JP3336607B2 - Thermal recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording medium having excellent image storability and stability of a ground color portion.

[0002]

2. Description of the Related Art In general, a thermosensitive recording medium is usually prepared by grinding and dispersing a colorless or pale-colored basic colorless dye and an organic developer such as a phenolic compound into fine particles, and then mixing the two. A coating obtained by adding a binder, a filler, a sensitivity improver, a lubricant and other auxiliaries to a support such as paper, synthetic paper, film, plastic, etc. , Hot stamp, hot pen, laser light, etc., the color is developed by an instantaneous chemical reaction, and a recorded image is obtained. The recording device of the thermal recording medium does not require replacement of toner or ribbon, and requires only maintenance because the recording can be performed only by causing the thermal head to generate heat. Therefore, a facsimile, a terminal printer of a computer, an automatic printer, etc. It is widely used in ticket vending machines, measurement recorders, and the like. As the heat-sensitive recording medium is used for various applications, in recent years, storage stability against heat, oil, plasticizer, and light has been required. More recently, as recording methods on plain paper such as electrophotography and ink-jet recording have become widespread, thermal recording has been increasingly compared with these plain paper recordings. Sex is needed.

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, a color image is formed over time. It has been known that the color will be decolorized, which has been a problem.
This decolorization is accelerated under light, high temperature and high humidity atmospheres, and further progresses significantly due to prolonged standing in water, contact with oil such as salad oil, plasticizer contained in wrap film, etc. The image becomes unreadable.

[0004] In order to suppress such a decoloring phenomenon of a recorded image, a number of techniques have been disclosed for a thermosensitive recording medium containing a basic colorless dye and a developer as main components. For example, JP-A-60-78782 and JP-A-59-114
JP-A-56-1467, in which a phenolic antioxidant is incorporated in a thermosensitive coloring layer as disclosed in JP-A-0996.
No. 94, which uses a hydrophobic polymer compound emulsion or the like for a protective layer, is known. In addition, a phenol-based developer combined with an epoxy compound (Japanese Patent Application Laid-Open No. 62-164579), an aziridine compound used in combination (Japanese Patent Application Laid-Open No. 4-113888), and a combination of various metal salts (JP-A-4-113888) 63-226
No. 83) is known. However, the effect on the plasticizer was not sufficient, and decolorization over time remained as a problem. Furthermore, when the above-mentioned additive is introduced, resistance to water and heat is lost, and there is a problem such as background contamination.

[0005] Further, for the purpose of high preservation, development of non-phenol type developer having no hydroxy group has been progressing in place of conventionally used phenol type developer. However, in the case of a thermosensitive recording medium using a compound having a plurality of sulfonyl (thio) urea groups described in JP-A-5-147357 as a developer, the contamination of the background progresses over time, There is a problem that background contamination progresses even in the presence or heat environment. Further, JP-A-5-3
In the case of a thermosensitive recording medium using a compound having a sulfonyl (thio) urea structure described in JP-A No. 2061 or JP-A-5-246146 as a developer, a plasticizer or the like can be used in combination with an aziridine compound. With this developer alone, sufficient plasticizer resistance cannot be obtained and there is also a problem of background contamination due to mixing. Also, the moisture resistance of the recorded image (40 degrees, 90 degrees)
% RH, 48 hours) is by no means satisfactory, and in particular, the image is decolorized by prolonged exposure to such an environment.

On the other hand, various methods have been tried for improving the light fastness. JP-A-63-307
No. 981 describes that an ultraviolet absorber is contained in a heat-sensitive recording layer. However, this method has a problem that heat resistance is poor because the melting point of the ultraviolet absorber is generally low. JP-A-61-193883 discloses that a benzotriazole-based hydrophobic ultraviolet absorber is contained in a protective layer. However, this method has a drawback that sticking and sticking occur during printing. The case where a water-soluble ultraviolet absorber is used is described in JP-A-7-17131. However, in this method, ions such as sodium salts are formed upon solubilization of the water-soluble ultraviolet absorber, so that there is a drawback that the thermal head is electrochemically worn. In Japanese Patent Application Laid-Open No. Sho 62-176879, for the purpose of absorbing ultraviolet rays from the back surface,
It is described that a benzotriazole compound is contained in the undercoat layer and the protective layer. However, even with this method, the ultraviolet absorber in the protective layer causes sticking and sticking during printing, and a heat-sensitive recording material of sufficient quality could not be obtained.

Japanese Patent Application Laid-Open No. 62-18626 describes that zinc oxide which is an inorganic filler having an ultraviolet shielding effect is contained in a heat-sensitive recording layer. However, in this method, in the case of an inorganic filler having an ultraviolet shielding effect, the ultraviolet shielding effect is large, but the transmittance in the visible light region is small, and the color-developed portion is concealed and the printing density is lowered. Therefore, if the amount used is reduced to such an extent that a sufficient print density can be maintained, there is a problem that the effect of blocking ultraviolet rays is deteriorated and is not practical. JP-A-6-64324 discloses that a protective layer contains cerium oxide fine particles. However, in this method, cerium oxide itself may be colored, which is not suitable as a material for a thermal recording medium.

Further, JP-A-7-25147 discloses that cerium oxide is coated on core particles made of an inorganic pigment,
It is described that a protective layer contains an ultraviolet ray blocking agent having a three-layer structure in which a cerium oxide-coated surface is coated with an inorganic pigment identical or different from the inorganic pigment. However, in this method, although the coloring of the cerium oxide is somewhat inconspicuous,
The ultraviolet blocking effect of cerium oxide was blocked, and sufficient light resistance could not be obtained.

[0009]

DISCLOSURE OF THE INVENTION The present invention is excellent in image preservability such as oil resistance, plasticizer resistance and the like, and is resistant to contamination of the ground color. An object of the present invention is to provide a thermosensitive recording medium having excellent ground color stability and image storability.

[0010]

The object of the present invention is to provide an undercoat layer, a heat-sensitive recording layer containing a leuco dye type coloring component comprising a colorless or pale color dye precursor and a color developer, and a protective layer on a support. Are laminated, a UV absorber is contained in the undercoat layer and / or the heat-sensitive recording layer, an ultraviolet ray blocking agent is contained in the heat-sensitive recording layer and / or the protective layer, and a fluorescent dye is contained in the protective layer. And at least one urea (thiourea) represented by the following general formula (I) in the heat-sensitive recording layer.
The present invention relates to a thermosensitive recording medium containing a compound.

[0011]

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. )

The compound represented by the formula (I) of the present invention exhibits excellent color developing ability and extremely high image preservability when used as an organic color developer. Further, when this compound is added to a heat-sensitive recording 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.

In the present invention, when the compound represented by the general formula (I) is used as a color developer, it contains 1 to 8 parts with respect to 1 part of the basic colorless dye 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 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 the other organic developer is used alone or in combination of two or more. To form a heat-sensitive recording layer.

The compound of the formula (I) used in the present invention has a reduced electron density adjacent to an electron-withdrawing group in the molecule.
Because it has a plurality of so-called acidified nitrogen atoms,
The chemical bonding strength of the base increases, and as a result, the color develops due to the reaction between the color developer and the basic colorless dye during the heat melting reaction, and the recorded image is stabilized, and the recorded image is affected by water, oil, and heat. It is considered that the stability of the color image is maintained even if the image is exposed to the environmental conditions for a long time. Although the reason why the heat-sensitive recording material of the present invention is excellent in heat resistance of the ground color is not clearly understood, in the compound represented by the general formula (I) used in the present invention, the aromatic ring bonded to the sulfonyl group has The melting point tends to be higher due to substitution with an aryl (thio) ureido group, and the presence of a (thio) urea group and a sulfonyl (thio) urea group makes it especially possible for the (thio) urea group to be around 100 ° C. It is presumed that at a temperature of, the thermal stability of the ground color portion is increased because a tautomerization from a neutral structure (a keto-type structure in the case of urea), which is considered to exhibit a color developing function, to an acidic-type structure does not occur. However, when the heat-sensitive recording material using the compound of the general formula (I) is exposed to direct sunlight or left for a long time under a fluorescent lamp in the room, the ground color is discolored and the image is discolored. It is difficult to say that light fastness has been obtained.

Therefore, at least one urea (thiourea) represented by the above general formula (I) is used for the purpose of improving light resistance.
When an ultraviolet absorber is contained in the heat-sensitive recording layer containing the derivative, the storage stability against oil, plasticizer, and the like tends to be reduced. Although the cause of this is not clearly understood, the ultraviolet absorbent melts in oil, plasticizer, etc. to exert some chemical action on the urea (thiourea) derivative of the present invention, and the dye-urea (thiourea) in a color-developed state is produced. This is considered to further promote the dissociation of the complex of the derivative or the complex of the dye-developer-urea (thiourea) derivative. In addition, the ground color stability against heat is also reduced by including an ultraviolet absorber. This is presumed to be because the ultraviolet absorber exerts a certain chemical action on the urea (thiourea) derivative, so that color formation is likely to occur even at a relatively low temperature. In addition, since the melting point of the ultraviolet absorber is generally 140 ° C. or less, it is considered that one of the causes is that the ultraviolet absorber melts at a relatively low temperature and provides an environment where the developer and the dye precursor are easily brought into contact with each other. . Further, when an ultraviolet absorber is contained in the protective layer, sticking of sticking and sticking are remarkably observed. Furthermore, even when various inorganic pigments having an ultraviolet blocking ability are contained in the protective layer, sufficient light resistance cannot be obtained, and when the content is increased to obtain high light resistance, a decrease in recording density is observed. As described above, the problem cannot be solved by the conventional technique, and the present inventors have conducted intensive studies and found that the problem can be achieved by adopting the above-described configuration, thereby completing the present invention. .

The reason why the heat-sensitive recording material of the present invention is extremely stable to oils and plasticizers, and also has excellent ground color stability and light resistance has not been elucidated clearly, but is presumed as follows. Is done. The ultraviolet absorber or the ultraviolet ray blocking agent used for improving the light fastness becomes unstable with respect to oil and plasticizer in the heat-sensitive recording medium containing the urea (thiourea) derivative of the present invention. The heat resistance is reduced, and if contained in the protective layer, it causes adverse effects such as adhesion of dregs and sticking. However, by using a combination of an ultraviolet absorber, an ultraviolet blocker and a fluorescent dye, these interactions are caused. By maintaining the excellent stability of the complex of the compound represented by the general formula (I) and the dye or the complex of the dye-developer-urea (thiourea) derivative, the urea (thio) Light resistance can be obtained without impairing the high ground color stability inherently possessed by the (urea) derivative.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to obtain a thermosensitive recording medium of the present invention,
For example, an undercoat layer coating solution is prepared by dispersing an ultraviolet absorber together with a binder and a filler, and is coated on a support and dried to form an undercoat layer. Next, a dispersion in which the dye precursor and the developer represented by the general formula (I) are respectively dispersed together with a binder is mixed, and if necessary, an ultraviolet ray blocking agent, an ultraviolet absorbent dispersion, a filler, and other necessary components. The coating liquid for the heat-sensitive recording layer is prepared by adding an additive, and is coated on the undercoat layer and dried to form a heat-sensitive recording layer. Further, a protective layer coating solution containing additives such as a fluorescent dye, an ultraviolet ray blocking agent, a water-soluble polymer, and a filler, if necessary, is prepared, and the protective layer is formed by coating and drying the thermosensitive recording layer. Thereby, the thermosensitive recording medium of the present invention can be manufactured.

In the heat-sensitive recording material of the present invention, the UV absorber contained in the undercoat layer or the heat-sensitive recording layer includes:
Various known hydrophobic or water-soluble substances can be used. Examples of the hydrophobic ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, and 2,2 ′. -Dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,
4'-dimethoxybenzophenone, 2-hydroxy-4
Benzophenone-based ultraviolet absorbers such as -methoxy-5-sulfobenzophenone, 2- (2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-
5′-methylphenyl) benzotriazole, 2-
(2′-hydroxy-5′-tert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′,
5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-
5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-
Butylphenyl) -5-chlorobenzotriazole, 2
-(2'-hydroxy-3 ', 5'-di-tert-aminophenyl) benzotriazole, 2- (2'-hydroxy-3', 5'-di-tert-butylphenyl) -5-te
rt-butylbenzotriazole, 2- (2′-hydroxy-3′-dodecyl-5′-methylphenyl) benzotriazole, 2- [2′-hydroxy-4 ′-(2 ″
-Ethylhexyl) oxyphenyl] benzotriazole, methyl-3- [3-tert-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate-polyethylene glycol (molecular weight about 300) Condensate of 5-tert-butyl-3- (5-
Chloro-2H-benzotriazol-2-yl) -4-
Hydroxybenzene-octyl propionate, 2,2-
Methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2′-hydroxy-3′-se
c-butyl-5'-tert-butylphenyl) -5-tert
Benzotriazole-based ultraviolet absorbers such as -butylbenzotriazole, salicylic acid-based ultraviolet absorbers such as phenyl salicylate, p-tert-butylphenyl salicylate and p-octylphenyl salicylate; 2-ethylhexyl-2-cyano-3; Cyanoacrylate-based ultraviolet absorbers such as 3'-diphenylacrylate and ethyl-2-cyano-3,3'-diphenylacrylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, succinic acid -Bis (2,2,6,6,-
Tetramethyl-4-piperidyl) ester, 2- (3,
Bis (1,2,2,5-di-tert-butyl) malonic acid
Hindered amine ultraviolet absorbers such as 6,6, -pentamethyl-4-piperidyl) ester can be exemplified.

As the water-soluble ultraviolet absorber, for example, 2
-Hydroxy-4-methoxybenzophenone-5-sulfonic acid, sodium 2-hydroxy-4-methoxybenzophenone-5-sulfonate, potassium 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 2,
Sodium 2'-dihydroxy-4,4'-dimethoxybenzophenone-5-sulfonate, sodium 2,4-dihydroxybenzophenone-5-sulfonate,
Sodium 2'-dihydroxy-4,4'-dimethoxybenzophenone-5,5'-disulfonate, Sodium 2,4-dihydroxybenzophenone-5'-sulfonate, 2,2 ', 4,4'-tetrahydroxybenzophenone- Benzophenone-based ultraviolet absorbers such as sodium 5,5'-disulfonate; 2- (2'-hydroxy-
4'-methoxy-5'-sulfophenyl) benzotriazole sodium salt, 2- (2'-hydroxy-4'-
Butoxy-5'-sulfophenyl) benzotriazole sodium salts such as sodium salt and the like.

The present invention is not limited to these, but among them, a benzotriazole-based ultraviolet absorber having the highest effect on light resistance is preferably used. Also, two or more kinds can be used in combination as needed. In particular, when it is contained in the heat-sensitive recording layer, it has a high light resistance and a high melting point.
Methylenebis [4- (1,1,3,3, -tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] is desirable because it causes less coloring and improves the heat resistance of the thermosensitive recording medium.

The UV absorber is used in an amount of 0.1% by weight to 15% by weight based on the dry weight of the undercoat layer, and 0.1% by weight to 8% by weight based on the dry weight of the heat-sensitive recording layer. Let it. More preferably, it is in the range of 1% to 10% by weight based on the dry weight of the undercoat layer, and 2% to 6% by weight based on the dry weight of the heat-sensitive recording layer. When the amount of the UV absorber used in the undercoat layer or the heat-sensitive recording layer is 0.1% by weight or less, the effect on light resistance is low, and 15% by weight or more of the undercoat layer or 8% by weight or more of the heat-sensitive recording layer. If this is the case, the heat resistance, color sensitivity and image storability of the thermosensitive recording medium will be reduced.

In the heat-sensitive recording medium of the present invention, the ultraviolet ray blocking agent contained in the heat-sensitive recording layer or the protective layer is desirably one having high transparency and low concealment from the viewpoint of color-forming sensitivity. Examples of such an ultraviolet blocking agent include a flaky pigment having a refractive index of 1.5 to 1.6 according to claim 4 of the present invention, which is coated with an insoluble cerium compound and further coated with amorphous silica. Fired products of particles having a layered structure,
Alternatively, a fired product of particles having a two-layer structure in which the insoluble cerium compound according to claim 5 of the present invention is coated with amorphous silica can be mentioned, and these are preferably used in the present invention.

With respect to such an ultraviolet ray blocking agent, a fired product of particles having a three-layer structure is disclosed in JP-A-6-145645 and is well known. A fired product of particles having a two-layer structure is described in JP-A-9-202048 and is well known. In order to produce the ultraviolet ray blocking agent having a three-layer structure, first, an aqueous cerium salt solution is added dropwise to an aqueous dispersion of the flake pigment under heating as 1 to 30% by weight as CeO ₂ to the pigment under heating to adjust the pH to 7 to 9. Then, an insoluble cerium compound is deposited on the pigment surface to obtain a cerium-coated pigment. Then, a silicate solution is added to the aqueous dispersion of the cerium-coated pigment under heating to adjust the pH to 6 to 8, and the amorphous silica is deposited and coated on the surface of the pigment, and then calcined at a high temperature of 200 ° C. or more. It is obtained by doing. The amount of amorphous silica deposited is ₂ as SiO _{2 with} respect to the cerium pigment.
-40% by weight.

The pigment serving as a nucleus is preferably in the form of a flake having a refractive index of about 1.5 to 1.6. Examples of such pigments include mica, talc, sericite, aluminum hydroxide, calcium carbonate, kaolin, calcium hydroxide, aluminum silicate, polyethylene powder,
Examples include polystyrene and latex. Among them, mica, talc, and sericite are preferable because a heat-sensitive recording material having a good coloring density can be obtained. Further, as the cerium compound, cerium chloride, cerium nitrate, cerium sulfate, etc. can be used, and as the silicate,
Organic silicates can be used in addition to inorganic salts such as sodium silicate.

The baked product of the particles having a two-layer structure is prepared by adding a cerium hydroxide slurry produced by adding a cerium salt solution and an alkaline solution to water maintained at a liquid temperature of 60 ° C. or less and a pH of 5 or more. It is manufactured by a method in which a non-crystalline silica is formed by adding a sodium silicate solution and a mineral acid solution while heating to not less than 9 ° C. and keeping the pH at not less than 9, washing with water, filtering, and then drying or calcining.

The amount of the ultraviolet blocking agent used is from 10% by weight to 40% by weight based on the dry weight of the heat-sensitive recording layer.
It is preferred to contain. When the content is 10% by weight or less, the effect on light resistance is small, and when the content is 40% by weight or more, the coloring sensitivity is reduced. In the protective layer, the content is preferably 5% by weight to 40% by weight based on the dry weight. 5
When the content is less than 40% by weight, the effect on light resistance is small, and
When the content is more than 10% by weight, the barrier properties of the protective layer and the color development sensitivity decrease.

As the fluorescent dye, various known dyes can be used, and examples thereof include stilbene derivatives, coumarin derivatives, pyrazoline derivatives, bisstyrylbiphenyl derivatives, naphthalimide derivatives, and bisbenzooxazolyl derivatives. However, a diaminostilbene disulfone derivative is particularly preferred because of its high effect on light resistance.

The amount of the fluorescent dye used is preferably 0.01 to 3% by weight based on the dry weight of the protective layer. More preferably, it is in the range of 0.1 to 2% by weight.
When the amount of the fluorescent dye in the protective layer is 0.01% by weight or less, the effect on light resistance is reduced. Connect.

The ultraviolet blocking agent used in the present invention has a characteristic layered structure and can maintain a sufficient whiteness. Further, since it is composed of a pigment generally used in a heat-sensitive recording medium, even when it is contained in the heat-sensitive recording layer, no adverse effects such as background fog and desensitization are observed. Further, the ultraviolet ray blocking agent may be contained in the undercoat layer.

However, the light resistance required by the present invention cannot be obtained even when the heat-sensitive recording medium contains only the ultraviolet ray blocking agent. Presumably, the cerium compound is covered with amorphous silica, and the ultraviolet blocking effect of the cerium compound is blocked. In particular, when the undercoat layer contains an ultraviolet absorber, the heat-sensitive recording layer contains an ultraviolet absorber or an ultraviolet ray blocking agent, and the protective layer further contains a fluorescent dye, a high light resistance is obtained. It is a target. When the heat-sensitive recording layer contains an ultraviolet absorber and an ultraviolet blocker, it is preferable to mix the ultraviolet absorber and the ultraviolet shield at a ratio of 1: 4 to 4: 1.

In the present invention, the undercoat layer or the heat-sensitive recording layer may contain an ultraviolet absorber,
It is considered that not only the ultraviolet ray from the rear surface of the thermosensitive recording medium is absorbed, but also the ultraviolet absorbing ability is increased due to a synergistic effect with the ultraviolet ray blocking agent in the thermosensitive recording layer.

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 compounds of the present invention have the formula (I)
It can be easily obtained by reacting 3-aminobenzenesulfonamide represented by I) with an isocyanate compound represented by general formula (III) or an isothiocyanate compound represented by general formula (IV).

[0034]

Embedded image

[0035]

Embedded image OCN—R ₅ —NCO (III) wherein R ₅ is a C ₄ -C ₁₂ alkyl group (for example, 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.). )

[0036]

Embedded image SCN—R ₅ —NCS (IV) wherein R ₅ is substituted with a C _{4 to} C ₁₂ alkyl group, an unsubstituted aromatic ring, a C _{1 to} 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 (thio). This produces carbanilide compounds. Generated 3-
Without isolating the sulfamoyl (thio) carbanilide compound, an aqueous alkali hydroxide solution was added according to the method described in French Patent No. 994465 to form an alkali metal salt of a 3-sulfamoyl (thio) carbanilide compound, and further, It can be easily produced by reacting with a corresponding isocyanate compound or isothiocyanate compound.

As the isocyanate compound, 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, toluene diisothiocyanate, 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.

Examples of the alkali hydroxide include 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 required.

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) sulfonylaminocarbonylamino diphenylmethane,
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 カ ル ボ ニ ル 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) sulfonylaminocarbonylaminodiphenylsulfone, 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 preferred. .

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 shown.

<Bisphenol A>4,4'-isopropylidenediphenol (also known as bisphenol A) 4,4'-cyclohexylidenediphenol p, p '-(1-methyl-normalhexylidene) diphenol 1, 7-di (hydroxyphenylthio) -3,5-dioxaheptane <4-hydroxybenzoates> Benzyl 4-hydroxybenzoate Ethyl 4-hydroxybenzoate Propyl 4-hydroxybenzoate 4-Isopropyl benzoate 4 -Butyl hydroxybenzoate 4-Isobutyl 4-hydroxybenzoate Methylbenzyl 4-hydroxybenzoate <Dimethyl 4-hydroxyphthalates> Dimethyl 4-hydroxyphthalate 4-Diisopropyl 4-hydroxyphthalate 4-Dibenzyl 4-hydroxyphthalate 4-hydro Dihexyl phthalate <Monoesters of phthalic acid> Monobenzyl phthalate Monocyclohexyl phthalate Monophenyl phthalate Monomethyl phthalate Monoethyl phthalate Monoethyl phenyl phthalate Monopropyl benzyl phthalate Monohalogen benzyl phthalate Phthalic acid Monoethoxybenzyl ester <Bis- (hydroxyphenyl) sulfides> Bis- (4-hydroxy-3-tert-butyl-6-
Methylphenyl) sulfide bis- (4-hydroxy-2,5-dimethylphenyl)
Sulfide bis- (4-hydroxy-2-methyl-5-ethylphenyl) sulfide bis- (4-hydroxy-2-methyl-5-isopropylphenyl) sulfide bis- (4-hydroxy-2,3-dimethylphenyl)
Sulfide bis- (4-hydroxy-2,5-dimethylphenyl)
Sulfide bis- (4-hydroxy-2,5-diisopropylphenyl) sulfide bis- (4-hydroxy-2,3,6-trimethylphenyl) sulfide bis- (2,4,5-trihydroxyphenyl) sulfide bis- ( 4-hydroxy-2-cyclohexyl-5-methylphenyl) sulfide bis- (2,3,4-trihydroxyphenyl) sulfide bis- (4,5-dihydroxy-2-tert-butylphenyl) sulfide bis- (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-h Droxyphenyl-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-hydroxybenzoyloxybenzoate 4-h Roxybenzoyloxy 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) sulfone bis- (3-ethyl-4-hydroxyphenyl) ) Sulfone bis- (3-propyl-4-hydroxyphenyl) sulfone bis- (3-methyl-4-hydroxyphenyl) sulfone bis- (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'-
Hydroxyphenylphorone 4-hydroxyphenyl-3'-secbutyl-4'-
Hydroxyphenylphorone 3-chloro-4-hydroxyphenyl-3'-isopropyl-4'-hydroxyphenylsulfone 2-hydroxy-5-t-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-t-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'-sulfonyldiphenol 3, 3'-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 phenol resin 4-hydroxyacetophenone p-phenylphenol benzyl-4-hydroxyphenylacetate p-benzylphenol

As the dye precursor to be used in the heat-sensitive recording material of the present invention, any of those known in the field of conventional pressure-sensitive or heat-sensitive recording paper can be used, and there is no particular limitation. Compounds, fluorane compounds, fluorene compounds, divinyl compounds and the like are preferred. Specific examples of typical dye precursors are shown below. These dye precursors may 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) fluorane 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-meth Le-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-anilinofur Oran 3-diethylamino-7-methylfluoran 3-diethylamino- -Chlorofluoran 3-diethylamino-7- (m-trifluoromethylanilino) fluoran 3-diethylamino-7- (o-chloroanilino) fluoran 3-diethylamino-7- (p-chloroanilino) fluoran 3-diethylamino-7- (O-fluoroanilino) fluoran 3-diethylamino-benzo [a] fluoran 3-diethylamino-benzo [c] fluoran 3-dibutylamino-6-methyl-fluoran 3-dibutylamino-6-methyl-7-anilinofur Oran 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-dibuty Amino-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-a Linofluoran 3-n-dipentylamino-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) aminoanilinofluoran 2- 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-Diacetylethane bis- [2,2,2 ', 2'-tetrakis- (p-dimethylaminophenyl) -ethenyl] -methylmalonic acid dimethyl ester

In the present invention, conventionally known sensitizers can be used as long as the desired effects on the above objects are not impaired. When manufacturing a heat-sensitive recording material having extremely excellent heat resistance, it is generally better not to use a sensitizer, but it is necessary to add an appropriate amount of the sensitizer according to the heat-resistant temperature characteristics of the target thermal environment. Can be. Examples of such sensitizers include fatty acid amides such as stearic acid amide and palmitic acid amide, ethylene bisamide, montanic acid wax, polyethylene wax, 1,2-di- (3-methylphenoxy) ethane, p-benzylbiphenyl, β- Benzyloxynaphthalene, 4-biphenyl-p-tolyl ether, m-terphenyl, 1,2-diphenoxyethane, dibenzyl oxalate, di (p-chlorobenzyl) oxalate, di (p-methylbenzyl) oxalate, Dibenzyl terephthalate, benzyl p-benzyloxybenzoate, di-p-tolyl carbonate, phenyl-α-naphthyl carbonate, 1,4-diethoxynaphthalene, 1
-Hydroxy-2-naphthoic acid phenyl ester, o-
Xylerin-bis- (phenyl ether), 4- (m-
Examples thereof include, but are not particularly limited to, methylphenoxymethyl) biphenyl. These sensitizers may be used alone or in combination of two or more.

As the binder used in the heat-sensitive recording layer of 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 Alcohol, modified polyvinyl alcohol such as butyral modified polyvinyl alcohol, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, cellulose derivatives such as acetyl cellulose, styrene-maleic anhydride copolymer, styrene-butadiene copolymer, polyvinyl chloride, poly (vinyl chloride) Vinyl acetate, polyacrylamide, polyacrylate,
Examples thereof include polyvinyl butyral, polystyrene and copolymers thereof, polyamide resin, silicone resin, petroleum resin, terpene resin, ketone resin, and cumarone resin. These polymer substances can be used by dissolving them in solvents such as water, alcohols, ketones, esters, and hydrocarbons, or they can be used in the form of emulsified or dispersed pastes in water or other media, depending on the required quality. You can also.

Further, in the present invention, metal salts of p-nitrobenzoic acid (Ca, Zn), which are known stabilizers exhibiting an oil resistance effect of a recorded image and the like, as long as the desired effects on the above-mentioned problems are not impaired, Alternatively, phthalic acid monobenzyl ester metal salt (Ca, Zn) can be added.

The fillers that can be used in the heat-sensitive recording layer of the present invention include silica, calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium oxide,
Examples include inorganic or organic fillers such as zinc oxide, aluminum hydroxide, polystyrene resin, urea-formalin resin, styrene-methacrylic acid copolymer, styrene-butadiene copolymer, and hollow plastic pigment.

In addition, release agents such as fatty acid metal salts, lubricants such as waxes, water-resistant agents such as glyoxal,
Dispersants, defoamers, antioxidants, fluorescent dyes and the like can be used.

In the undercoat layer of the present invention, as a binder, a commonly used emulsion of a water-soluble polymer or a hydrophobic polymer or the like can be appropriately used.
Specific examples include cellulose derivatives such as polyvinyl alcohol, polyvinyl acetal, hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, starch and its derivatives, sodium polyacrylate, polyvinylpyrrolidone, acrylamide / acrylate copolymer, and acrylamide. / Acrylic acid ester / methacrylic acid copolymer, styrene / maleic anhydride copolymer alkaline salt, isobutylene / maleic anhydride copolymer alkaline salt, polyacrylamide, sodium alginate, gelatin, casein and other water-soluble polymers, poly Vinyl acetate, polyurethane, styrene / butadiene copolymer, polyacrylic acid, polyacrylate, vinyl chloride / vinyl acetate copolymer, polybutyl methacrylate, ethylene / bi-acetate Alcohol copolymer can be used styrene / butadiene / emulsion of a hydrophobic polymer such as an acrylic copolymer.

As the filler in the undercoat layer, known fillers generally used in the prior art, such as calcium carbonate, silica, zinc oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, calcined kaolin, In addition to inorganic fillers such as clay and talc, organic fillers such as styrene-methacrylic copolymer resin, urea-formalin resin, and polystyrene resin can be used. Especially JIS
When a pigment having an oil absorption of 100 ml / 100 g or less based on K5101 is contained, color density and printability are improved.

In the protective layer of the present invention, various known fillers can be used. Specific examples of such fillers include kaolin, clay, calcium carbonate, calcined clay,
Inorganic pigments such as calcined kaolin, aluminum hydroxide, titanium oxide, diatomaceous earth, fine anhydrous silica, activated clay, and organic pigments such as styrene microballs, nylon powder, polyethylene powder, urea / formalin resin filler, raw starch particles, and the like. Can be

As the binder in the protective layer, a binder composed of a polymer compound usually used in the field of thermal recording can be used. Specific examples of such a binder include, for example, starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, polyvinyl acetate , Vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, acrylonitrile-butadiene-styrene copolymer, vinyl acetate-acrylic acid copolymer, ethylene-acrylic acid copolymer, styrene-acrylic acid copolymer Copolymer, acrylic ester resin, acrylic emulsion, diisobutylene / maleic anhydride copolymer, styrene / maleic anhydride copolymer, styrene / butadiene copolymer emulsion , Methyl methacrylate-butadiene copolymer, methyl methacrylate-styrene-butadiene copolymer, styrene polymer, isoprene polymer, butadiene polymer, vinyl chloride polymer, vinylidene chloride polymer, urea resin, melamine resin, amide Resin, polyurethane resin and the like can be exemplified.

Further, in the protective layer, if necessary, a lubricant such as zinc stearate, calcium stearate, polyethylene wax, carnauba wax, paraffin wax, ester wax or the like, or a surfactant such as sodium dioctyl sulfosuccinate (dispersant, wetting agent) ), An antifoaming agent, and various auxiliaries such as water-soluble polyvalent metal salts such as potassium alum and aluminum acetate. Further, in order to further improve the water resistance, a curing agent such as glyoxal, boric acid, dialdehyde starch, or an epoxy compound can be used in combination.

The amounts of the developer and the dye precursor and the types and amounts of other various components used in the heat-sensitive recording layer of the present invention are determined according to the required performance and recording suitability, and are not particularly limited. Usually, with respect to 1 part of the dye precursor,
The developer of 1 to 8 parts of the present invention and the filler of 1 to 20 parts are used, and the binder is suitably used at 10 to 25% of the total solid content. When the heat-sensitive recording layer contains an ultraviolet absorber and an ultraviolet ray blocking agent, the ratio of the ultraviolet ray absorbing agent and the ultraviolet ray blocking agent is 1: 4 to
It is good to mix at a ratio of 4: 1.

The above-mentioned developer, dye precursor, and optionally added materials are pulverized to a particle diameter of several microns or less by a pulverizer such as a ball mill, an attritor, a sand grinder or an appropriate emulsifying device. A coating liquid is prepared by adding a binder and various additives depending on the purpose.

As the support, paper, synthetic paper, plastic film, non-woven fabric, metal foil and the like can be used, or a composite sheet combining these can be used. The desired heat-sensitive recording medium can be obtained by sequentially applying a coating solution for each layer having the above composition to any of these supports.

[0061] The coating amount of the undercoat layer coating liquid for 2~12g / m ² by dry weight, 2 to preferably 3 to 10 g / m ² approximately, the coating amount of the heat-sensitive recording layer coating composition in a dry weight 12g /
m ^2, is preferably adjusted 3 to 10 g / m ² approximately, the coating amount of the protective layer coating composition is 0.1 to 20 g / m ² by dry weight, preferably 0.5 to 10 g / m ² range of about You.

[0062]

EXAMPLES <Production example 1 of ultraviolet blocking agent> Flake-like pigment 500 serving as a core material of the ultraviolet blocking agent used in the present invention
g was dispersed in 10 liters of water, and 264 g of an aqueous cerium nitrate solution was added dropwise while heating and stirring at 80 ° C. Subsequently, the mixture was neutralized to pH 7 to 9 with a sodium hydroxide solution, cerium hydroxide was deposited on the surface of the pigment, and then dried and pulverized to obtain a cerium-coated pigment. Next, after dispersing the cerium-coated pigment in 10 liters of water, 348 g of No. 3 sodium silicate was added with heating and stirring at 80 ° C. or higher, adjusted to pH 6 to 8 with sulfuric acid, and then dried and pulverized to obtain a cerium-silica coating. A pigment was obtained. This was further fired at 500 ° C. for 2 hours to obtain an ultraviolet ray blocking agent having a three-layer structure.

<Production Example 2 of Ultraviolet Ray Blocking Agent> 488 g of cerium chloride CeCl ₃ is dissolved in water to prepare 3.3 liter of cerium chloride solution. Also, sodium hydroxide Na
2. Dissolve 237 g of OH in water and add sodium hydroxide solution.
Prepare 3 liters. 7. Water heated to 30-40 ° C
The cerium chloride solution and the sodium hydroxide solution were added to 5 liters with stirring, and the pH after the reaction was 9 to 11 and the temperature was 5
Add dropwise simultaneously so that the temperature can be kept at 0 ° C or lower. After the dropping of both solutions is completed, stirring is continued for 30 minutes, and then the pH of the reaction solution is readjusted to 5 or more. The resulting cerium hydroxide slurry is decanted and washed with water 4 to 5 times to prepare a cerium hydroxide slurry. Sodium silicate solution 56
2 g (SiO ₂ content 28.5% by weight) is dissolved in water to prepare 2 liter of sodium silicate solution. 95% by weight
Is diluted with water to prepare 2 liter of dilute sulfuric acid solution. While heating and stirring the cerium hydroxide slurry at 80 ° C. or higher, a sodium silicate solution and a dilute sulfuric acid solution are simultaneously added dropwise so that the pH of the reaction solution can be maintained at 9 or higher. After the dropping of both solutions is completed, stirring is continued for 30 minutes, and then the reaction solution is prepared with dilute sulfuric acid so that the pH of the reaction solution becomes 7 to 8. This is filtered, washed with water, dried and pulverized to obtain S having a two-layer structure.
Cerium oxide / amorphous silica composite particles containing 32% by weight of iO ₂ were obtained.

<Synthesis Examples of Compounds; Synthesis Examples 1 and 2> [Synthesis Example 1] Synthesis of 4,4′-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane Stirrer, cooler In a 500 ml four-necked flask equipped with a thermometer, 34.4 g of 3-aminosulfonamide and acetone 2 were added.
00 ml was stirred and dissolved. 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 white crystals at a temperature of 43 ° C. were 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 performed 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, mp 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 crystal was 1-methyl-2,4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} benzene.

<Manufacture of Thermosensitive Recording Material> Examples 1 to 17 and Comparative Examples 1 to 34 Hereinafter, the thermosensitive recording material of the present invention will be described with reference to Examples.
In the description, parts and% indicate parts by weight and% by weight, respectively.
The compounds used in the heat-sensitive recording media of the present example and the comparative example are the above-described 4,4'-bis {(3-
(Phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino {diphenylmethane, 1-methyl-2,4-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino}
Benzene or bisphenol A, 4-hydroxy-4 '
Any one of -isopropoxydiphenylsulfone and 4-hydroxy-4'-n-propoxydiphenylsulfone, 3-dibutylamino-6-methyl-7-anilinofluoran (ODB-2) as a dye precursor, and a stabilizer Include 4,4'-bis {(3- (phenylcarbamoylamino) phenyl) sulfonylaminocarbonylamino} diphenylmethane and 1-methyl-2,4-bis} (3- (phenylcarbamoylamino) phenyl)
Sulfonylaminocarbonylamino dibenzene or 4,
4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane and 1,3-bis (p-toluenesulfonylaminocarbonylamino) benzene.

A developer dispersion (solution A), a dye precursor dispersion (solution B), and a stabilizer dispersion (solution C) having the following composition were separately separated by a sand grinder until the average particle diameter became 1 μm. Wet grinding was performed. Liquid A (Developer dispersion liquid) Developer 6.0 parts 10% aqueous polyvinyl alcohol solution 18.8 parts Water 11.2 parts Liquid B (Dye precursor dispersion liquid) 3-Nn-dibutylamino-6 Methyl-7-anilinofluoran (ODB-2) 2.0 parts 10% aqueous polyvinyl alcohol solution 4.6 parts Water 2.6 parts Liquid C (stabilizer dispersion) Stabilizer 2.0 parts 10% aqueous polyvinyl alcohol solution 2.5 parts water 1.5 parts

A dispersion was prepared by wet grinding with a sand grinder using an ultraviolet absorber having the following composition until the average particle diameter became 1 μm. Liquid D (UV absorber dispersion liquid 1) 2- (2'-hydroxy-5'-methylphenyl) benzotriazole 5 parts 3% aqueous polyvinyl alcohol solution 1 part Water 20 parts Liquid E (UV absorber dispersion liquid 2) 2, 2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] 1.0 part 10% aqueous solution of polyvinyl alcohol 2.0 parts Water 4 0.0 part F liquid (ultraviolet absorber dispersion liquid 2) 2,2-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] 3.0 parts 10% aqueous polyvinyl alcohol solution 6.0 parts Water 12.0 parts Liquid G (UV absorber dispersion liquid 1) 2- (2'-hydroxy-5'-methylphenyl) benzotriazole 1.0 3% aqueous solution of polyvinyl alcohol 0.2 part Water 5.0 parts Liquid H (ultraviolet absorbent dispersion 3) 2,4-dihydroxybenzophenone 1.0 part 10% aqueous solution of polyvinyl alcohol 2.0 parts Water 4.0 parts Liquid I (Ultraviolet absorber dispersion liquid 4) 2-hydroxy-4-n-octyloxybenzophenone 1.0 part 10% aqueous polyvinyl alcohol solution 2.0 parts Water 4.0 parts J liquid (ultraviolet absorber dispersion liquid 2) 2,2 -Methylenebis [4- (1,1,3,3, -tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol] 5.0 parts 10% aqueous solution of polyvinyl alcohol 10.0 parts Water 20. 0 parts K liquid (ultraviolet absorber dispersion liquid 3) 2,4-dihydroxybenzophenone 5.0 parts 10% aqueous solution of polyvinyl alcohol 10.0 parts water 20.0 parts Liquid (UV absorber dispersion 4) 2-hydroxy -4-n-octyloxy-benzophenone 5.0 parts of a 10% aqueous solution of polyvinyl alcohol 10.0 parts Water 20.0 parts

[Examples 1 and 2] (1) Formation of undercoat layer A dispersion was mixed at the following ratio to prepare a coating solution for an undercoat layer. Liquid D (UV absorber dispersion liquid 1) 26 parts 10% aqueous polyvinyl alcohol solution 5 parts Styrene-butadiene copolymer latex (solid content 48
%) 11 parts Calcined kaolin (40% dispersion) 250 parts Amount of the above coating solution applied to one side of 50 g / m ² base paper 6.0 g
/ M ² , and then dried to form an undercoat layer. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Liquid A (developer dispersion liquid) (see Table 1) 36.0 parts Liquid B (dye precursor “ODB-2” dispersion liquid) 9.2 parts Ultraviolet ray blocking agent of Production Example 1 (three-layer structure) % Dispersion)
(The core flake pigment is silica) 10.0 parts E liquid (UV absorber dispersion liquid) 7.0 parts Calcium carbonate (50% dispersion liquid) 6.0 parts The above coating liquid is applied on the undercoat layer. The coating was dried at an amount of 5.0 g / m ² to form a heat-sensitive recording layer. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts Aluminum hydroxide (50% dispersion) 30.0 parts Zinc stearate 10.0 parts Fluorescent dye (diaminostilbene sulfonic acid derivative; Tinopal ABPliq. Manufactured by Ciba-Gaiky) 0.5 part Water 70 0.0 part of the above coating solution was coated on the heat-sensitive recording layer so as to have a coating amount of 4.0 g / m ² , and then dried with a super calender having a smoothness of 7 g / m ^2.
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

[Examples 3 and 4] In the heat-sensitive recording materials of Examples 1 and 2, the ultraviolet ray blocking agent of Production Example 1 (three-layer structure) in the heat-sensitive recording layer was replaced with the ultraviolet ray shielding agent of Production Example 2 (two-layer structure). ) A heat-sensitive recording material was obtained in the same manner as in Examples 1 and 2, except that the above method was changed.

Examples 5 and 6 Heat-sensitive recording materials were obtained in the same manner as in Examples 1 and 2, except that the solution E in the heat-sensitive recording layer was removed from the heat-sensitive recording materials of Examples 1 and 2.

[Examples 7 and 8] The same as Examples 1 and 2 except that the ultraviolet ray blocking agent (three-layer structure) of Production Example 1 in the heat-sensitive recording layer was omitted from the heat-sensitive recording materials of Examples 1 and 2. To obtain a thermosensitive recording medium.

[Examples 9 and 10] Heat-sensitive recording materials were obtained in the same manner as in Examples 1 and 2, except that the heat-sensitive recording layers and the protective layer were changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Table 1) 36.0 parts Solution B (Dye precursor "ODB-2" dispersion) 9.2 parts Calcium carbonate (50% dispersion) 12.0 parts The liquid was applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried to form a heat-sensitive recording layer. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts UV-blocking agent of Production Example 1 (three-layer structure) (30% dispersion) (flake flake pigment serving as nucleus is silica) 30.0 parts Aluminum hydroxide (50% dispersion) 10.0 parts Zinc stearate 10.0 parts Fluorescent dye (diaminostilbene sulfonic acid derivative; Tinopal ABPliq. Manufactured by Ciba Gaiki) 0.5 parts Water 70.0 parts Coating amount of the above coating solution on thermal recording layer 4.0 g / smoothness of a super calender after coating and drying so as to m ² 7
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

Examples 11 and 12 Thermosensitive recording materials were obtained in the same manner as in Examples 1 and 2, except that the protective layer was changed as follows. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts UV-blocking agent of Production Example 1 (three-layer structure) (30% dispersion) (flake flake pigment serving as nucleus is silica) 30.0 parts Aluminum hydroxide (50% dispersion) 10.0 parts Zinc stearate 10.0 parts Fluorescent dye (diaminostilbene sulfonic acid derivative; Tinopal ABPliq. Manufactured by Ciba Gaiki) 0.5 parts Water 70.0 parts Coating amount of the above coating solution on thermal recording layer 4.0 g / smoothness of a super calender after coating and drying so as to m ² 7
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

Example 13 A heat-sensitive recording material was obtained in the same manner as in Examples 1 and 2, except that the solution E in the heat-sensitive recording layer was changed to the solution F in the heat-sensitive recording materials of Examples 1 and 2.

Example 14 A heat-sensitive recording material was obtained in the same manner as in Examples 1 and 2, except that the liquid E in the heat-sensitive recording layer was replaced with the liquid G in the heat-sensitive recording materials of Examples 1 and 2.

[Examples 15 and 16] Heat-sensitive recording materials were obtained in the same manner as in Examples 1 and 2, except that the heat-sensitive recording layers of the heat-sensitive recording materials of Examples 1 and 2 were changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Liquid A (color developer dispersion) (see Table 5) 36.0 parts Liquid B (dye precursor “ODB-2” dispersion) 9.2 parts Liquid C (stabilizer dispersion) (see Table 5) 6 0.0 parts UV blocking agent of Production Example 1 (three-layer structure) (30% dispersion)
(The core flake pigment is silica) 10.0 parts E liquid (UV absorber dispersion liquid) 7.0 parts Calcium carbonate (50% dispersion liquid) 6.0 parts The above coating liquid is applied on the undercoat layer. The coating was dried at an amount of 5.0 g / m ² to form a heat-sensitive recording layer.

[Comparative Examples 1 and 2] (1) Formation of Undercoat Layer Dispersions were mixed at the following ratios to prepare undercoat layer coating solutions. 10% aqueous solution of polyvinyl alcohol 5 parts Styrene / butadiene copolymer latex (solid content 48
%) 11 parts Calcined kaolin (40% dispersion) 250 parts Amount of the above coating solution applied to one side of 50 g / m ² base paper 6.0 g
/ M ² , and then dried to form an undercoat layer. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Table 2) 36.0 parts Solution B (Dye precursor “ODB-2” dispersion) 9.2 parts Calcium carbonate (50% dispersion) 12.0 parts The liquid was applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried to form a heat-sensitive recording layer. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous polyvinyl alcohol solution 60.0 parts Aluminum hydroxide (50% dispersion) 30.0 parts Zinc stearate 10.0 parts Water 70.0 parts Coating amount of the above coating solution on heat-sensitive recording layer 4.0 g / m smoothness of a super calender after coating and drying so as to be ² 7
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

[Comparative Examples 3 and 4] Comparative Examples 1 and 2 were the same as Comparative Examples 1 and 2 except that Liquid D was added to the undercoat layer.
In the same manner as in Example 2, a thermosensitive recording medium was obtained.

[Comparative Examples 5 and 6] The heat-sensitive recording materials of Comparative Examples 1 and 2 were obtained in the same manner as in Comparative Examples 1 and 2, except that Liquid J was added to the heat-sensitive recording layer.

[Comparative Example 7] Comparative Example 5 was used in the heat-sensitive recording medium of Comparative Example 5, except that Solution J in the heat-sensitive recording layer was changed to Solution D.
A thermosensitive recording medium was obtained in the same manner as described above.

[Comparative Example 8] In the heat-sensitive recording medium of Comparative Example 5, except that the solution J in the heat-sensitive recording layer was changed to the solution K, the comparative example 5 was performed.
A thermosensitive recording medium was obtained in the same manner as described above.

[Comparative Example 9] In the heat-sensitive recording medium of Comparative Example 5, except that Liquid J in the heat-sensitive recording layer was changed to Liquid L, Comparative Example 5 was used.
A thermosensitive recording medium was obtained in the same manner as described above.

Comparative Examples 10 and 11 Thermosensitive recording materials were obtained in the same manner as in Comparative Examples 1 and 2, except that the thermal recording layers of the thermal recording media of Comparative Examples 1 and 2 were changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Tables 2 and 3) 36.0 parts Solution B (Dye precursor “ODB-2” dispersion) 9.2 parts UV-blocking agent of Production Example 1 (three-layer structure) (30% dispersion) (The flake pigment serving as a nucleus is silica) 10.0 parts Calcium carbonate (50% dispersion) 6.0 parts The above coating solution is coated on the undercoat layer to a coating amount of 5.0 g / m ² . The coating was dried to form a heat-sensitive recording layer.

[Comparative Examples 12 and 13] The heat-sensitive recording materials of Comparative Examples 10 and 11 were obtained in the same manner as in Comparative Examples 10 and 11, except that the heat-sensitive recording layer was changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Liquid A (developer dispersion liquid) (see Table 3) 36.0 parts Liquid B (dye precursor “ODB-2” dispersion liquid) 9.2 parts UV blocking agent of Production Example 2 (two-layer structure) (30) % Dispersion)
(The core flake pigment is silica) 10.0 parts Calcium carbonate (50% dispersion) 6.0 parts The above coating solution is applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried. Thus, a heat-sensitive recording layer was formed.

Comparative Examples 14 and 15 Thermosensitive recording materials were obtained in the same manner as in Comparative Examples 1 and 2, except that the heat-sensitive recording layer and the protective layer were changed as follows. Was. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Table 3) 36.0 parts Solution B (Dye precursor “ODB-2” dispersion) 9.2 parts Calcium carbonate (50% dispersion) 12.0 parts The liquid was applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried to form a heat-sensitive recording layer. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts Aluminum hydroxide (50% dispersion) 30.0 parts Zinc stearate 10.0 parts Fluorescent dye (diaminostilbene sulfonic acid derivative; Tinopal ABPliq. Manufactured by Ciba-Gaiky) 0.5 part Water 70 0.0 part of the above coating solution was coated on the heat-sensitive recording layer so as to have a coating amount of 4.0 g / m ² , and then dried with a super calender having a smoothness of 7 g / m ^2.
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

Comparative Examples 16 and 17 Thermosensitive recording materials were obtained in the same manner as in Comparative Examples 1 and 2, except that the protective layers were changed as follows in Comparative Examples 1 and 2. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts UV blocking agent of Production Example 1 (three-layer structure) (30% dispersion)
(The flake pigment serving as a nucleus is silica) 30.0 parts Aluminum hydroxide (50% dispersion) 10.0 parts Zinc stearate 10.0 parts Water 70.0 parts Coating amount of the above coating solution on the heat-sensitive recording layer After coating and drying to 4.0 g / m ² , smoothness was 7 using a super calender.
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

[Comparative Examples 18 and 19] The heat-sensitive recording materials of Comparative Examples 1 and 2 were prepared in the same manner as in Comparative Examples 1 and 2, except that the undercoat layer and the heat-sensitive recording layer were changed as follows. Obtained. (1) Formation of undercoat layer The dispersion liquid was mixed at the following ratio to obtain an undercoat layer coating liquid. Liquid D (UV absorber dispersion liquid 1) 26 parts 10% aqueous polyvinyl alcohol solution 5 parts Styrene-butadiene copolymer latex (solid content 48
%) 11 parts Calcined kaolin (40% dispersion) 250 parts Amount of the above coating solution applied to one side of 50 g / m ² base paper 6.0 g
/ M ² , and then dried to form an undercoat layer. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to obtain a heat-sensitive layer coating solution. Solution A (Developer dispersion) (see Table 3) 36.0 parts Solution B (Dye precursor “ODB-2” dispersion) 9.2 parts UV-blocking agent of Production Example 1 (three-layer structure) (30) % Dispersion)
(The core flake pigment is silica) 10.0 parts Calcium carbonate (50% dispersion) 6.0 parts The above coating solution is applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried. Thus, a heat-sensitive recording layer was formed.

Comparative Example 20 Comparative Example 15 was performed except that the undercoat layer was changed as follows in the heat-sensitive recording medium of Comparative Example 15.
A thermosensitive recording medium was obtained in the same manner as described above. (1) Formation of undercoat layer The dispersion liquid was mixed at the following ratio to obtain an undercoat layer coating liquid. Liquid D (UV absorber dispersion liquid 1) 26 parts 10% aqueous polyvinyl alcohol solution 5 parts Styrene-butadiene copolymer latex (solid content 48
%) 11 parts Calcined kaolin (40% dispersion) 250 parts Amount of the above coating solution applied to one side of 50 g / m ² base paper 6.0 g
/ M ² , and then dried to form an undercoat layer.

Comparative Example 21 A heat-sensitive recording medium was obtained in the same manner as in Comparative Example 20, except that the heat-sensitive recording layer of the heat-sensitive recording medium of Comparative Example 20 was changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Table 4) 36.0 parts Solution B (Dye precursor “ODB-2” dispersion) 9.2 parts Calcium carbonate (50% dispersion) 12.0 parts The liquid was applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried to form a heat-sensitive recording layer.

Comparative Examples 22 and 23 A thermal recording medium was obtained in the same manner as in Comparative Example 15 except that the thermal recording layer of the thermal recording medium of Comparative Example 15 was changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Table 4) 36.0 parts Solution B (Dye precursor "ODB-2" dispersion) 9.2 parts UV-blocking agent of Production Example 1 (three-layer structure) % Dispersion)
(The core flake pigment is silica) 10.0 parts Calcium carbonate (50% dispersion) 6.0 parts The above coating solution is applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried. Thus, a heat-sensitive recording layer was formed.

[Comparative Example 24] A thermosensitive recording medium was obtained in the same manner as in Comparative Example 1, except that the thermosensitive recording layer and the protective layer were changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Table 4) 36.0 parts Solution B (Dye precursor “ODB-2” dispersion) 9.2 parts Calcium carbonate (50% dispersion) 12.0 parts The liquid was applied on the undercoat layer so as to have a coating amount of 5.0 g / m ² and dried to form a heat-sensitive recording layer. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts E solution (UV absorber dispersion liquid) 7.0 parts Aluminum hydroxide (50% dispersion liquid) 30.0 parts Zinc stearate 10.0 parts Water 70.0 parts The liquid was applied on the heat-sensitive recording layer so as to have a coating amount of 4.0 g / m ² and dried, and then the smoothness was determined to be 7 using a super calender.
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

[Comparative Example 25] Comparative Example 2 except that the liquid E in the protective layer was replaced with the liquid G in the thermosensitive recording medium of Comparative Example 24.
In the same manner as in Example 4, a thermosensitive recording medium was obtained.

[Comparative Example 26] Comparative Example 2 was the same as the thermal recording medium of Comparative Example 24 except that the E solution in the protective layer was replaced with the H solution.
In the same manner as in Example 4, a thermosensitive recording medium was obtained.

Comparative Example 27 Comparative Example 2 was carried out in the same manner as in the thermal recording medium of Comparative Example 24 except that Solution E in the protective layer was changed to Solution I.
In the same manner as in Example 4, a thermosensitive recording medium was obtained.

Comparative Example 28 A heat-sensitive recording medium was obtained in the same manner as in Comparative Example 24, except that the protective layer was changed as follows. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts Zinc oxide (50% dispersion) 18.0 parts Aluminum hydroxide (50% dispersion) 10.0 parts Zinc stearate 10.0 parts Water 82.0 parts After coating and drying on the heat-sensitive recording layer so as to have a coating amount of 4.0 g / m ² , the smoothness was 7 using a super calender.
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

Comparative Example 29 Comparative Example 28 was carried out in the same manner as in the thermal recording medium of Comparative Example 28 except that the protective layer was changed as follows.
A thermosensitive recording medium was obtained in the same manner as described above. (3) Preparation of protective layer A dispersion was mixed at the following ratio to obtain a coating liquid. 10% aqueous solution of polyvinyl alcohol 60.0 parts Cerium oxide (50% dispersion) 18.0 parts Aluminum hydroxide (50% dispersion) 10.0 parts Zinc stearate 10.0 parts Water 82.0 parts After coating and drying on the heat-sensitive recording layer so that the coating amount is 4.0 g / m ² , the smoothness is 7 with a super calender.
The processing was performed so that the time was from 00 to 800 seconds to obtain a thermosensitive recording medium.

Comparative Examples 30 and 31 Thermosensitive recording media were obtained in the same manner as in Examples 1 and 2, except that the thermosensitive recording layers of the thermosensitive recording media of Examples 1 and 2 were changed as follows. (2) Formation of heat-sensitive recording layer A dispersion was mixed at the following ratio to prepare a heat-sensitive layer coating liquid. Solution A (Developer dispersion) (see Table 4) 36.0 parts Solution B (Dye precursor "ODB-2" dispersion) 9.2 parts UV-blocking agent of Production Example 1 (three-layer structure) % Dispersion)
(The core flake pigment is silica) 10.0 parts E liquid (UV absorber dispersion liquid) 7.0 parts Calcium carbonate (50% dispersion liquid) 6.0 parts The above coating liquid is applied on the undercoat layer. The coating was dried at an amount of 5.0 g / m ² to form a heat-sensitive recording layer.

Comparative Examples 32 and 33 In the same manner as in Examples 15 and 16, thermosensitive recording media were obtained.

<Evaluation of Thermosensitive Recording Materials; Examples 1 to 16, Comparative Examples 1 to 33> For the thermosensitive recording materials of Examples 1 to 16 and Comparative Examples 1 to 33, a thermal recording test, measurement of ground color, oil resistance A plasticity test, a plasticizer resistance test, a light resistance test, a heat resistance test (however, Examples 15 and 16, and Comparative Examples 32 and 33 were excluded), and a cas stick test were performed. (Table 1,
6, 7 “quality test results 1 to 3 of Examples”, Tables 2 to 4, 8
~ 11 "quality test results 1-7 of comparative examples", Tables 5, 12,
13 "Characteristics 1 to 3 of thermosensitive recording media shown in Examples 15 and 16 and Comparative Examples 32 and 33").

[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 0.413 mj / dot. Then, the thermal recording was performed on the produced thermal recording medium. The recording density of the image area was measured with a Macbeth densitometer (RD-914, using an amber filter).

[Measurement of ground color] A blank paper portion was measured with a Macbeth densitometer (RD-914, using an amber filter). The heat-sensitive recording materials of Examples 1 to 16 satisfying the requirements of the present invention obtained a ground color having sufficiently high whiteness.

[Oil resistance test] 0.413 mj / dot
The salad oil was dropped on the image area and the ground color area dynamically printed under the conditions described above, and after 3 days, it was lightly wiped off with a filter paper, and then measured with a Macbeth densitometer (RD-914, using an amber filter). The heat-sensitive recording materials of Examples 1 to 14 satisfying the requirements of the present invention have an image area of 1.1 even after 3 days have passed after dripping of the salad oil.
As described above, the urea (thiourea) derivative of the present invention was used as a stabilizer and 0.9 or more of the image area remained in Examples 15 and 16 using a known developer. Also, the background color portion was not colored and showed good oil resistance.

[Plasticizer resistance test] 0.413 mj / d
Dynamic printing under the conditions of ot, triple on the surface of the sample,
And a single-layer vinyl chloride film (High Wrap KMA manufactured by Mitsui Toatsu Co., Ltd.) on the back side, and after standing in a constant temperature tester at 40 ° C. for 24 hours, the image density and blank paper density are measured using a Macbeth densitometer (R).
D-914, using an amber filter). The heat-sensitive recording materials of Examples 1 to 14 satisfying the requirements of the present invention have 1.1 or more image areas remaining, and use the urea (thiourea) derivative of the present invention as a stabilizer to obtain a known developer. The image portions of Examples 15 and 16 using 残 っ remained 0.9 or more.
Also, there was no coloring of the ground color portion, and good plasticizer resistance was exhibited.

[Light resistance test] 0.413 m as described above
The examples, the comparative examples, and the unprinted thermosensitive recording medium which had already been subjected to the thermosensitive recording under the condition of j / dot were subjected to a fade meter (BH, manufactured by Toyo Seiki Co., Ltd.) for 12 hours. -914, using an amber filter), the density of the white paper portion was measured at the yellow position of the Macbeth densitometer. Examples 1 to 1 that meet the requirements of the present invention
The thermosensitive recording medium of No. 6 showed a ground color of 0.15 or less and an image part of almost 1.0 or more after the fade meter 12H treatment,
High light resistance was obtained.

[Heat resistance test] The unprinted thermosensitive recording medium was 9
After being left in an environment of 0 ° C. for 5 minutes, the density of the blank portion was measured with a Macbeth densitometer (RD-914, using an amber filter). The heat-sensitive recording materials of Examples 1 to 14 satisfying the requirements of the present invention exhibited a ground color of 0.1 or less and extremely high heat resistance after being left in a 90 ° C environment for 5 minutes.

[Cast Test] TH-PM manufactured by Okura Electric Co., Ltd.
Using D, 20 solid black recordings of B4 size were performed at an applied energy of 0.413 mj / dot, and the amount of scum adhered to the thermal head was visually observed. Was evaluated. The thermal recording media of Examples 1 to 16 satisfying the requirements of the present invention all showed good results.

[Stick test] TH manufactured by Okura Electric Co., Ltd.
Using PMD, applied energy 0.413 mj / d
Solid black recording was performed at ot, and white spots on the recording surface and stick sound were confirmed. The results were evaluated as ○: good, Δ: slightly poor, ×: poor. The thermal recording media of Examples 1 to 16 satisfying the requirements of the present invention all showed good results.

[0109]

[Table 1]

[0110]

[Table 2]

[0111]

[Table 3]

[0112]

[Table 4]

[0113]

[Table 5]

[0114]

[Table 6]

[0115]

[Table 7]

[0116]

[Table 8]

[0117]

[Table 9]

[0118]

[Table 10]

[0119]

[Table 11]

[0120]

[Table 12]

[0121]

Table 13 Characteristics 3 of the thermosensitive recording medium shown in Examples 15 and 16 and Comparative Examples 32 and 33

[0122]

As described above, the heat-sensitive recording medium of the present invention has excellent image storability such as oil resistance and plasticizer resistance, is less likely to cause residue and sticking to a thermal head, and has a light resistance, It also has excellent ground color stability, and has a performance in which adhesion of scum to the thermal head and sticking are unlikely to occur. The effects of the present invention include the following.

(1) It can be used as a label for food or the like used in an environment where oil is in contact with a vinyl chloride film or in contact with oil. (2) Further, even if left in an environment where heat is applied, it can be used without discoloring the ground color. (3) Even when exposed to sunlight or indoor light for a long time, it can be used without discoloring the ground color and without fading the image portion.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yutaka Wakita 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Nihon Paper Industries Co., Ltd. Product Development Laboratory (56) References JP-A-9-207452 (JP, A) JP-A-8-156407 (JP, A) JP-A-8-118806 (JP, A) JP-A-7-278098 (JP, A) JP-A-7-267918 (JP, A) JP-A-6-320874 JP-A-11-217369 (JP, A) JP-A-11-217368 (JP, A) JP-A-9-156227 (JP, A) JP-A-9-202048 (JP, A) ( 58) Field surveyed (Int. Cl. ⁷ , DB name) B41M 5/30 B41M 5/28 CA (STN) REGISTRY (STN)

Claims (10)

(57) [Claims] 1. A thermosensitive recording material comprising a support, on which an undercoat layer, a thermosensitive recording layer containing a leuco dye-type coloring component comprising a colorless or pale color dye precursor and a developer, and a protective layer are laminated. The undercoat layer and / or the thermosensitive recording layer contains an ultraviolet absorber, the thermosensitive recording layer and / or the protective layer contains an ultraviolet ray blocking agent, and the protective layer contains a fluorescent dye. And a thermosensitive recording medium, wherein the thermosensitive recording layer further contains at least one compound 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. The heat-sensitive recording layer is characterized in that 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 1. 3. The thermosensitive recording 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 heat-sensitive recording material according to claim 1. 4. The ultraviolet blocking agent has a refractive index of 1.5 to 1.
4. The heat-sensitive recording material according to claim 1, comprising a baked product of particles having a three-layer structure in which the surface of the flake pigment is coated with an insoluble cerium compound and amorphous silica. 5. The heat-sensitive recording material according to claim 1, wherein the ultraviolet ray blocking agent comprises a baked product of particles having a two-layer structure in which an insoluble cerium compound is coated with amorphous silica. 6. The thermosensitive recording medium according to claim 1, wherein the ultraviolet absorbent is a benzotriazole compound. 7. The content of the UV absorber contained in the undercoat layer and / or the heat-sensitive recording layer is from 0.1% by weight to 15% by weight based on the dry weight of the undercoat layer, and the dry weight of the heat-sensitive recording layer 7. The heat-sensitive recording medium according to claim 1, wherein the content is 0.1% by weight to 8% by weight. 8. The thermosensitive recording medium according to claim 1, wherein the melting point of the ultraviolet absorbent contained in the thermosensitive recording layer is 130 ° C. or higher. 9. The content of the ultraviolet ray blocking agent contained in the heat-sensitive recording layer and / or the protective layer is 10% by weight to 40% by weight with respect to the dry weight of the heat-sensitive recording layer, and 5% by weight with respect to the dry weight of the protective layer. The heat-sensitive recording material according to any one of claims 1 to 8, wherein the content of the heat-sensitive recording material is from 10% to 40% by weight. 10. The thermosensitive recording medium according to claim 1, wherein the content of the fluorescent dye contained in the protective layer is 0.01 to 3% by weight based on the dry weight of the protective layer. .