JP3538830B2 - Novel urea (thiourea) derivative and thermal recording medium using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel urea (thiourea) derivative and a heat-sensitive recording material using this compound. In particular, the present invention relates to a heat-sensitive recording medium having excellent image storability such as a plasticizer and moisture resistance, and having excellent background soil resistance.

[0002]

2. Description of the Related Art In general, a heat-sensitive recording medium is usually prepared by grinding and dispersing a colorless or pale-colored dye precursor and a developer such as a phenolic compound into fine particles, and then mixing the two to form a binder. Filler, sensitivity improver, coating liquid obtained by adding a lubricant and other auxiliaries, coated on a support such as paper, synthetic paper, film, plastic, etc., thermal head, hot stamp, The color is developed by an instantaneous chemical reaction caused by heating with a hot pen, laser light, or the like, and a recorded image is obtained.

[0003] These heat-sensitive recording materials include a measuring recorder, a computer terminal printer, a facsimile,
It is applied to a wide range of fields, such as automatic ticket vending machines and bar code labels, but with the diversification and advancement of performance of these recording devices, the required quality for thermosensitive recording media has become higher. . For example, as recording speeds up,
It is required to obtain a high-density and clear color image even with minute heat energy, while light resistance, heat resistance, water resistance,
There is a demand for a heat-sensitive recording sheet having excellent storage properties such as oil resistance and plasticizer resistance.

However, in a conventional heat-sensitive recording material in which a heat-sensitive recording layer containing a basic colorless dye (dye precursor), a color developer and a binder as main components is coated on a support, the color image is formed over time. It has been known that the color is erased from the surface, which has been a problem.
This decolorization is accelerated in an atmosphere of light, high temperature and high humidity, and further progresses remarkably due to long standing in water, contact with oil such as salad oil, and plasticizer contained in wrap film, etc. The image becomes unreadable.

[0005] In order to suppress such a decoloring phenomenon of a recorded image, various techniques have been disclosed for a thermosensitive recording medium containing a basic colorless dye and a color developer as main components. For example, JP-A-60-77882 and JP-A-59-114
JP-A-56-1467, in which a phenolic antioxidant is incorporated in a heat-sensitive coloring layer as disclosed in JP-A-096.
No. 94, which uses a hydrophobic polymer compound emulsion or the like as a protective layer, is known. In addition, a phenolic developer combined with an epoxy compound (Japanese Patent Laid-Open No. 62-164579), an aziridine compound used together (Japanese Patent Laid-Open No. 4-113888), and a combination of various metal salts (Japanese Patent Application Laid-Open No. 4-113888) are used. 63-226
No. 83) is known. However, the effect on the plasticizer was not sufficient, and discoloration over time remained as a problem. Furthermore, when the above-mentioned additives are introduced, the resistance to water and heat is lost, and there is a problem such as background contamination.

[0006] Further, for the purpose of high preservation, non-phenolic colorants having no hydroxy group have been developed in place of conventionally used phenolic colorants. However, in the case of a heat-sensitive recording medium using a compound having a plurality of sulfonyl (thio) urea groups described in JP-A-5-147357 as a color developer, contamination of the background proceeds with time, There is a problem that background contamination progresses in the presence, in an environment of heat, or even in contact with a plasticizer. Further, Japanese Patent Application Laid-Open Nos.
Sulfonyl (thio) described in 46146
In the case of a thermosensitive recording medium in which a compound having a urea group is used as a developer, the stability of an image with respect to a plasticizer or the like is improved by being used in combination with an aziridine compound. In addition to being unable to obtain plasticizer resistance, there is also a problem of background contamination due to mixing.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel urea (thiourea) derivative and to use such a compound to provide a plasticizer, oil resistance, moisture resistance, water resistance and the like. It is an object of the present invention to provide a heat-sensitive recording medium having excellent image storability and background stain resistance.

[0008]

A novel urea (thiourea) derivative according to the present invention is represented by the following general formula (I).

[0009]

Embedded image

In the formula, R ₁ and R ₂ may be the same or different and represent a hydrogen atom, a C ₁ -C ₄ alkyl group, or a halogen atom. Examples of the C ₁ -C ₄ alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-
Butyl group, isobutyl group, sec-butyl group, or te
Examples thereof include an rt-butyl group, and examples of the halogen atom include fluorine, chlorine, bromine, and iodine. Among them, a hydrogen atom or a methyl group is preferable, and among them, a hydrogen atom is particularly preferable.

Further, R ₁ and R ₂ may be bonded to each other to form an aromatic ring, such as forming a naphthalene ring together with the benzene ring to which R ₁ and R ₂ are bonded. Can be

X and Y may be the same or different and represent an oxygen atom or a sulfur atom. That is, when X is an oxygen atom and Y is also an oxygen atom, when X is an oxygen atom and Y is a sulfur atom, when X is a sulfur atom and Y is an oxygen atom, X is a sulfur atom and Y is also a sulfur atom. Is the case.

Z may be any divalent organic residue, for example, diphenylmethane residue, benzene residue (phenylene group), diphenyl ether residue, diphenyl sulfone residue, diphenyl sulfide residue, tetraphenyl residue. , hexamethylene, octamethylene, decylmethylene, alkyl radical such as a C ₄ -C _12, such as dodecyl methylene are preferred. Among them, diphenylmethane residue,
A benzene residue (phenylene group) or the aforementioned alkyl residue is particularly preferred.

The present invention has solved the above-mentioned problems by including the compound represented by the general formula (I) in the thermosensitive coloring layer. That is, the general formula (I) of the present invention
The compound represented by the formula (1) exhibits excellent color developing ability when used as an organic color developer, and exhibits extremely high image storability. Further, when this compound is added to a thermosensitive coloring layer containing another organic color developer, it exhibits an action of stabilizing a recorded image even under severe storage conditions, and thus can be used as a stabilizer.

Since the compound of the present invention has a plurality of so-called acidified nitrogen atoms having a reduced electron density adjacent to the electron-withdrawing group in the molecule, the chemical bonding force between the acid and the base is increased, and as a result, the thermal melting The color is developed by the reaction between the developer and the basic colorless dye during the reaction, and the recorded image is stabilized. Even if the recorded image is exposed to water, oil, and heat for a long period of time, the color is developed. It is considered that the stability of the image is maintained.

In the compound of the present invention represented by the general formula (I), it is presumed that the sulfonyl (thio) urea group present in the molecule exerts the above-described color development and image stability more strongly. However, a single sulfonyl (thio) urea group cannot provide satisfactory image storability, and a plurality of sulfonyl (thio) urea groups have too high reactivity to cause contamination of the background. Therefore, the present inventors have found a compound having a (thio) urea group independently of a sulfonyl (thio) urea group in the molecule, thereby contaminating the background (ground color development) while maintaining sufficient image stability. The present invention succeeded in obtaining a heat-sensitive recording medium having no).

In the compound of the present invention represented by the general formula (I), the aromatic ring bonded to the sulfonyl group is substituted by an aryl (thio) ureido group, and the aromatic ring bonded to the sulfonyl group is a lower alkyl group. , A solubility in a plasticizer, oil, moisture, or the like can be reduced as compared with a compound substituted with a halogen atom, an alkoxy group, an acetyl group, a nitro group, or the like. As a result, the compound of the present invention does not dissolve even when touched with these substances, so that unnecessary coloration reaction (base color development) with a basic colorless dye does not occur, and it is considered that excellent ground stain resistance is obtained. Can be

In the present invention, when the compound represented by the general formula (I) is used as a color developer, 1 to 8 parts per 1 part of the basic colorless dye is contained so that a sufficient color developing function can be obtained. Obtainable. At this time, as long as the advantages of the compound of the present invention are not impaired, one or more other organic color developers can be used in combination.

In the present invention, the compound represented by the general formula (I) can be used as a stabilizer.
In this case, it is effective to contain the compound represented by the general formula (I) in an amount of 0.25 to 3 parts with respect to 1 part of the basic colorless dye, and to use another organic developer alone or in combination of two or more. To form a thermosensitive coloring layer.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The novel compound represented by the general formula (I) of the present invention can be synthesized by reacting 3-aminobenzenesulfonamide with an isocyanate compound or an isothiocyanate compound. The compound of the present invention can be easily obtained by reacting 3-aminobenzenesulfonamide represented by the formula (II) with an isocyanate compound represented by the general formula (III) or an isothiocyanate compound represented by the general formula (IV). Can be.

[0021]

Embedded image

[0022]

Embedded image OCN—R ₅ —NCO (III) wherein R ₅ is a C ₄ -C ₁₂ alkyl group (eg, butyl,
Hexyl, octyl, decyl, dodecyl, etc.), unsubstituted aromatic ring (such as phenylene, etc.), an aromatic ring substituted with an alkyl group or a halogen atom C ₁ -C ₄ or a methylene chain, a sulfonyl group, an oxygen atom or a sulfur Represents an aromatic ring bonded with an atom (for example, a diphenylmethane residue, a diphenylsulfone residue, a diphenylether residue, a diphenylsulfide residue, etc.). )

[0023]

Embedded image SCN—R ₅ —NCS (IV) (wherein R ₅ is substituted with a C ₄ -C ₁₂ alkyl group, an unsubstituted aromatic ring, a C ₁ -C ₄ alkyl group or a halogen atom. Represents an aromatic ring, or an aromatic ring linked by a methylene chain, a sulfonyl group, an oxygen atom or a sulfur atom. Examples of which are the same as those shown in the above formula (III))

That is, 3-aminobenzenesulfonamide is reacted with an isocyanate compound or an isothiocyanate compound in an organic solvent or a water-containing solvent at a reaction temperature of -10 ° C. to 60 ° C. under neutral conditions to give 3-sulfamoyl carbamide. Produces a vanillide compound. Without isolating the formed 3-sulfamoylcarbanilide compound, an aqueous alkali hydroxide solution was added according to the method described in French Patent No. 994465, and the alkali metal of the 3-sulfamoylcarbanilide compound was added. The compound can be easily produced by reacting with a corresponding isocyanate compound or isothiocyanate compound after forming the salt.

The isocyanate compounds include 1,4-diisocyanatobutane, 1,6-diisocyanatohexane, 1,8-diisocyanatooctane, 1,12
Aliphatic isocyanate compounds such as diisocyanate dodecane, phenylene diisocyanate, toluene diisocyanate, 4,4′-methylenebis (phenyl isocyanate), 4,4′-diisocyanate-3,3 ′
-Dimethyldiphenylmethane, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, 4,4'-oxabis (phenylisocyanate), 4,4'-thiobis (phenylisocyanate) and the like,
Examples of the isothiocyanate compound include 1,4-diisothiocyanatobutane, 1,6-diisothiocyanatohexane, 1,8-diisothiocyanatooctane,
Aliphatic isothiocyanate compounds such as 12-diisothiocyanato dodecane, phenylenediisothiocyanate, toluenediisothiocyanate, 4,4'-methylenebis (phenylisothiocyanate), 4,4'-oxabis (phenylisothiocyanate) ), 4,4'-
Thiobis (phenylisothiocyanate).

The organic solvent used in the reaction is acetone, methyl ethyl ketone, methyl isobutyl ketone, acetonitrile, dimethylformamide, dimethylsulfoxide, ethyl acetate, methanol, ethanol, preferably acetone, acetonitrile, dimethylformamide, dimethylsulfoxide. These can also be used as a mixed solvent with water, that is, a water-containing solvent.

The alkali hydroxide includes lithium hydroxide, sodium hydroxide, potassium hydroxide and calcium hydroxide.

Specific examples of the compound represented by formula (I) of the present invention include the following compounds, and these compounds can be used alone or in combination of two or more as needed.

4,4′-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane, 4,4′-bis} (3-
(P-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino diphenylmethane, 4,
4'-bis} (3- (m-tolylcarbamoylamino)
Phenyl) sulfonylaminocarbonylamino {diphenylmethane, 4,4′-bis} (3- (α-naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylamino {diphenylmethane, 4,4′-bis} (3
-(Β-naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylaminodiphenylmethane,
4,4′-bis {(3- (m-chlorophenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino {diphenylmethane, 4,4′-bis} (3- (p
-Bromophenylcarbamoylamino) phenyl) sulfonylaminocarbonylaminodiphenylmethane,
4,4'-bis {(3- (phenylthiocarbamoylamino) phenyl) sulfonylaminocarbonylamino}
Diphenylmethane, 4,4'-bis {(3- (α-naphthylthiocarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane, 4,4'-
Bis {(3- (p-tolylthiocarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane, 4,4′-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminothiocarbonylamino} diphenylmethane, 1,4 -Bis ｛(3-
(Phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino {benzene, 1,3-bis} (3- (p-tolylcarbamoylamino) phenyl)
Sulfonylaminocarbonylamino dibenzene, 1,4
-Bis {(3- (m-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene,
1,4-bis {(3- (p-chlorophenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1,4-bis {(3- (α-naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1,4-bis {(3- (β-naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1,4-bis {(3-
(Phenylthiocarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1,3-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminothiocarbonylamino} benzene, 1,
4-bis {(3- (p-chlorophenylthiocarbamoylamino) phenyl) sulfonylaminothiocarbonylamino} benzene, 1-methyl-2,4-bis} (3
-(Phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-
2,4-bis {(3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino}
Benzene, 1-methyl-2,4-bis {(3- (m-
Tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-2,4
-Bis {(3- (p-chlorophenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino}
Benzene, 1-methyl-2,4-bis {(3- (m-
Bromophenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-2,4-bis {(3- (α-naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-2,4 -Screw (3-
(Β-naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-2,4-bis {(3- (phenylthiocarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-2, 6-bis (3-
(Phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-
2,6-bis {(3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino}
Benzene, 1-methyl-2,6-bis {(3- (m-
Tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-2,6
-Bis {(3- (m-chlorophenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino}
Benzene, 1-methyl-2,6-bis {(3- (α-
Naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylamino @ benzene, 1-methyl-2,6
-Bis ｛(3- (phenylthiocarbamoylamino)
Phenyl) sulfonylaminocarbonylamino} benzene, 4,4′-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylether, 4,4′-bis} (3- (p
-Tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino {diphenyl ether, 4,4 ′
-Bis {(3- (m-chlorophenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenyl ether, 4,4′-bis {(3- (α-naphthylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenyl Ether, 4,4'-
Bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylsulfone, 4,4′-bis {(3- (m-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylsulfone, 4,4 '-Bis ｛(3-
(P-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino diphenylsulfone, 4,
4′-bis {(3- (p-chlorophenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylsulfone, 4,4′-bis} (3-
(Phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino diphenylsulfide, 4,
4'-bis} (3- (p-tolylcarbamoylamino)
Phenyl) sulfonylaminocarbonylamino diphenylsulfide, 1,4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} butane, 1,6-bis} (3- (phenylcarbamoylamino) phenyl) sulfonyl Aminocarbonylamino {hexane, 1,8-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} octane, 1,6-bis} (3- (p
-Tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino dihexane and the like.

Among the above specific examples, in particular, 4,4'-bis {(3- (phenylcarbamoylamino) phenyl)
Sulfonylaminocarbonylamino {diphenylmethane, 4,4′-bis} (3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino {diphenylmethane, 4,4′-bis} (3- (α-
Naphthylthiocarbamoylamino) phenyl) sulfonylaminocarbonylamino diphenylmethane, 4,
4'-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminothiocarbonylamino} diphenylmethane, 1,3-bis {(3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1, 4-bis {(3- (m-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1,4-bis {(3- (phenylthiocarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl −2
4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 1-methyl-2,6-bis {(3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene, 4,4'-bis {(3-
(P-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino diphenyl ether, 4,
Compounds such as 4'-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylsulfone and 1,6-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} hexane are desirable. .

In the present invention, as the organic developer which can be used in combination with the compound represented by the formula (I), conventionally known organic developers can be mentioned as described above. Hereinafter, specific examples of other organic color developers will be described.

<Bisphenol A>4,4'-isopropylidene diphenol (also called bisphenol A) 4,4'-cyclohexylidene diphenol p, p '-(1-methyl-normalhexylidene) diphenol 1, 7-di (hydroxyphenylthio) -3,5-dioxaheptane <4-hydroxybenzoic acid esters> benzyl 4-hydroxybenzoate ethyl 4-hydroxybenzoate propyl 4-hydroxybenzoate isopropyl 4-hydroxybenzoate 4 -Butyl 4-hydroxybenzoate Isobutyl 4-hydroxybenzoate Methylbenzyl 4-hydroxybenzoate <Diesters of 4-hydroxyphthalic acid> Dimethyl 4-hydroxyphthalate Diisopropyl 4-hydroxyphthalate Dibenzyl 4-hydroxyphthalate 4-Hydroxyphthalate Monohexyl phthalate Monobenzyl phthalate Monocyclohexyl phthalate Monophenyl phthalate Monomethyl phenyl phthalate Monoethyl phenyl phthalate Monopropyl benzyl phthalate Monopropyl benzyl phthalate Monohalogen benzyl phthalate Monophthalate Ethoxybenzyl ester <bis- (hydroxyphenyl) sulfides> bis- (4-hydroxy-3-tert-butyl-6-
Methylphenyl) sulfide bis- (4-hydroxy-2,5-dimethylphenyl)
Sulfidobis- (4-hydroxy-2-methyl-5-ethylphenyl) sulfidebis- (4-hydroxy-2-methyl-5-isopropylphenyl) sulfidebis- (4-hydroxy-2,3-dimethylphenyl)
Sulfide bis- (4-hydroxy-2,5-dimethylphenyl)
Sulfidobis- (4-hydroxy-2,5-diisopropylphenyl) sulfidebis- (4-hydroxy-2,3,6-trimethylphenyl) sulfidebis- (2,4,5-trihydroxyphenyl) sulfidebis- ( 4-hydroxy-2-cyclohexyl-5-methylphenyl) sulfidebis- (2,3,4-trihydroxyphenyl) sulfidebis- (4,5-dihydroxy-2-tert-butylphenyl) sulfidebis- (4- Hydroxy-2,5-diphenylphenyl) sulfide bis- (4-hydroxy-2-tert-octyl-5)
-Methylphenyl) sulfide <4-hydroxyphenylarylsulfones>4-hydroxy-4'-isopropoxydiphenylsulfone4-hydroxy-4'-n-butyloxydiphenylsulfone4-hydroxy-4'-n-propoxydiphenylsulfone<4-hydroxyphenylarylsulfonates> 4-hydroxyphenyl-benzenesulfonate 4-hydroxyphenyl-p-tolylsulfonate 4-hydroxyphenyl-mesitylenesulfonate 4-hydroxyphenyl-p-chlorobenzenesulfonate 4-hydroxy Phenyl-p-tert-butylbenzenesulfonate 4-hydroxyphenyl-p-isopropoxybenzenesulfonate 4-hydroxyphenyl-1'-naphthalenesulfonate 4-hydroxy Phenyl-2'-naphthalenesulfonate <1,3-di [2- (hydroxyphenyl) -2-propyl] benzenes> 1,3-di [2- (4-hydroxyphenyl) -2-propyl] benzene 1 , 3-Di [2- (4-hydroxy-3-alkylphenyl) -2-propyl] benzene 1,3-di [2- (2,4-dihydroxyphenyl)-
2-propyl] benzene 1,3-di [2- (2-hydroxy-5-methylphenyl) -2-propyl] benzene <resorcinols> 1,3-dihydroxy-6 (α, α-dimethylbenzyl) -benzene <4-Hydroxybenzoyloxybenzoate> Benzyl 4-hydroxybenzoyloxybenzoate Methyl 4-hydroxybenzoyloxybenzoate Ethyl 4-hydroxybenzoyloxybenzoate Propyl 4-hydroxybenzoyloxybenzoate Butyl 4-hydroxybenzoyloxybenzoate Isopropyl 4-hydroxybenzoyloxybenzoate tert-butyl 4-hydroxybenzoyloxybenzoate hexyl 4-hydroxybenzoyloxybenzoate octyl 4-hydroxy 4-hydroxybenzoyloxybenzoate Nonyloxybenzoyl nonyl 4-hydroxybenzoyloxybenzoate cyclohexyl 4-hydroxybenzoyloxybenzoate β-phenethyl 4-hydroxybenzoyloxybenzoate phenyl 4-hydroxybenzoyloxybenzoate α-naphthyl 4-hydroxybenzoyloxybenzoate β-naphthyl Sec-butyl 4-hydroxybenzoyloxybenzoate <bisphenolsulfones (I)> bis- (3-1-butyl-4-hydroxy-6-methylphenyl) sulfonebis- (3-ethyl-4-hydroxyphenyl) sulfonbis- (3-propyl-4-hydroxyphenyl) sulfonebis- (3-methyl-4-hydroxyphenyl) sulfonbis- (2-isopropyl-4-hydroxyphenyl)
Sulfone bis- (2-ethyl-4-hydroxyphenyl) sulfone bis- (3-chloro-4-hydroxyphenyl) sulfone bis- (2,3-dimethyl-4-hydroxyphenyl)
Sulfone bis- (2,5-dimethyl-4-hydroxyphenyl)
Sulfone bis- (3-methoxy-4-hydroxyphenyl) sulfone 4-hydroxyphenyl-2'-ethyl-4'-hydroxyphenylsulfone 4-hydroxyphenyl-2'-isopropyl-4'-
Hydroxyphenylsulfone 4-hydroxyphenyl-3'-isopropyl-4'-
Hydroxyphenylformone 4-hydroxyphenyl-3'-secbutyl-4'-
Hydroxyphenylformone 3-chloro-4-hydroxyphenyl-3'-isopropyl-4'-hydroxyphenylsulfone 2-hydroxy-5-tert-butylphenyl-4'-hydroxyphenylsulfone 2-hydroxy-5-t-amino Phenyl-4'-hydroxyphenylsulfone 2-hydroxy-5-t-isopropylphenyl-4 '
-Hydroxyphenylsulfone 2-hydroxy-5-t-octylphenyl-4'-hydroxyphenylsulfone 2-hydroxy-5-tert-butylphenyl-3'-chloro-4'-hydroxyphenylsulfone 2-hydroxy-5-t -Butylphenyl-3'-methyl-4'-hydroxyphenylsulfone 2-hydroxy-5-tert-butylphenyl-3'-isopropyl-4'-hydroxyphenylsulfone 2-hydroxy-5-tert-butylphenyl-2 '-Methyl-4'-hydroxyphenylsulfone<bisphenolsulfones(II)>4,4'-sulfonyldiphenol2,4'-sulfonyldiphenol3,3'-dichloro-4,4'-sulfonyldiphenol33'-dibromo-4,4'-sulfonyldiphenol 3,3 ', 5 5'-Tetrabromo-4,4'-sulfonyldiphenol 3,3'-diamino-4,4'-sulfonyldiphenol <Others> p-tert-butylphenol 2,4-dihydroxybenzophenone novolak type phenolic resin 4-hydroxyacetophenone p-phenylphenolbenzyl-4-hydroxyphenylacetate p-benzylphenol

The basic colorless dye used in the present invention is not particularly limited, but triphenylmethane type, fluoran type, fluorene type, divinyl type and the like are preferable, and specific examples thereof are shown below. These dyes can be used alone or in combination of two or more.

<Triphenylmethane leuco dye> 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide [also known as crystal violet lactone] 3,3-bis (p-dimethylaminophenyl) phthalide Malachite green lactone] <Fluoran leuco dye> 3-diethylamino-6-methylfluoran 3-diethylamino-6-methyl-7-anilinofluoran 3-diethylamino-6-methyl-7- (o, p-dimethyl Anilino) fluoran 3-diethylamino-6-methyl-7-chlorofluoran 3-diethylamino-6-methyl-7- (m-trifluoromethylanilino) fluoran 3-diethylamino-6-methyl-7- (o- Chloroanilino) fluoran 3-diethylamino-6-methyl- 7- (p-chloroanilino) fluoran 3-diethylamino-6-methyl-7- (o-fluoroanilino) fluoran 3-diethylamino-6-methyl-7-n-octylanilinofluoran 3-diethylamino-6-methyl -7-n-octylaminofluoran 3-diethylamino-6-methyl-7-benzylanilinofluoran 3-diethylamino-6-methyl-7-dibenzylanilinofluoran 3-diethylamino-6-chloro-7- Methylfluoran 3-diethylamino-6-chloro-7-anilinofluoran 3-diethylamino-6-chloro-7-p-methylanilinofluoran 3-diethylamino-6-ethoxyethyl-7-anilinofluoran 3 -Diethylamino-7-methylfluoran 3-diethylamino-7-chloroph Oran 3-diethylamino-7- (m-trifluoromethylanilino) fluoran 3-diethylamino-7- (o-chloroanilino) fluoran 3-diethylamino-7- (p-chloroanilino) fluoran 3-diethylamino-7- (o- Fluoranilino) fluoran 3-diethylamino-benzo [a] fluoran 3-diethylamino-benzo [c] fluoran 3-dibutylamino-6-methyl-fluoran 3-dibutylamino-6-methyl-7-anilinofluoran 3- Dibutylamino-6-methyl-7- (o, p-dimethylanilino) fluoran 3-dibutylamino-6-methyl-7- (o-chloroanilino) fluoran 3-dibutylamino-6-methyl-7- (p- Chloroanilino) fluoran 3-dibutylamino-6-methyl 7- (o-fluoroanilino) fluoran 3-dibutylamino-6-methyl-7- (m-trifluoromethylanilino) fluoran 3-dibutylamino-6-methyl-chlorofluoran 3-dibutylamino-6 Ethoxyethyl-7-anilinofluoran 3-dibutylamino-6-chloro-7-anilinofluoran 3-dibutylamino-6-methyl-7-p-methylanilinofluoran 3-dibutylamino-7- ( o-Chloroanilino) fluoran 3-dibutylamino-7- (o-fluoroanilino) fluoran 3-n-dipentylamino-6-methyl-7-anilinofluoran 3-n-dipentylamino-6-methyl-7- (P-chloroanilino) fluoran 3-n-dipentylamino-6-chloro-7-anilinofluoran 3-n-dipe Nthylamino-7- (p-chloroanilino) fluoran 3-pyrrolidino-6-methyl-7-anilinofluoran 3-piperidino-6-methyl-7-anilinofluoran 3- (N-methyl-N-propylamino) -6-Methyl-7-anilinofluoran 3- (N-methyl-N-cyclohexylamino) -6
Methyl-7-anilinofluoran 3- (N-ethyl-N-cyclohexylamino) -6
Methyl-7-anilinofluoran 3- (N-ethyl-N-xylamino) -6-methyl-
7- (p-chloroanilino) fluoran 3- (N-ethyl-p-toluidino) -6-methyl-
7-anilinofluoran 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran 3- (N-ethyl-N-isoamylamino) -6-chloro-7-anilino Fluoran 3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-anilinofluoran 3- (N-ethyl-N-isobutylamino) -6-methyl-7-anilinofluoran 3-cyclohexylamino-6-chlorofluoran 2- (4-oxahexyl) -3-dimethylamino-6
-Methyl-7-anilinofluoran 2- (4-oxahexyl) -3-diethylamino-6
-Methyl-7-anilinofluoran 2- (4-oxahexyl) -3-dipropylamino-
6-methyl-7-anilinofluoran 2-methyl-6-p- (p-dimethylaminophenyl)
Aminoanilinofluoran 2-methoxy-6-p- (p-dimethylaminophenyl) aminoanilinofluoran 2-chloro-3-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluoran 2 -Chloro-6-p- (p-dimethylaminophenyl)
Aminoanilinofluoran 2-nitro-6-p- (p-diethylaminophenyl)
Aminoanilinofluoran 2-amino-6-p- (p-diethylaminophenyl)
Aminoanilinofluoran 2-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluoran 2-phenyl-6-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluoran2- Benzyl-6-p- (p-phenylaminophenyl) aminoanilinofluoran 2-hydroxy-6-p- (p-phenylaminophenyl) aminoanilinofluoran 3-methyl-6-p- (p-dimethyl Aminophenyl)
Aminoanilinofluoran 3-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluoran 3-diethylamino-6-p- (p-dibutylaminophenyl) aminoanilinofluoran <fluorene leuco dye>3,6,6'-Tris (dimethylamino) spiro [fluorene-9,3'-phthalide] 3,6,6'-Tris (diethylamino) spiro [fluorene-9,3'-phthalide] <Divinyl leuco dye > 3,3-bis- [2- (p-dimethylaminophenyl)
-2- (p-methoxyphenyl) ethenyl] -4,5
6,7-tetrabromophthalide 3,3-bis- [2- (p-dimethylaminophenyl)
-2- (p-methoxyphenyl) ethenyl] -4,5
6,7-tetrachlorophthalide 3,3-bis- [1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrabromophthalide 3,3- Bis- [1- (4-methoxyphenyl) -1-
(4-pyrrolidinophenyl) ethylene-2-yl]-
4,5,6,7-tetrachlorophthalide <Others> 3- (4-diethylamino-2-ethoxyphenyl)-
3- (1-ethyl-2-methylindol-3-yl)
-4-azaphthalide 3- (4-diethylamino-2-ethoxyphenyl)-
3- (1-octyl-2-methylindol-3-yl) -4-azaphthalide 3- (4-cyclohexylethylamino-2-methoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) ) -4-Azaphthalide 3,3-bis (1-ethyl-2-methylindole-3)
-Yl) phthalide 3,6-bis (diethylamino) fluoran-γ- (3
'-Nitro) anilinolactam 3,6-bis (diethylamino) fluoran-γ- (4
'-Nitro) anilinolactam 1,1-bis- [2', 2 ', 2 ", 2" -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2,
2-dinitrileethane 1,1-bis- [2 ', 2', 2 ", 2" -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2-
β-naphthoylethane 1,1-bis- [2 ′, 2 ′, 2 ″, 2 ″ -tetrakis- (p-dimethylaminophenyl) -ethenyl] -2,
2-Diacetylethanebis- [2,2,2 ', 2'-tetrakis- (p-dimethylaminophenyl) -ethenyl] -methylmalonic acid dimethyl ester

Further, as sensitizers, fatty acid amides such as stearic acid amide and palmitic acid amide, ethylene bisamide, montan wax, polyethylene wax, dibenzyl terephthalate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate , P-benzylbiphenyl, phenyl-α-naphthyl carbonate, 1,4-diethoxynaphthalene, 1-hydroxy-
2-naphthoic acid phenyl ester, 1,2-di- (3-
Methylphenoxy) ethane, di (p-methylbenzyl) oxalate, β-benzyloxynaphthalene, 4-biphenyl-p-tolyl ether, o-xylerin-bis-
(Phenyl ether), 4- (m-methylphenoxymethyl) biphenyl and the like can also be added.

As the binder used in the present invention, completely saponified polyvinyl alcohol having a degree of polymerization of 200 to 1900, partially saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, amide-modified polyvinyl alcohol, sulfonic acid-modified polyvinyl alcohol, butyral-modified polyvinyl alcohol Alcohol, other modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, styrene-maleic anhydride copolymer, styrene-butadiene copolymer and ethyl cellulose, cellulose derivatives such as acetyl cellulose, polyvinyl chloride, polyvinyl acetate,
Examples thereof include polyacrylamide, polyacrylate, polyvinyl butyral polystyrene, and copolymers thereof, polyamide resin, silicone resin, petroleum resin, terpene resin, ketone resin, and cumarone resin. These macromolecules are water, alcohol, ketone,
In addition to dissolving in solvents such as esters and hydrocarbons,
It is used in a state of being emulsified or dispersed in a paste form in water or another medium, and can be used in combination depending on required quality.

In the present invention, a known stabilizer metal salt of p-nitrobenzoic acid (Ca, Zn) or metal salt of monobenzyl phthalate (Ca, Zn) is used as long as the effects of the present invention are not impaired. It is also possible to add.

As the filler used in the present invention, silica,
Examples include inorganic or organic fillers such as calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, tanks, titanium oxide, and aluminum hydroxide.

In addition, a releasing agent such as a fatty acid metal salt, a lubricant such as a wax, a benzophenone-based or triazole-based ultraviolet absorber, a water-proofing agent such as glyoxal, a dispersant, and an antifoaming agent. Can be.

The amounts of the developer and the basic colorless dye used in the present invention and the types and amounts of other various components are determined according to the required performance and recording suitability, and are not particularly limited. When the compound of the formula (1) is used as a developer, the developer is 1 to 8 with respect to 1 part of the basic colorless dye.
Parts, 1 to 20 parts of filler, and the binder is 1% of the total solid content.
0-25% is suitable. When the compound of the present invention is used as a stabilizer, 1 to 8 parts of a developer, 0.25 to 3 parts of a stabilizer, 1 part of a filler,
-20 parts are used and the binder is suitably 10-25% of the total solids.

The desired heat-sensitive recording sheet can be obtained by applying the coating solution having the above composition to any support such as paper, synthetic paper, plastic film, and non-woven fabric.

Further, an overcoat layer of a filler-containing polymer material or the like can be provided on the thermosensitive coloring layer for the purpose of enhancing the storage stability. Further, an undercoat layer containing an organic filler or an inorganic filler can be provided below the thermosensitive coloring layer for the purpose of enhancing the storage stability and sensitivity.

The above-mentioned organic color developer, basic colorless dye, and optionally added materials are finely divided by a pulverizer such as a ball mill, an attritor, a sand grinder or an appropriate emulsifying apparatus until the particle diameter becomes several microns or less. And a binder and various kinds of additive materials are added according to the purpose to obtain a coating liquid.

[0044]

The present invention will be described below with reference to examples.
In addition, in description, a part shows a weight part. Synthesis Example 1 Synthesis of 4,4′-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane 3-amino was placed in a 500 ml four-necked flask equipped with a stirrer, a condenser and a thermometer. 34.4 g of sulfonamide, acetone 2
00 ml was charged and dissolved by stirring. Next, while maintaining the liquid temperature at 20 ° C., 23.8 g of phenyl isocyanate dissolved in 50 ml of acetone was added dropwise over 1 hour. Thereafter, the reaction was performed for 6 hours to produce 3-sulfamoylcarbanilide. Without isolating the generated 3-sulfamoylcarbanilide, 84 g of a 10% aqueous sodium hydroxide solution was added to the reaction solution, and after stirring for 1 hour, 25 g of 4,4′-methylenebis (phenylisocyanate) was added. 1
The reaction was performed at 0 ° C. for 6 hours. After completion of the reaction, acetone was removed under reduced pressure, and 200 g of water and
0 ml was added, unreacted substances were extracted, and the aqueous layer was separated. When the aqueous solution was acidified with hydrochloric acid, white crystals were precipitated. The crystals were collected by filtration and recrystallized from acetone to give a melting point of 166 to 167.
43 g of a white crystal having a temperature of ° C was obtained. Infrared spectroscopy, mass spectrometry,
Elemental analysis confirmed that the white crystals were 4,4'-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane.

Synthesis Example 2 Synthesis of 1-methyl-2,4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene 4,4′-methylenebis (phenylisocyanate) of Synthesis Example 1 Was carried out in the same manner as in Synthesis Example 1 except that 17.4 g of 2,4-toluene diisocyanate was used instead of Recrystallized from ethyl acetate / toluene, melting point 165-1
26 g of 70 ° C. white crystals were obtained. From infrared spectroscopy, mass spectrometry and elemental analysis, it was confirmed that the white crystals were 1-methyl-2,4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene.

[Examples 1 to 12] Liquid A (color developer dispersion) Color developer (see Tables 1 and 2) 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Liquid B ( Dye dispersion) 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Of the above composition Each liquid was ground with a sand grinder to an average particle diameter of 1 micron. Next, the dispersion liquid was mixed at the following ratio to obtain a coating liquid. Liquid A 36.0 parts Liquid B 9.2 parts Kaolin clay (50% dispersion) 12.0 parts Each of the above coating liquids is applied to one surface of a 50 g / m ² base paper 6.0.
g / m ² and dried, and this sheet was treated with a super calender to have a smoothness of 500 to 600 seconds to produce a thermosensitive recording medium.

Example 13 The basic colorless dye used in the above-mentioned liquid B (dye dispersion) was prepared from 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran. A heat-sensitive recording material was prepared in the same manner as in Example 2, except that diethylamino-6-methyl-7-anilinofluoran was used.

Example 14 The basic colorless dye used in the above-mentioned liquid B (dye dispersion liquid) was obtained from 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran. A heat-sensitive recording material was produced in the same manner as in Example 2 except that dibutylamino-6-methyl-7-anilinofluoran was used.

Example 15 Liquid A (Developer Dispersion)
4, 4 ′ are added to the color developer of the general formula (I) of the present invention used for
Examples using -bis {(3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane and 4,4′-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane It is. The dispersion liquid was mixed at the following ratio to obtain a coating liquid. Solution A (4,4'-bis {(3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane dispersion) 18.0 parts Solution A (4,4'-bis} (3- (phenyl Carbamoylamino) phenyl) sulfonylaminocarbonylamino diphenylmethane dispersion 18.0 parts Liquid B 9.2 parts Kaolin clay (50% dispersion) 12.0 parts One side of a base paper of 50 g / m ² of each of the above coating solutions. 6.0 coating amount
g / m ² and dried, and this sheet was treated with a super calender so that the smoothness became 500 to 600 seconds to prepare a thermosensitive recording medium (mixing of a developer).

Example 16 Liquid A (Developer Dispersion)
4, 4 ′ are added to the color developer of the general formula (I) of the present invention used for
-Bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane and 1-methyl-2,4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene were used. It is an example. The dispersion liquid was mixed at the following ratio to obtain a coating liquid. Solution A (4,4'-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane dispersion) 20.0 parts Solution A (1-methyl-2,4-bis} (3- ( Phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino｝ benzene dispersion) 16.0 parts B liquid 9.2 parts Kaolin clay (50% dispersion) 12.0 parts Each of the above coating liquids was coated on a 50 g / m ² base paper. 6.0 coating amount on one side
g / m ² and dried, and this sheet was treated with a super calender so that the smoothness became 500 to 600 seconds to prepare a thermosensitive recording medium (mixing of a developer).

[Comparative Examples 1 to 8] Liquid C (color developer dispersion) Color developer (see Table 3) 6.0 parts 10% polyvinyl alcohol aqueous solution 18.8 parts water 11.2 parts Liquid B (dye dispersion) Liquid) 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran 2.0 parts 10% aqueous solution of polyvinyl alcohol 4.6 parts Water 2.6 parts Each liquid of the above composition Was ground with a sand grinder to an average particle size of 1 micron. Next, a dispersion was mixed at the following ratio to form a coating liquid, and a thermosensitive recording medium was prepared in the same manner as in Example 1. Liquid C 36.0 parts Liquid B 9.2 parts Kaolin clay (50% dispersion) 12.0 parts

[Examples 17 to 19] Liquid C (developer dispersion liquid) Developer (see Table 5) 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Liquid B (dye dispersion) Liquid) 3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluoran 2.0 parts 10% aqueous solution of polyvinyl alcohol 4.6 parts Water 2.6 parts Liquid D (stabilizer dispersion liquid) ) Stabilizer (see Table 5) 2.0 parts 10% aqueous solution of polyvinyl alcohol 2.5 parts Water 1.5 parts Each liquid of the above composition was ground with a sand grinder to an average particle diameter of 1 micron. Next, a dispersion was mixed at the following ratio to form a coating liquid, and a thermosensitive recording medium was prepared in the same manner as in Example 1. Liquid C 36.0 parts Liquid B 9.2 parts Liquid D 6.0 parts Kaolin clay (50% dispersion) 12.0 parts

[Comparative Example 9] The compound used in the liquid D (stabilizer dispersion) was prepared by converting 4,4'-bis {(3- (p-tolylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane to 4, A thermosensitive recording medium was prepared in the same manner as in Example 17, except that 4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane was used.

Comparative Example 10 Liquid D (Stabilizer Dispersion)
The compound used for 1,4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane is 1,3-bis (p
-Toluenesulfonylaminocarbonylamino) benzene was used in the same manner as in Example 18 except that the heat-sensitive recording material was changed.

Tables 4, 5 and 7 show the results of the following quality performance tests performed on the thermal recording media obtained in the above Examples and Comparative Examples.

[Thermal Recording Test (Dynamic Color Density)] Using an Okura Electric Co., Ltd. TH-PMD (thermosensitive recording paper printing tester, equipped with a Kyocera thermal head) at an applied energy of 0.38 mj / dot. Thermal recording was performed on the produced thermal recording medium (the same thermal recording was performed under the same conditions).
The recording density of the recording unit was measured using a Macbeth densitometer (RD-914,
The measurement was carried out under the same conditions using an amber filter. Examples 1 to 19 in which the compound of the present invention was used as a developer
With regard to the heat-sensitive recording medium, a sufficient recording density was obtained by a printer.

[Plasticizer resistance test] A vinyl chloride wrap (Hi-wrap KMA manufactured by Mitsui Toatsu) was wrapped around a paper tube in a single layer, and a thermosensitive recording medium recorded by the printer (0.38 mj / dot) was pasted thereon. Further, a layer obtained by wrapping PVC wrap three times thereon was allowed to stand at 40 ° C. for 24 hours, and then the Macbeth densities in the image area and the ground color area were measured. In the heat-sensitive recording materials of Examples 1 to 19 of the present invention, the recorded image almost remained, and coloring of the ground color portion did not occur.

[Moisture Resistance Test] The printer (0.3
8 mj / dot) at 40 ° C. 9
After leaving for 72 hours in an environment of 0% RH, the Macbeth density of the ground color portion was measured. In the heat-sensitive recording materials of Examples 1 to 19 of the present invention, coloring of the ground color portion was hardly recognized.

[0059]

[Table 1] Table 1 Developer 1 used in Examples

[0060]

Table 2 Developer 2 used in Examples

[0061]

[Table 3] Table 3 Developers used in Comparative Examples

[0062]

Table 4 Characteristics of the heat-sensitive recording materials of Examples 1 to 16

[0063]

Table 5 Characteristics of heat-sensitive recording materials of Comparative Examples 1 to 8

[0064]

Table 6: Developers used in Examples and Comparative Examples,
Stabilizer

[0065]

Table 7 Examples 7 to 19 and Comparative Examples 9 to 10
Of thermal recording medium

[0066]

The thermal recording medium according to the present invention has the following excellent effects on the storage stability of recorded images and background. (1) The recorded image is stable without erasing even when it comes into contact with a plasticizer or salad oil. (2) The background is stable without color development even when it comes into contact with a plasticizer or salad oil. (3) The background is stable without coloring even under high humidity conditions.

──────────────────────────────────────────────────続 き Continued on the front page (72) Reiko Sato, Inventor 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Nihon Paper Industries Co., Ltd. Product Development Laboratory (72) Inventor Yutaka Wakita 1-30, Kamiochiai, Shinjuku-ku, Tokyo No. 6 Nippon Paper Industries Co., Ltd. Product Development Laboratory (72) Inventor Kaoru Hamada 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Nippon Paper Industries Co., Ltd. Product Development Laboratory (72) Inventor Ryoichi Kinishi Tsukigami-gun, Fukuoka Prefecture 955, Yoshitomi-cho, Komatsuri, Yoshitomi Fine Chemical Co., Ltd. (72) Inventor Mamoru Suga, 955, Kotomicho, Yoshitomi-cho, Chikugami-gun, Fukuoka Yoshitomi Fine Chemical Co., Ltd. (JP, A) JP-A-6-255262 (JP, A) JP-A-5-147357 (JP, A) JP-A-51-98241 (JP, A) ) Fields investigated (Int. Cl. ⁷ , DB name) C07C 311/57 C07C 335/16 C07C 335/42 B41M 5/26 CAPLUS (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. A novel urea (thiourea) derivative represented by the following general formula (I). Embedded image (Wherein, R ₁ and R ₂ may be the same or different and represent a hydrogen atom, a C ₁ -C ₄ alkyl group, a halogen atom,
R ₁ and R ₂ may combine with each other to form an aromatic ring.
X and Y may be the same or different and represent an oxygen atom or a sulfur atom, and Z represents a divalent organic residue. ) 2. A thermosensitive recording medium comprising a support having thereon a thermosensitive coloring layer containing a colorless or pale-colored basic colorless dye and an organic developer as main components. A thermosensitive recording medium comprising at least one compound represented by the formula (I). 3. The thermosensitive coloring layer, wherein the compound represented by the general formula (I) is contained as an organic developer in an amount of 1 to 8 parts with respect to 1 part of a basic colorless dye. The thermosensitive recording medium according to claim 2. 4. The thermosensitive coloring layer, wherein the compound represented by the general formula (I) is contained as a stabilizer in an amount of 0.25 to 3 parts with respect to 1 part of the basic colorless dye. The thermosensitive recording medium according to claim 2.