layer 2, a protective layer 3, and a printing layer 4 on a support 1 in that order.

[0183] (Image recording method) The image recording method of the present invention records an image on a thermal recording medium of the present invention using a thermal head. There are no particular restrictions on the shape, structure, size, etc., of the thermal head, and it can be appropriately selected according to the purpose. In this case, considering the durability of the thermal recording layer and its compatibility with the thermal head, it is preferable to provide a protective layer on top of the thermal recording layer. However, if a colorant system with high image and background preservation properties is applied, or if the thermal recording layer itself is given compatibility with the thermal head using fillers, lubricants, etc., then it is not always necessary to provide a protective layer. Furthermore, when a filler is added to the protective layer or thermal recording layer for the purpose of matching with the thermal head, the 50% cumulative volume particle size (D) is measured using a laser diffraction / scattering particle size distribution analyzer (device name: LA-960, manufactured by Horiba, Ltd.). 50 If the particle size is too small, it will not be possible to achieve the intended purpose of matching with the thermal head. Conversely, if the particle size is too large, the head will wear down easily and transparency will be difficult to impart. Therefore, a particle size of approximately 0.25 μm to 0.75 μm is preferable, but this is not an absolute requirement.

[0184] The image recording method of the present invention records an image by irradiating a thermal recording medium of the present invention with laser light. While various methods can be considered for heating with laser light, it is preferable to use laser light that can heat without contact. There are no particular restrictions on the laser light, and it can be appropriately selected according to the purpose. For example, various commonly known laser devices can be used, such as gas lasers using gases like CO2, solid-state lasers using solids like YAG or YVO4, and semiconductor lasers using III-V or IV-VI semiconductors. The device should be selected according to the intended use and method of use. Among these methods, CO2 lasers, with their 10,000 nm wavelength, are used because most materials absorb light from them, allowing for thermal recording without the need for special absorbent materials. Furthermore, while the addition of photothermal conversion materials, which absorb laser wavelengths of 800nm ​​to 1100nm and convert them into heat, is necessary for semiconductor lasers and solid-state lasers such as YAG and fiber lasers, transparent plastic films such as PET and OPP do not absorb laser light. Therefore, it is possible to record on the thermal recording layer on the opposite side of the film by irradiating it with a laser from the transparent film side, rather than directly irradiating the thermal recording layer with a laser. This expands the range of applications. There are no particular restrictions on the output power of the laser light irradiated in the image forming process of the image forming apparatus, and it can be appropriately selected according to the purpose, but 1W or more is preferred, 3W or more is more preferred, and 5W or more is particularly preferred. If it is less than 1W, image forming will take a long time, and if the image forming time is to be shortened, the output will be insufficient. Furthermore, there is no particular upper limit to the output power of the laser light, and it can be appropriately selected according to the purpose, but it is preferably 200W or less, more preferably 150W or less, and particularly preferably 100W or less. Exceeding 200W may lead to an increase in the size of the laser device.

[0185] Furthermore, when performing high-speed image recording on a thermal recording medium, it is preferable to use an image forming apparatus having a laser array in which multiple laser light-emitting elements are arranged in an array.

[0186] Next, as an example, we will describe a laser recording device that records images on a long thermal recording medium.

[0187] Here, Figure 9 is a schematic perspective view of the image recording system 100, which is a laser recording device. In the following explanation, the transport direction (movement direction) of the thermal recording medium will be described as the X-axis direction, the vertical direction as the Z-axis direction, and the direction perpendicular to both the movement direction and the vertical direction as the Y-axis direction. The image recording system 100 irradiates the thermal recording medium 101, which is the object to be recorded, with laser light to perform surface processing and image recording processing, as detailed below. As shown in Figure 9, the image recording system 100 includes a transport device 10, a recording device 20, a main unit 30, an optical fiber 42, an encoder unit 60, and the like. The recording device 20 irradiates the object to be recorded with laser light to perform processing on the surface of the object or to record a visible image on the object, and is equivalent to a laser irradiation device. The recording device 20 is located on the -Y side of the transport device 10, that is, on the -Y side of the transport path. The transport device 10 transports the thermal recording medium 101, which is the object to be recorded, using, for example, multiple rotating rollers. The main unit 30 is connected to the transport device 10, the recording device 20, and other components, and controls the entire image recording system 100. The encoder unit 60 acquires the movement speed of the thermal recording medium 101.

[0188] Figure 10 is a schematic perspective view showing the configuration of the image recording system 100. The image recording system 100 includes a laser processing device 30, which is a laser light source. The laser processing device 30 includes a laser irradiation device 14 having a laser array section 14a and a fiber array section 14b, and an optical section 43. Here, as the laser irradiation device 14, a fiber array recording device is used that performs surface processing and image recording using a fiber array in which the laser emission sections of multiple optical fibers are arranged in an array in the main scanning direction (Z axis direction) perpendicular to the sub-scanning direction (X axis direction), which is the movement direction of the thermal recording medium 101, which is the object to be recorded. The laser processing device 30 irradiates the thermal recording medium with laser light emitted from the laser light-emitting element 41 via the fiber array and records an image (visible image) consisting of drawing units. The laser array unit 14a comprises a plurality of laser light-emitting elements 41 arranged in an array, a cooling unit 50 for cooling the laser light-emitting elements 41, a plurality of drive drivers 45 provided corresponding to the laser light-emitting elements 41 for driving the corresponding laser light-emitting elements 41, and a controller 46 for controlling the plurality of drive drivers 45. The controller 46 is connected to a power supply 48 for supplying power to the laser light-emitting elements 41 and an image information output unit 47 such as a personal computer that outputs image information. Normally, in the laser light-emitting element 41, energy that is not converted into laser light is converted into heat, causing heat generation. Therefore, the laser light-emitting element 41 is cooled by a cooling unit 50, which is a cooling means. Furthermore, the laser irradiation device 14 here uses a fiber array section 14b, making it possible to arrange each laser light-emitting element 41 separately. This makes it possible to reduce the heat influence from adjacent laser light-emitting elements 41, and allows for efficient cooling of the laser light-emitting elements 41, thereby avoiding temperature rise and variation in the laser light-emitting elements 41, reducing variations in laser light output, and improving density uniformity. Note that the laser light output is the average output measured by a power meter. There are two methods for controlling the laser light output: controlling the peak power and controlling the pulse emission ratio (duty cycle: laser emission time / period time). The cooling unit 50 is a liquid-cooling system that cools the laser light-emitting elements 41 by circulating a coolant. It comprises a heat receiving section 51 that receives heat from each laser light-emitting element 41 and a heat dissipation section 52 that dissipates the heat from the coolant. The heat receiving section 51 and the heat dissipation section 52 are connected by cooling pipes 53a and 53b. The heat receiving section 51 has a cooling pipe inside a case made of a material with good thermal conductivity through which a coolant made of a material with good thermal conductivity flows. Multiple laser light-emitting elements 41 are arranged in an array on the heat receiving section 51. The heat dissipation unit 52 includes a radiator and a pump for circulating the coolant. The coolant pumped out by the heat dissipation unit 52 flows through the cooling pipe 53a into the heat receiving unit 51. The coolant then moves through the cooling pipes within the heat receiving unit 51, absorbing heat from the laser light-emitting elements 41 arranged in the heat receiving unit 51 and cooling them. The coolant, whose temperature has risen after absorbing heat from the laser light-emitting elements 41 and flowing out of the heat receiving unit 51, moves through the cooling pipe 53b and flows into the radiator of the heat dissipation unit 52, where it is cooled by the radiator. The coolant cooled by the radiator is then pumped back into the heat receiving unit 51. The fiber array section 14b comprises a plurality of optical fibers 42 provided in correspondence with the laser light-emitting element 41, and an array head 44 that holds the vicinity of the laser emission portion 42a of these optical fibers 42 in an array shape in the vertical direction (Z-axis direction). The laser incident portion of each optical fiber 42 is attached to the laser emission surface of the corresponding laser light-emitting element 41. Furthermore, if an array head 44 were to attempt to hold all the optical fibers 42, the array head 44 would become long and prone to deformation. As a result, it would be difficult to maintain the linearity of the beam arrangement and the uniformity of the beam pitch with a single array head 44. For this reason, the array head 44 is designed to hold 100 to 200 optical fibers 42. In addition, it is preferable that the laser irradiation device 14 arranges multiple array heads 44, each holding 100 to 200 optical fibers 42, in the Z-axis direction, which is perpendicular to the direction of movement of the thermal recording medium 101.

[0189] Figure 11 is a diagram illustrating the arrangement of the laser array. As shown in Figure 11, the optical fibers 42 of the array head 44 in Figure 10 are arranged so that the dots of diameter R1 formed by irradiating the thermal recording medium with a laser and producing color at the focal position focused by the optical unit 43 are connected. The scanning direction of the laser light has a primary scanning direction and a secondary scanning direction, and the primary and secondary scanning directions are orthogonal to each other. The primary scanning direction is the direction in which the multiple optical fibers 42 are arranged. The secondary scanning direction is the direction in which the thermal recording medium moves. Furthermore, since the array head 44 and the thermal recording medium are moved relative to each other to record an image on the thermal recording medium, the array head 44 may move relative to the thermal recording medium, or the thermal recording medium may move relative to the array head 44. Even when the array head 44 moves relative to the thermal recording medium, if the array head 44 is considered the observation point, the expression "movement speed of the thermal recording medium" can be used.

[0190] Furthermore, as shown in Figure 10, the optical unit 43, which is an example of an optical system, has a collimating lens 43a that converts the divergent laser beam emitted from each optical fiber 42 into a parallel beam, and a focusing lens 43b that focuses the laser beam onto the surface of the thermal recording medium, which is the laser irradiation surface. Whether or not to provide the optical unit 43 can be appropriately selected depending on the purpose.

[0191] The image information output unit 47 of a personal computer or the like inputs image information to the controller 46. The controller 46 generates drive signals (control pulses) to drive each drive driver 45 based on the input image information. The controller 46 transmits the generated drive signals (control pulses) to each drive driver 45. Specifically, the controller 46 is equipped with a clock generator. When the number of clocks oscillated by the clock generator reaches a predetermined number of clocks, the controller 46 transmits drive signals (control pulses) to each drive driver 45 to drive each drive driver 45. Each drive driver 45, upon receiving a drive signal (control pulse), transmits a current pulse to drive the corresponding laser light-emitting element 41. The laser light-emitting element 41 outputs a light emission pulse and emits laser light in accordance with the drive of the drive driver 45. The laser light emitted from the laser light-emitting element 41 enters the corresponding optical fiber 42 and is emitted from the laser emission section 42a of the optical fiber 42. The laser light emitted from the laser emission section 42a of the optical fiber 42 passes through the collimating lens 43a and the focusing lens 43b of the optical section 43 and then irradiates the thermal recording medium, which is the object to be recorded. An image is recorded on the thermal recording medium by heating it with the laser light irradiated onto it.

[0192] Incidentally, when using a recording device that uses a galvanometer mirror to deflect laser light and record images onto an object, images such as characters are recorded by irradiating them with laser light in a single continuous line as the galvanometer mirror rotates. Therefore, when recording a certain amount of information onto an object, there is a constraint that the recording cannot be completed in time unless the transport of the object is stopped. On the other hand, the laser irradiation device 14 uses a laser array in which multiple laser light-emitting elements 41 are arranged in an array, and by controlling the ON / OFF state of the laser light-emitting elements corresponding to each pixel, an image can be recorded on the thermal recording medium. As a result, even with a large amount of information, an image can be recorded on the thermal recording medium without stopping the transport of the thermal recording medium. Therefore, with the laser irradiation device 14, even when recording a large amount of information on the object to be recorded, an image can be recorded without reducing productivity.

[0193] The laser irradiation device 14 records an image on a thermal recording medium by irradiating it with laser light and heating the medium, so it is necessary to use a laser light-emitting element 41 with a certain level of high output. As a result, the laser light-emitting element 41 generates a large amount of heat. In conventional laser array recording devices that do not have a fiber array section 14b, it is necessary to arrange the laser light-emitting elements 41 in an array at intervals corresponding to the resolution. Therefore, in conventional laser array recording devices, in order to achieve a resolution of 200 dpi, the laser light-emitting elements 41 must be arranged at a very narrow pitch. As a result, in conventional laser array recording devices, the heat from the laser light-emitting elements 41 does not dissipate easily, and the laser light-emitting elements 41 become hot. In conventional laser array recording devices, when the laser light-emitting elements 41 become hot, the wavelength and light output of the laser light-emitting elements 41 fluctuate, making it impossible to heat the object to be recorded to the specified temperature, and thus it becomes impossible to obtain a good image. Furthermore, in conventional laser array recording devices, in order to suppress such a temperature rise of the laser light-emitting elements 41, it is necessary to reduce the transport speed of the object to be recorded and increase the emission interval of the laser light-emitting elements 41, which does not sufficiently increase productivity.

[0194] Typically, the cooling unit 50 uses a chiller system, which only cools and does not heat. Therefore, the temperature of the light source will not exceed the chiller's set temperature, but the temperature of the cooling unit 50 and the laser light-emitting element 41 in contact with it will fluctuate from the ambient temperature. On the other hand, when a semiconductor laser is used as the laser light-emitting element 41, a phenomenon occurs where the laser output changes depending on the temperature of the laser light-emitting element 41 (the laser output increases when the temperature of the laser light-emitting element 41 decreases). Therefore, in order to control the laser output, it is preferable to measure the temperature of the laser light-emitting element 41 or the temperature of the cooling unit 50 and control the input signal to the drive driver 45 that controls the laser output so that the laser output remains constant, thereby achieving normal image formation. In contrast, the laser irradiation device 14 is a fiber array recording device using a fiber array section 14b. By using a fiber array recording device, the laser emission sections 42a of the fiber array section 14b only need to be arranged at a pitch corresponding to the resolution, eliminating the need to set the pitch between the laser light-emitting elements 41 of the laser array section 14a at a pitch corresponding to the image resolution. As a result, with the laser irradiation device 14, the pitch between the laser light-emitting elements 41 can be made sufficiently wide so that the heat from the laser light-emitting elements 41 can be adequately dissipated. As a result, with the laser irradiation device 14, it is possible to suppress the high temperature of the laser light-emitting elements 41 and suppress fluctuations in the wavelength and light output of the laser light-emitting elements 41. Consequently, with the laser irradiation device 14, a good image can be recorded on the thermal recording medium. Furthermore, even if the emission interval of the laser light-emitting elements 41 is shortened, the temperature rise of the laser light-emitting elements 41 can be suppressed, the movement speed of the thermal recording medium can be increased, and productivity can be improved.

[0195] Furthermore, in the laser irradiation device 14, by providing a cooling unit 50 and liquid-cooling the laser light-emitting element 41, the temperature rise of the laser light-emitting element 41 can be further suppressed. As a result, with the laser irradiation device 14, the emission interval of the laser light-emitting element 41 can be shortened, the movement speed of the thermal recording medium can be increased, and productivity can be improved. In the laser irradiation device 14, the laser light-emitting element 41 is liquid-cooled, but it may also be air-cooled using a cooling fan or the like. Liquid cooling has the advantage of higher cooling efficiency than air cooling, allowing for better cooling of the laser light-emitting element 41. On the other hand, air cooling has the advantage of lower cooling efficiency than liquid cooling, but allows for inexpensive cooling of the laser light-emitting element 41. [Examples]

[0196] The following describes embodiments of the present invention, but the present invention is not limited in any way to these embodiments.

[0197] The compounds numbered 1 to 5 used in the following examples were synthesized in the same manner as described in the synthesis example in Japanese Patent Publication No. 6751479.

[0198] (Example 1) <Manufacturing of thermal recording media> -Preparation of dye dispersion- 36 parts by mass of 3-di-n-butylamino-6-methyl-7-anilinofluorane, 10 parts by mass of carboxyl group-containing acrylic resin aqueous solution (styrene-acrylic resin, trade name: HPD-196, solid content 36% by mass, manufactured by BASF), 3.6 parts by mass of surfactant (trade name: PD-001, solid content 10% by mass, manufactured by Nisshin Chemical Industry Co., Ltd.), and 50.4 parts by mass of ion-exchanged water are added, and the 50% cumulative volume particle size (D) is measured using a laser diffraction / scattering particle size distribution analyzer (device name: LA-960, manufactured by Horiba, Ltd.). 50 A dye dispersion was obtained by dispersing the particles using a sand mill so that the particle size was 0.2 μm or less.

[0199] -Preparation of color developer dispersion- 36 parts by mass of compound number 1 represented by the structural formula below, 10 parts by mass of carboxyl group-containing acrylic resin aqueous solution (styrene-acrylic resin, trade name: HPD-196, solid content 36% by mass, manufactured by BASF), 3.6 parts by mass of surfactant (trade name: PD-001, solid content 10% by mass, manufactured by Nisshin Chemical Industry Co., Ltd.), and 50.4 parts by mass of ion-exchanged water are added, and the 50% cumulative volume particle size (D) is measured using a laser diffraction / scattering particle size distribution analyzer (device name: LA-960, manufactured by Horiba, Ltd.). 50 A color developer dispersion was obtained by dispersing the particles using a sand mill so that the particle size was 0.2 μm.

[0200] <Compound number 1> [ka]

[0201] -Preparation of thermal recording layer forming solution- Next, 12.4 parts by mass of the obtained dye dispersion, 37.3 parts by mass of the developer dispersion, 21.8 parts by mass of acrylic emulsion (styrene-acrylic resin, trade name: EK-61, solid content 41% by mass, manufactured by Saiden Chemical Co., Ltd.), and 28.5 parts by mass of ion-exchanged water were mixed and stirred to obtain a thermal recording layer forming solution.

[0202] -Formation of the thermal recording layer- Next, on one side of a polyethylene terephthalate film (product name: E5100, average thickness: 50 μm, manufactured by Toyobo Co., Ltd., haze degree: 4.5), the amount of the heat-sensitive recording layer forming liquid that adheres after drying is 4.0 g / m². 2 A thermal recording medium 1 was prepared by applying the material using a bar coater and drying it. The haze level of the polyethylene terephthalate film was measured using a haze meter (device name: HZ-V3, manufactured by Suga Test Co., Ltd.).

[0203] (Example 2) The developer dispersion was prepared in the same manner as in Example 1, except that the compound no. 1 was replaced with the compound no. 2 represented by the following structural formula. Next, a thermal recording medium 2 was prepared in the same manner as in Example 1, except that the developer dispersion was used to form the thermal recording layer.

[0204] <Compound number 2> [ka]

[0205] (Example 3) The developer dispersion was prepared in the same manner as in Example 1, except that the compound no. 1 was replaced with the compound no. 3 represented by the following structural formula. Next, a thermal recording medium 3 was prepared in the same manner as in Example 1, except that the developer dispersion was used to form the thermal recording layer.

[0206] Compound No. 3 compound

Chemical formula

[0207] (Example 4) In the preparation of the developer dispersion liquid of Example 1, except that the compound of Compound No. 1 was changed to the compound of Compound No. 4 represented by the following structural formula, a developer dispersion liquid was prepared in the same manner as in Example 1. Next, in Example 1, except that the developer dispersion liquid was used for forming the heat-sensitive recording layer, a heat-sensitive recording medium 4 was produced in the same manner as in Example 1.

[0208] Compound No. 4 compound

Chemical formula

[0209] (Example 5) In the preparation of the developer dispersion liquid of Example 1, except that the compound of Compound No. 1 was changed to the compound of Compound No. 5 represented by the following structural formula, a developer dispersion liquid was prepared in the same manner as in Example 1. Next, in Example 1, except that the developer dispersion liquid was used for forming the heat-sensitive recording layer, a heat-sensitive recording medium 5 was produced in the same manner as in Example 1.

[0210] Compound No. 5 compound

Chemical formula

[0211] (Example 6) In Example 1, on the heat-sensitive recording layer, the following coating liquid for the protective layer was applied using a bar coater so that the adhesion amount after drying was 2.0 g / m 2 and a heat-sensitive recording medium 6 was produced in the same manner as in Example 1, except for forming the protective layer.

[0212] <Preparation of the coating liquid for the protective layer> 40.7 parts by mass of calcium carbonate, 11.3 parts by mass of an aqueous carboxyl group-containing acrylic resin solution (styrene-acrylic resin, trade name: HPD-196, solid content 36% by mass, manufactured by BASF), 2 parts by mass of a surfactant (trade name: PD-001, solid content 10% by mass, manufactured by Nisshin Chemical Industry Co., Ltd.), and 46 parts by mass of ion-exchanged water were added, and the mixture was dispersed with a sand mill so that the 50% cumulative volume particle size (D 50 ) was 0.2 μm or less to obtain a dispersion liquid, which was measured with a laser diffraction / scattering particle size distribution measuring device (device name: LA-960, manufactured by Horiba, Ltd.). Next, 19.9 parts by mass of the obtained dispersion liquid, 21.9 parts by mass of an acrylic emulsion (styrene-acrylic resin, trade name: EK-61, solid content 41% by mass, manufactured by Saiden Chemical Co., Ltd.), 9.2 parts by mass of an oxazoline group-containing polymer emulsion (trade name: WS-500, solid content 39% by mass, manufactured by Nippon Shokubai Co., Ltd.), 4.5 parts by mass of a polyethylene oxide wax dispersion liquid (solid content 30%), and 44.5 parts by mass of ion-exchanged water were mixed and stirred to obtain a coating liquid for the protective layer.

[0213] (Example 7) In the preparation of the dye dispersion liquid of Example 1, a dye dispersion liquid was prepared in the same manner as in Example 1, except that 3-di-n-butylamino-6-methyl-7-anilinofluoran was changed to 6'-(diethylamino)-2'-(2-fluoroanilino)spiro[phthalide-3,9'-xanthene]. Next, in Example 1, a thermal recording medium 7 was produced in the same manner as in Example 1, except that the dye dispersion liquid was used for forming the thermal recording layer.

[0214] (Example 8) In Example 1, a thermal recording medium 8 was produced in the same manner as in Example 1, except that the following thermal recording layer forming liquid was used to form the thermal recording layer.

[0215] <Thermal recording layer forming liquid> A thermal recording layer forming solution was prepared by mixing and stirring 6.7 parts by mass of the dye dispersion prepared in Example 1, 20 parts by mass of the developer dispersion prepared in Example 1, 5.9 parts by mass of acrylic emulsion (styrene-acrylic resin, trade name: EK-61, solids content 41% by mass, manufactured by Saiden Chemical Co., Ltd.), 24.1 parts by mass of itaconic acid-modified polyvinyl alcohol aqueous solution (trade name: Kuraray Poval 25-88KL, solids content 10% by mass, manufactured by Kuraray Co., Ltd.), and 43.4 parts by mass of ion-exchanged water.

[0216] (Example 9) A thermal recording medium 9 was prepared in the same manner as in Example 1, except that a thermal recording layer was formed using the thermal recording layer forming solution described below. <Thermal recording layer forming liquid> A thermal recording layer forming solution was prepared by mixing and stirring 12 parts by mass of the dye dispersion prepared in Example 1, 36.2 parts by mass of the developer dispersion prepared in Example 1, 21.2 parts by mass of acrylic emulsion (styrene-acrylic resin, trade name: EK-61, solids content 41% by mass, manufactured by Saiden Chemical Co., Ltd.), 3 parts by mass of cesium tungsten oxide dispersion as a photothermal conversion material (trade name: YMW-D20, solids content 28.5% by mass, manufactured by Sumitomo Metal Mining Co., Ltd.), and 27.6 parts by mass of ion-exchanged water.

[0217] (Example 10) In Example 1, the amount of printing ink (product name: Finart R794 White G8, solid content 42% by mass, manufactured by DIC Graphics Co., Ltd.) applied to the surface of the support after drying was 1.0 g / m². 2 A thermal recording medium 10 was prepared in the same manner as in Example 1, except that a printed layer was formed by applying the material using a bar coater.

[0218] (Comparative Example 1) The developer dispersion was prepared in the same manner as in Example 1, except that the compound no. 1 was replaced with N-[2-[[(phenylamino)carbonyl]amino]phenyl]benzenesulfonamide (trade name: NKK-1304, manufactured by Nippon Soda Co., Ltd.). Next, a thermal recording medium 11 was prepared in the same manner as in Example 1, except that the developer dispersion was used to form the thermal recording layer.

[0219] (Comparative Example 2) The developer dispersion was prepared in the same manner as in Example 1, except that the compound no. 1 was replaced with 4-methyl-N-[[[3-[[(4-methylphenyl)sulfonyl]oxy]phenyl]amino]carbonyl]benzenesulfonamide (trade name: P-201, manufactured by BASF). Next, a thermal recording medium 12 was prepared in the same manner as in Example 1, except that the developer dispersion was used to form the thermal recording layer.

[0220] (Comparative Example 3) The developer dispersion was prepared in the same manner as in Example 1, except that the compound no. 1 was replaced with 4-hydroxy-4'-isopropoxydiphenylsulfone (trade name: D-8, manufactured by Nippon Soda Co., Ltd.). Next, a thermal recording medium 13 was prepared in the same manner as in Example 1, except that the developer dispersion was used to form the thermal recording layer.

[0221] (Comparative Example 4) The developer dispersion was prepared in the same manner as in Example 1, except that the compound no. 1 was replaced with bis(4-hydroxyphenyl)sulfone monoallyl ether (trade name: BPS-MAE, manufactured by Nikka Chemical Co., Ltd.). Next, a thermal recording medium 14 was prepared in the same manner as in Example 1, except that the developer dispersion was used to form the thermal recording layer.

[0222] (Comparative Example 5) In preparing the dye dispersion and developer dispersion of Example 1, the dye dispersion and developer dispersion were prepared in the same manner as in Example 1, except that 10 parts by mass of aqueous carboxyl group-containing acrylic resin (styrene-acrylic resin, trade name: HPD-196, solid content 36% by mass, manufactured by BASF) was replaced with 18 parts by mass of aqueous polyvinyl alcohol (trade name: Gosenex L-3266, solid content 30% by mass, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and 50.4 parts by mass of ion-exchanged water was changed to 42.3 parts by mass. Next, 8.7 parts by mass of the obtained dye dispersion, 25.9 parts by mass of the developer dispersion, 31.2 parts by mass of itaconic acid-modified polyvinyl alcohol aqueous solution (product name: Kuraray Poval 25-88KL, solid content 10% by mass, manufactured by Kuraray Co., Ltd.), 5 parts by mass of polyamide epochlorohydrin resin aqueous solution (product name: WS-525, solid content 25% by mass, manufactured by Seikoh PMC Co., Ltd.), and 29.3 parts by mass of ion-exchanged water were mixed and stirred to prepare a thermal recording layer forming solution. Next, a thermal recording medium 15 was prepared in the same manner as in Example 1, except that a thermal recording layer was formed using the thermal recording layer forming solution described above.

[0223] (Comparative Example 6) In preparing the dye dispersion and developer dispersion of Example 1, the dye dispersion and developer dispersion were prepared in the same manner as in Example 1, except that 10 parts by mass of aqueous carboxyl group-containing acrylic resin (styrene-acrylic resin, trade name: HPD-196, solid content 36% by mass, manufactured by BASF) was replaced with 7.2 parts by mass of aqueous polyurethane resin (trade name: Gen 0851, solid content 50% by mass, manufactured by Borchers), and 50.4 parts by mass of deionized water was changed to 53.2 parts by mass. Next, 14.7 parts by mass of the obtained dye dispersion, 44.1 parts by mass of the color developer dispersion, 15.1 parts by mass of polyurethane resin dispersion (product name: WLS-201, solid content 35% by mass, manufactured by DIC Corporation), and 26 parts by mass of ion-exchanged water were mixed and stirred to prepare a thermal recording layer forming solution. Next, a thermal recording medium 16 was prepared in the same manner as in Example 1, except that a thermal recording layer was formed using the thermal recording layer forming solution described above.

[0224] Next, using the prepared thermal recording media of Examples 1 to 10 and Comparative Examples 1 to 6, the following evaluations were carried out: "hot water resistance (60°C)", "hot water resistance (40°C)", "water resistance", "ethanol resistance", "temperature and humidity resistance", "water rubbing resistance", "heat resistance (110°C)", "heat resistance (90°C)", and "feasibility of LD laser printing". The results of "hot water resistance (60°C)", "hot water resistance (40°C)", "water resistance", "ethanol resistance", "temperature and humidity resistance", "water rubbing resistance", "heat resistance (110°C)", and "heat resistance (90°C)" are shown in Tables 1 and 2.

[0225] <Hot water resistance (60°C)> For each thermal recording medium, a pre-test image sample was prepared by printing using a CO2 laser marker (device name: LP-435TU, manufactured by SUNX Ltd.) under the following printing conditions. The prepared pre-test image sample was immersed in tap water at 60°C, and the image density before and after storage for 96 hours while maintaining the water temperature at 60°C using a thermostatic bath was measured with a reflection densitometer (X-Rite eXact, manufactured by X-Rite). The image residual rate was calculated from the following formula and evaluated according to the following criteria. Image residual rate (%) = [(image density after the test) / (image density before the test)] × 100 [Printing conditions] · Work distance: 275 mm · Scanning speed: 900 mm / s · Laser light wavelength: 10.6 μm · Laser power: 10% [Evaluation criteria] ◎: Image residual rate is 90% or more ○: Image residual rate is 80% or more and 89% or less ×: Image residual rate is 79% or less

[0226] <Hot water resistance (40°C)> Each prepared pre-test image sample was immersed in tap water at 40°C, and the image density before and after storage for 96 hours while maintaining the water temperature at 40°C using a thermostatic bath was measured with a reflection densitometer (X-Rite eXact, manufactured by X-Rite). The image residual rate was calculated from the following formula and evaluated according to the following criteria. Image retention rate (%) = [(Image density after testing) / (Image density before testing)] × 100 [Evaluation Criteria] ◎: Image retention rate of 90% or higher ○: Image retention rate is between 80% and 89%. ×: Image retention rate is 79% or less

[0227] <Water resistance> The image density of each prepared image sample was measured before and after immersion in tap water at 23°C for 96 hours using a reflectance densitometer (X-Rite eXact, manufactured by X-Rite). The image retention rate was calculated using the following formula and evaluated according to the following criteria. Image retention rate (%) = [(Image density after testing) / (Image density before testing)] × 100 [Evaluation Criteria] ◎: Image retention rate of 90% or higher ○: Image retention rate is between 80% and 89%. ×: Image retention rate is 79% or less

[0228] <Ethanol resistance> Each prepared image sample was immersed in an 80% by mass ethanol aqueous solution for 30 seconds. The image density before and after immersion was measured using a reflectance densitometer (X-Rite eXact, manufactured by X-Rite). The image retention rate was calculated using the following formula and evaluated according to the following criteria. Image retention rate (%) = [(Image density after testing) / (Image density before testing)] × 100 [Evaluation Criteria] ◎: Image retention rate of 90% or higher ○: Image retention rate is between 80% and 89%. ×: Image retention rate is 79% or less

[0229] <Temperature and humidity resistance> The image density of each prepared image sample was measured before and after storage for 72 hours at 40°C and 90% RH using a reflectance densitometer (X-Rite eXact, manufactured by X-Rite). The image retention rate was calculated using the following formula and evaluated according to the following criteria. Image retention rate (%) = [(Image density after testing) / (Image density before testing)] × 100 [Evaluation Criteria] ◎: Image residual rate is 90% or more ○: Image residual rate is 80% or more and 89% or less ×: Image residual rate is 79% or less

[0230] <Water rub resistance> One drop of water was dropped onto each prepared image sample and strongly rubbed 100 times with a finger, and then the presence or absence of peeling, dissolution, and bleeding of each layer was visually observed and evaluated according to the following criteria. [Evaluation criteria] ○: No peeling, elution, or bleeding ×: Peeling, elution, or bleeding present

[0231] <Heat resistance> After storing each prepared image sample under environmental conditions of 110 °C and 90 °C for 1 hour, the density of the sample base fabric part was measured with a reflection densitometer (X-Rite eXact, manufactured by X-Rite) and evaluated according to the following criteria. [Evaluation criteria] ○: Density of the base fabric part is 0.29 or less ×: Density of the base fabric part is 0.30 or more

[0232] <Feasibility of LD laser printing> Using an LD laser marker (device name: Ricoh Rewritable Laser Marker LDM200, manufactured by Ricoh Co., Ltd.), heat-sensitive recording media prepared in Examples 1 to 10 and Comparative Examples 1 to 6 were printed under the following printing conditions to prepare image samples, and evaluated based on the following evaluation criteria. [Printing conditions] Work distance: 150 mm Scanning speed: 3,000 mm / s Laser light wavelength: 980 nm Laser power: 70% [Evaluation criteria] ○: Printable ×: Non-printable

[0233] [Evaluation results] Example 9, which contained a photothermal conversion material in the thermal recording layer, was printable (○), but Examples 1-8, 10 and Comparative Examples 1-6, which did not contain a photothermal conversion material in the thermal recording layer, were not printable (×).

[0234] [Table 1]

[0235] [Table 2]

[0236] Examples of the present invention are as follows: <1> A thermal recording medium having a support and a thermal recording layer on the support, The thermal recording medium is characterized in that the thermal recording layer contains a compound represented by the following general formula (1) and a styrene-acrylic resin. [ka] However, in the general formula (1) above, R2 is a linear, branched, or alicyclic alkyl group having 1 to 12 carbon atoms, an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C7 to 12 aralkyl group substituted with a halogen atom, or an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C6 to 12 aryl group substituted with a halogen atom, and multiple R2s may be the same or different. A1 represents a hydrogen atom or a C1 to C4 alkyl group. Multiple A1s may be the same or different. <2> The compound represented by the above general formula (1) is the compound represented by the following general formula (2), <1> It is a thermal recording medium as described in [reference]. [ka] However, in the general formula (2) above, R2 is a linear, branched, or alicyclic alkyl group having 1 to 12 carbon atoms, an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C7 to 12 aralkyl group substituted with a halogen atom, or an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C6 to 12 aryl group substituted with a halogen atom, and multiple R2s may be the same or different. <3> The compound represented by the above general formula (2) is the compound represented by the following general formula (3), <2> It is a thermal recording medium as described in [reference]. [ka] However, in the general formula (3) above, R represents an alkyl group and n represents an integer from 0 to 3. <4> The thermal recording layer contains a photothermal conversion material, <1> from <3> It is a thermal recording medium described in any of the following. <5> The support is a plastic film, <1> from <4> It is a thermal recording medium described in any of the following. <6> The support is a transparent film, <1> from <5> It is a thermal recording medium described in any of the following. <7> The thermal recording layer has a protective layer, <1> from <6> It is a thermal recording medium described in any of the following. <8> The print layer is located between the support and the thermal recording layer, on the side of the support opposite to the thermal recording layer, and on either the support or the thermal recording layer. <1> from <6> It is a thermal recording medium described in any of the following. <9> This is a thermal recording layer forming liquid characterized by containing a compound represented by the following general formula (1), a styrene-acrylic resin, and a solvent. [ka] However, in the general formula (1) above, R2 is a linear, branched, or alicyclic alkyl group having 1 to 12 carbon atoms, an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C7 to 12 aralkyl group substituted with a halogen atom, or an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C6 to 12 aryl group substituted with a halogen atom, and multiple R2s may be the same or different. A1 represents a hydrogen atom or a C1 to C4 alkyl group. Multiple A1s may be the same or different. <10> The compound represented by the above general formula (1) is the compound represented by the following general formula (2), <9> This is the thermal recording layer forming liquid described above. [ka] However, in the general formula (2) above, R2 is a linear, branched, or alicyclic alkyl group having 1 to 12 carbon atoms, an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C7 to 12 aralkyl group substituted with a halogen atom, or an unsubstituted or C1 to 12 alkyl group, a C1 to 12 alkoxy group, a C6 to 12 aryl group, or a C6 to 12 aryl group substituted with a halogen atom, and multiple R2s may be the same or different. <11> The compound represented by the above general formula (2) is the compound represented by the following general formula (3), <10> This is the thermal recording layer forming liquid described above. [ka] However, in the general formula (3) above, R represents an alkyl group and n represents an integer from 0 to 3. <12> The support <9> from <11> A method for manufacturing a thermal recording medium, characterized by including a thermal recording layer formation step of applying a thermal recording layer forming liquid described in any of the above to form a thermal recording layer. <13> The aforementioned <1> from <8> This is an image recording method characterized by recording an image by irradiating a thermal recording medium described in any of the above with laser light. <14> The aforementioned <1> from <8> This is an image recording method characterized by recording an image on a thermal recording medium described in any of the above using a thermal head.

[0237] The aforementioned <1> from <8> A thermal recording medium described in any of the above <9> from <11> The heat-sensitive recording layer forming liquid described in any of the above, <12> The method for manufacturing a thermal recording medium described above, and the <13> from <14> According to any of the image recording methods described herein, the problems of the conventional methods can be solved and the objectives of the present invention can be achieved. [Explanation of Symbols]

[0238] 1 Support 2. Thermal recording layer 3 protective layer 4 printing layer [Prior art documents] [Patent Documents]

[0239] [Patent Document 1] Patent No. 6751479

Claims

1. A thermal recording layer included in a thermal recording medium, The product is characterized by containing a compound represented by the following general formula (3), and a styrene-acrylic resin. Thermal recording layer. 【Chemistry 1】 However, in the general formula (3) above, R represents an alkyl group and n represents an integer from 0 to 3.

2. In the above general formula (3), R is a methyl group, The thermal recording layer according to claim 1.

3. A thermal recording layer included in a thermal recording medium, The product is characterized by containing a compound represented by the following general formula (1), and a styrene-acrylic resin. Thermal recording layer. 【Chemistry 2】 However, in the above general formula (1), R ２ is one of the following (i) to (iii), and multiple R ２ They may be the same or different. (i) Linear, branched, or alicyclic alkyl groups having 1 to 12 carbon atoms, (ii) Unsubstituted or C1-C12 alkyl groups, C1-C12 alkoxy groups, C6-C12 aryl groups, or C7-C12 aralkyl groups substituted with halogen atoms, (iii) Unsubstituted or C1-C12 alkyl groups, C1-C12 alkoxy groups, C6-C12 aryl groups, or C6-C12 aryl groups substituted with halogen atoms. A １ A represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ They may be the same or different.

4. The thermal recording layer according to claim 3, wherein the compound represented by the general formula (1) is the following compound: N,N'-di-[3-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-5-methylphenyl]urea, or N,N'-di-[3-(benzenesulfonyloxy)-4-propylphenyl]urea; 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-methylphenyl]urea, N,N'-di-[3-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(mesitylenesulfonyl [Oxy)phenyl]urea, 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 ] 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, or N,N'-di-[3-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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-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-methoxy] [Benzenesulfonyloxy)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,Alternatively, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea; N,N'-di-[3-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[3-(benzylsulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[3-(phenylpropanesulfonyloxy)phenyl]urea, or N,N'-di-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea, N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(ethanesulfonyloxy)phenyl]urea, or N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea; N,N'-di-[3-(methanesulfonyloxy)phenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4,5-dimethylphenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)-4-methylphenyl]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, or N,N'-di-[3-(dodecanesulfonyloxy)phenyl]urea; 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, or N-[3-(ethanesulfonyloxy)phenyl]-N'-[3-(cyclohexanesulfonyloxy)phenyl]urea; N,N'-di-[4-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-ethylphenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-propylphenyl]urea, or N,N'-di-[4-(benzenesulfonyloxy)-3-t-butylphenyl]urea; N,N'-di-[4-(o-toluenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-toluenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-toluenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-toluenesulfonyloxy)-3-methylphenyl]urea; N,N'-di-[4-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-xylenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(mesitylenesulfonyloxy)phenyl]urea; N,N'-di-[4-(1-naphthalenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(2-naphthalenesulfonyloxy)phenyl]urea; N,N'-di-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-propylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-isopropylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N,N'-di-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea; N,N'-di-[4-(p-cumylbenzylsulfonyloxy)phenyl]urea, N,N'-di-[4-(p-cumylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(o-phenylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea; N,N'-di-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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-(ben [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-toluenes [4-(o-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, or 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, or N-[4-(p-toluenesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; N,N'-di-[4-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[4-(benzylsulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[4-(phenylpropanesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-methoxybenzylsulfonyloxy)phenyl)urea; N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, or N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea; N,N'-di-[4-(methanesulfonyloxy)phenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3,5-dimethylphenyl]urea, N,N'-di-[4-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[4-(ethanesulfonyloxy)-3-methylphenyl]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, or N,N'-di-[4-(dodecanesulfonyloxy)phenyl]urea; N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, or N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea; N,N'-di-[2-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-5-methylphenyl]urea, or N,N'-di-[2-(benzenesulfonyloxy)-4-propylphenyl]urea; N,N'-di-[2-(o-toluenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-toluenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-toluenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-toluenesulfonyloxy)-4-methylphenyl]urea; N,N'-di-[2-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-xylenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(mesitylenesulfonyloxy)phenyl]urea; N,N'-di-[2-(1-naphthalenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(2-naphthalenesulfonyloxy)phenyl]urea; N,N'-di-[2-(p-ethylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-propylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-isopropylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N,N'-di-[2-(p-butoxybenzenesulfonyloxy)phenyl]urea; N,N'-di-[2-(p-cumylbenzylsulfonyloxy)phenyl]urea, N,N'-di-[2-(p-cumylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(o-phenylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-phenylbenzenesulfonyloxy)phenyl]urea; N,N'-di-[2-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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-(ben [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-toluenes [(2-(o-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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[2-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[2-(butanesulfonyloxy)phenyl]urea; N,N'-di-[2-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[2-(benzylsulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[2-(phenylpropanesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, or N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea; N,N'-di-[2-(methanesulfonyloxy)phenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4,5-dimethylphenyl]urea, N,N'-di-[2-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[2-(ethanesulfonyloxy)-4-methylphenyl]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, or N,N'-di-[2-(dodecanesulfonyloxy)phenyl]urea; N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, or N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(hexanesulfonyloxy)phenyl]urea; 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]-N'-[4-(m-toluenesulfonyloxy)phenyl]urea, or N-[3-(o-toluenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea; N-[3-(p-xylenesulfonyloxy)phenyl]-N'-[4-(p-xylenesulfonyloxy)phenyl]urea, N-[3-(m-xylenesulfonyloxy)phenyl]-N'-[4-(m-xylenesulfonyloxy)phenyl]urea, or N-[3-(mesitylenesulfonyloxy)phenyl]-N'-[4-(mesitylenesulfonyloxy)phenyl]urea; N-[3-(1-naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, or N-[3-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-t-butylbenzenesulfonyloxy)phenyl]-N'-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-butoxybenzenesulfonyloxy)phenyl]-N'-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea; N-[3-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea; 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, or N-[3-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[4-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea, or N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(p-methylbenzylsulfonyloxy)phenyl]urea; 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, or N-[3-(dodecanesulfonyloxy)phenyl]-N'-[4-(dodecanesulfonyloxy)phenyl]urea; N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, or N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; 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, or N-[2-(o-toluenesulfonyloxy)phenyl]-N'-[4-(o-toluenesulfonyloxy)phenyl]urea; N-[2-(p-xylenesulfonyloxy)phenyl]-N'-[4-(p-xylenesulfonyloxy)phenyl]urea, N-[2-(m-xylenesulfonyloxy)phenyl]-N'-[4-(m-xylenesulfonyloxy)phenyl]urea, or N-[2-(mesitylenesulfonyloxy)phenyl]-N'-[4-(mesitylenesulfonyloxy)phenyl]urea; N-[2-(1-naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[4-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-t-butylbenzenesulfonyloxy)phenyl]-N'-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-butoxybenzenesulfonyloxy)phenyl]-N'-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea; 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)benzenesulfonyloxyenyl]urea, or N-[2-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea; N-[2-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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) [Phenyloxy)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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[4-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, or N-[2-(benzylsulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; 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, or N-[2-(dodecanesulfonyloxy)phenyl]-N'-[4-(dodecanesulfonyloxy)phenyl]urea; N-[2-(methanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea, or N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(benzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(m-toluenesulfonyloxy)phenyl]-N'-[3-(m-toluenesulfonyloxy)phenyl]urea, or N-[2-(o-toluenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea; N-[2-(p-xylenesulfonyloxy)phenyl]-N'-[3-(p-xylenesulfonyloxy)phenyl]urea, N-[2-(m-xylenesulfonyloxy)phenyl]-N'-[3-(m-xylenesulfonyloxy)phenyl]urea, or N-[2-(mesitylenesulfonyloxy)phenyl]-N'-[3-(cyylenesulfonyloxy)phenyl]urea; N-[2-(1-naphthalenesulfonyloxy)phenyl]-N'-[3-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-t-butylbenzenesulfonyloxy)phenyl]-N'-[3-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-butoxybenzenesulfonyloxy)phenyl]-N'-[3-(p-butoxybenzenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[3-(p-phenylbenzenesulfonyloxy)phenyl]urea; N-[2-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[3-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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) [Phenyloxy)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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(1-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[3-(methanesulfonyloxy)phenyl]urea, or N-[2-(benzylsulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea; 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, or N-[2-(dodecanesulfonyloxy)phenyl]-N'-[3-(dodecanesulfonyloxy)phenyl]urea; or N-[2-(methanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, or N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea.

5. Having the thermal recording layer according to claim 2 or 4, Thermal recording medium.

6. A packaging film or packaging label comprising a thermal recording medium as described in claim 5, product.

7. A thermal recording layer forming solution for forming a thermal recording layer contained in a thermal recording medium, It contains a compound represented by the following general formula (1), a leuco dye, and a styrene-acrylic resin. The styrene-acrylic resin is characterized in that it is a resin emulsion dispersed in an aqueous medium by a self-emulsification method. Thermal recording layer forming liquid. 【Transformation 3】 However, in the above general formula (1), R ２ is one of the following (i) to (iii), and multiple R ２ They may be the same or different. (i) Linear, branched, or alicyclic alkyl groups having 1 to 12 carbon atoms, (ii) Unsubstituted or C1-C12 alkyl groups, C1-C12 alkoxy groups, C6-C12 aryl groups, or C7-C12 aralkyl groups substituted with halogen atoms, (iii) Unsubstituted or C1-C12 alkyl groups, C1-C12 alkoxy groups, C6-C12 aryl groups, or C6-C12 aryl groups substituted with halogen atoms. A １ A represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ They may be the same or different.

8. The thermal recording layer forming liquid according to claim 7, wherein the compound represented by the general formula (1) is the following compound: N,N'-di-[3-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[3-(benzenesulfonyloxy)-5-methylphenyl]urea, or N,N'-di-[3-(benzenesulfonyloxy)-4-propylphenyl]urea; 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-methylphenyl]urea, N,N'-di-[3-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(m-xylenesulfonyloxy)phenyl]urea, N,N'-di-[3-(mesitylenesulfonyl [Oxy)phenyl]urea, 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 ] 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, or N,N'-di-[3-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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-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-methoxy] [Benzenesulfonyloxy)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,Alternatively, N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea; N,N'-di-[3-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[3-(benzylsulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[3-(phenylpropanesulfonyloxy)phenyl]urea, or N,N'-di-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea, N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(ethanesulfonyloxy)phenyl]urea, or N-[3-(benzylsulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea; N,N'-di-[3-(methanesulfonyloxy)phenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[3-(methanesulfonyloxy)-4,5-dimethylphenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[3-(ethanesulfonyloxy)-4-methylphenyl]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, or N,N'-di-[3-(dodecanesulfonyloxy)phenyl]urea; 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, or N-[3-(ethanesulfonyloxy)phenyl]-N'-[3-(cyclohexanesulfonyloxy)phenyl]urea; N,N'-di-[4-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-ethylphenyl]urea, N,N'-di-[4-(benzenesulfonyloxy)-3-propylphenyl]urea, or N,N'-di-[4-(benzenesulfonyloxy)-3-t-butylphenyl]urea; N,N'-di-[4-(o-toluenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-toluenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-toluenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-toluenesulfonyloxy)-3-methylphenyl]urea; N,N'-di-[4-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[4-(m-xylenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(mesitylenesulfonyloxy)phenyl]urea; N,N'-di-[4-(1-naphthalenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(2-naphthalenesulfonyloxy)phenyl]urea; N,N'-di-[4-(p-ethylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-propylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(p-isopropylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N,N'-di-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea; N,N'-di-[4-(p-cumylbenzylsulfonyloxy)phenyl]urea, N,N'-di-[4-(p-cumylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[4-(o-phenylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea; N,N'-di-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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-(ben [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-toluenes [4-(o-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, or 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, or N-[4-(p-toluenesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; N,N'-di-[4-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[4-(benzylsulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[4-(phenylpropanesulfonyloxy)phenyl]urea, or N,N'-di-[4-(p-methoxybenzylsulfonyloxy)phenyl)urea; N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, or N-[4-(benzylsulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea; N,N'-di-[4-(methanesulfonyloxy)phenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3-methylphenyl]urea, N,N'-di-[4-(methanesulfonyloxy)-3,5-dimethylphenyl]urea, N,N'-di-[4-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[4-(ethanesulfonyloxy)-3-methylphenyl]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, or N,N'-di-[4-(dodecanesulfonyloxy)phenyl]urea; N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, or N-[4-(methanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea; N,N'-di-[2-(benzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[2-(benzenesulfonyloxy)-5-methylphenyl]urea, or N,N'-di-[2-(benzenesulfonyloxy)-4-propylphenyl]urea; N,N'-di-[2-(o-toluenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-toluenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-toluenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-toluenesulfonyloxy)-4-methylphenyl]urea; N,N'-di-[2-(p-xylenesulfonyloxy)phenyl]urea, N,N'-di-[2-(m-xylenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(mesitylenesulfonyloxy)phenyl]urea; N,N'-di-[2-(1-naphthalenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(2-naphthalenesulfonyloxy)phenyl]urea; N,N'-di-[2-(p-ethylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-propylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(p-isopropylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N,N'-di-[2-(p-butoxybenzenesulfonyloxy)phenyl]urea; N,N'-di-[2-(p-cumylbenzylsulfonyloxy)phenyl]urea, N,N'-di-[2-(p-cumylbenzenesulfonyloxy)phenyl]urea, N,N'-di-[2-(o-phenylbenzenesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-phenylbenzenesulfonyloxy)phenyl]urea; N,N'-di-[2-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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-(ben [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-toluenes [(2-(o-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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[2-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[2-(butanesulfonyloxy)phenyl]urea; N,N'-di-[2-(benzylsulfonyloxy)phenyl]urea, N,N'-di-[2-(benzylsulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(phenylethanesulfonyloxy)phenyl]urea, N,N'-di-[2-(phenylpropanesulfonyloxy)phenyl]urea, or N,N'-di-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, or N-[2-(benzylsulfonyloxy)phenyl]-N'-[2-(p-methoxybenzylsulfonyloxy)phenyl]urea; N,N'-di-[2-(methanesulfonyloxy)phenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-methylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4-ethylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-5-methylphenyl]urea, N,N'-di-[2-(methanesulfonyloxy)-4,5-dimethylphenyl]urea, N,N'-di-[2-(ethanesulfonyloxy)phenyl]urea, N,N'-di-[2-(ethanesulfonyloxy)-4-methylphenyl]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, or N,N'-di-[2-(dodecanesulfonyloxy)phenyl]urea; N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(propanesulfonyloxy)phenyl]urea, or N-[2-(ethanesulfonyloxy)phenyl]-N'-[2-(hexanesulfonyloxy)phenyl]urea; 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]-N'-[4-(m-toluenesulfonyloxy)phenyl]urea, or N-[3-(o-toluenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea; N-[3-(p-xylenesulfonyloxy)phenyl]-N'-[4-(p-xylenesulfonyloxy)phenyl]urea, N-[3-(m-xylenesulfonyloxy)phenyl]-N'-[4-(m-xylenesulfonyloxy)phenyl]urea, or N-[3-(mesitylenesulfonyloxy)phenyl]-N'-[4-(mesitylenesulfonyloxy)phenyl]urea; N-[3-(1-naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, or N-[3-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-t-butylbenzenesulfonyloxy)phenyl]-N'-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-butoxybenzenesulfonyloxy)phenyl]-N'-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea; N-[3-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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, or N-[3-(p-toluenesulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea; 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, or N-[3-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[4-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea, or N-[3-(benzylsulfonyloxy)phenyl]-N'-[4-(p-methylbenzylsulfonyloxy)phenyl]urea; 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, or N-[3-(dodecanesulfonyloxy)phenyl]-N'-[4-(dodecanesulfonyloxy)phenyl]urea; N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(ethanesulfonyloxy)phenyl]urea, or N-[3-(methanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; 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, or N-[2-(o-toluenesulfonyloxy)phenyl]-N'-[4-(o-toluenesulfonyloxy)phenyl]urea; N-[2-(p-xylenesulfonyloxy)phenyl]-N'-[4-(p-xylenesulfonyloxy)phenyl]urea, N-[2-(m-xylenesulfonyloxy)phenyl]-N'-[4-(m-xylenesulfonyloxy)phenyl]urea, or N-[2-(mesitylenesulfonyloxy)phenyl]-N'-[4-(mesitylenesulfonyloxy)phenyl]urea; N-[2-(1-naphthalenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[4-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-t-butylbenzenesulfonyloxy)phenyl]-N'-[4-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-butoxybenzenesulfonyloxy)phenyl]-N'-[4-(p-butoxybenzenesulfonyloxy)phenyl]urea; 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)benzenesulfonyloxyenyl]urea, or N-[2-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[4-(p-phenylbenzenesulfonyloxy)phenyl]urea; N-[2-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[4-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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) [Phenyloxy)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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[4-(1-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[4-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[4-(methanesulfonyloxy)phenyl]urea, or N-[2-(benzylsulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; 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, or N-[2-(dodecanesulfonyloxy)phenyl]-N'-[4-(dodecanesulfonyloxy)phenyl]urea; N-[2-(methanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(propanesulfonyloxy)phenyl]urea, or N-[2-(ethanesulfonyloxy)phenyl]-N'-[4-(butanesulfonyloxy)phenyl]urea; N-[2-(benzenesulfonyloxy)phenyl]-N'-[3-(benzenesulfonyloxy)phenyl]urea, N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(p-toluenesulfonyloxy)phenyl]urea, N-[2-(m-toluenesulfonyloxy)phenyl]-N'-[3-(m-toluenesulfonyloxy)phenyl]urea, or N-[2-(o-toluenesulfonyloxy)phenyl]-N'-[3-(o-toluenesulfonyloxy)phenyl]urea; N-[2-(p-xylenesulfonyloxy)phenyl]-N'-[3-(p-xylenesulfonyloxy)phenyl]urea, N-[2-(m-xylenesulfonyloxy)phenyl]-N'-[3-(m-xylenesulfonyloxy)phenyl]urea, or N-[2-(mesitylenesulfonyloxy)phenyl]-N'-[3-(cyylenesulfonyloxy)phenyl]urea; N-[2-(1-naphthalenesulfonyloxy)phenyl]-N'-[3-(1-naphthalenesulfonyloxy)phenyl]urea, N-[2-(2-naphthalenesulfonyloxy)phenyl]-N'-[3-(2-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-t-butylbenzenesulfonyloxy)phenyl]-N'-[3-(p-t-butylbenzenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-butoxybenzenesulfonyloxy)phenyl]-N'-[3-(p-butoxybenzenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-phenylbenzenesulfonyloxy)phenyl]-N'-[3-(p-phenylbenzenesulfonyloxy)phenyl]urea; N-[2-(p-chlorobenzenesulfonyloxy)phenyl]-N'-[3-(p-chlorobenzenesulfonyloxy)phenyl]urea; 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) [Phenyloxy)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, or N-[2-(p-toluenesulfonyloxy)phenyl]-N'-[3-(1-naphthalenesulfonyloxy)phenyl]urea; 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, or N-[2-(p-methoxybenzylsulfonyloxy)phenyl]-N'-[3-(p-methoxybenzylsulfonyloxy)phenyl]urea; N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(benzylsulfonyloxy)phenyl]urea, N-[2-(benzylsulfonyloxy)phenyl]-N'-[3-(methanesulfonyloxy)phenyl]urea, or N-[2-(benzylsulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea; 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, or N-[2-(dodecanesulfonyloxy)phenyl]-N'-[3-(dodecanesulfonyloxy)phenyl]urea; or N-[2-(methanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(propanesulfonyloxy)phenyl]urea, or N-[2-(ethanesulfonyloxy)phenyl]-N'-[3-(butanesulfonyloxy)phenyl]urea.

9. The invention is characterized by including a step of forming a thermal recording layer by applying the thermal recording layer forming liquid according to claim 7 or 8 to form a thermal recording layer, A method for manufacturing a thermal recording medium.

10. The thermal recording medium described in claim 5 is characterized by recording an image by irradiating it with laser light, Image recording method.

11. The thermal recording medium described in claim 5 is characterized by recording an image using a thermal head. Image recording method.

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