JP2002127614A - Heat-sensitive recording body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly sensitive heat-sensitive recording body with excellent storing properties of recorded parts to such chemicals as plasticizers and oils and storing properties with time and resistance to ground skin fog of the recorded parts. SOLUTION: In the heat-sensitive recording body with a heat-sensitive recording layer containing a leuco dye, a developing agent and an adhesive on a substrate, as one of means for solving the above described problem, a compound of the below described general formula (1) is used as the developing agent and a paraffin wax is incorporated in the heat-sensitive recording layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording medium utilizing a color development reaction between a leuco dye and a color developer.

[0002]

2. Description of the Related Art A thermosensitive recording medium utilizing a color development reaction between a leuco dye and a color developer by heat is relatively inexpensive, the recording equipment is compact, and its maintenance is easy. It is used in media and other broad areas.

[0003] With the expansion of the field of use, there has been a demand for a heat-sensitive recording material which is excellent in the preservability of compounds such as plasticizers, edible oils, and cosmetics in a recording area by a color-forming reaction between a leuco dye and a developer. ing.

In order to enhance the plasticizer resistance and oil resistance of the recording section, a color developer such as 2,2'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] diethyl ether is used in the above general formula (1). Thermosensitive recording materials using the compounds shown in JP-A-8-333329 and JP-A-10-2
No. 9969, etc.
JP-A-297089 and JP-A-10-297092 disclose a thermosensitive recording medium containing 2,2'-bis [4- (4-hydroxyphenylsulfonyl) phenoxy] diethyl ether and a diphenylsulfone derivative. There is a demand for improved ground fog resistance.

There is a heat-sensitive recording medium in which a protective layer is provided on a heat-sensitive recording layer in order to enhance the plasticizer resistance and oil resistance of the recording portion, but there is a problem that the color density is reduced due to the provision of the protective layer. .

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat-sensitive recording medium having excellent storage stability over time and excellent background fog resistance.

[0007]

Means for Solving the Problems In a heat-sensitive recording material having a heat-sensitive recording layer containing a leuco dye and a developer on a support, as one means for solving the above problems,
In the present invention, a compound represented by the following general formula (1) is used as a color developer, and a paraffin wax is contained in the heat-sensitive recording layer.

[0008]

Embedded image

[N in the general formula (1) represents an integer of 1 to 7. ]

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is characterized in that the thermosensitive recording layer contains a specific developer comprising the compound represented by the above general formula (1) and paraffin wax,
The amount of the specific developer used is not particularly limited, but the specific developer is about 1 to 50% by weight, preferably about 5 to 30% by weight, based on the total solid content of the heat-sensitive recording layer.

The amount of paraffin wax is about 1 to 15% by weight, preferably 1 to 15% by weight, based on the total solid content of the heat-sensitive recording layer.
It is about 10% by weight. If the amount of paraffin wax is less than 1% by weight based on the total solid content of the heat-sensitive recording layer, the background fog resistance may decrease. If the amount exceeds 15% by weight, the adhesiveness of the heat-sensitive recording layer to the support decreases. There is fear.

By using a paraffin wax in combination with a specific color developer, the background fog resistance is improved, the water resistance of the heat-sensitive recording layer is improved, and a water-based adhesive is contained on the surface of the heat-sensitive recording layer. When the coating liquid for the protective layer is applied,
Infiltration of the coating liquid for the protective layer into the heat-sensitive recording layer is suppressed, and as a result, an effect of extremely lowering the recording sensitivity is obtained.

The melting point of paraffin wax is 60
To 75 ° C. are preferred, and the average particle diameter is particularly preferably 0.
Paraffin wax obtained by emulsification and dispersion so as to have a thickness of 8 μm or less is preferable. If the melting point of the paraffin wax is lower than 60 ° C., the adhesiveness of the heat-sensitive recording layer to the support may decrease. If it exceeds 75 ° C., the background fog resistance may decrease.

Various known leuco dyes can be used in the heat-sensitive recording layer. Specific examples of such leuco dyes include the following. 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2)
Blue-coloring dyes such as-(methylphenyl) -3- (4-dimethylaminophenyl) -6-dimethylaminophthalide, 3-diethylamino-7-dibenzylamino-benzo [a] fluoran, 3- (N-ethyl -Np-tolyl)
Green coloring dyes such as amino-7-N-methylanilinofluoran, 3-diethylamino-7-anilinofluoran, 3-diethylamino-7-dibenzylaminofluoran, 3-cyclohexylamino-6-chlorofluorin Orane, 3-diethylamino-6-methyl-7-chlorofluoran, 3-diethylamino-7-chlorofluoran,
Red-coloring dyes such as rhodamine (o-chloroanilino) lactam, 3-diethylamino-6,8-dimethylfluoran, 3- (N-ethyl-N-isoamyl) amino-6
-Methyl-7-anilinofluoran, 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7
-Anilinofluoran, 3-di (n-butyl) amino-
6-methyl-7-anilinofluoran, 3-di (n-butyl) amino-7- (o-fluorophenylamino) fluoran, 3- (N-ethyl-p-toluidino) -6
Methyl-7-anilinofluoran, 3- (N-ethyl-
N-tetrahydrofurfurylamino) -6-methyl-7
-Anilinofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-pyrrolidino-6-methyl-7-anilinofluoran, 3-piperidino-6
Black-color-forming dyes such as methyl-7-anilinofluoran;
3,3-bis [1- (4-methoxyphenyl) -1-
(4-dimethylaminophenyl) ethylene-2-yl]
-4,5,6,7-tetrachlorophthalide, 3-p-
(P-dimethylaminoanilino) anilino-6-methyl-7-chlorofluoran, 3-p- (p-chloroanilino) anilino-6-methyl-7-chlorofluoran,
Dyes having an absorption wavelength in the near-infrared region, such as 3,6-bis (dimethylamino) fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide. Also, two or more kinds can be used in combination.

In the present invention, a specific color developer is used as the color developer, but various other known color developers can be used in combination as long as the desired effects of the present invention are not impaired.

Examples of such a developer include 4-hydroxy-4'-isopropoxydiphenyl sulfone,
4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, 3,3'-diallyl-
4,4'-dihydroxydiphenyl sulfone, 2,4-
Bis (phenylsulfonyl) phenol, p-toluenesulfonyl-m-aminophenol, p-toluenesulfonyl-p-aminophenol, 4,4'-isopropylidenediphenol, 4,4'-cyclohexylidenediphenol, 2,2 -Bis (4-hydroxyphenyl)
Phenolic compounds such as -4-methylpentane, benzyl 4-hydroxybenzoate and 1,1-bis (4-hydroxyphenyl) -1-phenylethane; p-cumyl N- (p-tolylsulfonyl) carbamoylate Phenyl ester, N- (o-tolyl) -p-tolylsulfonamide, 4,4′-bis (Np-tolylsulfonylaminocabonylamino) diphenylmethane, etc.
Those having a ₂ NH-bond, zinc 4- [2- (p-methoxyphenoxy) ethyloxy] salicylate, 4- [3
And zinc salts of aromatic carboxylic acids such as-(p-tolylsulfonyl) propyloxy] salicylate and 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] salicylic acid.

Among them, 4-hydroxy-4'-isopropoxydiphenylsulfone, 2,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, 3,3'-diallyl-4,4'-dihydroxydiphenyl Sulfone, p-toluenesulfonyl-p
-Combination with at least one selected from aminophenols is preferred.

The use ratio of the leuco dye to the specific color developer is not particularly limited, but the weight ratio is 1: 8 to 1: 8.
A ratio of about 2: 1 is preferable.

Further, the heat-sensitive recording layer may contain various sensitizers for increasing the recording sensitivity and a storability improver for further improving the storability of the recording portion. Examples of such a sensitizer include diphenyl sulfone, stearic acid amide, methylenebisstearic acid amide, dibenzyl terephthalate, benzyl p-benzyloxybenzoate, 2-naphthylbenzyl ether, m-terphenyl, p-benzylbiphenyl, p-benzylbiphenyl -Tolylbiphenyl ether, di (4-methoxyphenoxyethyl) ether, 1,2-di (3-methylphenoxy) ethane, 1,
2-di (4-methylphenoxy) ethane, 1,2-di (4-methoxyphenoxy) ethane, 1,2-di (4-
Chlorophenoxy) ethane, 1,2-diphenoxyethane, 1- (4-methoxyphenoxy) -2- (3-methylphenoxy) ethane, p-methylthiophenylbenzyl ether, di (β-biphenylethoxy) benzene,
Examples thereof include di-p-chlorobenzyl oxalate, di-p-methylbenzyl oxalate, and dibenzyl oxalate.

As such a preservability improver, for example,
2′-methylenebis (4-methyl-6-tert-butylphenol), 4,4′-thiobis (2-methyl-6-te
rt-butylphenol), 4-4′-butylidenebis (6-tert-butyl-m-cresol), 1,1,1
3-tris (2-methyl-4-hydroxy-5-tert-
Butylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl)
Hindered phenol compounds such as butane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane and 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane; 4,4 ′ -Diglycidyloxydiphenyl sulfone, 4-benzyloxy-4 '-(2-
Examples include epoxy compounds such as methyl glycidyloxy) diphenyl sulfone, diglycidyl terephthalate, cresol novolak type epoxy resin, phenol novolak type epoxy resin, and bisphenol A type epoxy resin.

The amounts of these sensitizers and storability improvers are not particularly limited, but are generally preferably about 0.1 to 4 parts by weight with respect to 1 part by weight of the leuco dye.

The heat-sensitive recording layer generally uses water as a dispersion medium,
A leuco dye, a specific color developer, and if necessary, a preservability improver, a sensitizer, etc., together or separately with a stirring / pulverizer such as a ball mill, an attritor, a sand mill or the like so that the average particle diameter becomes 2 μm or less. After finely dispersing, a coating solution for the heat-sensitive recording layer prepared by adding an aqueous adhesive is applied to a support such as high-quality paper (neutral or acidic paper), synthetic paper, transparent film, and dried to form a coating. You.

Examples of the aqueous adhesive include polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, diacetone-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, starch oxide, gelatin, casein, starch-vinyl acetate graft copolymer, Water-soluble resins such as styrene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, isopropylene-maleic anhydride copolymer, and styrene-butadiene-based latex,
Water-dispersible resins such as acrylic latex and urethane latex are exemplified.

Furthermore, various auxiliaries can be added to the coating solution for the heat-sensitive recording layer, if necessary, for example, kaolin,
Light (heavy) calcium carbonate, calcined kaolin, titanium oxide, magnesium carbonate, aluminum hydroxide, amorphous silica, pigments such as urea / formalin resin filler, sodium dioctyl sulfosuccinate, sodium dodecylbenzene sulfonate, lauryl alcohol sulfate Surfactants such as sodium and fatty acid metal salts, zinc stearate, calcium stearate, waxes such as polyethylene wax, carnauba wax, paraffin wax, ester wax, glyoxal, urea formalin resin, polyamide resin, polyamideamine epichlorohydrin resin, adipic dihydrazide , Boric acid, borax, ammonium zirconium carbonate and the like, as well as UV absorbers, defoamers, fluorescent dyes, coloring dyes and the like.

A protective layer can be provided on the heat-sensitive recording layer in order to further improve the recording running property and the preservability of the recording portion against chemicals such as a plasticizer and edible oil. Such a protective layer is formed by applying a coating solution for a protective layer containing a water-based adhesive and, if necessary, an auxiliary agent which can be added to the coating solution for a heat-sensitive recording layer on the surface of the heat-sensitive recording layer and drying.

The coating liquid for each layer is applied by a known coating equipment such as a bar coater, an air knife coater, a blade coater, a gravure coater, a die coater, and a curtain coater. After coating and drying, for example, super calender,
Each layer can be treated with a gloss calender or the like to impart smoothness to each surface.

Further, the coating amount of the heat-sensitive recording layer coating composition is 2~12g / m ² in dry weight, preferably 3 to 10 g / m ² approximately, the coating amount of the protective layer coating composition in a dry weight 0.5 -10 g
/ M ² , preferably about 1 to 5 g / m ² .

Further, in order to improve the recording sensitivity and the recording quality, an undercoat layer containing an oil-absorbing pigment or hollow particles as a main component is provided between the support and the heat-sensitive recording layer. It is also possible to provide an agent layer, a magnetic recording layer and the like. Various other known techniques in the field of heat-sensitive recording medium production can be added as needed.

[0029]

The present invention will be described in more detail with reference to the following Examples, but it should be understood that the present invention is by no means restricted thereto. In the examples, [parts] and [%] indicate [parts by weight] and [% by weight], respectively, unless otherwise specified.

Example 1 Preparation of Coating Liquid for Undercoat Layer 70 parts of calcined clay (trade name: Ansilex, manufactured by Engel Hard Co., oil absorption 110 ml / 100 g), plastic pigment (trade name: Grosdale 104S, solid content) : 46%, manufactured by Mitsui Chemicals, Inc., 38 parts, starch-polyvinyl acetate graft copolymer (trade name: Petrocoat C)
-8, 33 parts of a 12% aqueous solution of Nisse Chemical Co., Ltd., 2 parts of carboxymethyl cellulose (trade name: Cellogen 7A, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), styrene-butadiene latex (trade name: L-1537Y, solid content) : 50%, manufactured by Asahi Kasei Kogyo Co., Ltd.) and 14 parts of water and 100 parts of water were mixed and stirred by a high-speed stirrer to obtain a coating liquid for an undercoat layer.

Preparation of Solution A 40 parts of 3-di (n-butyl) amino-6-methyl-7-anilinofluoran, 10 parts of a 10% aqueous solution of polyvinyl alcohol (degree of saponification 65 mol%, degree of polymerization 200) , And 50 parts of water were pulverized with a sand grinder until the average particle diameter became 0.6 μm to obtain a liquid A.

Solution B Preparation 20 parts of 4-hydroxy-4'-isopropoxydiphenylsulfone, 20 parts of di-p-methylbenzyl oxalate, polyvinyl alcohol (degree of saponification 65 mol%,
A composition comprising 10 parts of a 10% aqueous solution having a degree of polymerization of 200) and 50 parts of water is subjected to a sand grinder to obtain an average particle size of 0.1%.
It was pulverized to 8 μm to obtain a liquid B.

Preparation of Solution C 20 parts of a specific developer (trade name: D-90, total content of about 86% of compounds in which n is 1 to 7 in the general formula (1), manufactured by Nippon Soda Co., Ltd.) 20 parts of acid di-p-methylbenzyl ester, 10 parts of a 10% aqueous solution of polyvinyl alcohol (degree of saponification 65 mol%, degree of polymerization 200), and water 50
Part C was pulverized with a sand grinder until the average particle diameter became 0.8 μm to obtain a liquid C.

Preparation of coating liquid for heat-sensitive recording layer 25 parts of liquid A, 70 parts of liquid B, 30 liquid C, 10 parts of calcium carbonate (trade name: Brilliant 15, manufactured by Shiraishi Calcium Co., Ltd.), aluminum hydroxide (trade name) : 15 parts of Heidilite H-42, manufactured by Showa Denko KK, 25 parts of a 30% dispersion of zinc stearate, and a 30% dispersion of paraffin wax prepared by emulsification and dispersion (trade name: D-336, melting point: 60) 5 ° C., average particle size 0.5 μm, manufactured by Chukyo Yushi)
A 20% aqueous solution of a starch-vinyl acetate graft copolymer (trade name: Petrocoat C-8, manufactured by Nisseki Chemical Co., Ltd.) 60
Part, polyvinyl alcohol (trade name: PVA-110,
A composition consisting of 40 parts of a 10% aqueous solution of Kuraray Co., Ltd.) and 30 parts of water was stirred and mixed to obtain a thermosensitive recording layer coating liquid.

Preparation of Coating Solution for Protective Layer 59 parts of Kaolinite Clay (trade name: HG-90, manufactured by Engelhard Co.), 20% aqueous solution of acetoacetyl-modified polyvinyl alcohol (trade name: Gosefimer Z) −
100, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 200 parts, 25% aqueous solution of polyamideamine / epichlorohydrin resin (trade name: WS-547, manufactured by Nippon PMC), 38% dispersion of zinc stearate (product) (Name: Z-8-36, manufactured by Chukyo Yushi Co., Ltd.) 4 parts and water 300 parts were stirred and mixed to obtain a coating liquid for a protective layer.

Preparation of thermosensitive recording medium 8.0 g of a coating solution for an undercoat layer after drying with a pure blade coater on acidic woodfree paper having a basis weight of 50 g / m ^2.
/ M ² after coating and drying, and then applying and drying the heat-sensitive recording layer coating liquid with a rod blade coater so that the coating amount after drying is 6 g / m ^2, and then drying the protective layer coating liquid. After coating and drying with a rod blade coater so that the subsequent coating amount is 3 g / m ² , Oken-type smoothness (JAPAN TAPPI No. 5) is 2000 with a super calender.
A second heat treatment was performed to obtain a heat-sensitive recording medium.

Example 2 In the preparation of the coating solution for the heat-sensitive recording layer of Example 1, 25 parts of a 30% dispersion of zinc stearate and 5 parts of a 30% dispersion of a paraffin wax prepared by emulsification and dispersion were used. A thermosensitive recording medium was obtained in the same manner as in Example 1, except that 5 parts of a 30% dispersion of the same zinc stearate and 25 parts of a 30% dispersion of the same paraffin wax were used.

Example 3 In the preparation of the coating solution for the heat-sensitive recording layer of Example 1, 25 parts of a 30% dispersion of zinc stearate and 5 parts of a 30% dispersion of a paraffin wax prepared by emulsification and dispersion were used. A thermosensitive recording medium was obtained in the same manner as in Example 1, except that 29 parts of a 30% dispersion of the same zinc stearate and 1 part of a 30% dispersion of the same paraffin wax were used.

Example 4 A 30% dispersion of paraffin wax (trade name: D-336, melting point: 60 ° C., average particle size: 0) prepared by emulsifying and dispersing in the preparation of the coating solution for the heat-sensitive recording layer in Example 1. .5μ
m, manufactured by Chukyo Yushi Co., Ltd. instead of 5 parts of a 30% dispersion of paraffin wax prepared by emulsification and dispersion (trade name: D-3)
38, melting point 74 ° C., average particle diameter 0.5 μm, manufactured by Chukyo Yushi Co., Ltd.), and a thermosensitive recording medium was obtained in the same manner as in Example 1.

Example 5 A 30% dispersion of paraffin wax prepared by emulsification and dispersion (trade name: D-336, melting point: 60 ° C., average particle size: 0) was prepared in the preparation of the coating solution for the heat-sensitive recording layer in Example 1. .5μ
m, manufactured by Chukyo Yushi) instead of 5 parts of a 30% dispersion of paraffin wax prepared by emulsifying and dispersing (trade name: cellosol A, melting point: 53 ° C., average particle diameter: 0.5 μm, manufactured by Chukyo Yushi) Except for the above, a thermosensitive recording medium was obtained in the same manner as in Example 1.

Example 6 A 30% dispersion of paraffin wax prepared by emulsification and dispersion (trade name: D-336, melting point: 60 ° C., average particle size: 0) .5μ
m, manufactured by Chukyo Yushi Co., Ltd. instead of 5 parts of a 30% dispersion of a mixed melt of paraffin wax and polyethylene wax prepared by emulsification and dispersion (trade name: J-199 (prototype), melting point: 105 ° C., average) A thermosensitive recording medium was obtained in the same manner as in Example 1 except that a particle diameter of 0.3 μm, manufactured by Chukyo Yushi Co., Ltd.) was used.

Comparative Example 1 In the preparation of the coating solution for the heat-sensitive recording layer in Example 1, a 30% dispersion of paraffin wax prepared by emulsification and dispersion (trade name: D-336, melting point: 60 ° C., average particle size: 0.3%). 5 μm,
Instead of using 5 parts of Chukyo Yushi, a 30% dispersion of polyethylene wax prepared by emulsification and dispersion (trade name: Polylon A, melting point 102 ° C, average particle size 0.2 μm, manufactured by Chukyo Yushi) was used instead of 5 parts. In the same manner as in Example 1, a thermosensitive recording medium was obtained.

Comparative Example 2 In the preparation of the coating solution for the heat-sensitive recording layer of Example 1, a 30% dispersion of paraffin wax prepared by emulsification and dispersion (trade name: D-336; 5 μm,
Instead of 5 parts of Chukyo Yushi, 5 parts of a 30% dispersion of carnauba wax prepared by emulsification and dispersion (trade name: Cerosol 524, melting point 83 ° C., average particle diameter 0.2 μm, Chukyo Yushi) is used instead of 5 parts. A heat-sensitive recording material was obtained in the same manner as in Example 1 except for the difference.

Comparative Example 3 A 30% dispersion of paraffin wax prepared by emulsification and dispersion (trade name: D-336, melting point: 60 ° C., average particle diameter: 0.3%) was prepared in the preparation of the coating solution for the heat-sensitive recording layer in Example 1. 5 μm,
Instead of 5 parts of Chukyo Yushi, a 30% dispersion of stearamide prepared by emulsification and dispersion (trade name: Himicron G-270, melting point 100 ° C., average particle diameter 0.2 μm,
A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 5 parts of (Kyogyo oil and fat) was used.

The thus-obtained thermosensitive recording medium was subjected to the following evaluation tests, and the results are shown in Table 1.

[Background Fog Resistance] The background fog resistance of the heat-sensitive recording medium after standing at 40 ° C. and 90% RH for 24 hours was measured for whiteness using a Hunter whiteness meter. The larger the value, the more excellent the background fog resistance.

[Recording density] Thermal recording medium evaluation machine (trade name:
Using a TH-PMD (manufactured by Okura Electric Co., Ltd.), recording was performed at an applied energy of 0.27 mj / dot, and the density of the recorded portion was measured in a visual mode using a Macbeth densitometer (RD-914, manufactured by Macbeth).

[Temporal Storage Property of Recording Section] The density of the recording section after the thermal recording medium recorded in the above evaluation of the recording density was allowed to stand at 50 ° C. and 80% RH for 7 days was measured using a Macbeth densitometer (R).
D-914, manufactured by Macbeth) in the visual mode.

[Plasticizer resistance] Polypropylene pipe (4
A vinyl chloride wrap film (manufactured by Nippon Carbide Industrial Co., Ltd.) is wound three times on a 0 mmφ tube, and the thermosensitive recording medium recorded in the above-described evaluation of the recording density is sandwiched therebetween so that the recording surface is outside. A vinyl chloride wrap film was wound three times from above, and after standing at 25 ° C. for 24 hours, the density of the recording portion was measured with a Macbeth densitometer (RD-914, manufactured by Macbeth) in visual mode.

[Oil resistance] One drop of salad oil is dripped on the recording portion of the heat-sensitive recording medium recorded in the above evaluation of the recording density.
After one minute, wipe off excess oil with tissue paper,
The density of the recording portion was measured in a visual mode using a Macbeth densitometer (RD-914, manufactured by Macbeth).

[0051]

[Table 1]

[0052]

The heat-sensitive recording material of the present invention is excellent in the storage stability of the recording portion over time and the background fog resistance.

Claims (5)

[Claims] 1. A thermosensitive recording medium having a thermosensitive recording layer containing a leuco dye and a color developer on a support, wherein the color developer is at least a compound represented by the following general formula (1): A heat-sensitive recording material comprising paraffin wax therein. Embedded image [N in the general formula (1) represents an integer of 1 to 7. ] 2. The paraffin wax in the heat-sensitive recording layer,
The heat-sensitive recording material according to claim 1, wherein the content is 1 to 10% by weight based on the total solid content of the heat-sensitive recording layer. 3. The paraffin wax in the heat-sensitive recording layer,
3. The thermosensitive recording medium according to claim 1, which is obtained by emulsification and dispersion. 4. The thermosensitive recording medium according to claim 1, wherein the melting point of the paraffin wax in the thermosensitive recording layer is 60 to 75 ° C. 5. The heat-sensitive recording material according to claim 1, wherein a protective layer mainly composed of an aqueous adhesive is provided on the heat-sensitive recording layer.