JPH09207439A - Thermal recording body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermal recording body which generates only a little texture fog, has excellent preservative property of recorded image against chemicals such as an oil and a plasticizer and excellent recording sensitivity by providing a recording layer which contains a developer consisting of a colorless or light color basic dye and a specified compound on a support body. SOLUTION: On a support body, a recording layer which contains a colorless or light color basic dye and a developer is provided so as to form a thermal recording body. For the developer, a 4,4'-bis(p-toluenesulfonyl amino carbonyl amino) diphenylmethane and a 2,4-dihydroxy-2'-methoxy benzanilide are used. As for the mixing quantity of the developer, based on 100 pts.wt. of diphenyl- methane, 5-200 pts.wt. of benzanilide is suitable, and 10-100 pts.wt. is more suitable. As a concrete example of the basic dye, a 3,3-bis(p-dimethyl amino phenyl)-6-dimethyl amino phthalide can be named.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive recording material utilizing a color-developing reaction between a colorless or light-colored basic dye and a color developer, and more particularly to a heat-sensitive recording material excellent in storage stability and recording sensitivity of recorded images. Is.

[0002]

2. Description of the Related Art Heretofore, a heat-sensitive recording material has been well known which uses a heat energy of a heat-sensitive head or the like to develop a colorless or light-colored basic dye and a color developer. Since such a thermosensitive recording medium is relatively inexpensive, the recording device is compact, and its maintenance is relatively easy, it is used not only as a recording medium for facsimiles and various computers but also as a recording medium for labels. There is.

In recent years, there has been a further demand for higher sensitivity of thermal recording materials. In addition, POS for the purpose of labor saving in retail business etc.
With the expansion of the system, the use of high-sensitivity thermal recording labels is increasing. However, since a high-sensitivity heat-sensitive recording material usually uses a phenol-based color developer such as bisphenol A as a color developer, background fogging occurs due to a solvent or the like, and the color-developing material changes due to oils or chemicals. It has the drawback of fading. Therefore, for example, when touching stationery and office supplies such as water-based pens, oil-based pens, fluorescent pens, vermillion flesh, adhesives, glues, diazo developers, etc., the white part is colored, or the density of the recorded image is significantly reduced. , And the product value was significantly impaired due to discoloration.

For the purpose of improving such drawbacks, a heat-sensitive recording material using a combination of 4,4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane and a hydroxydiphenylsulfone derivative as a color developer is disclosed in JP-A-7-47772. It is described in Japanese Patent Publication No. Such a thermal recording material is excellent in oil resistance and plasticizer resistance of a recorded image, but has a problem in recording sensitivity.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermosensitive recording medium which has less background fog and is excellent in storability of a recorded image with respect to chemicals such as oil and plasticizer, and recording sensitivity. .

[0006]

DISCLOSURE OF THE INVENTION The inventor of the present invention provides a thermosensitive recording medium comprising a support and a recording layer containing a colorless or light-colored basic dye and a developer.
It was found that the above problems can be solved by using 4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane and 2,4-dihydroxy-2'-methoxybenzanilide in combination, and the present invention has been completed. It was

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a thermosensitive recording medium comprising a support and a recording layer containing a colorless or light-colored basic dye and a color developer, wherein the recording layer contains 4,4'- Screw (p
-Toluenesulfonylaminocarbonylamino) diphenylmethane and 2,4-dihydroxy-2'-methoxybenzanilide as a specific colorant.

4,4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane and 2,4-
The compounding ratio of dihydroxy-2'-methoxybenzanilide is not particularly limited, but 4,4'-
5 to 20 parts of 2,4-dihydroxy-2'-methoxybenzanilide is added to 100 parts by weight of bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane.
The amount is 0 parts by weight, preferably about 10 to 100 parts by weight.

In the present invention, as the colorless or pale basic dye contained in the recording layer, known colorless or pale basic dyes can be used. Specific examples of such basic dyes include the following. 3,3-
Bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2-methylphenyl) -3- (4-dimethylaminophenyl) -6
-Dimethylaminophthalide, 3-diethylamino-7-
Blue-coloring dyes such as dibenzylamino-benzo [a] fluorane; 3- (N-ethyl-Np-tolyl) amino-7-N-methylanilinofluorane, 3-diethylamino-7-anilinoflu Green coloring dye such as Oran;

3-diethylamino-7-methylfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluorane,
Rhodamine (p-chloroanilino) lactam, 3- (N
-Ethyl-p-toluidino) -7-methylfluoran,
Red color-forming dye such as 3,3′-bis (1-n-butyl-2-methylindol-3-yl) phthalide;

3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluorane, 3- (N-
Methyl-N-cyclohexyl) amino-6-methyl-7
-Anilinofluorane, 3- (N-ethyl-N-ethoxypropylamino) -6-methyl-7-anilinofluorane, 3-dimethylamino-6-methyl-7-anilinofluorane, 3-diethylamino -6-Methyl-7-anilinofluorane, 3-di (n-butyl) amino-6-
Methyl-7-anilinofluorane, 3-di (n-amyl) amino-6-methyl-7-anilinofluorane, 3
-Diethylamino-7- (o-chloroanilino) fluorane, 3-di (n-butyl) amino-7- (o-chloroanilino) fluorane, 3-diethylamino-7- (o
-Fluoroanilino) fluorane, 3-di (n-butyl) amino-7- (o-fluoroanilino) fluorane, 3-diethylamino-7- (m-trifluoromethylanilino) fluorane, 3- (N- Ethyl-p-toluidino) -6-methyl-7-anilinofluorane, 3-
(N-ethyl-p-toluidino) -6-methyl-7-
(P-toluidino) fluoran, 3-diethylamino-
6-chloro-7-anilinofluorane, 3-di (n-butyl) amino-6-methyl-7-m-toluidinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, etc. Such as black coloring dyes. Of course, it is not limited to these, and two or more kinds may be used in combination as required. The amount of the basic dye used is not particularly limited, but is 5 to 50% by weight, preferably 1
It is about 0 to 40% by weight.

The use ratio of the basic dye and the specific developer in the recording layer is not particularly limited, but is generally 1 to 7 parts by weight, preferably 1 to 4 parts by weight with respect to 1 part by weight of the basic dye. Partial, a specific developer is used.

The present invention uses a specific developer composed of 4,4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane and 2,4-dihydroxy-2'-methoxybenzanilide as a developer. Although the following publicly known developers can be used in combination within a range that does not impair the effects of the present invention, it is preferably 20% by weight or less with respect to a specific developer.

4,4'-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxyphenyl) -4
-Methylpentane, benzyl 4-hydroxybenzoate,
4,4'-dihydroxydiphenyl sulfone, 2,4 '
-Dihydroxydiphenylsulfone, 4-hydroxy-
4'-isopropoxydiphenyl sulfone, bis (3-
Allyl-4-hydroxyphenyl) sulfone, 4-hydroxy-4′-methyldiphenyl sulfone, 4-hydroxyphenyl-4′-benzyloxyphenyl sulfone, 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 A phenolic compound such as (3-tert-octylphenol); N,
Thiourea compounds such as N'-di-m-chlorophenylthiourea; zinc p-chlorobenzoate, 4- [2- (p-
Methoxyphenoxy) ethyloxy] zinc salicylate,
4- [3- (p-tolylsulfonyl) propyloxy]
Zinc salts of aromatic carboxylic acids such as zinc salicylate and zinc 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] salicylate.

In the present invention, if necessary, a sensitizer may be added to the recording layer in order to further increase the recording sensitivity. Specific examples of such a sensitizer include stearic acid amide, methoxycarbonyl-N-stearic acid benzamide, N-benzoylstearic acid amide, ethylenebisstearic acid amide, methylenebisstearic acid amide, N-methylolstearic acid amide, Dibenzyl terephthalate, p-benzyloxybenzoate benzyl, 2-naphthylbenzyl ether, m-terphenyl, dibenzyl oxalate, oxalate-di-p-methylbenzyl, oxalate-di-p-chlorobenzyl, p-benzyl. Biphenyl, di (p-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- (2
-Methylphenoxy) ethane, biphenyl-p-tolyl ether p-methylthiophenylbenzyl ether,
1,4-di (phenylthio) butane, p-acetotoluidide, p-acetophenetide, N-acetoacetyl-
Examples thereof include p-toluidine, di (β-biphenylethoxy) benzene, p-di (vinyloxyethoxy) benzene, 1-isopropylphenyl-2-phenylethane and the like.

Further, unless the effects of the present invention are impaired,
If necessary, a preservative improving agent may be used in combination in order to further enhance the preservability of the recorded image. Specific examples of such storage improvers include 1,4-diglycidyloxybenzene, 4,4′-diglycidyloxydiphenyl sulfone, 4-benzyloxy-4 ′-(2-methyl-).
Epoxy compounds such as 2,3-epoxypropyloxy) diphenyl sulfone and bisphenol A type epoxy resin, 2,2′-methylenebis (4-methyl-6-tert-)
Butylphenol), 2,2'-methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-ethylidenebis (4,6-di-tert-butylphenol),
4,4'-thiobis (3-methyl-6-tert-butylphenol), 4,4'-thiobis (2-methyl-6-te
rt-butylphenol), 4,4′-butylidene bis (6-tert-butyl-m-cresol), 1,1,3-
Tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 4,4'-thiobis (3 -Methylphenol),
4,4'-dihydroxy-3,3 ', 5,5'-tetrabromodiphenyl sulfone, 4,4'-dihydroxy-
3,3 ′, 5,5′-tetramethyldiphenyl sulfone, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-)
Hindered phenol compounds such as 3,5-dichlorophenyl) propane and 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl ] -4-
[Α ', α'-bis (4 "-hydroxyphenyl) ethyl] benzene, N, N'-di-2-naphthyl-p-phenylenediamine, 2,2'-methylenebis (4,6-di-tert- Examples thereof include a metal salt of butylphenyl) phosphoric acid.

The amount of the sensitizer used and the improvement of storage stability are 4 parts by weight or less with respect to 1 part by weight of the basic dye.

The recording layer and liquid containing a basic dye, a specific developer, a sensitizer, a storability improver and the like generally use water as a dispersion medium and agitate and grind with a ball mill, attritor, sand mill or the like. It is prepared by finely dispersing a basic dye, a specific developer, a sensitizer and a storability improver together or separately by a machine and then adding an adhesive.

Specific examples of the adhesive include, for example, oxidized starch, hydroxyethyl cellulose, methyl cellulose,
Carboxymethyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohol, diisobutylene
Examples thereof include maleic anhydride copolymer salt, styrene / maleic anhydride copolymer salt, ethylene / acrylic acid copolymer salt, styrene / acrylic acid copolymer salt, polyurethane latex and the like. Such an adhesive is added in an amount of 10 to 40% by weight, preferably 15 to 35% by weight, based on the total solid content of the recording layer.

If desired, various auxiliary agents can be added to the coating liquid for the recording layer. For example, surfactants such as sodium dioctyl sulfosuccinate, sodium dodecylbenzene sulfonate and sodium lauryl alcohol sulfate. , Kaolin, clay, calcium carbonate, calcined clay, calcined kaolin, aluminum hydroxide,
Amorphous fine particle silica, styrene microballs, nylon powder, polyethylene powder, pigments such as urea / formalin resin filler, other defoaming agents, fluorescent dyes, coloring dyes, etc. are appropriately added.

In the heat-sensitive recording material of the present invention, the method of forming the recording layer is not particularly limited, and the recording layer can be formed according to a conventionally well-known and common technique, for example, air knife coating, variber blade coating, Pure blade coating, short
Apply the coating liquid for the recording layer to the support such as high quality paper, synthetic paper, film, non-woven fabric by dwell coating.
It is formed by a method such as drying. Further, 2~12g / m ² at normal dry weight no particular limitation on the coating amount of the recording layer coating liquid, preferably 3 to 10 g / m ² approximately.

On the recording layer, a protective layer containing an adhesive having a film-forming property as a main component for the purpose of improving writing property, recording running property and the like is 0.5 to 7 g / m ^{2 in} dry weight. It is also possible to form. Specific examples of such an adhesive include starches such as oxidized starch, esterified starch and etherified starch, cellulose derivatives such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, completely (or partially) saponified polyvinyl alcohol, and carboxy. Modified polyvinyl alcohol, acetoacetylated polyvinyl alcohol,
Polyvinyl alcohols such as silicon-modified polyvinyl alcohol, styrene-maleic anhydride copolymer alkali salts, isobutylene-maleic anhydride copolymer alkali salts, water-soluble resins such as gelatin and casein, and polyester polyurethane ionomers and polyether polyurethane ionomers , Water-dispersible resins such as acrylic resin latex.

The coating liquid for the protective layer is prepared by using water as a dispersion medium and mixing and stirring the adhesive. In such coating liquid,
If necessary, auxiliary agents such as dispersants, defoamers, coloring dyes, fluorescent dyes, curing agents, UV absorbers, various modified silicone oil emulsions, zinc stearate, calcium stearate, carnauba wax, paraffin wax, ester wax, etc. Lubricant, calcium carbonate, zinc oxide, aluminum oxide, titanium dioxide, silicon dioxide, aluminum hydroxide, barium sulfate, talc, kaolin, clay,
It is also possible to add pigments such as calcined clay and colloidal silica.

If desired, a protective layer may be provided on the back side of the thermosensitive recording medium to further improve the storability of the recorded image. Further, by providing an undercoat layer between the support and the recording layer to improve the image quality and sensitivity, or to subject the back surface side of the thermal recording material to an adhesive treatment to process it into an adhesive label, various types of thermal recording material manufacturing fields can be prepared. Well-known techniques can be added as needed. In the present invention, if necessary, a super calender is applied after the recording layer coating,
It is also possible to improve image quality and image density.

[0025]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, "part" and "%" in the examples are
"Parts by weight" and "% by weight" are shown, respectively.

Example 1 Preparation of solution A 10 parts of 3-di (n-butyl) amino-6-methyl-7-anilinofluorane, 5% aqueous solution of methylcellulose 5
Parts and 35 parts of water were pulverized with a sand mill until the average particle size became 1.5 μm.

Preparation of Solution B A composition comprising 30 parts of 4,4′-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane, 15 parts of a 5% aqueous solution of methylcellulose, and 105 parts of water having a mean particle size of 1. It was pulverized until it became 0 μm or less.

Preparation of Solution C A composition consisting of 30 parts of 2,4-dihydroxy-2′-methoxybenzanilide, 15 parts of a 5% aqueous solution of methylcellulose, and 105 parts of water was sand-milled until the average particle size reached 1.5 μm. Crushed.

Preparation of Solution D A composition comprising 20 parts of 1,2-di (3-methylphenoxy) ethane, 10 parts of a 5% aqueous solution of methylcellulose, and 70 parts of water was sand-milled until the average particle size reached 1.5 μm. Crushed.

Formation of Recording Layer Liquid A 50 parts, liquid B 100 parts, liquid C 50 parts, liquid D 100
Part, 160 parts of a 10% aqueous solution of polyvinyl alcohol (trade name: PVA110, manufactured by Kuraray Co., Ltd.), 10 parts of a 30% dispersion of zinc stearate, and 25 parts of clay (trade name: HG Clay, manufactured by Huber) are mixed and stirred. a recording layer coating solution obtained by, after the coating amount after drying on one surface of woodfree paper of 45 g / m ² was formed a recording layer by applying and drying such that 4g / m ^2, supercalendered Then, a thermosensitive recording medium was obtained.

Example 2 In the preparation of solution A of Example 1, 3- (N-ethyl-N- instead of 10 parts of 3-di (n-butyl) amino-6-methyl-7-anilinofluorane was used. A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 10 parts of ethoxypropylamino) -6-methyl-7-anilinofluorane was used.

Example 3 In the preparation of solution A of Example 1, 3-di (n-butyl) amino was used instead of 10 parts of 3-di (n-butyl) amino-6-methyl-7-anilinofluorane. A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 10 parts of -7- (o-chloroanilino) fluorane was used.

Example 4 In the preparation of solution D of Example 1, 20 parts of 1,2-di (3-methylphenoxy) ethane was replaced by oxalic acid-di-
A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 20 parts of p-methylbenzyl ester was used.

Example 5 In the formation of the recording layer of Example 1, a 21.5% dispersion of stearic acid amide (trade name:
G-270, manufactured by Chukyo Yushi Co., Ltd., average particle size = 0.4 μm)
A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 80 parts was used.

Example 6 Same as Example 1 except that 20 parts of 2-naphthylbenzyl ether was used in place of 20 parts of 1,2-di (3-methylphenoxy) ethane in the preparation of liquid D of Example 1. A thermosensitive recording medium was obtained.

Example 7 In the same manner as in Example 1 except that 50 parts of solution B and 100 parts of solution C were used in place of 100 parts of solution B and 50 parts of solution C in the formation of the recording layer of Example 1. A thermosensitive recording medium was obtained.

Example 8 In the same manner as in Example 1 except that 140 parts of solution B and 10 parts of solution C were used in place of 100 parts of solution B and 50 parts of solution C in the formation of the recording layer of Example 1. A thermosensitive recording medium was obtained.

Example 9 Preparation of Solution E Consisting of 10 parts of 4-benzyloxy-4 ′-(2-methyl-2,3-epoxypropyloxy) diphenylsulfone, 5 parts of a 5% aqueous solution of methylcellulose, and 35 parts of water. The composition was ground with a sand mill until the average particle size was 1.5 μm.

Formation of Recording Layer 55 parts of solution A, 75 parts of solution B, 75 parts of solution C, 80 parts of solution D, E
Liquid 25 parts, polyvinyl alcohol (trade name: PVA11
0, manufactured by Kuraray Co., Ltd., 160 parts of a 10% aqueous solution, 10 parts of a 30% dispersion of zinc stearate, and 25 parts of aluminum hydroxide (trade name: Hydilite H42, manufactured by Showa Denko KK) were mixed and stirred. the recording layer coating solution, the coating amount after drying on one surface of woodfree paper of 45 g / m ² was obtained heat-sensitive recording material was supercalendered after coating and drying so as to 4g / m ^2.

Example 10 Preparation of Coating Liquid for Undercoat Layer 100 parts of calcined clay (trade name: Ansilex, manufactured by EMC, oil absorption = 110 ml / 100 g), 10 parts of polyvinyl alcohol (trade name: PVA210, manufactured by Kuraray Co., Ltd.)
% 100% aqueous solution and 200 parts water were mixed and stirred to obtain a coating liquid for undercoat layer.

Preparation of thermal recording material 45 g / m^TwoDry the undercoat layer coating solution on one side of the high-quality paper
Later application amount is 8g / m ^TwoApply and dry to undercoat
Forming a recording layer, on which the recording layer of Example 1 is formed.
The coating amount after drying the recording layer coating liquid was 4 g / m.^TwoBecomes
After coating and drying to form the recording layer,
Rendering was performed to obtain a heat sensitive recording material.

Example 11 In the same manner as in Example 1, except that 100 parts of a 20% dispersion liquid of paraffin wax (melting point: 75 ° C.) was used in place of 100 parts of the liquid D in the formation of the recording layer of the first embodiment. A thermosensitive recording medium was obtained.

Comparative Example 1 In the preparation of the liquid C of Example 1, 2,4-dihydroxy-
4'instead of 30 parts of 2'-methoxybenzanilide
A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 30 parts of 4'-isopropylidenediphenol was used.

Comparative Example 2 In the preparation of the liquid C of Example 1, 2,4-dihydroxy-
4-Hydroxy-4'-isopropoxydiphenyl sulfone 3 instead of 30 parts of 2'-methoxybenzanilide
A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 0 part was used.

Comparative Example 3 In the preparation of the liquid B of Example 1, 30 parts of 4,4'-isopropylidenediphenol was used instead of 30 parts of 4,4'-bis (p-toluenesulfonylaminocarbonylamino) diphenylmethane. A thermal recording material was obtained in the same manner as in Example 1 except for the above.

Comparative Example 4 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that in the formation of the recording layer of Example 1, 150 parts of solution B was used instead of 100 parts of solution B and 50 parts of solution C. It was

Comparative Example 5 A thermosensitive recording medium was obtained in the same manner as in Example 1 except that in the formation of the recording layer of Example 1, 150 parts of C solution was used instead of 100 parts of B solution and 50 parts of C solution. It was

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

[Coloring Density and Whiteness] Each thermosensitive recording material was developed by applying an applied voltage of 24 V and a pulse time of 2 ms using a thermosensitive recording material evaluation device (trade name: TH-PMD, manufactured by Okura Electric Co., Ltd.). The color density of the recorded image was measured in a visual mode with a Macbeth densitometer (RD-914 type, manufactured by Macbeth), and the whiteness of the unrecorded portion was measured with a Hunter whiteness meter.

[Oil resistance] Thermal recording medium evaluation machine (trade name: T
H-PMD, manufactured by Okura Electric Co., Ltd., applied voltage 24V,
A drop of edible oil was dropped on the recording portion recorded under the condition of pulse time of 2 ms, and the state of printing after standing for 24 hours was visually evaluated. Evaluation criteria

[Plasticizer resistance] polypropylene pipe (4
A vinyl chloride wrap film (manufactured by Mitsui Toatsu Chemical Co., Inc.) was wound in three layers on a 0 mmφ tube, and the thermosensitive recording medium used for the test of [color density and whiteness] was placed on the outer side of the recording layer side. Sandwiched, and further wrapped with a vinyl chloride wrap film in three layers, and the color density after standing for 24 hours at 30 ° C. was measured with a Macbeth densitometer (RD-914 type, manufactured by Macbeth Co.) in a visual mode. The whiteness of the unrecorded area was measured using a Hunter whiteness meter.

[Background fog] A thermosensitive recording medium was recorded at 40 ° C. for 75 minutes.
After processing for 24 hours under the condition of% RH, the whiteness of the recording layer side was measured using a Hunter whiteness meter.

[0053]

[Table 1]

[0054]

As is clear from the results shown in Table 1, the thermosensitive recording medium of the present invention has less background fog, has excellent storability of a recorded image with respect to chemicals such as oil and plasticizer, and has excellent recording sensitivity. It was a thermosensitive recording medium.

Claims (1)

[Claims] 1. A thermosensitive recording medium comprising a support and a recording layer containing a colorless or light-colored basic dye and a developer, wherein the developer is 4,4'-bis (p-toluenesulfonylamino). Carbonylamino) diphenylmethane and 2,
A heat-sensitive recording material, which is 4-dihydroxy-2'-methoxybenzanilide.