JP2960266B2 - Thermal recording material - Google Patents

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, and more particularly to a heat-sensitive recording material having improved colorability, raw storage stability, and stability of a color image.

[0002]

2. Description of the Related Art Recording materials using a colorless or pale-color electron-donating dye precursor and an electron-accepting compound are already well known as pressure-sensitive paper, heat-sensitive paper, photosensitive pressure-sensitive paper, current-sensitive heat-sensitive recording paper, heat-sensitive transfer paper, and the like. For example, British Patent No. 2,14
No. 4,449, U.S. Pat. Nos. 4,480,052, 4,436,920, JP-B-60-23992, JP-A-57-179636, and JP-A-60-123556.
No. 60-123557, and the like.

[0003] In particular, a heat-sensitive recording material is disclosed in
No. 4,160, No. 45-14039 and the like. These thermal recording materials are facsimile,
It is applied to various fields such as printers and labels, and needs are expanding. However, these thermal recording materials are
In the field of labels, slips, word processing paper, plotter paper, etc., there is a drawback that fogging occurs due to the attachment of solvents, etc., and the colored body is discolored by oils and fats and chemicals etc. , The commercial value is significantly impaired.

The present inventors have proposed a colorless or pale-color electron-donating dye precursor and an electron-accepting compound, respectively.
Focusing on its oil solubility, solubility in water, partition coefficient, pKa, polarity of substituents and positions of substituents, etc., the development of materials for recording materials and recording materials has been pursued. However, in the case where the fogging due to the solvent or the like is difficult to occur, the color forming body is easily faded by the oil or the like, or the like. Tends to occur easily.

[0005]

Accordingly, the present inventors have
As a result of intensive studies to solve such a drawback, they have found that the isocyanate compound and the amino compound react upon heating to form a urea compound and act as an electron accepting compound, and have completed the present invention. SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosensitive recording material having high sensitivity, high raw preservability and good stability of a color image, and high printing quality.

[0006]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
Colorless or light-colored electron-donating dye precursor, and when heated
Urea compound that reacts with water and acts as an electron-accepting compound
Heat-sensitive recording material comprising a support and a thermosensitive coloring layer containing an isocyanate compound and an amino compound forming
Wherein the electron-donating dye precursor is represented by the following formula:
Achieved by a thermal recording material characterized by being a fluoran compound .

Embedded image Wherein R ₁ and R ₂ are an alkoxy group or tetrahydro
Alkyl optionally substituted with any of furfuryl groups
R ₁ and R ₂ may be the same or different
R ₃ , R ₄ and R ₅ are a hydrogen atom, a halogen atom
Or R ₃ , R ₄ and R ₅ are the same
Or different.

JP-A-60-184879 and JP-A-60-210491 disclose heat-sensitive recording materials in which blocked phenol is used as an electron-accepting compound, and isocyanates are also used. In these cases, the isocyanate compound merely plays a role of blocking the phenol compound, and the isocyanate is generated by being decomposed by a thermal reaction, so that a large amount of heat is required to generate the isocyanate. This is greatly different from the present invention in that the thermal sensitivity is deteriorated. The isocyanate compound used in the present invention can be appropriately selected and used from colorless or pale-colored isocyanate compounds which are solid at ordinary temperature. In particular, aromatic isocyanate compounds having two or more -NCO groups can be used. It is preferred to use.

Representative isocyanate compounds usable in the present invention include, for example, 2,6-dichlorophenyl isocyanate, p-chlorophenyl isocyanate, 1,3-phenylene diisocyanate,
4-phenylene diisocyanate, 1,3-dimethylbenzene-4,6-diisocyanate, 1,4-dimethylbenzene-2,5-diisocyanate, 1-methoxybenzene-2,4-diisocyanate, 1-methoxybenzene-2,5-diisocyanate, 1-ethoxybenzene-2,4-diisocyanate, 2,5-dimethoxybenzene-1,4-diisocyanate, 2,5-diethoxybenzene-1 , 4-Diisocyanate, 2,5-dibutoxybenzene-1,4-diisocyanate, azobenzene-4,4'-diisocyanate, diphenylether-4,4'-diisocyanate, naphthalene-1,4
Diisocyanate, naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 3,3′-dimethyl-biphenyl-4,4′-di Isocyanate, diphenylmethane-4,4'-diisocyanate, benzophenone-3,3'-diisocyanate, fluorene-2,
7-diisocyanate, anthraquinone-2,6-diisocyanate, 9-ethylcarbazole-3,6-diisocyanate, pyrene-3,8-diisocyanate, naphthalene-1,3,7-triisocyanate , Biphenyl-2,4,4'-triisocyanate, 4,4 ',
4 "-triisocyanate-2,5-dimethoxytriphenylamine, p-dimethylaminophenylisocyanate, tris (4-phenylisocyanate) thiophosphate, etc. These may be used alone or in combination of two or more. The isocyanate compound is preferably used in an amount of from 50 to 800% by weight, more preferably from 100 to 500% by weight of the colorless or pale-colored electron-donating dye precursor.
% By weight.

[0009] The amino compound in the present invention refers to a compound having a NH ₂ group, may be the number of NH ₂ groups in one molecule a plurality even one, but an amino compound having a NH ₂ group two or more It is particularly preferable to use in combination with an aromatic isocyanate compound having two or more NCO groups. In the present invention, it is particularly preferable to use an amino compound represented by the following formula (4).

Embedded image

In the above formula, X is a direct bond, -CO-, -SO
₂ -, - CONH- or -SO ₂ NH- R _1, R ₂ and R ₃ are a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a sulfonyloxy group, an oxycarbonyl group, a carbamoyl group, a sulfamoyl Group, oxysulfonyl group, acyl group, sulfonyl group, halogen atom, nitro group, cyano group, hydroxy group, -CON
_{H 2, -SO 2 NH 2,} -CONHNH 2, -SO 2 NHN
H ₂ or the following formula:

Embedded image

In the above formula, Y represents a divalent group, R ₄ and R ₅ represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an acyl group, a sulfonyl group, a halogen atom, a nitro group or a cyano group; ₂ is a direct _{bond, -CO -, - SO 2 -} , - C
ONH- or an -SO ₂ NH-. These substituents may further have a substituent, and R ₁ and R ₂ ,
R ₄ and R ₅ may be linked to each other to form a ring.

In the heat-sensitive recording material of the present invention, it is more preferable to use a compound having two or more amino groups as the amino compound as described above, and among the compounds having two or more amino groups, Those represented are preferred.

Embedded image

In the above formula, Z represents a divalent group, and R ₆ , R ₇ ,
R ₈ and R ₉ each represent a hydrogen atom, an alkyl group, an aryl group,
Represents an alkoxy group, an acyl group, a sulfonyl group, a halogen atom, a nitro group or a cyano group. As an example of Z:
Single bond -O -, - CO -, - S -, - SO -, - SO 2
-, - CH ₂ -, the other SO ₂ NH-, can be mentioned various groups represented by the following chemical formula 7.

Embedded image

Representative amino compounds that can be used in the present invention include, for example, 4-biphenyloxyaniline, 3-diphenylmethyloxyaniline, 4-phenoxyacetylaniline, 4-phenylacetylaniline, 4-myristoylaniline , 3-phenylsulfonylaniline, 3-biphenylsulfonylaniline, 3
-Dodecylsulfonylaniline, 3-biphenylsulfonyloxyaniline, 3-β-naphthalenesulfonyloxyaniline, 4-benzyloxycarbonylaniline, 3-dodecyloxycarbonylaniline, 4-N-
Phenylcarbamoylaniline, 4-N-dodecylcarbamoylaniline, 4-N-benzylcarbamoylaniline, 4-N-phenylsulfamoylaniline, 4-
N-dodecylsulfamoylaniline, 4-N-benzylsulfamoylaniline, 4-biphenyloxysulfonylaniline, 3-β-naphthyloxysulfonylaniline, 4-benzyloxybenzamide, 4-dodecyloxybenzamide, 4-benzyloxy Carbonylbenzamide, 3-benzyloxycarbonylbenzamide, 2-benzyloxybenzamide, 3,5-dicumylsalicylamide, 3,5-di-t-butylsalicylamide, 4-benzyloxybenzenesulfonamide,
4-benzyloxycarbonylbenzenesulfonamide, 4-benzyloxybenzohydrazide, β-naphthohydrazide, 1-p-toluenesulfonylhydrazine,
1- (4-benzyloxybansensulfonyl) hydrazine;

3,3'-dimethyl-4,4'-diaminodiphenyl, 2,2'5,5'-tetrachloro-4,
4'-diaminodiphenyl, 4,4'-methylenebis (2-chloroaniline), 3,4'-diaminodiphenylether, 4,4'-diaminodiphenylether,
4,4′-diaminodiphenyl sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane,
Bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (4-amino) Phenoxy) phenyl] ether, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,3-bis (4-aminophenoxy) phenoxy) benzene,
1,4-bis (4-aminophenoxy) benzene, 4,
4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzanilide, 9,10-bis (4-aminophenyl) anthracene, 9,9-bis (4-aminophenyl) fluorene , O-toluidine sulfone, 2,2-bis [4- (4
-Aminophenylmethyl) phenyl] hexafluoropropane, 2,2-bis [4- (4-aminobenzoyl)
Phenyl] hexafluoropropane, 2,2-bis [4
-(N-4-aminophenylcarbamoyl) phenyl]
Hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxymethyl) phenyl] propane, 2,2-bis [4- ( 4-aminobenzoyl) phenyl] propane, 2,2-bis [4- (N-4-aminophenylcarbamoyl) phenyl] propane, 2,2
-Bis [4-β- (4-aminophenoxy) ethoxyphenyl] propane and the like. These can be used alone,
Two or more kinds may be used in combination.

The amount of the amino compound to be added is preferably from 5 to 1,000% by weight, more preferably from 10 to 500% by weight of the isocyanate compound.
The dispersion particle size of the isocyanate compound or amino compound after atomization by a sand mill or the like is preferably 3 μm or less, particularly 2 μm in order to improve the color sensitivity.
It is preferable to atomize the particles to m or less. Further, the isocyanate compound may be simultaneously dispersed with the amino compound and / or the alcoholic compound.

In the present invention, together with the isocyanate compound and the amino compound, well-known phenol derivatives, phenol resins, novolak resins, metal-treated novolak resins, metal complexes, salicylic acid derivatives, metal salts of aromatic carboxylic acids, An electron-accepting compound such as acid clay and bentonite may be used in combination. Examples of these are described in JP-B-40-9309 and JP-B-45-14039, JP-A-52-140483, JP-A-48-51510, and JP-A-55-1510.
7-210886, 58-87089, 59-
No. 11286, No. 60-177675, No. 61-95
No. 988, etc.

Specific examples thereof include, for example, 4-tert-butylphenol, 4-phenylphenol, 2,2'-dihydroxybiphenyl, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 4'-sec-butylidene diphenol,
4,4'-cyclohexylidenediphenol, bis (3
-Aryl-4-hydroxyphenyl) sulfone, 4-
Hydroxyphenyl-3 ′, 4′-dimethylphenylsulfone, 4- (4-isopropoxyphenylsulfonyl) phenol, 4,4′-dihydroxydiphenylsulfide, 1,4-bis- (4′-hydroxycumyl) benzene, 1,3-bis- (4′-hydroxycumyl) benzene, 4,4′-thiobis (6-tert-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy -5-tert-butylphenyl) butane, 4,4'-butylidene-bis- (3
-Methyl-6-tert-butylphenol), 4,
4'-dihydroxydiphenylsulfone, 4-hydroxybenzoic acid benzyl ester;

3,5-di-tert-butylsalicylic acid, 3-phenyl-5- (α, α-dimethylbenzyl)
Salicylic acid, 3-cumyl-5-t-octylsalicylic acid, 3,5-di-t-butylsalicylic acid, 3-phenyl-5-t-octylsalicylic acid, 3-methyl-5-α-
Methylbenzylsalicylic acid, 3-methyl-5-cumylsalicylic acid, 3,5-di-t-octylsalicylic acid, 3,
5-bis (α-methylbenzyl) salicylic acid, 3-cumyl-5-phenylsalicylic acid, 5-n-octadecylsalicylic acid, 4-pentadecylsalicylic acid, 3,5-bis (α, α-dimethylbenzyl) salicylic acid, 3, 5-bis-t-octylsalicylic acid, 4-β-dodecyloxyethoxysalicylic acid, 4-methoxy-6-dodecyloxysalicylic acid, 4-β-phenoxyethoxysalicylic acid, 4-β-p-ethylphenoxyethoxysalicylic acid, 4-β -P-methoxyphenoxyethoxysalicylic acid and the like, and metal salts thereof.

The above-mentioned electron accepting compound is preferably mixed with the isocyanate compound in the present invention at a ratio of 0 to 200% by weight. Further, two or more of the above electron accepting compounds may be used in combination. Colorless or light-colored electron-donating dye precursor used in the present invention are compounds of fluoran represented by the following formula 8 mentioned above.

Embedded image Wherein R ₁ and R ₂ represent an alkyl group which may be substituted with either an alkoxy group or a tetrahydrofurfuryl group, and R ₁ and R ₂ may be the same or different; ₃ , R ₄ and R ₅ represent a hydrogen atom, a halogen atom or an alkyl group, and R ₃ , R ₄ and R ₅ may be the same or different.

Specific examples of phthalides are described in US Pat. No. Re. 23,024 and US Pat. No. 3,491,1.
No. 11, 3,491, 112, 3,491,
Nos. 116 and 3,509,174, and specific examples of fluorans are described in U.S. Pat. No. 3,624,107;
No. 3,627,787, No. 3,641,011
No. 3,462,828, No. 3,681,39
No. 0, No. 3,920,510, No. 3,959,5
No. 71, specific examples of spirodipyrans are described in U.S. Pat. No. 3,971,808, and pyridine and pyrazine compounds are described in U.S. Pat. Nos. 3,775,424 and 3,853,869. No. 4,246,318 and specific examples of fluorene compounds are described in JP-A-63-94878.

Of these, black aryl 2-arylamino-3-, halogen or alkyl-6-substituted aminofluorans are particularly effective, and specific examples thereof include 2-anilino-3-methyl-6. -Diethylaminofluoran, 2-anilino-3-methyl-6-N-cyclohexyl-N-methylaminofluoran, 2-p-chloroanilino-3-methyl-6-dibutylaminofluoran,
2-anilino-3-chloro-6-diethylaminofluoran, 2-anilino-3-methyl-6-N-ethyl-N
-Isoamylaminofluoran, 2-anilino-3-methyl-6-N-ethyl-N-dodecylaminofluoran, 2-anilino-3-pentadecyl-6-diethylaminofluoran, 2-anilino-3-ethyl-6 -Dibutylaminofluoran, 2-o-toluidino-3-methyl-6-diisopropylaminofluoran, 2-anilino-3-methyl-6-N-isobutyl-N-ethylaminofluoran, 2-anilino-3- Methyl-6-N-ethyl-N-tetrahydrofurfurylaminofluoran,
2-anilino-3-chloro-6-N-ethyl-N-isoamylaminofluoran, 2-anilino-3-methyl-
6-N-methyl-N-γ-ethoxypropylaminofluoran, 2-anilino-3-methyl-6-N-ethyl-
N-γ-ethoxypropylaminofluoran, 2-anilino-3-methyl-6-N-ethyl-N-γ-propoxypropylaminofluoran, 2-anilino-3-methyl-6-N-methyl-N- Propylaminofluoran and the like.

Examples of sensitizers that can be used in the present invention are described in JP-A-58-57989 and JP-A-58-87094.
And JP-A-63-39375. Specific examples thereof include aromatic ethers (particularly, benzyl ethers, di (substituted phenoxy) alkanes), aromatic esters, aliphatic amides, aromatic amides and ureas.

Next, a method for producing a typical thermosensitive coloring layer of the present invention will be described. The colorless or light-colored electron-donating dye precursor, isocyanate compound, amino compound and sensitizer are dispersed together with a water-soluble polymer aqueous solution such as polyvinyl alcohol to a size of several microns or less using a ball mill or a sand mill. The sensitizer may be added to one or both of the colorless or light-colored electron-donating dye precursor, the isocyanate compound, and the amino compound, and may be simultaneously dispersed.

These dispersions are mixed after dispersion, and if necessary, pigments, surfactants, binders, metal soaps, waxes, antioxidants, ultraviolet absorbers and the like are added to form a heat-sensitive coating solution. The obtained heat-sensitive coating liquid is coated and dried on a support such as a high-quality paper, a high-quality paper having an undercoat layer, a synthetic paper, a plastic film, and the like. Get the material.

In this case, it is particularly preferable to use a support having a smoothness specified by JIS-8119 of 500 seconds or more, particularly 800 seconds or more, from the viewpoint of dot reproducibility. In order to obtain a support having a smoothness of 500 seconds or more, (1) a material having high smoothness such as synthetic paper or a plastic film is used. (2) an undercoat layer containing a pigment as a main component on the support. And (3) means for increasing the smoothness of the support using a super calender or the like.

As the binder, a compound which is soluble in water at 25 ° C. in an amount of 5% by weight or more is preferable.
Polyvinyl alcohol (including modified polyvinyl alcohol such as carboxy-modified, itaconic acid-modified, maleic acid-modified, and silica-modified), methyl cellulose, carboxymethyl cellulose, starches (including modified starch), gelatin, gum arabic, casein, styrene-maleic anhydride Examples include acid copolymer hydrolysates, polyacrylamide, and saponified vinyl acetate-polyacrylic acid copolymer.

These binders are used not only at the time of dispersion but also for the purpose of improving the strength of the coating film. However, for the purpose of improving the strength of the coating film, a styrene / butadiene copolymer or a vinyl acetate copolymer is used. Latex binders of synthetic polymers such as acrylonitrile-butadiene copolymer, methyl acrylate-butadiene copolymer, and polyvinylidene chloride can also be used in combination. Further, an appropriate crosslinking agent may be added according to the kind of the binder.

Examples of the pigment include calcium carbonate, barium sulfate, lithopone, laurite, kaolin, silica, amorphous silica and the like. As the metal soap, higher fatty acid metal salts are used, such as zinc stearate, calcium stearate, and aluminum stearate. Furthermore, if necessary, a surfactant, an antistatic agent, an ultraviolet absorber,
An antifoaming agent, a conductive agent, a fluorescent dye, a coloring dye, or the like may be added.

The applied heat-sensitive recording material is dried, subjected to a treatment such as a calender, and used for use. Further, a protective layer may be provided on the thermosensitive coloring layer as needed. The protective layer can be appropriately selected from those known as protective layers for heat-sensitive recording materials. Further, if necessary, a back coat layer may be provided on the surface of the support of the thermosensitive recording material opposite to the thermosensitive coloring layer. As the back coat layer, any of those known as a back coat layer of a thermosensitive recording material can be used.

[0031]

As described in detail above, in the heat-sensitive recording material of the present invention, the electron-accepting compound is produced only when the isocyanate compound and the amino compound react during heating, so that the raw preservability is extremely good. Further, since the generated electron accepting compound is a urea compound, the reaction with the electron donating dye precursor is extremely rapid, so that not only the thermal sensitivity but also the coloring density is high.

[0032]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Embodiment 1 2-anilino-3-methyl-6-N-methyl-NN-propylaminofluoran as a colorless or pale-color electron-donating dye precursor, 4,4 ', 4 "-triisocyanate as an isocyanate compound 20 g each of -2,5-dimethoxytriphenylamine, 3,3'-diaminodiphenylsulfone as an amino compound and β-naphthylbenzyl ether as a sensitizer
With 100 g of 5% polyvinyl alcohol (PVA-1).
05: Kuraray Co., Ltd.) Aqueous solution was dispersed with a ball mill for 24 hours to obtain each dispersion having an average particle size of 1.5 μm or less. Separately, 80 g of calcium carbonate was dispersed in 160 g of a 0.5% sodium hexametaphosphate solution with a homogenizer to obtain a pigment dispersion.

Each of the dispersions prepared as described above was subjected to 5 g of a colorless or light-colored electron-donating dye precursor dispersion, 5 g of an isocyanate compound dispersion, 5 g of an amino compound dispersion,
A mixture of 10 g of β-naphthyl benzyl ether dispersion and 5 g of calcium carbonate dispersion was added, and 3 g of a 21% zinc stearate emulsion was added to obtain a coating solution for a thermosensitive coloring layer. This thermosensitive coloring layer coating solution was applied with a basis weight of 50 g / m ^2.
Was applied using a wire bar so that the dry weight of the coating layer was 5 g / m ^2, and dried at 50 ° C. for 1 minute to obtain a thermosensitive recording paper.

Next, the obtained heat-sensitive recording paper was subjected to a surface treatment with a calender, and the smoothness was set to a Beck smoothness of 300 ± 5.
It was adjusted to 0 seconds to obtain a thermosensitive recording material. The thus obtained thermosensitive recording paper was evaluated as follows. (1) Color density Using a print tester manufactured by Kyocera Co., Ltd., the color density when printing at a printing energy of 30 mJ / mm ² was measured with a Macbeth densitometer. It is determined that the higher the value, the higher the sensitivity of the recording paper. (2) Chemical resistance test of thermal recording paper Using a printing tester manufactured by Kyocera Co., Ltd., a portion printed and colored with a printing energy of 30 mJ / mm ² is impregnated with ethanol or a plasticizer (dioctyl phthalate). Each of them was superimposed on a filter paper, and the degree of fog and discoloration (discoloration) of the colored portion after 48 hours was evaluated. Table 1 shows the above results.

[0036]

[0037]

[0038]

[0039]

Embodiment 2 FIG. A thermosensitive recording material was obtained in exactly the same manner as in Example 1 except that bis [4- (4-aminophenoxy) phenyl] sulfone was used instead of 3,3'-diaminodiphenylsulfone in Example 1. The color density was measured in the same manner as in Example 1, and a chemical resistance test was performed. The results are as shown in Table 1.

Embodiment 3 FIG. A thermosensitive recording material was obtained in exactly the same manner as in Example 1 except that bis [4- (3-aminophenoxy) phenyl] sulfone was used instead of 3,3'-diaminodiphenylsulfone in Example 1. The color density was measured in the same manner as in Example 1, and a chemical resistance test was performed. The results are as shown in Table 1.

Embodiment 4 FIG. A heat-sensitive recording material was obtained in exactly the same manner as in Example 1 except that 4,4'-diaminobenzanilide was used instead of 3,3'-diaminodiphenylsulfone in Example 1. In addition to measuring the coloring density, a chemical resistance test was performed. The results are as shown in Table 1.

Embodiment 5 FIG. A thermosensitive recording material was obtained in exactly the same manner as in Example 1 except that bis [4- (4-aminophenoxy) phenyl] ether was used in place of 3,3'-diaminodiphenylsulfone in Example 1. The color density was measured in the same manner as in Example 1, and a chemical resistance test was performed. The results are as shown in Table 1.

Embodiment 6 FIG. Instead of 3,3'-diaminodiphenylsulfone of Example 1, 2,2-bis [4- (4-aminophenoxy)
[Phenyl] hexafluoropropane was used, except that a heat-sensitive recording material was obtained in exactly the same manner as in Example 1. The color density was measured and a chemical resistance test was carried out in the same manner as in Example 1. The results are as shown in Table 1.

Embodiment 7 FIG. A heat-sensitive recording material was obtained in exactly the same manner as in Example 1 except that 1-p-toluenesulfonylhydrazine was used instead of 3,3′-diaminodiphenylsulfone of Example 1.
The color density was measured in exactly the same manner as in Example 1, and
A chemical resistance test was performed. The results are as shown in Table 1.

Embodiment 8 FIG. A heat-sensitive recording material was obtained in exactly the same manner as in Example 1 except that m-toluenesulfonamide was used in place of 3,3'-diaminodiphenylsulfone in Example 1, and a color density was obtained in exactly the same manner as in Example 1. And a chemical resistance test was performed. The results are as shown in Table 1.

Comparative Example 1 A heat-sensitive recording material was prepared in exactly the same manner as in Example 1 except that the heat-sensitive coating solution was prepared without adding 3,3'-diaminodiphenylsulfone used in Example 1. The color density was measured in the same manner as in Example 1, and a chemical resistance test was performed. The results are as shown in Table 1.

Comparative Examples 2-5. 4, used in Example 1
Instead of using 5 g of 4 ', 4 "-triisocyanato-2,5-dimethoxytriphenylamine dispersion and 5 g of 3,3'-diaminodiphenylsulfone dispersion, bisphenol A and 4- (4-isopropoxy, respectively) were used. Phenylsulfonyl) phenol, 4,4'-butylidene-bis- (3-methyl-6-tert-butylphenol), 1,4-bis- (4'-hydroxycumyl) benzene A heat-sensitive recording material was prepared exactly in the same manner as in Example 1, and the color density was measured and the chemical resistance test was performed in the same manner as in Example 1. The results are as shown in Table 1.

Comparative Example 6 4, 4 ', used in Example 1
Instead of using 5 g of 4 "-triisocyanate-2,5-dimethoxytriphenylamine dispersion and 5 g of 3,3'-diaminodiphenylsulfone dispersion, 4,4 ', 4" -triene was previously prepared in a toluene solution. 20 g of a compound obtained by reacting isocyanate-2,5-dimethoxytriphenylamine with an equimolar amount of 3,3′-diaminodiphenylsulfone at 50 ° C. for 2 hours, together with 100 g of a 5% aqueous solution of polyvinyl alcohol (PVA-105), A heat-sensitive recording material was prepared in exactly the same manner as in Example 1 except that 10 g of the dispersion liquid dispersed all day and night by a ball mill was used, and the color density was measured and a chemical resistance test was performed in the same manner as in Example 1. Was. The results are as shown in Table 1.

[0050]

[Table 1] From the results shown in Table 1, it was proved that the recording material of the present invention had a sufficient color density, did not cause fogging or decoloration of the color-developed portion due to chemicals, and had extremely excellent performance. Was.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-92664 (JP, A) JP-A-4-232777 (JP, A) JP-A-2-103180 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) B41M 5/28-5/34

Claims (4)

(57) [Claims] 1. A colorless or light-colored electron-donating dye precursor,
Reacts when heated and acts as an electron-accepting compound
A thermosensitive recording material comprising a support provided with a thermosensitive coloring layer containing an isocyanate compound and an amino compound forming a urea compound , wherein the electron-donating dye precursor is
A fluoran compound represented by the following chemical formula 1.
That the heat-sensitive recording material; [Formula 1] Wherein R ₁ and R ₂ are an alkoxy group or tetrahydro
Alkyl optionally substituted with any of furfuryl groups
R ₁ and R ₂ may be the same or different
R ₃ , R ₄ and R ₅ are a hydrogen atom, a halogen atom
Or R ₃ , R ₄ and R ₅ are the same
Or different. 2. The heat-sensitive recording material according to claim 1, wherein the isocyanate compound is an aromatic isocyanate compound having two or more —NCO groups. 3. The heat-sensitive recording material according to claim 1, wherein the amino compound is a compound represented by the following formula (2). Embedded image In the above formulas, X is a direct _{bond, -CO -, - SO 2 -} , - CO
Represents NH— or —SO ₂ NH—, and R ₁ , R ₂ and R ₃ are each a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a sulfonyloxy group, an oxycarbonyl group, a carbamoyl group, a sulfamoyl group Oxysulfonyl group, acyl group, sulfonyl group, halogen atom, nitro group, cyano group, hydroxy group, -CON
_{H 2, -SO 2 NH 2,} -CONHNH 2, -SO 2 NHN
Represents H ₂ or Embedded image In the above formula, Y is a divalent group, R ₄ and R ₅ are each a hydrogen atom,
Alkyl group, an aryl group, an alkoxy group, an acyl group, a sulfonyl group, a halogen atom, a nitro group or a cyano group, X ₂ is a direct _{bond, -CO -, - SO 2 -} , - CONH
- or an -SO ₂ NH-. These substituents may further have a substituent, and R ₁ and R ₂ and R ₄
And R ₅ may be linked to each other to form a ring. 4. The heat-sensitive recording material according to claim 1, wherein the amino compound has two or more —NH ₂ groups.