JP5485608B2 - Phenolsulfonic acid ester, developer and heat-sensitive recording material - Google Patents

Description

  The present invention relates to a novel phenol sulfonate ester, its use as a developer, and a heat-sensitive recording material.

  A colorless or light-colored basic (electron-donating) leuco dye (hereinafter, also simply referred to as “dye”) and an electron-accepting developer (hereinafter simply referred to as “dye”) that reacts with the dye by heating to develop the dye. A heat-sensitive recording material having a heat-sensitive color developing layer mainly composed of “developer” is widely used. And in order to record on the said heat-sensitive recording material, the thermal printer etc. which incorporated the thermal head are normally used. Compared with other recording systems in practical use, such thermal recording systems are 1) no noise during recording, 2) no development and fixing process, 3) maintenance-free, 4) equipment It is relatively inexpensive, 5) the equipment is compact, and 6) the resulting color is very clear. It is used for facsimiles, computer terminal printers, automatic ticket vending machines, measurement recorders, and outdoor use. It is widely used for handy terminals.

  In recent years, this type of heat-sensitive recording material has come to be used not only for the above-mentioned output paper of various devices but also for cash voucher paper in various fields. However, when used for various tickets, receipts, labels, bank ATMs, gas and electricity meter readings, and vouchers in various fields such as car bets, etc. Even if the product is stored for a long time in contact with synthetic leather, in high temperature and high humidity conditions, or in the light of sunlight or fluorescent light, the printed part can be read. Excellent storage stability (plasticizer resistance, heat resistance, moisture resistance, light resistance, etc.) that does not cause problems in suitability is required.

  Conventionally, for improving the storage stability of printed parts, in addition to heat-sensitive recording materials (Patent Documents 1 and 2), dyes and developers that use diphenylsulfone derivatives as developers or image stabilizers, diphenylsulfone derivatives are added as stabilizers. A heat-sensitive recording material (Patent Document 3) has been proposed.

  However, as heat-sensitive recording materials are increasingly used for the above-mentioned applications such as voucher applications, further improvement in storage stability of the printed portion, particularly plasticizer resistance, is required. Due to the downsizing of printers and the like, there is an increasing demand for high sensitivity for color development with lower energy in thermal recording materials. However, conventional heat-sensitive recording materials that use a developer that is advantageous for the plasticizer resistance of the printed portion generally have low color development sensitivity, and conversely, conventional heat-sensitive recording that uses a developer that is advantageous for sensitivity. The materials were generally inferior in plasticizer resistance, and none of them had a sufficient combination of both performances.

JP-A-8-333329 Japanese Patent Laid-Open No. 10-29969 JP 2003-212841 A

The present invention has been made in view of the circumstances as described above, and the problem to be solved is sufficiently high color development sensitivity, and even when it is in contact with a film or synthetic leather for a long period of time, it is a fading color. It is an object of the present invention to provide a novel developer capable of realizing a heat-sensitive recording material having excellent plasticizer resistance that is extremely unlikely to occur, and a heat-sensitive recording material using the developer.
In addition, a novel developer that can realize a heat-sensitive recording material having sufficiently high color development sensitivity and excellent plasticizer resistance, and also good storage stability other than plasticizer resistance such as moisture resistance and water resistance. And a thermosensitive recording material using the developer.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a phenolsulfonic acid ester derivative having a specific structure, that is, a phenolsulfonic acid ester represented by the following general formula (I), has been revealed in a heat-sensitive recording material. It is excellent as a colorant, and the heat-sensitive recording material containing the phenolsulfonic acid ester in the heat-sensitive color developing layer has a good color developing sensitivity, the plasticizer resistance of the printed part is extremely good, and further, moisture resistance, The present inventors have found that the retentivity other than the plasticizer resistance such as water resistance is improved, and have completed the present invention.

That is, the present invention
[1] General formula (I):

[Wherein, R represents a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an alkoxyl group, a cyano group, a nitro group, an aryl group or an aralkyl group, and the m Rs may be the same or different from each other; Represents a divalent to tetravalent linking group, m is an integer of 0 to 4, and n is an integer of 2 to 4. A phenolsulfonic acid ester represented by
[2] In the formula, Z represents an arylene group having one or two benzene rings which may have a substituent, and an arylene group in which two or more benzene rings which may have a substituent are condensed. Or a phenolsulfonic acid ester according to the above [1], which is a bisarylene group in which two or more benzene rings optionally having a substituent via a divalent group are linked,
[3] A developer for a heat-sensitive recording material comprising the phenolsulfonic acid ester according to the above [1] or [2],
[4] A heat-sensitive recording material in which a heat-sensitive color-developing layer containing a colorless or light-colored basic leuco dye and a developer is provided on a support, and the developer described in [1] or [2] 1 or 2 or more types of phenolsulfonic acid esters described in the above, and [5] carboxy-modified polyvinyl alcohol, epichlorohydrin resin and polyamine resin on the thermosensitive coloring layer / Thermal recording material according to [4], wherein a protective layer containing a polyamide-based resin is further provided.

  The reason why the heat-sensitive recording material of the present invention is excellent in the plasticizer resistance of the printed portion has not been clearly clarified, but the phenolsulfonic acid ester represented by the general formula (I) is present together with the dye in the heat-sensitive coloring layer. Therefore, it is presumed that it acts as an electron-accepting developer that develops the dye, and the stability of the electron transfer complex, which is a reaction product of the developer and the dye, is increased.

  Further, the reason why the heat-sensitive recording material of the present invention has high color development sensitivity has not been clearly clarified, but the reactivity with a basic dye is high because the phenolsulfonic acid ester represented by the general formula (I) has high acidity. Is estimated to be high.

  Furthermore, since the hue of the reaction product of the phenol sulfonate ester represented by the general formula (I) and the dye is green, the print portion of the heat-sensitive recording material of the present invention exhibits a green hue and is excellent. Shows bar code readability. That is, even if an undesired discoloration occurs and the print density is lowered, the bar code reading apparatus generally using infrared rays exhibits excellent bar code reading aptitude.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.
The phenolsulfonic acid ester represented by the general formula (I) of the present invention (hereinafter also simply referred to as “the phenolsulfonic acid ester of the present invention”) is a novel compound.

  In the phenolsulfonic acid ester represented by the general formula (I) of the present invention, R in the formula represents a halogen atom, hydroxyl group, alkyl group, alkenyl group, alkoxyl group, cyano group, nitro group, aryl group or aralkyl group. The m Rs may be the same as or different from each other. In view of industrial availability, R is preferably a hydroxyl group, an alkyl group, an alkenyl group or an alkoxyl group, and particularly preferably a hydroxyl group.

  Examples of the halogen atom include chlorine, bromine, fluorine, iodine and the like, but chlorine and bromine are preferable from the viewpoint of excellent industrial handling.

  Examples of the alkyl group include linear or branched alkyl groups having 1 to 12 carbon atoms, preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, n-hexyl group, An isohexyl group, a 1-methylpentyl group, a 2-methylpentyl group, and the like can be mentioned. Since the melting point may decrease when the number of carbon atoms increases, among them, a methyl group, an ethyl group, an n-propyl group, an isopropyl group , N-butyl group and t-butyl group are preferable.

  Examples of the alkenyl group include unsaturated hydrocarbons having 2 to 12 carbon atoms, preferably 2 to 4 carbon atoms, which are linear or branched. For example, vinyl group, allyl group, isopropenyl group, 1-propenyl group, 2-butenyl group, 3-butenyl group, 1,3-butanedienyl group, 2-methyl-2-propenyl group and the like can be mentioned. From the viewpoint of easiness, a vinyl group and an allyl group are preferred industrially.

  As an alkoxyl group, a C1-C6, Preferably a C1-C4 alkoxyl group is mentioned. Examples include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, sec-butoxy group, isobutoxy group, tert-butoxy group, and allyloxy group. Group, ethoxy group, n-propoxy group, isopropoxy group, isobutoxy group and tert-butoxy group are preferred.

  Examples of the aryl group include monocyclic to tricyclic aromatic hydrocarbon groups having 6 to 14 carbon atoms, such as a phenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A phenyl group is preferable from the viewpoint of ease of synthesis.

  The aryl group may have a substituent such as an alkyl group, an aryl group, a hydroxyl group, or a halogen atom, and examples of the alkyl group and aryl group as the substituent include the same as those described above. . The position and number of substituents may be appropriately selected within a range that does not impair the properties of the derivative of the present invention, and are not particularly limited. When the aryl group is substituted with two or more substituents, the substituents may be the same or different. Specific examples of such a substituted aryl group include a biphenyl group and an alkyl-substituted aryl group having 1 to 4 carbon atoms.

  Aralkyl groups include phenylmethyl group (benzyl group), phenylethyl group (phenethyl group), diphenylmethyl group, 3-phenylpropyl group, 2-phenylpropyl group, 4-phenylbutyl group, biphenylmethyl group, naphthylmethyl group Etc.

  The aralkyl group may have a substituent such as an alkyl group, an aryl group, a hydroxyl group, or a halogen atom. Examples of the substituent alkyl group and aryl group are the same as those described above. The position and number of substituents may be appropriately selected within a range that does not impair the properties of the derivative of the present invention, and are not particularly limited. When the aralkyl group is substituted with two or more substituents, the substituents may be the same or different. As the aralkyl group having a substituent, an alkyl-substituted aralkyl group having 6 to 8 carbon atoms is preferable.

  M in the formula represents an integer of 0 to 4, and is preferably 0 to 2 and more preferably 0 from the viewpoint of ease of synthesis. However, when m is 2 to 4, the m Rs may be the same or different, and the same is preferable from the viewpoint of ease of synthesis.

  Z represents a divalent to tetravalent linking group, preferably a divalent to trivalent linking group, more preferably a divalent linking group. Examples of the linking group include an aliphatic hydrocarbon group or an optionally substituted arylene group. Among them, an arylene group is preferable from the viewpoint of stability, and a divalent arylene group is more preferable.

  Here, examples of the aliphatic hydrocarbon group include linear, branched or cyclic saturated or unsaturated hydrocarbon groups having 1 to 12 carbon atoms which may have an ether bond. A saturated hydrocarbon group which may have an ether bond is preferable, and a saturated hydrocarbon group which does not have a linear ether bond is more preferable.

  The linear, branched or cyclic saturated hydrocarbon group having 1 to 12 carbon atoms preferably has 2 to 6 carbon atoms, more preferably 3 to 4 carbon atoms, and linear or branched chain having 1 to 12 carbon atoms. Alternatively, the cyclic unsaturated hydrocarbon group preferably has 2 to 6 carbon atoms, and more preferably 2 to 4 carbon atoms.

  Specific examples of the saturated hydrocarbon group having no ether bond include, for example, methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene. Group, undecamethylene group, dodecamethylene group, methylmethylene group, dimethylmethylene group, methylethylene group, methyleneethylene group, ethylethylene group, 1,2-dimethylethylene group, 1-methyltrimethylene group, 1-methyltetramethyl group Methylene group, 1,3-dimethyltrimethylene group, 1-ethyl-4-methyl-tetramethylene group, cyclohexylene group, and the like. Among them, ethylene group which is a saturated hydrocarbon group having no linear ether bond, Trimethylene group, tetramethylene group, pentamethylene group, hexa Styrene group, and the like are preferable.

  Specific examples of the unsaturated hydrocarbon group having no ether bond include a vinylene group, an ethynylene group, a propenylene group, a 2-butenylene group, a 2-butynylene group, a 1-vinylethylene group, and the like. , 2-butenylene group is preferable.

  Specific examples of the hydrocarbon group having an ether bond include, for example, an ethyleneoxyethylene group, a tetramethyleneoxytetramethylene group, an ethyleneoxyethyleneoxyethylene group, an ethyleneoxymethyleneoxyethylene group, and 1,3-dioxane-5,5. -Bismethylene group etc. are mentioned, The ethyleneoxyethylene group and ethyleneoxyethylene oxyethylene group which are saturated hydrocarbons which have a linear ether bond are especially preferable.

  The arylene group which may be substituted includes an arylene group having one or two benzene rings which may have a substituent, and an arylene in which two or more benzene rings which may have a substituent are condensed. A bisarylene group in which two or more benzene rings which may have a substituent via a group or a divalent group are connected is preferable. Specifically,

(In the formula, A represents a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an alkoxyl group, a cyano group, a nitro group, an aryl group or an aralkyl group, and o A's may be the same as or different from each other. Represents an integer of 0 to 4. X represents a divalent group, Y represents —NH—, —O—, or —S—.

Is preferred.

Here, A is preferably a hydroxyl group, an alkyl group, an alkenyl group, an aryl group, or a phenolsulfonic acid group from the viewpoint of ease of synthesis and availability of raw materials. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a tert-butyl group. Examples of the alkenyl group include a vinyl group, an allyl group, and a 2-butynyl group. , Phenyl group, xylyl group, mesityl group, cumenyl group and the like. Further, as o, 1 to 0 are preferable and 0 is particularly preferable from the viewpoint of easy synthesis and availability of raw materials. The divalent is a group _{X, -CH 2 -, - C} (CH 3) 2 -, - CHCH 3 -, - CH (C 2 H 5) -, - CH (C 3 H 7) - , —C (cyclo-C ₅ H ₁₀ ) —, —CH (C ₆ H ₄ ) —, —O—, —S—, —SO—, —SO ₂ —, —SO ₃ —, —CO
-, -NH-, -CONH-, -NHCONH- and the like.

  n represents an integer of 2 to 4, preferably 2 to 3, and more preferably 2.

  The phenolsulfonic acid ester represented by the general formula (I) of the present invention may be a compound having a specific n in the general formula (I), or any of the compounds having different n in the general formula (I). May be a mixture of

  Specific examples of the phenolsulfonic acid ester represented by the general formula (I) of the present invention include the following compounds, but are not limited thereto.

  Among these, the compounds (7) to (30) are preferable from the viewpoint of the balance between the color development sensitivity and the storage stability (particularly plasticizer resistance) in the target heat-sensitive recording material of the present invention.

The phenolsulfonic acid ester of the present invention is synthesized according to a known method for producing a sulfonic acid ester. That is, for example,
Formula (II)

(Wherein R and m are as defined above.)
A compound (II) represented by formula (III)

(Wherein, Z and n are as defined above.)
It can manufacture by making the compound (III) represented by these react.

  This reaction is performed in an aprotic organic solvent using, for example, an organic base such as triethylamine, triethylamine, or pyridine or an inorganic base such as sodium hydroxide or potassium hydroxide as a deoxidizing agent. The reaction temperature is usually 5 ° C. to boiling point, and the reaction time can be appropriately selected. Examples of aprotic organic solvents include halogen solvents such as dichloromethane, dichloroethane and chloroform, aromatic solvents such as benzene, toluene and chlorobenzene, ketone solvents such as acetone and methyl ethyl ketone, tetrahydrofuran (THF), dioxane and dimethoxyethane. And ether solvents. An organic base such as triethylamine or pyridine may be used as a solvent.

  The phenolsulfonic acid ester derivative produced by this reaction is obtained by subjecting the reaction mixture to extraction of the target product after completion of the reaction and further purifying by a known purification method (back extraction, column chromatography, recrystallization, etc.). I can do it.

  Moreover, the compound (IV) represented by the following formula (IV) can also be used instead of the compound (II).

(In the formula, R and m are as defined above, and P represents a general protecting group.)
Specific examples of the general protecting group represented by P in the formula include an acetyl group, a pivaloyl group, a benzoyl group, a methyl group, a t-butyl group, and a benzyl group.

  When such compound (IV) is used, compound (IV) and compound (III) are reacted under the same conditions as described above, and the desired compound is obtained by deprotecting the obtained compound by a known method. . For example, when P in the formula of the compound (IV) is an acetyl group, the reaction product of the compound (IV) and the compound (III) is deprotected by hydrolysis in a solvent to which an alkali is added. You can get things.

  The heat-sensitive recording material of the present invention is a heat-sensitive recording material in which a heat-sensitive color developing layer containing a colorless or light basic leuco dye and a developer is provided on a support. It contains at least one phenolsulfonic acid ester represented by 1) (the phenolsulfonic acid ester of the present invention).

  In the thermosensitive coloring layer, another developer can be used in combination as long as the effects of the present invention are not impaired. Further, a sensitizer, an image stabilizer, a binder, a cross-linking agent, a pigment, a lubricant and the like can be contained within a range that does not inhibit the effect of the present invention. Binders, crosslinking agents, pigments and the like can be used not only in the heat-sensitive color developing layer but also in each coating layer provided as necessary, including a protective layer.

Examples of various materials used for the thermosensitive coloring layer of the thermosensitive recording material of the present invention are shown below.
As the colorless to light-colored basic leuco dye used in the present invention, all known ones in the conventional pressure-sensitive or thermal recording field can be used, and are not particularly limited. Fluorane compounds, fluorene compounds, divinyl compounds and the like are preferable. Specific examples of typical colorless or light-colored basic leuco dyes (dye precursors) are shown below. These dyes (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 (also known as malachite green lactone)

<Fluoran leuco dye>
3-diethylamino-6-methylfluorane;
3-diethylamino-6-methyl-7-anilinofluorane;
3-diethylamino-6-methyl-7- (o, p-dimethylanilino) fluorane;
3-diethylamino-6-methyl-7-chlorofluorane;
3-diethylamino-6-methyl-7- (m-trifluoromethylanilino) fluorane;
3-diethylamino-6-methyl-7- (o-chloroanilino) fluorane;
3-diethylamino-6-methyl-7- (p-chloroanilino) fluorane;
3-diethylamino-6-methyl-7- (o-fluoroanilino) fluorane;
3-diethylamino-6-methyl-7- (m-methylanilino) fluorane;
3-diethylamino-6-methyl-7-n-octylanilinofluorane;
3-diethylamino-6-methyl-7-n-octylaminofluorane;
3-diethylamino-6-methyl-7-benzylaminofluorane;
3-diethylamino-6-methyl-7-dibenzylaminofluorane;
3-diethylamino-6-chloro-7-methylfluorane;
3-diethylamino-6-chloro-7-anilinofluorane;
3-diethylamino-6-chloro-7-p-methylanilinofluorane;
3-diethylamino-6-ethoxyethyl-7-anilinofluorane;
3-diethylamino-7-methylfluorane;
3-diethylamino-7-chlorofluorane;
3-diethylamino-7- (m-trifluoromethylanilino) fluorane;
3-diethylamino-7- (o-chloroanilino) fluorane;
3-diethylamino-7- (p-chloroanilino) fluorane;
3-diethylamino-7- (o-fluoroanilino) fluorane;
3-diethylamino-benzo [a] fluorane;
3-diethylamino-benzo [c] fluorane;
3-dibutylamino-6-methyl-fluorane;
3-dibutylamino-6-methyl-7-anilinofluorane;
3-dibutylamino-6-methyl-7- (o, p-dimethylanilino) fluorane;
3-dibutylamino-6-methyl-7- (o-chloroanilino) fluorane;
3-dibutylamino-6-methyl-7- (p-chloroanilino) fluorane;
3-dibutylamino-6-methyl-7- (o-fluoroanilino) fluorane;
3-dibutylamino-6-methyl-7- (m-trifluoromethylanilino) fluorane;
3-dibutylamino-6-methyl-chlorofluorane;
3-dibutylamino-6-ethoxyethyl-7-anilinofluorane;
3-dibutylamino-6-chloro-7-anilinofluorane;
3-dibutylamino-6-methyl-7-p-methylanilinofluorane;
3-dibutylamino-7- (o-chloroanilino) fluorane;
3-dibutylamino-7- (o-fluoroanilino) fluorane;
3-di-n-pentylamino-6-methyl-7-anilinofluorane;
3-di-n-pentylamino-6-methyl-7- (p-chloroanilino) fluorane;
3-di-n-pentylamino-7- (m-trifluoromethylanilino) fluorane;
3-di-n-pentylamino-6-chloro-7-anilinofluorane;
3-di-n-pentylamino-7- (p-chloroanilino) fluorane;
3-pyrrolidino-6-methyl-7-anilinofluorane;
3-piperidino-6-methyl-7-anilinofluorane;
3- (N-methyl-N-propylamino) -6-methyl-7-anilinofluorane;
3- (N-methyl-N-cyclohexylamino) -6-methyl-7-anilinofluorane;
3- (N-ethyl-N-cyclohexylamino) -6-methyl-7-anilinofluorane;
3- (N-ethyl-N-xylamino) -6-methyl-7- (p-chloroanilino) fluorane;
3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluorane;
3- (N-ethyl-N-isoamylamino) -6-methyl-7-anilinofluorane;
3- (N-ethyl-N-isoamylamino) -6-chloro-7-anilinofluorane;
3- (N-ethyl-N-tetrahydrofurfurylamino) -6-methyl-7-anilinofluorane;
3- (N-ethyl-N-isobutylamino) -6-methyl-7-anilinofluorane;
3- (N-ethyl-N-ethoxypropylamino) -6-methyl-7-anilinofluorane;
3-cyclohexylamino-6-chlorofluorane;
2- (4-oxahexyl) -3-dimethylamino-6-methyl-7-anilinofluorane;
2- (4-oxahexyl) -3-diethylamino-6-methyl-7-anilinofluorane;
2- (4-oxahexyl) -3-dipropylamino-6-methyl-7-anilinofluorane;
2-methyl-6-p- (p-dimethylaminophenyl) aminoanilinofluorane;
2-methoxy-6-p- (p-dimethylaminophenyl) aminoanilinofluorane;
2-chloro-3-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane;
2-chloro-6-p- (p-dimethylaminophenyl) aminoanilinofluorane;
2-nitro-6-p- (p-diethylaminophenyl) aminoanilinofluorane;
2-amino-6-p- (p-diethylaminophenyl) aminoanilinofluorane;
2-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluorane;
2-phenyl-6-methyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane;
2-benzyl-6-p- (p-phenylaminophenyl) aminoanilinofluorane;
2-hydroxy-6-p- (p-phenylaminophenyl) aminoanilinofluorane;
3-methyl-6-p- (p-dimethylaminophenyl) aminoanilinofluorane;
3-diethylamino-6-p- (p-diethylaminophenyl) aminoanilinofluorane;
3-diethylamino-6-p- (p-dibutylaminophenyl) aminoanilinofluorane;
2,4-Dimethyl-6-[(4-dimethylamino) anilino] -fluorane

<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-methylindol-3-yl) phthalide;
3,6-bis (diethylamino) fluorane-γ- (3′-nitro) anilinolactam;
3,6-bis (diethylamino) fluorane-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

<Developer that can be used in combination>
As the color developer that can be used in combination with the phenolsulfonic acid ester of the present invention, any of those known in the field of conventional pressure-sensitive or thermal recording, such as various electron-accepting compounds or oxidizing agents, can be used. There is no particular limitation.

  For example, inorganic acidic substances such as activated clay, attapulgite, colloidal silica, aluminum silicate, 4,4′-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy) Phenyl) -4-methylpentane, 4,4′-dihydroxydiphenyl sulfide, hydroquinone monobenzyl ether, benzyl 4-hydroxybenzoate, 2,4′-dihydroxydiphenyl sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone 4-hydroxyphenyl-4′-benzyloxyphenylsulfone, 3,4-dihydroxyphenyl-4′-methylphenylsulfone, aminobenzenesulfonamide derivatives described in JP-A-8-59603, bis (4-hydroxyphenylthiol) Ethoxy) methane, 1,5-di (4-hydroxyphenylthio) -3-oxapentane, butyl bis (p-hydroxyphenyl) acetate, methyl bis (p-hydroxyphenyl) acetate, 1,1-bis (4- Hydroxyphenyl) -1-phenylethane, 1,4-bis [α-methyl-α- (4′-hydroxyphenyl) ethyl] benzene, 1,3-bis [α-methyl-α- (4′-hydroxyphenyl) ) Ethyl] benzene, di (4-hydroxy-3-methylphenyl) sulfide, 2,2′-thiobis (3-tert-octylphenol), 2,2′-thiobis (4-tert-octylphenol), international publication WO02 / Examples include compounds described in pamphlet No. 081229 or JP-A No. 2002-301873. Also, thiourea compounds such as N, N′-di-m-chlorophenylthiourea, p-chlorobenzoic acid, stearyl gallate, zinc bis [4- (n-octyloxycarbonylamino) salicylate] dihydrate, 4 Aromatic of [2- (p-methoxyphenoxy) ethyloxy] salicylic acid, 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid, 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] salicylic acid Carboxylic acids and salts of these aromatic carboxylic acids with zinc, magnesium, aluminum, calcium, titanium, manganese, tin, nickel and other polyvalent metal salts, as well as antipyrine complexes of zinc thiocyanate, terephthalaldehyde acid and other Examples include complex zinc salts with aromatic carboxylic acids. These developers can be used alone or in admixture of two or more. Further, it may contain a metal chelate coloring component such as a higher fatty acid metal double salt and a polyvalent hydroxyaromatic compound described in JP-A-10-258577.

<Sensitizer>
A conventionally well-known sensitizer can be used as a sensitizer. Examples of such sensitizers include fatty acid amides such as stearamide 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-xylene-bis -(Phenyl ether), 4- (m-methyl) Ruphenoxymethyl) biphenyl, 4,4′-ethylenedioxy-bis-benzoic acid dibenzyl ester, dibenzoyloxymethane, 1,2-di (3-methylphenoxy) ethylene, bis [2- (4-methoxy- Examples thereof include, but are not limited to, phenoxy) ethyl] ether, methyl p-nitrobenzoate and phenyl p-toluenesulfonate. These sensitizers may be used alone or in admixture of two or more.

<Image stabilizer>
In the present invention, an image stabilizer can be used for the oil resistance effect of the recorded image. Examples of the image stabilizer include 4,4′-butylidene (6-tert-butyl-3-methylphenol), 2,2′-di-tert-butyl-5,5′-dimethyl-4,4′-. Sulfonyldiphenol, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) Although butane etc. can be illustrated, it does not restrict | limit in particular to these. These image stabilizers may be used alone or in admixture of two or more.

<Binder>
There is no restriction | limiting in particular as a binder, According to the objective, it can select suitably from well-known things. For example, fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, acetoacetylated polyvinyl alcohol, carboxy modified polyvinyl alcohol, amide modified polyvinyl alcohol, sulfonic acid modified polyvinyl alcohol, butyral modified polyvinyl alcohol, olefin modified polyvinyl alcohol, nitrile modified polyvinyl alcohol , Pyrrolidone-modified polyvinyl alcohol, silicone-modified polyvinyl alcohol, and other polyvinyl alcohol-based polymer substances such as modified polyvinyl alcohol; cellulose derivatives such as hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, and acetyl cellulose; styrene-maleic anhydride copolymer , Such as styrene-butadiene copolymer Emissions-based copolymer, and the like. Also, casein, arabic rubber, oxidized starch, etherified starch, dialdehyde starch, esterified starch, polyvinyl chloride, polyvinyl acetate, polyacrylamide, polyacrylate, polyvinyl butyral, polystyrose and copolymers thereof, polyamide Examples thereof include resin, silicone resin, petroleum resin, terpene resin, ketone resin, and coumaro resin. These polymer substances can be used by being dissolved in a solvent such as water, alcohol, ketones, esters, hydrocarbons, etc., or in a state of being emulsified or pasted in water or other media, Moreover, it can also use together according to the target quality.

<Crosslinking agent>
The crosslinking agent is not particularly limited and can be appropriately selected from known ones according to the purpose. For example, glyoxal, methylol melamine, melamine formaldehyde resin, melamine urea resin, polyamine epichlorohydrin resin, polyamide epi Chlorohydrin resin, potassium persulfate, ammonium persulfate, sodium persulfate, ferric chloride, magnesium chloride, borax, boric acid, alum, ammonium chloride, etc. can be used and used together according to the intended quality You can also

<Pigment>
The pigment is not particularly limited and may be appropriately selected from known ones according to the purpose. For example, silica, calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium oxide, aluminum hydroxide, etc. Examples include inorganic or organic fillers. These pigments may be used alone or in combination of two or more.

<Lubricant>
There is no restriction | limiting in particular as a lubricant, According to the objective, it can select suitably according to the objective, For example, fatty acid metal salts, such as a zinc stearate and a calcium stearate, waxes, silicone resins, etc. are mentioned. These lubricants may be used alone or in combination of two or more.

  In addition to these, benzophenone-based or triazole-based ultraviolet absorbers, dispersants, antifoaming agents, antioxidants, fluorescent dyes, and the like can be used depending on the purpose.

  The amount of the phenol sulfonic acid ester of the present invention used as the developer is determined according to the required performance and recordability, and is not particularly limited, but is usually 0.1 weight per 1 part by weight of the dye. Parts to 10 parts by weight, preferably 0.5 parts to 5 parts by weight. If the amount used is too large, the storability may be lowered, and if it is too small, the print density may be lowered or the storability may be lowered.

  When a developer other than the phenolsulfonic acid ester of the present invention is used in combination, the amount of the developer to be used is determined according to the required performance and recording suitability and is not particularly limited. About 0.0001 to 10000 parts by weight, preferably 0.005 to 20 parts by weight, and more preferably about 0.01 to 10 parts by weight with respect to 1 part by weight of the phenol sulfonate ester.

  Further, the type and amount of other various components such as a sensitizer, an image stabilizer, a pigment, a lubricant and the like used in the thermosensitive coloring layer are determined according to required performance and recording suitability, and are not particularly limited. Usually, about 1 to 10 parts by weight of the sensitizer, about 0.01 to 10 parts by weight of the image stabilizer, and about 0.01 to 10 parts by weight of the other components are used per 1 part by weight of the dye. The

<Support>
There is no restriction | limiting in particular about the shape, a structure, a magnitude | size, material, etc. as a support body, According to the objective, it can select suitably. Examples of the shape include a sheet shape, a roll shape, and a flat plate shape. The structure may be a single layer structure or a laminated structure, and the size can be appropriately selected according to the intended use of the heat-sensitive recording material. Examples of materials include plastic film, synthetic paper, fine paper, waste paper pulp, recycled paper, glossy paper, oil-resistant paper, coated paper, art paper, cast coated paper, fine coated paper, resin laminated paper, release paper, etc. Is mentioned. Moreover, you may use the composite sheet which combined these as a support body.

  There is no restriction | limiting in particular as thickness of a support body, According to the objective, it can select suitably, 30-2,000 micrometers is preferable and 50-1,000 micrometers is more preferable.

  In the heat-sensitive recording material of the present invention, the method for forming the heat-sensitive coloring layer is not particularly limited, and can be formed by a generally known method. For example, a dye, a developer, and materials to be added as necessary are separately atomized by a pulverizer such as a ball mill, an attritor, a sand glider, or a suitable emulsifier to a particle size of several microns or less. A coating solution is prepared by adding various additives according to the purpose and the crosslinking agent. As the solvent used in the coating solution, water, alcohol, or the like can be used, and the solid content of the coating solution is usually preferably about 20 to 40% by weight.

  The heat-sensitive recording material of the present invention can be obtained by applying the coating liquid on a support to form a heat-sensitive color developing layer. The means for applying is not particularly limited, and can be applied according to well-known conventional techniques. For example, it includes various coaters such as an air knife coater, a rod blade coater, a vent blade coater, a bevel blade coater, a roll coater, and a curtain coater. An off-machine coating machine or an on-machine coating machine is appropriately selected and used.

The coating amount of the thermosensitive coloring layer can be appropriately selected depending on the composition and use of the thermosensitive recording material, but is usually in the range of 1 to ²⁰ g / m ² , preferably ² to 12 g / m ² in terms of dry weight. .

<Protective layer>
In the thermosensitive recording material of the present invention, it is preferable to provide a protective layer on the thermosensitive coloring layer. From the viewpoint of heat resistance, water resistance, moist heat resistance, solvent resistance, etc., a) carboxy-modified polyvinyl alcohol, b It is particularly preferable to contain an epichlorohydrin resin and c) a polyamine resin / polyamide resin.

  In addition, it is important that b) epichlorohydrin resin and c) polyamine resin / polyamide resin are used in combination, and when each is used alone in the protective layer, sufficient water resistance is obtained. It is not possible. In addition, even when a general crosslinking agent (for example, glyoxal) is used in combination with an epichlorohydrin resin or a polyamine resin / polyamide resin, sufficient water resistance cannot be obtained.

  "Carboxy-modified polyvinyl alcohol" used in the present invention is a product obtained by introducing a carboxyl group into polyvinyl alcohol for the purpose of increasing reactivity, such as polyvinyl alcohol and fumaric acid, phthalic anhydride, melittic anhydride, itaconic anhydride, etc. A reaction product of a polycarboxylic acid, or an esterified product of these reaction products, and an ethylenically unsaturated dicarboxylic acid such as vinyl acetate and maleic acid, fumaric acid, itaconic acid, crotonic acid, acrylic acid or methacrylic acid As a saponified product of Specific examples include the production methods exemplified in JP-A-53-91995.

  In addition, specific examples of the “epichlorohydrin resin” used in the present invention include polyamide epichlorohydrin resin, polyamine epichlorohydrin resin, and the like. Which of these is used alone? Or it can use together. Moreover, as an amine which exists in the principal chain of an epichlorohydrin-type resin, the thing from a primary to a quaternary can be used, and there is no restriction | limiting in particular. Further, the degree of cationization and the molecular weight preferably have a cationization degree of 5 meq / g · Solid (measured value at pH 7) and a molecular weight of 500,000 or more because of good water resistance. Specific examples include Sumire Resin 650 (30), Sumire Resin 675A, Sumire Resin 6615 (above, manufactured by Sumitomo Chemical Co., Ltd.), WS4002, WS4020, WS4024, WS4030, WS4046, WS4010, CP8970 (above, Starlight PMC) Manufactured).

  In the present invention, the term “polyamine resin / polyamide resin” means a polyamine resin and / or a polyamide resin, and the “polyamine resin / polyamide resin” includes a polyamide resin, a polyamine resin, Includes polyamidourea resin, polyethyleneimine resin, polyalkylene polyamine resin, polyalkylene polyamide resin, polyamine polyurea resin, modified polyamine resin, modified polyamide resin, polyalkylene polyamine urea formalin resin, polyalkylene polyamine polyamide polyurea resin, etc. These can be used alone or in combination of two or more. Specific examples include Sumire Resin 302 (manufactured by Sumitomo Chemical: polyamine polyurea resin), Sumire Resin 712 (manufactured by Sumitomo Chemical: polyamine polyurea resin), Sumire Resin 703 (manufactured by Sumitomo Chemical: polyamine). Polyurea resin), Sumire Resin 636 (manufactured by Sumitomo Chemical Co., Ltd .: polyamine polyurea resin), Sumire Resin SPI-100 (manufactured by Sumitomo Chemical Co., Ltd .: modified polyamine resin), Sumire Resin SPI-102A (Sumitomo Chemical Co., Ltd.) Manufactured: modified polyamine resin), Sumire Resin SPI-106N (Sumitomo Chemical Co .: modified polyamide resin), Sumire Resin SPI-203 (50) (Sumitomo Chemical: polyamide resin), Sumire Resin SPI-198 ( Sumitomo Chemical Co., Ltd .: polyamide resin), printable A-700 (manufactured by Asahi Kasei Co., Ltd.), pre- Tive A-600 (manufactured by Asahi Kasei Co., Ltd.), PA 6500 (manufactured by Seiko PMC: polyalkylene polyamine urea formalin resin), PA 6504 (manufactured by Seiko PMC: polyalkylene polyamine urea formalin resin), PA 6634, PA 6638, PA 6640, PA 6644, PA 6646, PA6654, PA6702, PA6704 (the above, the Starlight PMC company make: polyalkylene polyamine polyamide polyurea resin), CP8994 (the Starlight PMC company make: polyethyleneimine resin) etc. are mentioned. Although not particularly limited, at least in terms of color development sensitivity, at least polyamine resins (polyalkylene polyamine resins, polyamine polyurea resins, modified polyamine resins, polyalkylene polyamine urea formalin resins, polyalkylene polyamine polyamide polyurea resins, etc. It is desirable to use at least one selected from

  The content of b) epichlorohydrin resin and c) polyamine resin / polyamide resin in the protective layer is preferably 1 to 100 parts by weight with respect to 100 parts by weight of a) carboxy-modified polyvinyl alcohol, More preferably, it is 5 to 50 parts by weight. If the content is too small, the crosslinking reaction is insufficient and good water resistance cannot be obtained. If the content is too large, there is a problem of deterioration in operability due to an increase in viscosity of the coating liquid or gelation. In addition, since epichlorohydrin resin crosslinks at pH 6.0 or higher, it is desirable to adjust the pH of the coating liquid for the protective layer to 6.0 or higher.

  In the present invention, the protective layer preferably contains a pigment in the above-described polymer substance (binder component). Examples of the pigment include kaolin, (calcined) kaolin, calcium carbonate, aluminum oxide, titanium oxide, and carbonic acid. Examples thereof include magnesium, aluminum silicate, magnesium silicate, calcium silicate, aluminum hydroxide, diatomaceous earth, talc and the like. These pigments can be used alone or in admixture of two or more. The content of the pigment and binder in the protective layer is preferably about 30 to 300 parts by weight of binder (solid content) with respect to 100 parts by weight of pigment.

The types and amounts of various components used in the protective layer are determined according to the required performance and recordability and are not particularly limited, but generally the coating amount of the protective layer is in the range of 1 to 5 g / m ² . It is.

  In the heat-sensitive recording material of the present invention, an undercoat layer such as a polymer material containing a filler can be provided under the heat-sensitive color developing layer for the purpose of further enhancing the color developing sensitivity. Further, it is possible to correct the curl by providing a backcoat layer on the surface of the support opposite to the thermosensitive coloring layer. An intermediate layer (heat insulating layer) may be formed between the support and the thermosensitive coloring layer, between the thermosensitive coloring layer and the protective layer, and between the support and the back layer. Also, various known techniques in the heat-sensitive recording material field, such as a smoothing process using a super calender after application of each layer, can be added as appropriate.

  The printed portion of the heat-sensitive recording material of the present invention exhibits a green hue. Therefore, a bar code reader that generally uses infrared rays even if a slight discoloration may occur due to being left for a long time under extremely harsh conditions after printing, and the print density may decrease. In contrast, it exhibits excellent bar code reading aptitude.

  Hereinafter, although this invention is illustrated, this invention is not limited by an Example, unless the summary is exceeded.

[Example 1]
Synthesis of Exemplary Compound (4) (Synthesis Example 1)
4-acetoxybenzenesulfonyl chloride (30.0 g), 1,4-butanediol (4.6 g) and toluene (100 ml) were placed in a 300 ml four-necked flask, and 26 g of triethylamine was added dropwise with stirring, followed by reaction at 25 ° C. for 3 hours. It was. After completion of the reaction, a 10% aqueous acetic acid solution was added to the reaction solution, and extraction operation was performed. The organic layer was washed with water several times until the pH became near neutral, and then toluene was distilled off from the organic layer under reduced pressure. After adding 100 ml of methanol and 3 g of potassium carbonate to the residue, the mixture was stirred in an atmosphere at 25 ° C. for 1 hour to perform a deacetylation reaction. After completion of the reaction, a 10% aqueous acetic acid solution was added to the reaction solution, and extraction with ethyl acetate was performed. After washing with water and drying using anhydrous sodium sulfate, ethyl acetate was distilled off, and the residue was purified by a recrystallization method to obtain white crystals having a purity of 99.5% as a target exemplified compound (4).
Analysis by high performance liquid chromatography (HPLC analysis) was performed under the following conditions.
Column: Cadenza CD-C18
Particle size: 3μm
Column: inner diameter 4.6 mm x length 100 mm
Eluent: Acetonitrile: 0.05 vol% phosphoric acid aqueous solution = 60: 40 (volume ratio)
Flow rate: 0.8 ml / min Wavelength: 254 nm
Injection volume: 1 μL
Column temperature: 40 ° C
Analysis time: 20 minutes Sample concentration: about 10 ppm

The physical properties of the obtained white crystals were as follows.
<Melting point>
113 ° C-115 ° C
<IR spectrum (KBr)>
3413, 1603, 1588, 1502, 1445, 1351, 1285, 1187, 1164, 937, 836 cm ^-1
<1 H-NMR spectrum _{(270 MHz, DMSO-d 6} )>
δ1.46-1.60 (4H, m), 3.86-3.96 (4H, m), 6.99 (4H, d, J = 8.9 Hz), 7.70 (4H, d, J = 8.9 Hz), 10.77 (2H, br- s)
< ¹³ C-NMR spectrum (270 MHz, DMSO-d ₆ )>
δ24.5, 69.6, 116.1, 124.7, 130.1, 162.5
<Molecular weight>
401.0 (MH) ⁺

[Example 2]
Synthesis of Exemplary Compound (8) (Synthesis Example 2)
Except that 4.6 g of 1,4-butanediol was changed to 8.5 g of t-butylhydroquinone, the same operation as in Synthesis Example 1 was performed, and the target exemplified compound (8) had a purity of 99.5% as white crystals Got.

The physical properties of the obtained white crystals were as follows.
<Melting point>
178 ° C-181 ° C
<IR spectrum (KBr)>
3424, 2970, 1601, 1587, 1499, 1481, 1362, 1289, 1191, 1166, 861, 838, 554 cm ⁻¹ < ¹ H-NMR spectrum (270 MHz, DMSO-d ₆ )>
δ1.09 (3H, s), 6.62 (1H, d, J = 3.0 Hz), 6..93 (2H, d, J = 8.9 Hz), 7.01 (2H, d, J = 8.9 Hz), 7.05 ( 1H, dd, J = 3.0, 8.9 Hz), 7.27 (1H, d, J = 8.9 Hz), 7.58
(2H, d, J = 8.9 Hz), 7.82 (2H, d, J = 8.9 Hz), 11.00 (2H, br-s)
< ¹³ C-NMR spectrum (270 MHz, DMSO-d ₆ )>
δ 29.6, 34.4, 116.1, 116.4, 121.3, 121.5, 122.0, 123.0, 125.0, 130.7, 131.1, 142.3, 146.2, 147.2, 163.3
<Molecular weight>
477.5 (MH) ⁺

[Example 3]
Synthesis of Exemplary Compound (9) (Synthesis Example 3)
The same operation as in Synthesis Example 1 was conducted except that 4.6 g of 1,4-butanediol was changed to 6.4 g of methylhydroquinone, and white crystals having a purity of 98.2% of the intended exemplified compound (9) were obtained. .

The physical properties of the obtained white crystals were as follows.
<Melting point>
205 ° C-208 ° C
<IR spectrum (KBr)>
3450, 1602, 1588, 1499, 1362, 1193, 1169, 1155, 852, 835, 555 cm ^-1
<1 H-NMR spectrum _{(270 MHz, DMSO-d 6} )>
δ1.90 (3H, s), 6.82 (1H, dd, J = 3.0, 8.9 Hz), 6.92-7.04 (6H, m), 7.61 (2H, d, J = 3.0 Hz), 7.64 (2H, d, J = 3.0 Hz), 10.98 (2H, br-s)
< ¹³ C-NMR spectrum (270 MHz, DMSO-d ₆ )>
δ 15.8, 116.1, 116.3, 120.9, 123.2, 123.5, 123.7, 125.1, 130.8, 130.9, 133.2, 146.1, 147.1, 163.2, 163.4
<Molecular weight>
435.4 (MH) ⁺

[Example 4]
Synthesis of Exemplary Compound (12) (Synthesis Example 4)
The same procedure as in Synthesis Example 1 was conducted except that 4.6 g of 1,4-butanediol was changed to 8.5 g of 4-t-butylcatechol, and the target compound (12) had a purity of 98.6% white. Crystals were obtained.

The physical properties of the obtained white crystals were as follows.
<Melting point>
176 ° C-183 ° C
<IR spectrum (KBr)>
3412, 2965, 1599, 1585, 1502, 1361, 1196, 1185, 1164, 1074, 846, 554 cm ^-1
<1 H-NMR spectrum _{(270 MHz, DMSO-d 6} )>
δ8.95 (9H, s), 6.85 (1H, d, J = 2.4 Hz), 6.93 (2H, d, J = 8.9 Hz), 6.94 (2H, d, J = 8.9 Hz), 7.08 (1H, d , J = 8.6 Hz), 7.36 (1H, dd, J = 2.4, 8.6 Hz), 7.56 (2H ,, d, J = 8.9 Hz), 7.62 (2H, d, J = 8.9 Hz)
< ¹³ C-NMR spectrum (270 MHz, DMSO-d ₆ )>
δ 30.7, 34.4, 116.2, 120.9, 123.5, 123.9, 125.1, 130.8, 131.0, 138.7, 140.5, 151.1, 163.3, 163.4
<Molecular weight>
477.3 (MH) ⁺

[Example 5]
Synthesis of Exemplary Compound (18) (Synthesis Example 5)
The same procedure as in Synthesis Example 1 was conducted except that 4.6 g of 1,4-butanediol was changed to 8.2 g of 2,7-dihydroxynaphthalene, and the target compound (18) had a purity of 98.0% white. Crystals were obtained.

The physical properties of the obtained white crystals were as follows.
<Melting point>
193 ° C-198 ° C
<IR spectrum (KBr)>
3440, 1602, 1588, 1504, 1437, 1354, 1190, 1168, 1092, 860, 839, 557 cm ^-1
<1 H-NMR spectrum _{(270 MHz, DMSO-d 6} )>
δ6.95 (4H, d, J = 8.9 Hz), 7.12 (2H, dd, J = 2.4, 8.9 Hz), 7.65-7.74 (6H, m)
7.95 (2H, d, J = 9.2 Hz), 10.9 (2H, br-s)
< ¹³ C-NMR spectrum (270 MHz, DMSO-d ₆ )>
δ116.2, 119.8, 121.6, 123.5, 129.9, 130.0, 130.9, 133.5, 1475, 163.2
<Molecular weight>
471.5 (MH) ⁺

[Example 6]
Synthesis of Exemplary Compound (21) (Synthesis Example 6)
The same procedure as in Synthesis Example 1 was performed except that 4.6 g of 1,4-butanediol was changed to 9.5 g of 4,4′-dihydroxybiphenyl, and the purity of the intended exemplary compound (21) was 98.4%. White crystals were obtained.

The physical properties of the obtained white crystals were as follows.
<Melting point>
205 ° C-209 ° C
<IR spectrum (KBr)>
3398, 1588, 1489, 1344, 1189, 1163, 1092, 858, 842, 740, 721, 556 cm ^-1
<1 H-NMR spectrum _{(270 MHz, DMSO-d 6} )>
δ6.96 (4H, d, J = 8.9 Hz), 7.07 (4H, d, J = 8.6 Hz), 7.60-7.72 (8H, m), 10.93 (2H, br-s)
< ¹³ C-NMR spectrum (270 MHz, DMSO-d ₆ )>
δ116.2, 122.7, 123.6, 128.2, 130.9, 137.6, 148.8, 163.2
<Molecular weight>
497.6 (MH) ⁺

  In the following examples and comparative examples, an undercoat layer, a thermosensitive coloring layer (recording layer) and a protective layer were formed on one side of the support. In the following description, parts and% represent parts by weight and% by weight, respectively.

[Example 7]
Undercoat layer coating solution calcined kaolin (Ansilex 90 manufactured by BASF) 90.0 parts Styrene-butadiene copolymer latex (solid content 50%) 10.0 parts Water 50.0 parts A mixture of the above composition is mixed and stirred. An undercoat layer coating solution was prepared.

Thermosensitive coloring layer coating solution The following solutions A to D were separately wet-ground with a sand grinder until the average particle size was about 0.5 μm. Here, the average particle diameter is a volume average diameter in a number-based distribution, and was measured with a laser diffraction / scattering particle size distribution measuring apparatus.

Liquid A (developer dispersion)
Naphthalene-2,7-bis (4-hydroxyphenylsulfonate) (Exemplary Compound (18)) 6.0 parts Polyvinyl alcohol 10% aqueous solution 5.0 parts Water 1.5 parts

Liquid B (basic colorless dye dispersion)
3-dibutylamino-6-methyl-7-anilinofluorane (manufactured by Yamamoto Kasei Co., Ltd., trade name: ODB-2) 6.0 parts polyvinyl alcohol 10% aqueous solution 5.0 parts water 1.5 parts

C liquid (sensitizer dispersion)
1,2-di- (3-methylphenoxy) ethane (manufactured by Sanko Co., Ltd., trade name: KS232)
6.0 parts polyvinyl alcohol 10% aqueous solution 5.0 parts water 1.5 parts

The dispersions were mixed at the following ratios to form a thermosensitive coloring layer coating solution.
Liquid A (developer dispersion) 36.0 parts Liquid B (basic colorless dye dispersion) 18.0 parts Liquid C (sensitizer dispersion) 36.0 parts Silica (manufactured by Mizusawa Chemical Co., Ltd., trade name: P537 25% dispersion) 17.5 parts Polyvinyl alcohol (10% solution) 25.0 parts

Protective layer coating solution The following materials were mixed in the following ratio to obtain a protective layer coating solution.
Aluminum hydroxide 50% dispersion (trade name: Martinfin OL, manufactured by Martinsberg) 9.0 parts Carboxy-modified polyvinyl alcohol (manufactured by Kuraray, trade name: KL318, degree of polymerization: about 1700, degree of saponification: 95- 99 mol%) 10% aqueous solution 30.0 parts Polyamide epichlorohydrin resin (trade name: WS4030, solid content 25%, degree of cationization: 2.7, molecular weight: 2.2 million, quaternary amine, manufactured by Seiko PMC) 4 0.0 part modified polyamine resin (trade name manufactured by Sumitomo Chemical Co., Ltd .: Sumirez resin SPI-102A, solid content 45%) 2.2 parts zinc stearate (trade name manufactured by Chukyo Yushi Co., Ltd .: Hydrin Z-7-30, solid content 30%)
2.0 parts

Coating and drying (drying) with an undercoat layer coating solution on one side of a high-quality paper (47 g / m ² base paper) as a support with a Meyer bar so that the coating weight is 10.0 g / m ² by dry weight. (Dryer, 60 ° C., 2 minutes) to obtain an undercoat coated paper. The thermosensitive color-developing layer coating solution was applied onto the undercoat layer of this undercoat coated paper and dried (blow dryer, 60 ° C., 2 minutes) so that the dry weight was 6.0 g / m ² . . This sheet was processed with a super calendar so that the smoothness was 500 to 1000 seconds to obtain a heat-sensitive recording material.

[Example 8]
A heat-sensitive recording material was prepared in the same manner as in Example 7 except that 1,2-di- (3-methylphenoxy) ethane in Liquid C (sensitizer dispersion) of Example 7 was changed to benzyloxynaphthalene. .

[Example 9]
A thermosensitive recording material was produced in the same manner as in Example 7 except that Exemplified Compound (18) in Liquid A (developer dispersion) of Example 7 was changed to Exemplified Compound (12).

[Example 10]
A thermosensitive recording material was prepared in the same manner as in Example 9, except that 1,2-di- (3-methylphenoxy) ethane in the C liquid (sensitizer dispersion) of Example 9 was changed to diphenyl sulfone.

[Example 11]
A thermosensitive recording material was produced in the same manner as in Example 7 except that Exemplified Compound (18) in Liquid A (developer dispersion) of Example 7 was changed to Exemplified Compound (8).

[Example 12]
A thermosensitive recording material was produced in the same manner as in Example 7 except that Exemplified Compound (18) in Liquid A (developer dispersion) of Example 7 was changed to Exemplified Compound (9).

[Example 13]
A thermosensitive recording material was produced in the same manner as in Example 7 except that the exemplified compound (18) in the liquid A (developer dispersion) in Example 7 was changed to the exemplified compound (21).

[Example 14]
A thermosensitive recording material was produced in the same manner as in Example 7 except that Exemplified Compound (18) in Liquid A (developer dispersion) of Example 7 was changed to Exemplified Compound (4).

[Comparative Example 1]
Similar to Example 7 except that Exemplified Compound (18) in Liquid A (Developer Dispersion) of Example 7 was changed to a diphenylsulfone cross-linked compound (Nippon Soda Co., Ltd., trade name: D-90). Thus, a thermosensitive recording material was produced.
The “D-90” is represented by the following equation.

[Comparative Example 2]
A heat-sensitive recording material was prepared in the same manner as in Comparative Example 1 except that 1,2-di- (3-methylphenoxy) ethane in Liquid C (sensitizer dispersion) of Comparative Example 1 was changed to benzyloxynaphthalene. did.

[Comparative Example 3]
Except for changing Exemplified Compound (18) in Liquid A (developer dispersion) of Example 7 to 4-hydroxy-4′-isopropoxydiphenyl sulfone (manufactured by Nippon Soda Co., Ltd., trade name: D-8). A thermosensitive recording material was produced in the same manner as in Example 7.

[Comparative Example 4]
A heat-sensitive recording material was prepared in the same manner as in Comparative Example 3, except that 1,2-di- (3-methylphenoxy) ethane in Liquid C (sensitizer dispersion) of Comparative Example 3 was changed to benzyloxynaphthalene. did.

[Comparative Example 5]
1- [4- (4-Hydroxyphenylsulfonyl) phenoxy] -4 is a diphenylsulfone crosslinked compound (manufactured by Nippon Soda Co., Ltd., trade name: D-90) in the liquid A (developer dispersion) of Comparative Example 2. A heat-sensitive recording material was prepared in the same manner as in Comparative Example 2 except that it was changed to-[4- (4-isopropoxyphenylsulfonyl) phenoxy] butane.

  The thermosensitive recording materials obtained in the above examples and comparative examples were evaluated as follows. The results are shown in Table 1.

<Dye density>
A checkerboard pattern (0.8 cm on one side of the solid print part) is printed with a thermal printer (TH-PMD) manufactured by Okura Electric Co., Ltd. with an applied energy of 0.35 mJ / dot, and the density of the colored part is measured by the Macbeth densitometer (Gretag Macbeth RD-914 (using amber filter)).

<Plasticizer resistance>
After performing a test in which Hilap KMA (manufactured by Mitsui Chemicals) is brought into contact with the front and back of the heat-sensitive recording material printed as described above and left at 20 ° C. for 24 hours, the density of the color development portion is measured with a Macbeth densitometer. The image residual ratio was calculated from the values before and after.
Image residual ratio (%) = (density after test / density before test) × 100
The results are shown in the following table (Table 1).

<Moisture resistance>
After checking a checkered pattern (one side of the solid print part is 0.8 cm) with an applied energy of 0.35 mJ / dot with a thermal printer (TH-PMD) manufactured by Okura Electric Co., Ltd., and measuring the density of the colored part with a Macbeth densitometer Then, a test was performed in which the heat-sensitive recording material was allowed to stand for 24 hours in an environment of 40 ° C. and 90% Rh, and the density of the colored portion after the test was measured with a Macbeth densitometer. .
Image residual ratio (%) = (density after test / density before test) × 100

<Water resistance>
After checking a checkered pattern (one side of the solid print part is 0.8 cm) with an applied energy of 0.35 mJ / dot with a thermal printer (TH-PMD) manufactured by Okura Electric Co., Ltd., and measuring the density of the colored part with a Macbeth densitometer Then, a test in which the heat-sensitive recording material was allowed to stand in water at 20 ° C. for 24 hours was performed, the density of the colored portion after the test was measured with a Macbeth densitometer, and the image residual ratio was calculated by the following formula.
Image residual ratio (%) = (density after test / density before test) × 100

  These results are shown in the following table (Table 2).

  As is apparent from the results in Table 1, the heat-sensitive recording materials of Examples 7 to 14 using the phenolsulfonic acid ester of the present invention as a developer are conventional developers that have been effective for plasticizer resistance. Compared with the heat-sensitive recording materials of Comparative Examples 1-2, 5 using No. 1, it can be seen that the coloring sensitivity is remarkably high and the plasticizer resistance is equal to or higher than that. In addition, compared with the heat-sensitive recording materials of Comparative Examples 3 and 4 using a conventional developer that has been effective for color development sensitivity, the color development sensitivity has a high level of sensitivity, and the resistance to plasticizer is high. It is much better. Therefore, the phenol sulfonic acid ester of the present invention is a very excellent developer capable of realizing a heat-sensitive recording material having both high color development sensitivity and plasticizer resistance, and is clear from the results in Table 2. Thus, it can be seen that by using the phenol sulfonic acid ester of the present invention as a developer, it is possible to realize a heat-sensitive recording material that is excellent not only in color development sensitivity and plasticizer resistance but also in water resistance and moisture resistance.

Claims (4)

Formula (I):

[Wherein R represents a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an alkoxyl group,
A cyano group, a nitro group, an aryl group or an aralkyl group, wherein m Rs may be the same as or different from each other, and Z is an arylene group having one or two benzene rings which may have a substituent. An arylene group in which two or more benzene rings optionally having substituents are condensed or a bisarylene in which two or more benzene rings optionally having a substituent are connected via a divalent group Represents a group , m is an integer of 0 to 4, and n is an integer of 2 to 4. ] The phenolsulfonic acid ester represented by this. Heat-sensitive recording material for color developer containing phenolsulfonic acid ester of claim 1 Symbol placement. On a support, and a basic leuco dye colorless or light-colored, a heat-sensitive recording material having a thermosensitive color developing layer containing a color developer, phenolsulfonic acid ester of claim 1 Symbol placement as the color developer A heat-sensitive recording material containing one or more of these. 4. The heat-sensitive recording material according to claim 3 , wherein a protective layer comprising carboxy-modified polyvinyl alcohol, epichlorohydrin resin and polyamine resin / polyamide resin is further provided on the heat-sensitive coloring layer.