JPH09142034A - Heat sensitive recording sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve recording sensitivity greatly by a method wherein specified aminobenzene sulfonamide derivative is incorporated as organic developer and specified sulfonamide compound is contained as sensitivity increasing agent in a heat sensitive coloring agent. SOLUTION: The heat sensitive color producing layer of a heat sensitive recording sheet is provided with aminobenzen sulfonamide derivative, shown by a formula I, as organic developer while sulfonamide compound, shown by a formula II, is contained in the heat sensitive color producing layer as sensitivity increasing agent with the rate of 0.01-2 pts. with respect to 1 pts. of color developer. In the formula I, X means the atom of oxygen or sulfur, Y represents lower alkyl group of 1-6C or electronic attractive group and (m) is an integer of 0-4. R represents non-replaced or replaced phenyl group, alalkyl group lower alkyl group of 1-6C, cycloalkyl group of 3-6C, lower alkenyl group of 2-6C or naphthyl group. In the formula II, Z represents lower alkyl group carbon of 1-6C or electron attractive group. (n) is an integer of 0-2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording material having excellent color development sensitivity.

[0002]

2. Description of the Related Art Generally, a heat-sensitive recording sheet is usually prepared by grinding and dispersing a colorless or light-colored basic colorless dye and an organic developer such as a phenolic compound into fine particles, and then mixing the both. A coating obtained by adding a binder, a filler, a sensitivity improver, a lubricant and other auxiliaries is applied to a support such as paper, synthetic paper, film and plastic. , Hot stamp, hot pen, laser light, etc. develops color by an instant chemical reaction by heating,
A recorded image is obtained. Thermosensitive recording media are widely used in facsimiles, computer terminal printers, automatic ticket vending machines, recorders for measurement, and the like. In recent years, high-speed printing and high-speed image formation have become possible along with the diversification of recording apparatuses and the advancement of performance, and higher quality is required for the recording sensitivity of a thermosensitive recording medium.

As a method for satisfying this requirement, it has been proposed to use a dye and a developer together with a sensitizer. For example, when the color developer consists of a phenolic compound represented by bisphenol A, p-benzylbiphenyl (JP-A-60-82382) and benzyl p-benzyloxybenzoate (JP-A-57-201691) No.), benzyl naphthyl ether (JP-A-58-87094) and the like have been used as suitable sensitizers. When using a sensitizer,
When heated, the sensitizer first melts, and when it melts the dye and developer, they both mix at the molecular level and induce a color development reaction. Is important.

On the other hand, the inventors of the present invention filed Japanese Patent Application No. 6-1000.
No. 82, Japanese Patent Application No. 6-168516, Japanese Patent Application No. 6-195568, etc., an aminobenzenesulfonamide derivative having an aminosulfonyl group (—SO ₂ NH ₂ ) is used as a developer. However, when the applied energy is high, the color development sensitivity is good, but when the applied energy is low or when printing is performed at a high speed, sufficient color density cannot be obtained. It was insufficient for practical use in equipment that requires them.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a thermosensitive recording material using an aminobenzenesulfonamide derivative as a color developer, in which the coloring sensitivity is greatly improved.

[0006]

The inventors of the present invention have conducted extensive studies to develop a thermosensitive recording medium having the above-mentioned properties, and as a result, have used an aminobenzenesulfonamide derivative as a color developer, which has aminosulfonyl groups. group (-SO ₂ N
By using an aromatic compound having H ₂ ) as a sensitizer, the recording sensitivity was significantly improved and the present invention was completed.

That is, the present invention provides a thermosensitive recording sheet comprising a support and a thermosensitive coloring layer containing a colorless or light-colored basic colorless dye and an organic developer as main components. As an organic developer, the following general formula (I)
A sulfonamide compound represented by the following general formula (II) as a sensitizer is contained for 1 part of the color developing agent represented by the following general formula (I). The present invention relates to a thermosensitive recording sheet characterized by containing 0.01 to 2 parts.

[0008]

Embedded image (In the formula, X represents an oxygen atom or a sulfur atom, and Y represents 1 carbon atom.
~ 6 represents a lower alkyl group or an electron-withdrawing group, and m represents an integer of 0-4. R represents an unsubstituted or substituted phenyl group, an aralkyl group, a lower alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a lower alkenyl group having 2 to 6 carbon atoms, or a naphthyl group. )

[0009]

Embedded image (In the formula, Z represents a lower alkyl group having 1 to 6 carbon atoms or an electron-withdrawing group. N represents an integer of 0 to 2.)

In the present invention, at least one aminobenzenesulfonamide derivative represented by the general formula (I) is used as an organic developer. Generally, a color developer having an acidic functional group such as a phenolic hydroxyl group or a carboxyl group has high color developing ability. The aminobenzenesulfonamide derivative represented by the formula (I) used in the present invention does not have these functional groups, but exhibits a strong color developing ability for a basic dye. The reason for this is not clearly understood, but it is presumed as follows.

It is considered that the aminobenzenesulfonamide derivative used in the present invention undergoes a structural change (tautomerism) from a neutral type to an acidic type as shown in the following formula,
It functions as a developer when it has an acidic structure. A high temperature is necessary to cause the tautomerism from the neutral type to the acidic type, and in the case of heat-sensitive recording, the thermal head momentarily changes to 2
Since the temperature is high from 00 to 300 ° C. or higher, the compound represented by the formula (I) contained in the recording layer of the thermosensitive recording medium undergoes tautomerism to become an acidic type and develops color developing ability. It is considered that this causes the lactone ring of the dye to be cleaved to develop a color.

[0012]

Embedded image (In the formula, X represents an oxygen atom or a sulfur atom)

In the general formula (I), X represents an oxygen atom or a sulfur atom, and Y may be a substituent which does not deteriorate the coloring ability. Such a substituent has a carbon number such as a methyl group or an ethyl group. Examples thereof include lower alkyl groups of 1 to 6 or electron withdrawing groups such as chlorine atom, nitro group and methoxy group. R represents a hydrocarbon group, specifically, a phenyl group, an aralkyl group, a lower alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and 2 to 6 carbon atoms.
And lower alkenyl groups, naphthyl groups and the like. In addition, R may be substituted with a substituent that does not inhibit color development, and examples of the substituent include a lower alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group or a chlorine atom, a nitro group, a methoxy group and the like. Examples thereof include electron-withdrawing groups.

Specific examples of the compound represented by the general formula (I) include the following (I-1) to (I-72), and the present invention is not limited to these, but a raw material. (I-10) is preferably used from the standpoints of availability and easiness of synthesis. Further, in the invention, for the purpose of improving the sensitivity, it is possible to use a conventionally known developer together with about 0.01 to 0.9 parts by weight per 1 part of the compound of the general formula (I).

[0015]

[Chemical 6]

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[0016]

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[0017]

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[0018]

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Further, in the present invention, at least one sulfonamide compound represented by the general formula (II) is used as a sensitizer. The formula (I
It is considered that the sensitizer represented by I) has an action of inducing a structural change from the neutral type to the acid type of the developer when melted together with the developer represented by the formula (I). To be

In the general formula (II), Z may be a substituent which does not inhibit the sensitizing effect, and such a substituent is a lower alkyl group having 1 to 6 carbon atoms such as methyl group and ethyl group. Alternatively, electron withdrawing groups such as chlorine atom, nitro group, methoxy group and the like can be mentioned. Specific examples of the compound represented by the general formula (II) are shown below (II-1) to (II
-30), but the invention is not limited thereto. Above all, (II-2) or (II-4) is preferably used since the effect when used with the above-mentioned color developer (I-10) is good.

In the present invention, the content of the sensitizer represented by the general formula (II) is the developer 1 represented by the general formula (I).
If the amount is less than 0.01 part by weight, the sensitizing effect is not sufficient, and if the amount is more than 2 parts by weight with respect to 1 part of the color developer, sufficient color density cannot be obtained. Therefore, the sensitizer represented by the general formula (II) is preferably used in a proportion of 0.01 to 2 parts with respect to 1 part of the developer represented by the general formula (I).

[0022]

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[0023]

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[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-sensitive recording material of the present invention comprises a basic colorless dye, at least one aminobenzenesulfonamide derivative represented by the general formula (I) as a developer, and a sensitizer. At least one kind of sulfonamide compound represented by the general formula (II) is dispersed together with a binder, and a filler and, if necessary, a sensitizer, a lubricant, an ultraviolet absorber, a water resistant agent and a defoaming agent. A thermosensitive color developing layer coating liquid is prepared by adding an auxiliary agent such as the above, and this is coated on a support and dried. The sulfonamide compound represented by the general formula (II) is used in a proportion of 0.01 to 2 parts with respect to 1 part of the developer represented by the general formula (I).

As the dye to be used in the heat-sensitive recording material of the present invention, any dye known in the field of conventional pressure-sensitive or heat-sensitive recording paper can be used, and it is not particularly limited, but it is a triphenylmethane type dye. Compounds, fluoran compounds, fluorene compounds, divinyl compounds and the like are preferable. Specific examples of typical dyes are shown below. These dyes may be used alone or in combination of two or more.

<Triphenylmethane type 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 ) Fluoran 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-n-octylanilino Fluoran 3-diethylamino-6-methyl-7-n-octylua Nofluorane 3-diethylamino-6-methyl-7-benzylanilinofluorane 3-diethylamino-6-methyl-7-dibenzylanilinofluorane 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- ( -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-chlorofluoran 3-dibutylamino-6-ethoxyethyl- -Anilinofluorane 3-dibutylamino-6-chloro-7-anilinofluorane 3-dibutylamino-6-methyl-7-p-methylanilinofluorane 3-dibutylamino-7- (o-chloroanilino) Fluoran 3-dibutylamino-7- (o-fluoroanilino) fluorane 3-n-dipentylamino-6-methyl-7-anilino fluorane 3-n-dipentylamino-6-methyl-7- (p-chloroanilino ) Fluoran 3-n-dipentylamino-7- (m-trifluoromethylanilino) fluoran 3-n-dipentylamino-6-chloro-7-anilinofluorane 3-n-dipentylamino-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-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- (N-ethyl-N-ethoxypropylamino) -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 2,4-dimethyl- 6-[(4-dimethylamino) anilino] -fluoran

<Fluorene-based leuco dye> 3, 6, 6 '
-Tris (dimethylamino) spiro [fluorene-9,
3'-phthalide] 3,6,6'-tris (diethylamino) spiro [fluorene-9,3'-phthalide]

<Divinyl type 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) 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

In the present invention, conventionally known sensitizers can be used in combination as long as the desired effects for the above problems are not impaired. Examples of such a sensitizer 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-
Examples thereof include 2-naphthoic acid phenyl ester, o-xylelin-bis- (phenyl ether), and 4- (m-methylphenoxymethyl) biphenyl, but they are not particularly limited thereto. You may use these sensitizers individually or in mixture of 2 or more types.

As the binder used in the present invention, completely saponified polyvinyl alcohol having a degree of polymerization of 200 to 1900, partially saponified polyvinyl alcohol, carboxy modified polyvinyl alcohol, amide modified polyvinyl alcohol, sulfonic acid modified polyvinyl alcohol, butyral modified polyvinyl. Modified polyvinyl alcohol such as alcohol, cellulose derivative such as hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, carboxymethyl cellulose, acetyl cellulose, styrene-maleic anhydride copolymer, styrene-butadiene copolymer, polyvinyl chloride, polyvinyl acetate, polyacrylamide , Polyacrylic acid ester, polyvinyl butyral, polystyrene and their copolymers, polyamide resin, silicone Butter, petroleum resins, terpene resins, ketone resins, and coumarone resins. These polymeric substances include water, alcohol, ketones, esters,
In addition to being used by being dissolved in a solvent such as a hydrocarbon, it may be used in a state of being emulsified in water or another medium or dispersed in a paste form, and may be used together depending on the required quality.

Further, in the present invention, p-nitrobenzoic acid metal salt (Ca, Zn), which is a known stabilizer showing an oil resistance effect of a recorded image, etc., within a range that does not impair the desired effect for the above problems, Alternatively, phthalic acid monobenzyl ester metal salt (Ca, Zn) can be added.

As the filler which can be used in the present invention, silica, calcium carbonate, kaolin, calcined kaolin, diatomaceous earth, talc, titanium oxide, zinc oxide, aluminum hydroxide, polystyrene resin, urea-formalin resin, styrene- Examples thereof include methacrylic acid copolymers, styrene-butadiene copolymers, and inorganic or organic fillers such as hollow plastic pigments.

In addition to these, release agents such as fatty acid metal salts, lubricants such as waxes, UV absorbers of benzophenone type and triazole type, water resistance agents such as glyoxal, dispersants, defoaming agents, antioxidants, and fluorescent agents. A dye or the like can be used.

The amount of the color developer and the dye used in the heat-sensitive recording material of the present invention and the types and amounts of other various components are determined according to the required performance and recording suitability and are not particularly limited, but are usually , A developer 1 represented by the general formula (I)
0.1 to 2 parts of the dye, 0.01 to 2 parts of the sensitizer represented by the general formula (II), and 0.5 to 4 parts of the filler are used for each part.
It is suitable that the binder has a total solid content of 5 to 25%.

As the support, paper, synthetic paper, plastic film, non-woven fabric, metal foil or the like can be used, and a composite sheet in which these are combined may be used. An intended thermosensitive recording medium can be obtained by applying a coating solution having the above composition to any of these supports.

Further, an overcoat layer of a polymer substance or the like may be provided on the thermosensitive color developing layer for the purpose of improving the storage stability. Further, an undercoat layer containing an organic filler or an inorganic filler may be provided between the color forming layer and the support for the purpose of enhancing the storage stability and sensitivity.

[0039]

【Example】

<Production of Thermal Recording Material> The thermal recording material of the present invention will be described below with reference to examples. The parts and% in the description represent parts by weight and% by weight, respectively, unless otherwise specified.

[Examples 1 to 5] In Examples 1 to 5, compounds (I-1) and (I) were used as color developers in the heat-sensitive recording material of the present invention.
-10), (I-13), (I-19) or (I-2
6), 3-diethylamino-6-methyl-7 as a dye
In this example, anilinofluorane (ODB) and compound (II-4) were used as a sensitizer. A developer dispersion (solution A), a dye dispersion (solution B), and a sensitizer dispersion (solution C) having the following formulations were separately wet-polished with a sand grinder until the average particle diameter became 1 micron. It was crushed. Liquid A (developer dispersion liquid) Developer 6.0 parts 10% polyvinyl alcohol aqueous solution 18.8 parts Water 11.2 parts Liquid B (dye dispersion liquid) 3-diethylamino-6-methyl-7-ani Rinofluoran (ODB) 2.0 parts 10% polyvinyl alcohol aqueous solution 4.6 parts Water 2.6 parts C liquid (sensitizer dispersion) Compound (II-4) 4.0 parts 10% polyvinyl alcohol Aqueous solution 18.8 parts Water 11.2 parts Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer dispersion liquid) 36.0 parts Liquid B (dye [ODB] dispersion liquid) 9.2 parts Liquid C (sensitizer [compound (II-4)] dispersion liquid) 34.0 parts Kaolin clay (50% dispersion liquid) 12.0 parts Each of the above coating liquids was applied to one side of a base paper of 50 g / m ² and then dried, and this sheet was supercalendered to have a smoothness of 500 to 600 seconds. And a coating amount of 6.0 g / m ² was obtained.

[Examples 6 to 8] In Examples 6 to 8, the compound (I-10) was used as the developer, the dyes shown below other than ODB were used as the dye, and the compound (II-4) was used as the sensitizer. It is an example. (Dye) ODB-2; 3-dibutylamino-6-methyl-7-anilinofluorane PSD-170; 3-pyrrolidino-6-methyl-7-anilinofluorane CVL; 3,3-bis (p- Dimethylaminophenyl)
-6-Dimethylaminophthalide The developer dispersion of compound (I-10) and the sensitizer dispersion of compound (II-4) were treated in the same manner as in Examples 1-5. Dye dispersions (liquid D) other than ODB were separately wet-milled with a sand grinder until the average particle size became 1 micron. D liquid (dye dispersion other than ODB) Dye 2.0 parts 10% polyvinyl alcohol aqueous solution 4.6 parts water 2.6 parts Dispersion liquid is mixed and stirred at the following ratio to prepare a coating liquid. did. Liquid A (developer [compound (I-10)] dispersion) 36.0 parts Liquid D (dye dispersion other than ODB) 9.2 parts Liquid C (sensitizer [compound (II-4)] dispersion Liquid) 34.0 parts Kaolin clay (50% dispersion liquid) 12.0 parts Each of the above coating liquids is applied to one side of a 50 g / m ² base paper and then dried, and this sheet is supercalendered. And a smoothness of 500 to 600 seconds was applied to obtain a thermal recording material having a coating amount of 6.0 g / m ² .

[Example 9] Example 9 is an example in which the compound (I-10) was used as the developer, the ODB was used as the dye, and the compound (II-2) was used as the sensitizer. In the same manner as in Examples 6 to 8, a developer dispersion liquid of compound (I-10) and ODB.
The dispersion liquid is treated, and the compound (II-2) is converted to the compound (II-4).
Dispersion E liquid was obtained by treating in the same manner as. Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer [compound (I-10)] dispersion) 36.0 parts Liquid D (dye [ODB] dispersion) 9.2 parts Liquid E (sensitizer [compound (II-2)] dispersion Liquid) 34.0 parts Kaolin clay (50% dispersion liquid) 12.0 parts Each of the above coating liquids is applied to one side of a 50 g / m ² base paper and then dried, and this sheet is supercalendered. And a smoothness of 500 to 600 seconds was applied to obtain a thermal recording material having a coating amount of 6.0 g / m ² .

[Example 10] In Example 10, compounds (I-1) and (I-10) were used as developers and OD was used as a dye.
B is an example of using the compound (II-4) as a sensitizer. The developer dispersions of the compounds (I-1) and (I-10), the ODB dispersion, and the sensitizer dispersion of the compound (II-4) were treated in the same manner as in Examples 1 to 4. Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer [compound (I-1)] dispersion liquid) 18.0 parts Liquid A (developer [compound (I-10)] dispersion liquid) 18.0 parts Liquid B (dye [ODB] dispersion) Liquid) 9.2 parts Liquid C (sensitizer [compound (II-4)] dispersion liquid) 34.0 parts Kaolin clay (50% dispersion liquid) 12.0 parts Each of the above-mentioned coating liquids of 50 g / m ² After coating on one side of the paper, it is dried, and this sheet is processed by a super calender to have a smoothness of 500 to 600 seconds to obtain a thermal recording material having a coating amount of 6.0 g / m ^2. It was

Example 11 In Example 11, compound (I-10) was used as a color developer, and ODB and PSD- were used as dyes.
170, an example of using the compound (II-4) as a sensitizer. The developer dispersion of compound (I-10), ODB dispersion and PSD-170 dispersion, and sensitizer dispersion of compound (II-4) were treated in the same manner as in Examples 1 to 8.
Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. A liquid (developer [compound (I-10)] dispersion liquid) 36.0 parts B liquid (dye [ODB] dispersion liquid) 4.6 parts D liquid (dye [PSD-170] dispersion liquid) 4.6 Parts C liquid (sensitizer [compound (II-4)] dispersion liquid) 34.0 parts kaolin clay (50% dispersion liquid) 12.0 parts each of the above coating liquids is applied to one side of a base paper of 50 g / m ^2. After that, it was dried, and this sheet was treated with a super calender so that the smoothness was 500 to 600 seconds to obtain a thermal recording material having a coating amount of 6.0 g / m ² .

[Example 12] Example 12 is an example in which the compound (I-10) was used as the color developer, the ODB was used as the dye, and the compounds (II-2) and (II-4) were used as the sensitizers. . The developer dispersion of compound (I-10), ODB dispersion, sensitizer dispersion of compound (II-2) and compound (II-4) were treated in the same manner as in Examples 1 to 9. Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer [compound (I-10)] dispersion) 36.0 parts Liquid D (dye [ODB] dispersion) 9.2 parts Liquid C (sensitizer [compound (II-4)] dispersion Liquid) 17.0 parts E liquid (sensitizer [compound (II-2)] dispersion) 17.0 parts Kaolin clay (50% dispersion) 12.0 parts Each of the above coating solutions was added to a base of 50 g / m ² . After coating on one side of the paper, it is dried, and this sheet is processed by a super calender to have a smoothness of 500 to 600 seconds to obtain a thermal recording material having a coating amount of 6.0 g / m ^2. It was

[Examples 13 to 17] Examples 13 to 17
Is a compound (I-1) or a compound (I-1) as a developer.
0) or the compound (I-19), the compound shown below is used as the dye, and the compound (II-2) or the compound (II-4) is used as the sensitizer. Yes (described in Table 1). (Dye) S205; 3- (N-ethyl-N-isoamylamino)
-6-Methyl-7-anilinofluorane Black 100; 3-diethylamino-7- (m-trifluoromethylanilino) fluorane The above dye dispersions (F liquid) were separately sand-grinded with an average particle size of 1 Wet milling was done to micron. Regarding the color developer and the sensitizer, the above Examples 1 to
The dispersion was treated as in 10. Liquid F (dye dispersion) Dye 2.0 parts 10% polyvinyl alcohol aqueous solution 4.6 parts Water 2.6 parts The dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer dispersion liquid) 36.0 parts Liquid F (dye dispersion liquid) 9.2 parts Liquid C (sensitizer dispersion liquid) 34.0 parts Kaolin clay (50% dispersion liquid) 12.0 parts After coating each coating solution on one side of 50 g / m ² of base paper, it was dried, and this sheet was treated with a super calender to have a smoothness of 500 to 600 seconds. To obtain 6.0 g / m ² thermosensitive recording medium.

Example 18 In Example 18, compound (I-10) was used as the color developer, and ODB and S20 were used as the dye.
5 is an example of using the compound (II-4) as a sensitizer. The developer dispersion of the compound (I-10), the ODB dispersion and the S205 dispersion, and the sensitizer dispersion of the compound (II-4) were treated in the same manner as in Examples 1 to 17. Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer [compound (I-10)] dispersion) 36.0 parts Liquid B (dye [ODB] dispersion) 4.6 parts Liquid F (dye [S205] dispersion) 4.6 parts C Liquid (sensitizer [Compound (II-4)] dispersion liquid) 34.0 parts Kaolin clay (50% dispersion liquid) 12.0 parts After applying each of the above-mentioned coating liquids to one side of 50 g / m ² base paper The sheet was dried, and the sheet was treated with a super calender so that the smoothness was 500 to 600 seconds to obtain a thermal recording material having a coating amount of 6.0 g / m ² .

Example 19 In Example 19, the compound (I-10) was used as a color developer, and ODB-2 and S2 were used as dyes.
05 is an example of using the compound (II-4) as a sensitizer. In the same manner as in Examples 1 to 17, a developer dispersion liquid of the compound (I-10), an ODB-2 dispersion liquid and a S205 dispersion liquid,
And a sensitizer dispersion of the compound (II-4) was processed. Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer [compound (I-10)] dispersion liquid) 36.0 parts Liquid D (dye [ODB-2] dispersion liquid) 4.6 parts Liquid F (dye [S205] dispersion liquid) 4.6 Parts C liquid (sensitizer [compound (II-4)] dispersion liquid) 34.0 parts kaolin clay (50% dispersion liquid) 12.0 parts each of the above coating liquids is applied to one side of a base paper of 50 g / m ^2. After that, the sheet was dried, and this sheet was treated with a super calender so as to have a smoothness of 500 to 600 seconds to obtain a thermal recording material having a coating amount of 6.0 g / m ² .

[Example 20] Example 20 is an example in which the compound (I-10) was used as the color developer, PSD-170 and Black 100 were used as the dye, and the compound (II-2) was used as the sensitizer. The developer dispersion of compound (I-10), PSD-170 dispersion and Black100 dispersion, and sensitizer dispersion of compound (II-2) were treated in the same manner as in Examples 1 to 17. Next, the dispersions were mixed and stirred at the following ratios to prepare coating solutions. Liquid A (developer [Compound (I-10)] dispersion liquid) 36.0 parts Liquid D (dye [PSD-170] dispersion liquid) 4.6 parts Liquid F (dye [Black100] dispersion liquid) 4.6 Part C liquid (sensitizer [compound (II-2)] dispersion liquid) 34.0 parts kaolin clay (50% dispersion liquid) 12.0 parts each of the above coating liquids is applied to one side of a base paper of 50 g / m ^2. After that, the sheet was dried, and this sheet was treated with a super calender so as to have a smoothness of 500 to 600 seconds to obtain a thermal recording material having a coating amount of 6.0 g / m ² .

Comparative Example 1 The same operation as in Example 9 was performed. However, Dispersion E was not mixed in the formation of the color forming layer.

Comparative Example 2 The same operation as in Example 9 was performed. However, the compound (II-
P-Benzylbiphenyl (PBB) was used instead of 2).

<Evaluation of thermosensitive recording medium> With respect to the prepared thermosensitive recording medium, TH-PMD (a thermosensitive recording paper printing tester, Kyocera, equipped with a thermal head) manufactured by Okura Electric Co., Ltd. was used and applied energy of 0. .30 mj / dot and 0.38
Printed at mj / dot. The recording density of the recording portion was measured with a Macbeth densitometer (RD-914, using an amber filter) (see Table 1).

[0053]

[Table 1]

As is clear from Table 1, in Examples 1 to 20 of the present invention using the developer represented by the general formula (I) and the sensitizer represented by the general formula (II), A high sensitizing effect is obtained. On the other hand, by having an excellent sensitizing effect on Comparative Example 1 in which the sensitizer represented by the general formula (II) is not used, and bisphenol A which is a typical conventional developer, In Comparative Example 2 using known p-benzylbiphenyl, the sensitizing effect is poor and the recording density is low.

[0055]

According to the present invention, when the aminobenzenesulfonamide derivative represented by the general formula (I) is used as the color developer, the sulfonamide compound represented by the general formula (II) is sensitized. By containing it as an agent, a thermosensitive recording material having a high color developing sensitivity and a good recorded image can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kyosho Nagai 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Inside Nippon Paper Industries Co., Ltd. Product Development Laboratory (72) Akio Sekine 1-30-30 Kamiochiai, Shinjuku-ku, Tokyo No. 6 Nippon Paper Industries Co., Ltd. Product Development Laboratory (72) Inventor Hiroshi Ueda 1-30-6 Kamiochiai, Shinjuku-ku, Tokyo Japan Paper Manufacturing Co., Ltd. Product Development Laboratory

Claims (1)

[Claims] 1. A thermosensitive recording sheet comprising a support and a thermosensitive coloring layer containing a colorless or light-colored basic colorless dye and an organic developer as main components, wherein the thermosensitive coloring layer is an organic developer. As a sensitizer, the sulfonamide compound represented by the following general formula (II) is used as a sensitizer to develop a color represented by the general formula (I). 0.01-2 for 1 part of agent
A heat-sensitive recording sheet, characterized in that it is contained in a ratio of parts. Embedded image (In the formula, X represents an oxygen atom or a sulfur atom, and Y represents 1 carbon atom.
~ 6 represents a lower alkyl group or an electron-withdrawing group, and m represents an integer of 0-4. R represents an unsubstituted or substituted phenyl group, an aralkyl group, a lower alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a lower alkenyl group having 2 to 6 carbon atoms, or a naphthyl group. ) (In the formula, Z represents a lower alkyl group having 1 to 6 carbon atoms or an electron-withdrawing group. N represents an integer of 0 to 2.)