JPH06227142A - Thermal recording body - Google Patents

Abstract

PURPOSE:To enhance sensitivity of a thermal recording body and also to enhance various durabilities and long-term stability of a color developing image by incorporating aminocarbonyl amino-based compound having the specified structure as the developer of a thermal color developing layer. CONSTITUTION:A thermal recording body is constituted by forming a thermal color developing layer on at least one side of base material on a sheet. The thermal color developing layer contains a colorless or light-colored dye precursor and a developer which reacts with the same under heating to generate color development. In the case, at least one kind of compound shown in a general formula mentioned elsewhere is incorporated as the developer. However, in the formula, X shows oxygen or sulfur atom. R' shows substituted aromatic group or the like. R<2> and R<3> show hydrogen atom and lower alkyl group mutually independently. A shows bivalent group. (m) and (n) show an integer of >=1 mutually independently. Thereby sensitivity of the thermal recording body is enhanced and also various durabilities and long-term stability of the color developing image are enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material on which a color-developed image is formed by heating, and more particularly to a heat-sensitive recording material which is free from loss of a once-color-developed image and has excellent storage stability. More specifically, the long-term storability of the record is good, and at the same time, the recorded image is excellent in moisture resistance, environment resistance such as heat resistance, oil resistance, and plasticizer resistance. The present invention relates to a thermal recording medium useful for cash dispenser paper, boarding tickets, commuter passes, labels such as POS labels, cards such as prepaid cards, and pass tickets.

[0002]

2. Description of the Related Art A thermal recording material is generally composed of a support such as paper, synthetic paper or plastic film on which a color-forming substance such as an electron-donating leuco dye and an organic acid substance such as an electron-accepting phenolic compound. A thermosensitive coloring layer mainly containing such a color-developing substance as described above is provided, and a recorded image can be formed by reacting these coloring components with thermal energy. Such a thermal recording material,
JP-B-43-4160, JP-B-45-14039,
And Japanese Patent Application Laid-Open No. 48-27736.
Widely used in practice.

The thermal recording medium as described above has a compact and inexpensive recording device and is easy to maintain, so that the output of a computer, a facsimile, an automatic ticket vending machine,
It is widely used as a printer for scientific measuring instruments, a printer for CRT medical measurement, and the like.

However, in a conventional so-called dye-type thermosensitive recording medium in which a thermosensitive coloring layer containing a color-developing dye substance, a color-developing substance and a binder as an active ingredient is coated on a support, the coloring reaction does not occur. Since it is reversible, it is known that the color image disappears over time. This decoloring is accelerated under exposure to light, high humidity and high temperature, and further progresses rapidly due to contact with a plasticizer and oil, and the image is decolorized to an unreadable level.

When a coloring system using a dye precursor mainly composed of a colorless or light-colored lactone ring compound is used, many techniques have been developed for suppressing this decoloring phenomenon. For example, JP-A-60-78782 and JP-A-59-78782
No. 167,292, JP-A-59-114096, and JP-A-59-93387, a compound containing a phenolic antioxidant in a thermosensitive coloring layer, and JP-A-56-146796. Such as those having a protective layer formed of a hydrophobic polymer emulsion,
As disclosed in JP-A-58-199189, a water-soluble polymer compound or a hydrophobic polymer compound emulsion is provided as an intermediate layer on a thermosensitive coloring layer, and the hydrophobic polymer compound is used as a resin component on the intermediate layer. One provided with a surface layer made of an oil-based paint, one containing an epoxy compound in the thermosensitive coloring layer as seen in JP-A-62-164579,
And as seen in JP-A-62-169681,
It is known that a metal salt of a specific salicylic acid derivative is used as a developer.

Further, regarding a developer compound having a urea type structure which is related to the present invention, JP-A-59-13309.
6, JP-A-59-136288, and JP-A-60.
No. 145884 is disclosed.

In the heat-sensitive color-forming layer containing the above-mentioned phenolic antioxidant, compared with the image without it,
Although the environmental resistance is somewhat improved, oil resistance (for example, storage ratio of image density after a certain time when salad oil is brought into contact with the color development surface), plasticizer resistance (wrap film containing plasticizer, etc.) No improvement is observed in the storage ratio of the image density after a certain period of time when it is brought into contact with the coloring surface).

On the other hand, the thermal recording material provided with the protective layer or the surface layer has a slightly improved environmental resistance, but decolorization is inevitable in a long-term test. Regarding the oil resistance, the image storability immediately after contact with oil is improved, but the image disappears almost completely as the oil permeates,
It is not an essential solution to the above problems.

Further, in the case of containing an epoxy compound, a relatively long time is required from the heating color development operation to the stabilization of the color image, and for example, salad oil is applied to the color image immediately after color development. If it is exposed to light, or if it is brought into contact with a plasticizer, a considerable part of the color image is erased.

Further, in the case of using a specific metal salt of salicylic acid, although oil resistance and plasticizer resistance are improved, color development of a white paper part is observed in a heat resistance test, and an effective chemical structure of a specific salicylic acid is complicated. It has the disadvantage of being expensive.

Further, as disclosed in JP-A-59-133096 and JP-A-59-136288, heat-sensitive recording using a developer compound having one thiourea type structure in the molecule. Paper has the drawback that the whiteness is liable to be lowered, and the oil resistance and plasticizer resistance of the formed image are very low.

Further, as disclosed in JP-A-60-145884, a thermosensitive recording paper using three specific compounds having two urea type structures in the molecule has a weak coloring ability and The formed image has the drawback that the oil resistance and the plasticizer resistance are also extremely weak (see Comparative Example 2 below).

[0013]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a colored image excellent in oil resistance, plasticizer resistance, moisture resistance, heat resistance and the like, and thus excellent in long-term storage stability. It is intended to provide a thermosensitive recording medium to be formed. INDUSTRIAL APPLICABILITY The thermosensitive recording material of the present invention is useful, for example, as a thermosensitive recording type ticket for an automatic ticket vending machine, and can be used for a number-of-times ticket or a commuter ticket that requires preservability, and can avoid contact with a plasticizer or oil and fat. Not only suitable as a label for POS bar code system that is attached to the packaging surface of foods that are wrapped with polyvinyl chloride film, but also usable as facsimile paper or word processor paper for long-term storage, and as image printer paper for CRT. It is a thing.

[0014]

DISCLOSURE OF THE INVENTION The inventors of the present invention have developed a thermosensitive color development in which a storage stability improving effect such as oil resistance and plasticizer resistance of a color image is developed within a short time after color image formation. The layer improvement method was examined, and as a result, the arylamino (thio) carbonylamino group represented by the formula (II):

[Chemical 2] (Wherein, X represents an oxygen or sulfur atom, R ¹ represents a substituted aromatic group, an unsubstituted aromatic group, a substituted aralkyl group, or an unsubstituted aralkyl group). By using a compound having more than that as a color developer, excellent thermal development capability and high oil and plasticizer resistance to the color image are provided, and thus a thermal recording material having an excellent long-term storage stabilization effect of the color image can be obtained. It was discovered that the present invention was completed.

The heat-sensitive recording material of the present invention comprises a sheet-shaped substrate,
Formed on at least one surface of the sheet-like substrate, and
It has a colorless or light-colored dye precursor, and a thermosensitive coloring layer containing the dye precursor and a developer which reacts under heating to develop a color, and the developer has the following general formula (I):

[Chemical 3] (However, X represents an oxygen or sulfur atom, R ¹ represents a substituted aromatic group, an unsubstituted aromatic group, a substituted aralkyl group or an unsubstituted aralkyl group, and R ²
And R ³ each independently represent a hydrogen atom, a halogen atom, or a lower alkyl group, A represents a divalent group, and m and n each independently represent an integer of 1 or more. . ) At least one compound represented by

[0016]

In the compound of formula (I), A is not particularly limited as long as it is a divalent group, but preferable examples include the following groups. a: carbonyl group, thiocarbonyl group, sulfonyl group,
An oxy group and a divalent group such as a sulfide group, b: a divalent group derived from an aliphatic hydrocarbon, such as a methylene group, an ethylene group, and a trimethylene group, c: one or more groups in the main chain A divalent group derived from an aliphatic hydrocarbon containing a hetero atom, such as a methylenedioxy group, an ethylenedioxy group, and an ethylenedithiooxy group, and d: one or more carbonyl groups in the main chain, thio A carbonyl group, an imide group, an imino group, a sulfonyl group, a divalent group derived from an aliphatic hydrocarbon containing an ester bond, such as a malonyl group, a succinyl group, a ureylene group, and a methylenesulfonylmethylene group.

The compound of formula (I) used in the present invention acts as a developer. That is, the compound of the formula (I) does not have an acidic functional group such as a phenolic hydroxyl group or a carboxyl group, but has a structural feature that it strongly interacts with a basic leuco dye, It exhibits a strong color developing ability for dyes. Having a compound molecule of formula (I) having at least four aromatic rings in an arrangement as shown in formula (I) enhances the interaction with the dye molecule and increases the color developing ability. It is estimated to be an important factor for Further, the oil resistance and the plasticizer resistance of the image formed by the developer compound of the formula (I) are high because the arylamino (thio) of the formula (II) present in two or more in one molecule. It is considered that this is due to the concerted action of the carbonylamino group.

Specific examples of the compound of the formula (I) are as follows. 4,4'-bis (3,4-dichlorobenzeneaminocarbonylamino) diphenylmethane,
4,4'-bis (benzeneaminocarbonylamino) diphenylmethane, 4,4'-bis (m-trifluoromethylbenzeneaminocarbonylamino) diphenylmethane, 4,4'-bis (2,4,6-tribromobenzeneamino) Carbonylamino) diphenylmethane, 4,4 '
-Bis (benzeneaminocarbonylamino) diphenylsulfone, 4,4'-bis (p-chlorobenzeneaminocarbonylamino) diphenylsulfone, 4,4'-bis (m-chlorobenzeneaminocarbonylamino) diphenylsulfone, 1,3'- Bis (3,4-dichlorobenzeneaminocarbonylamino) diphenyl sulfone,
1,3'-bis (benzeneaminocarbonylamino) diphenyl sulfone, 4,4'-bis (benzeneaminothiocarbonylamino) diphenylmethane, 4,4'-bis (p-chlorobenzeneaminothiocarbonylamino)
Diphenylmethane, 4,4'-bis (m-chlorobenzeneaminothiocarbonylamino) diphenylmethane,
4,4'-bis (3,4-dichlorobenzeneaminothiocarbonylamino) diphenyl sulfone, 4,4'-bis (benzeneaminothiocarbonylamino) diphenyl sulfone, 4,4'-bis (p-chlorobenzeneaminothiocarbonyl) Amino) diphenyl sulfone, 1,3 '
-Bis (3,4-dichlorobenzeneaminothiocarbonylamino) diphenyl sulfone, 1,3'-bis (benzeneaminothiocarbonylamino) diphenyl sulfone, 1,3'-bis (m-trifluoromethylbenzeneaminothiocarbonylamino) ) Diphenyl sulfone,
4,4'-bis (benzylaminothiocarbonylamino) diphenylmethane, 4,4'-bis (benzylaminocarbonylamino) diphenylsulfone, 4,4'-
Bis (benzylaminothiocarbonylamino) diphenyl sulfone, 4,4′-bis (benzeneaminothiocarbonylamino) 3,3′-dichlorodiphenylmethane,
4,4'-bis (benzeneaminocarbonylamino)
2,2'-dimethyldiphenylethane, and 4,4 '
-Bis (benzeneaminothiocarbonylamino) 2,
2'-Dimethyldiphenylethane.

These compounds of formula (I) may be used alone or in combination of two or more. Many of the compounds of formula (I) as described above are novel compounds that have not been reported so far, and their synthesis can be carried out, for example, by the following reactions (1) and (2).

[Chemical 4] (However, R ¹ , R ² , R ³ , A, and X in the above reaction formula are as defined above.)

In the present invention, the leuco dye used as the dye precursor can be selected from conventionally known ones such as triphenylmethane type, fluorane type and diphenylmethane type compounds. For example, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1-ethyl-2-methylindol-3-yl) -4-azaphthalide, crystal violet lactone, 3- (N-ethyl-N-).
Isopentylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-
(O, p-dimethylanilino) fluorane, 3- (N-
Ethyl-N-p-toluidino) -6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-
7-anilinofluorane, 3- (N-cyclohexyl-
N-methylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-7- (o-chloroanilino) fluorane, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-diethylamino-7-
(M-trifluoromethylanilino) fluorane, 3-
Diethylamino-6-methyl-7-chlorofluorane,
3-diethylamino-6-methylfluorane, and 3
One or more selected from -cyclohexylamino-6-chlorofluorane, 3- (N-ethyl-N-hexylamino) -6-methyl-7- (p-chloroanilino) fluorane and the like can be used.

Further, in the present invention, a conventionally known developer containing a phenol or an organic acid can be used in combination with the compound of the formula (I) of the present invention within a range that does not impair the desired effect. . These conventional color developers are, for example, 2,2
-Bis (4-hydroxyphenyl) propane (bisphenol A), 1,1-bis (4-hydroxyphenyl)
-1-phenylethane, 1,4-bis (1-methyl-1)
-(4'-hydroxyphenyl) ethyl) benzene,
1,3-bis (1-methyl-1- (4'-hydroxyphenyl) ethyl) benzene, dihydroxydiphenyl ether (JP-A-1-180382), benzyl p-hydroxybenzoate (JP-A-52-140483), Bisphenol S, 4-hydroxy-4'-isopropyloxydiphenyl sulfone (JP-A-60-13852)
No.), 1,1-di (4-hydroxyphenyl) cyclohexane, 1,7-di (4-hydroxyphenylthio)-
3,5-Dioxaheptane (JP-A-59-52694)
No.), and 3,3'-diallyl-4,4'-dihydroxydiphenyl sulfone (JP-A-60-208286).
No.) etc.

Further, a thermofusible substance (so-called sensitizer) is preferably used in combination with the thermosensitive coloring layer of the present invention. As the sensitizer, a heat-fusible organic compound having a melting point of 50 to 150 ° C. is generally used, and examples thereof include 1-hydroxy-2-naphthoic acid phenyl ester (JP-A-57-1).
91089), p-benzylbiphenyl (JP-A-60).
-82382), benzylnaphthyl ether (JP-A-58-87094), dibenzyl terephthalate (JP-A-58-98285), benzyl p-benzyloxybenzoate (JP-A-57-201691), diphenyl carbonate. , Ditolyl carbonate (JP-A-58-136489)
No.), m-terphenyl (JP-A-57-89994).
No.), 1,2-bis (m-tolyloxy) ethane (JP-A-60-56588), 1,5-bis (p-methoxyphenoxy) -3-oxapentane (JP-A-62-18).
1183), oxalic acid diesters (JP-A-64-1)
583), 1,4-bis (p-tolyloxy) benzene (JP-A-2-153787), diphenyl sulfone (Japanese Patent Publication No. 59-25673), and the like.

The thermosensitive coloring layer of the present invention may further contain a hindered phenol compound or an ultraviolet absorber. They are, for example, JP-A-57-151394, JP-A-58-160191, and JP-A-58-69096.
JP-A-59-2884, JP-A-59-95190
JP-A-60-22288 and JP-A-60-2554.
85, JP-A-61-44686, JP-A-62-16
9683, JP-A-63-17081, JP-A 1-2
It can be selected from the compounds disclosed in JP-A-49385 and JP-A-2-266645, and specifically, for example, 1,1,3-tris (3′-cyclohexyl-4 ′).
-Hydroxyphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 4,4'-thiobis (3-methyl-)
6-tert-butylphenol), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-)
Butyl-4-hydroxybenzyl) benzene, 2,2 '
-Dihydroxy-4,4'-dimethoxybenzophenone, p-octylphenyl salicylate, 2- (2'-
Hydroxy-5'-methylphenyl) benzotriazole, ethyl-2-cyano-3,3'-diphenylacrylate, and tetra (2,2,6,6, -tetramethyl-4-piperidyl) 1,2,3,3. 4-Butane tetracarboate or the like can be used.

The heat-sensitive color forming layer of the heat-sensitive recording material of the present invention contains a dye precursor and the compound of the above formula (I) of the present invention,
Further, it is preferable to include a sensitizer. Further, the heat-sensitive color developing layer may contain a conventionally known phenol-based or organic acid-based developer, antioxidant, ultraviolet absorber, or wax, if necessary. It may also contain organic or inorganic pigments. Further, the heat-sensitive color forming layer of the heat-sensitive recording material of the present invention contains a binder for fixing these components to the support.

The content of the above-mentioned dye precursor in the thermosensitive coloring layer is preferably 5 to 20% by weight based on the dry weight of the thermosensitive coloring layer, and the content of the dye precursor of the formula (I) of the present invention is also preferable. The content of the developer compound is generally 10 to 10.
It is preferably 50% by weight. When the content of the compound of the formula (I) is less than 10% by weight, the color developing ability of the obtained thermosensitive color developing layer is insufficient, and even when it exceeds 50% by weight, the color developing ability of the thermosensitive color developing layer obtained is saturated. There is no particular improvement, which may be economically disadvantageous.

When the thermosensitive coloring layer contains an antioxidant or an ultraviolet absorber, its content is preferably 1 to 10% by weight. When a conventionally known phenol-based or organic acid-based color developer is contained, its content is 5 to 40.
The content is preferably 10% by weight, and when the sensitizer is contained, its content is preferably 10 to 40% by weight. When waxes and white pigments are contained in the thermosensitive coloring layer, their contents are preferably 5 to 20% by weight and 10 to 50% by weight, respectively, and the content of the binder is generally 5 to 5% by weight.
It is 20% by weight.

Examples of the above-mentioned organic or inorganic pigments include calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate, clay, calcined clay, talc, and surface-treated calcium carbonate. Examples thereof include inorganic fine powders such as silica and silica, and organic fine powders such as urea-formalin resin, styrene / methacrylic acid copolymer, and polystyrene resin.

As the waxes, known waxes such as paraffin, amide wax, bisimide wax, and metal salt of higher fatty acid can be used.

Regarding the binder, polyvinyl alcohols having various molecular weights, starch and derivatives thereof, cellulose derivatives such as methoxycellulose, carboxymethylcellulose, methylcellulose and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic acid amide / acrylic acid ester Polymers, acrylic acid amides / acrylic acid esters / methacrylic acid terpolymers, styrene / maleic anhydride copolymers alkaline salts, polyacrylamides, sodium alginates, gelatin, and water-soluble polymeric materials such as casein, and
Polyvinyl acetate, polyurethane, styrene / butadiene copolymer, polyacrylic acid, polyacrylic ester,
Each latex such as vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, ethylene / vinyl acetate copolymer, and styrene / butadiene / acrylic copolymer can be used.

The sheet-like substrate used in the heat-sensitive recording material of the present invention is paper, coated paper having a surface coated with a pigment and / or latex, laminated paper, synthetic paper made of polyolefin resin, and plastic film. You can choose from

On at least one surface of such a sheet-like substrate, a coating solution containing a mixture of the above-mentioned required components is applied and dried to form a thermosensitive coloring layer to produce a thermosensitive recording material. The coating amount of the thermosensitive coloring layer is 1 to 1 when the coating liquid layer is dried.
Preferably 5 g / m ^2, and more preferably 2 to 10 g / m ^2. In the heat-sensitive recording material of the present invention, a coating layer such as a protective layer or a printing layer can be further formed on the heat-sensitive color developing layer.

[0032]

EXAMPLES The present invention will be specifically described with reference to the following examples. In the examples, "parts" and "%" represent "parts by weight" and "% by weight", respectively, unless otherwise specified.

Synthesis Example 1 (4,4'-bis (benzeneami)
Synthesis of (nothiocarbonylamino) diphenylmethane) In a three-necked flask equipped with a dropping funnel and a thermometer,
9.9 g of 4,4'-diaminodiphenylmethane was added to 20
It was dissolved in 0 ml of acetonitrile. While vigorously stirring this solution with a magnetic stirrer, 13.5 g of phenyl isothiocyanate was added dropwise from a dropping funnel. After the dropwise addition, stirring was continued at 80 ° C., and a white solid was precipitated after 30 minutes, but the stirring was continued for 2 hours, then allowed to cool to room temperature and then filtered to obtain 22.5 g of white crystals. It was Its melting point was 178 ° C. NMR measurement,
The white crystals obtained were identified to be the above target compound by mass spectrometry and IR measurement.

The results of NMR (in heavy DMSO) are as follows. δ = 3.89 (s, 2H) 7.11 to 7.5
7 (m, 18H), and other peaks that are thought to be due to NH appeared in the vicinity of δ = 9.7. In addition, IR measurement (K
In the Br tablet method), the following characteristic absorption was confirmed. 1530cm ^-1 (derived from thiocarbonyl group of thiourea)

Synthesis Example 2 (4,4'-bis (m-triflu
Oromethylbenzeneaminothiocarbonylamino) diph
Synthesis of phenylmethane) The same synthetic procedure as in Synthesis Example 1 was performed. However, with respect to 9.9 g of 4,4'-diaminodiphenylmethane, 23.4
g of m-trifluoromethylphenyl thioisocyanate was used. 26.3 g of white crystals were obtained. Its melting point was 160 ° C. By NMR measurement, mass spectrometry and IR measurement, the obtained white crystals were identified as the above target compound.

The results of NMR measurement (in heavy DMSO) were as follows. δ = 3.87 (s, 2H), 7.22
(T, 5H), 7.43 to 7.61 (m, 7H), 7.
82 (d, 2H), 8.02 (s, 2H), other N-
A peak thought to be due to H appeared around δ = 9.3. In addition, IR measurement (KBr tablet method) confirmed the following characteristic absorption. 1330 cm ^-1 (derived from fluoromethyl group) 1530 cm ^-1 (derived from thiocarbonyl groups thiourea)

Synthesis Example 3 (1,3-bis (p-chloroben
Zenaminothiocarbonylamino) diphenyl sulfone
Synthesis) The same synthesis operation as in Synthesis Example 1 was performed while replacing the inside of the three-necked flask with dry nitrogen. However, 9.9 g of 4,4'-
Instead of diaminodiphenylmethane, 9.4 g of 3,
13. Using 3'-diaminodiphenyl sulfone, and
Instead of 5 g of phenyl isothiocyanate, 14.8 g
P-chlorophenyl isothiocyanate was used. 1
8.2 g of white crystals were obtained. Its melting point was 171 ° C. By NMR measurement, mass spectrometry and IR measurement, the obtained white crystals were identified as the above target compound.

The results of NMR measurement (in heavy DMSO) are as follows. δ = 7.41 to 7.90 (m, 14
H), 8.51 (s, 2H), and other peaks that are thought to be due to NH appear in the vicinity of δ = 8.2, 10.4. In addition, the following characteristic absorption was confirmed by IR measurement (KBr tablet method). 1150 cm ^-1 (derived from sulfonyl group) 1540 cm ^-1 (derived from thiocarbonyl group of thiourea group)

Synthesis Example 4 (4,4'-bis (m-chlorobenzene)
Nenaminothiocarbonylamino) diphenylsulfo
While replacing the down synthetic) three-necked flask with dry nitrogen, it was subjected to the same synthetic procedure as Synthesis Example 1. However, 9.9 g of 4,4'-
Instead of diaminodiphenylmethane, 9.3 g of 4,
Using 4'-diaminodiphenyl sulfone, and 1
14. Instead of 3.5 g of phenyl isothiocyanate, 14.
8 g of m-chlorophenyl isothiocyanate was used.
21.3 g of white crystals were obtained. Its melting point was 155 ° C. By NMR measurement, mass spectrometry and IR measurement, the obtained white crystals were identified as the above target compound.

The results of NMR measurement (in heavy DMSO) are as follows. δ = 7.40 (d, 2H), 7.75
(T, 8H), 7.94 (d, 6H), and other peaks due to N-H appeared near δ = 10.3, 10.4, 10.6. In addition, the following characteristic absorption was confirmed by IR measurement (KBr tablet method). 1152cm ^-1 (derived from sulfonyl group) 1530 cm ^-1 (derived from thiocarbonyl groups thiourea group)

Synthesis Example 5 (4,4'-bis (benzeneami)
Synthesis of Nothiocarbonylamino) diphenylsulfone) While replacing the inside of the three-necked flask with dry nitrogen, 15 g of 4,4'-diaminodiphenylsulfone was put into this three-necked flask, and this was dissolved in 60 ml of pyridine. While vigorously stirring this solution with a magnetic stirrer, 17.6 g of phenyl isothiocyanate was added dropwise from a dropping funnel. After the dropping is completed, the mixture is stirred at a temperature of 110 ° C for 7 hours,
Again, 8.8 g of phenyl isothiocyanate was added dropwise, and the mixture was further stirred at a temperature of 110 ° C. for 1 hour. After completion of the reaction, the mixture was allowed to cool, acidified with 5% hydrochloric acid aqueous solution, and extracted with chloroform. Chloroform was distilled off from the extract, and 13.6 g
White crystals were obtained. Its melting point was 146 ° C. N
It was identified by MR measurement, mass spectrometry and IR measurement that the obtained white crystals were the above target compound.

The results of NMR measurement (in heavy DMSO) are as follows. δ = 7.12 (t, 4H), 7.36
(M, 7H), 7.55 (d, 7H), and other peaks that are thought to be due to NH appear in the vicinity of δ = 9.1. In addition, the following characteristic absorption was confirmed by IR measurement (KBr tablet method). 1,535 cm ^-1 (derived from thiocarbonyl group of thiourea group)

Synthesis Example 6 (4,4'-bis (2,4,6-
Tribromobenzene aminocarbonylamino) dipheni
2) in a three-necked flask equipped with a thermometer.
8.5 g of 2,4,6-tribromoaniline was added to 400
It was dissolved in 80 ml of toluene by heating at a temperature of 80 ° C. The solution was vigorously stirred with a magnetic stirrer, to which
38 g of di-n-butyltin dilaurate was added and, with vigorous stirring, another 9.4 g of 4,4 'of diisocyanic acid.
-Diphenylmethane was added. Although it became a little cloudy in about 30 minutes, stirring was continued for 4 hours at a temperature of 80 ° C. The reaction solution was left overnight and a small amount of white solid formed. This solid was removed by filtration, and toluene was distilled off from the obtained filtrate to obtain 17.5 g of white crystals. Its melting point was 300 ° C. or higher. By NMR measurement, the obtained white crystals were identified as the above target compound.

The results of NMR measurement (in heavy DMSO) were as follows. δ = 3.82 (s, 2H), 7.10
(D, 4H), 7.39 (d, 6H), and other peaks due to N-H appeared near δ = 8.5.

Example 1 A thermosensitive recording paper was prepared by the following operation. (1) Preparation Ingredient Quantity dye precursor dispersion A (parts) 3- (N-isopentyl -N- ethylamino) - 20 6-methyl-7-anilinofluoran polyvinyl alcohol 10% solution 10 Water 70 The above The composition was pulverized using a sand grinder until the average particle size became 1 μm or less.

[0046] (2) Preparation Ingredients Amount of Developer Dispersion B (parts) of 4,4'-bis (benzene aminothiocarbonyl 10) diphenylmethane diphenyl sulfone 10 polyvinyl alcohol 10% solution 10 Water 70 The composition It grind | pulverized using a sand grinder until the average particle diameter became 1 micrometer or less.

(3) Preparation of Pigmented Undercoat Paper 85 parts of calcined clay (trademark: Ansilex) was added to 320 parts of water.
40 parts of styrene-butadiene copolymer emulsion (solid content 50%) and 10 parts of
% Oxidized starch aqueous solution was mixed with 50 parts, on one surface of the resulting coating liquid having a basis weight of 48 g / m ² base paper, the coating amount after drying was coated so as to 7.0 g / m ² A pigment-coated paper was prepared.

(4) Formation of Thermosensitive Coloring Layer 30 parts of calcium carbonate pigment, 20 parts of 25% zinc stearate dispersion liquid were added to 50 parts of solution A and 200 parts of solution B.
15 parts of 30% paraffin dispersion and 100 parts of 10% aqueous solution of polyvinyl alcohol were mixed and stirred to prepare a coating solution. This coating solution, on one side of the pigment-undercoated paper,
A thermosensitive coloring layer was formed by coating and drying so that the coating amount after drying was 5.0 g / m ^2, and a thermosensitive recording paper was prepared. The heat-sensitive recording paper obtained as described above was smoothed by a super calendar and the surface smoothness was adjusted to 800 to 10
It was set to 00 seconds.

(5) Test For the sample thus obtained, a dynamic color tester, which is a modification of a commercial thermal facsimile machine manufactured by Hitachi, was used.
The sample was colored with an applied energy of 0.49 mj / dot.
The color density was measured with a Macbeth reflection densitometer RD-914 (this color density is called the original density and is represented by D ₀ ). Then, a predetermined test piece was prepared from this color-developed sample, and after the color development,
Salad oil was applied to the test piece within minutes, left at room temperature for 3 hours, excess oil was wiped off, and the residual image density D ₁ was measured with a Macbeth reflection densitometer. The above measured value D ₀
Then, the image preservation ratio was calculated from D ₁ and D ₁ according to the following formula.
Image preservation ratio (%) = D ₁ / D ₀ × 100 Test results are shown in Table 1.

Example 2 A thermal recording paper was prepared and tested in the same manner as in Example 1. However, in the preparation of Dispersion B, 4,4′-bis (m-chlorobenzeneaminothiocarbonylamino) diphenylsulfone was used instead of 4,4′-bis (benzeneaminothiocarbonylamino) diphenylmethane. The test results are shown in Table 1.

Example 3 A thermosensitive recording paper was prepared and tested in the same manner as in Example 1. However, in the preparation of Dispersion B, 4,4′-bis (benzeneaminothiocarbonylamino) diphenylsulfone was used instead of 4,4′-bis (benzeneaminothiocarbonylamino) diphenylmethane. The test results are shown in Table 1.

Example 4 A thermosensitive recording paper was prepared in the same manner as in Example 1 and tested. However, in preparing the dispersion B, 4,4 ′
Instead of -bis (benzeneaminothiocarbonylamino) diphenylmethane, 4,4'-bis (m-chlorobenzeneaminocarbonylamino) diphenylsulfone was used. The test results are shown in Table 1.

Example 5 A thermosensitive recording paper was prepared in the same manner as in Example 1 and tested. However, in preparing the dispersion B, 4,4 ′
Instead of -bis (benzeneaminothiocarbonylamino) diphenylmethane, 4,4'-bis (m-trifluoromethylbenzeneaminothiocarbonylamino) diphenylmethane was used. The test results are shown in Table 1.

Example 6 A thermosensitive recording paper was prepared in the same manner as in Example 1 and tested. However, in preparing the dispersion B, 4,4 ′
Instead of -bis (benzeneaminothiocarbonylamino) diphenylmethane, 4,4'-bis (3,4-dichlorobenzeneaminocarbonylamino) diphenylmethane was used. The test results are shown in Table 1.

Comparative Example 1 A thermosensitive recording paper was prepared and tested in the same manner as in Example 1. However, in preparing the dispersion B, 4,4 ′
Instead of -bis (benzeneaminothiocarbonylamino) diphenylmethane, 2,2-bis (4-hydroxyphenyl) propane (ie bisphenol A) was used. The test results are shown in Table 1.

Comparative Example 2 A thermosensitive recording paper was prepared in the same manner as in Example 1 and tested. However, in preparing the dispersion B, 4,4 ′
Instead of -bis (benzeneaminothiocarbonylamino) diphenylmethane, 4,4'-bis (benzeneaminothiocarbonylamino) phenyl (JP-A-60-14)
The compound described in No. 5884) was used. The test results are shown in Table 1.

[0057]

[Table 1]

As is clear from Table 1 above, the color-developed image obtained using the novel developer compound of the present invention has a color difference that is higher than that obtained when bisphenol A, which is a typical developer, is used.
It showed excellent oil resistance and plasticizer resistance.

[0059]

In the heat-sensitive recording material of the present invention, the heat-sensitive color forming layer contains an aminocarbonylamino compound having the above-mentioned specific chemical structure (formula (I)) as a developer. Shows a color-forming ability comparable to that of a conventional color developer, and the obtained color-developed image shows better oil resistance and plasticizer resistance immediately after the color-developing operation.

Claims (1)

[Claims] 1. A sheet-shaped substrate and a small number of the sheet-shaped substrate.
Before the colorless or light-colored dye is formed on at least one side
React with the precursor and the dye precursor under heating to
And a thermosensitive coloring layer containing a color developing agent,
The agent has the following general formula (I):(However, X represents an oxygen or sulfur atom, and R¹Is
Substituted aromatic group, unsubstituted aromatic group, substituted aral
Represents a alkyl group or an unsubstituted aralkyl group, R ², R
³Are each independently of each other a hydrogen atom, a halogen atom,
Or represents a lower alkyl group, and A represents a divalent group.
However, m and n are each independently an integer of 1 or more.
Represents ) At least one compound represented by
A heat-sensitive recording material containing an object.