JPH06227134A - Thermal recording body - Google Patents

Abstract

PURPOSE:To provide a thermal recording body wherein texture blushing is hardly caused by effect of temperature and humidity and excellent in shelf life of a recording image for chemicals such as fats and oils and a plasticizer and also excellent in recording sensitivity. CONSTITUTION:A thermal recording body is constituted by providing a recording layer containing a colorless or light-colored basic dye and a developer on a supporting body. In the thermal recording body, bis(3-allyl-4-hydroxyphenyl) sulfone and 4-benzyloxy-4'-(2methyl-2,3-epoxypropyloxy)diphenylsulfone are incorporated into the recording layer.

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 having less background fog, excellent storability of a recorded image against chemicals such as oils and fats and plasticizers, and excellent recording sensitivity. .

[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 thermal recording material is relatively inexpensive and the recording equipment is compact and its maintenance is relatively easy, it is used not only as a recording medium for facsimiles and various computers but also in a wide range of fields such as thermal labels. .

In recent years, recording speeds of 10 seconds or less in A4 size for thermal fax and 120 characters / second or more for thermal printer have become possible, and there is a further demand for higher sensitivity of the thermal recording material. In addition, the use of heat-sensitive recording labels is increasing with the expansion of POS systems aimed at labor saving in the retail industry. However, in a normal thermal recording material, fogging occurs due to a plasticizer, a solvent, etc.
It has the drawback of discoloration due to chemicals. Therefore, for example, water-based pen, oil-based pen, highlighter pen,
Touching stationery such as red meat, adhesive, glue, diazo developer and office supplies, etc. or cosmetics such as hand cream, emulsion will cause white part to develop color, and the density of recorded image will be significantly reduced or discolored. However, the product value was significantly impaired. For the purpose of improving such defects, various proposals have been made such as a method of providing a protective layer on the recording layer and a method of adding a storage stability improver to the recording layer, but all of them have new defects. However, since it is not always possible to obtain a sufficiently satisfactory effect, further improvement is strongly demanded.

[0004]

DISCLOSURE OF THE INVENTION The object of the present invention is thermal recording which is less likely to cause fog on the background due to the influence of temperature and humidity, has excellent storability of recorded images against chemicals such as oils and fats and plasticizers, and has excellent recording sensitivity. To provide the body.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have proposed a thermosensitive recording medium having a recording layer containing a colorless or light-colored basic dye and a color developer on a support, and (3-allyl-4-hydroxyphenyl) sulfone and 4
It has been found that the above object can be achieved by incorporating -benzyloxy-4 '-(2-methyl-2,3-epoxypropyloxy) diphenyl sulfone, and has completed the present invention.

[0006]

A thermosensitive recording material using bis (3-allyl-4-hydroxyphenyl) sulfone as a color developer exhibits excellent color development sensitivity and excellent storage stability against high temperature and high humidity of recorded images. However, there is a drawback that the recorded image is discolored by a plasticizer or hand cream. Therefore, bis (3-allyl-4-hydroxyphenyl) sulfone and 4
-Benzyloxy-4 '-(2-methyl-2,3-epoxypropyloxy) diphenyl sulfone is used in combination, it is possible to obtain a recorded image with a plasticizer or a hand cream without damaging the characteristics of background fog and color development sensitivity. The storability was also improved. In the present invention, the proportion of 4-benzyloxy-4 '-(2-methyl-2,3-epoxypropyloxy) diphenyl sulfone is not particularly limited, but it is 5 to 100 parts by weight of the color developer. It is desirable to adjust within the range of about 500 parts by weight.

In order to further improve the storage stability of recorded images, 4- [3- (p-tolylsulfonyl) propyloxy] is used.
It is desirable to use a zinc salt of salicylic acid together as a developer. The zinc salt of 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid is, for example, 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid in water or a mixed medium of water and an organic solvent. Of the alkali metal salt of 4 and a zinc compound, 4- [3
-(P-tolylsulfonyl) propyloxy] salicylic acid and a zinc compound can be produced by a method such as wet simultaneous pulverization.

Although the above method has some difficulty in operability during production, it has an advantage in terms of the yield and purity of zinc chloride. On the other hand, the above method has some drawbacks in terms of the yield and purity of zinc chloride, but has the advantage that a complex zinc salt can be produced very easily.

As the organic solvent used in the above method, those having a low solubility in water and a high solubility of the zinc salt of the aromatic carboxylic acid produced are preferable, for example, aromatic compounds, halides and esters. A compound etc. are mentioned. More specifically, toluene, xylene, trichlene, ethyl acetate and the like can be exemplified. Further, as the zinc compound in preparing the zinc salt, zinc oxide, zinc hydroxide, zinc carbonate, zinc sulfate, zinc chloride and the like can be used, but zinc sulfate and zinc chloride are particularly preferable in the above method. Zinc oxide is particularly preferably used in the above method. The amount of the zinc compound used is not particularly limited, but it is desirable to use it so that it is equivalent to 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid.

In the heat-sensitive recording material of the present invention, various known compounds can be used as the colorless to light-colored basic dye contained in the heat-sensitive recording layer.
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2)
-Methylphenyl) -3- (4-dimethylaminophenyl) -6-dimethylaminophthalide, 3-diethylamino-7-dibenzylamino-benzo [a] fluorane,
3- (N-ethyl-Np-tolyl) amino-7-N-
Methylanilinofluorane, 3-diethylamino-7-
Anilinofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3,6-bis (diethylamino) fluorane-γ-anilinolactam, 3-cyclohexylamino-6-chlorofluorane, 3-diethylamino-6- Methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7- (m-trifluoromethylanilino) fluorane, 3- (N-ethyl-N-isoamyl) amino-6-
Methyl-7-anilinofluorane, 3- (N-methyl-
N-cyclohexyl) amino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-
Anilinofluorane, 3-di (n-butyl) amino-6
-Methyl-7-anilinofluorane, 3-di (n-pentyl) amino-6-methyl-7-anilinofluorane,
3-diethylamino-7- (o-chlorophenylamino) fluorane, 3-di (n-butyl) amino-7-
(O-Chlorophenylamino) fluorane, 3-diethylamino-7- (o-fluorophenylamino) fluorane, 3-di (n-butyl) amino-7- (o-fluorophenylamino) fluorane, 3- (N-ethyl) -P
-Toluidino) -6-methyl-7-anilinofluorane, 3- (N-ethyl-p-toluidino) -6-methyl-7- (p-toluidino) fluorane, 3- (N-ethyl-N-flu) Furylamino) -6-methyl-7-anilinofluorane, 3-diethylamino-6-chloro-7-
Anilinofluorane, 3- (N-methyl-Nn-propylamino) -6-methyl-7-anilinofluorane,
3,3-bis [1- (4-methoxyphenyl) -1-
(4-Dimethylaminophenyl) ethylene-2-yl]
-4,5,6,7-Tetrachlorophthalide, 3,3-bis [1- (4-methoxyphenyl) -1- (4-pyrrolidinophenyl) ethylene-2-yl] -4,5,6 , 7
-Tetrachlorophthalide, 3,3-bis [1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl]-
4,5,6,7-tetrabromophthalide, 3-p- (p
-Anilinoanilino) anilino-6-methyl-7-chlorofluorane, 2,2-bis {4- [6 '-(N-cyclohexyl-N-methylamino) -3'-methylspiro [phthalide-3,9'- Xanthene-2′-ylamino] phenyl} propane, 3,6, -bis (dimethylamino) fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide and the like can be mentioned. Of course, it is not limited to these, and two or more kinds may be used in combination as required.

In the heat-sensitive recording material of the present invention, the ratio of the basic dye and the developer to be contained in the recording layer is not particularly limited, but the basic dye and the developer to be used are constituted. Bis (3-allyl-4-hydroxyphenyl) sulfone and 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid zinc salt should be appropriately selected according to the ratio thereof, and generally 1 weight of the basic dye. It is desirable to use about 0.5 to 50 parts by weight, and preferably about 1 to 10 parts by weight, of the color developing agent.

The present invention is characterized in that bis (3-allyl-4-hydroxyphenyl) sulfone is used as a color developing agent. However, within the range that does not impair the effects of the present invention, for example, the following known methods are known. It is also possible to use the above color developer in combination. Activated clay, attapulgite, colloidal silica, inorganic acidic substances such as aluminum silicate, 4-cumylphenol, hydroquinone monobenzyl ether,
4,4'-isopropylidenediphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,
4'-dihydroxydiphenyl-2,2-butane, 4,
4'-dihydroxydiphenylmethane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane,
2,2-bis (4-hydroxyphenyl) heptane, bis (4-hydroxyphenylthioethoxy) methane,
1,5-di (4-hydroxyphenylthio) -3-oxapentane, 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, 4,4′-dihydroxydiphenyl sulfide, bis (4-hydroxy-3-methylphenyl) sulfine, 2,4′- Dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxyphenyl-4'-benzyloxyphenyl sulfone, 4 -Hydroxy-3 ', 4'
-Tetramethylene biphenyl sulfone, 3,4-dihydroxyphenyl-p-tolyl sulfone, benzyl 4-hydroxybenzoate, butyl bis (p-hydroxyphenyl) acetate, methyl bis (p-hydroxyphenyl) acetate, (4-hydroxyphenyl) Thio) acetic acid-2- (4-
Phenolic compounds such as hydroxyphenylthio) ethyl ester, di (p-hydroxyphenylthioethyl) ether, N, N'-di-m-chlorophenylthiourea, N- (phenoxyethyl) -4-hydroxyphenylsulfonamide, 4- [3- (p-tolylsulfonyl)
Propyloxy] salicylic acid, 4- [2- (p-methoxyphenoxy) ethyloxy] salicylic acid, 5- [p-
(2-p-Methoxyphenoxyethoxy) cumyl] salicylic acid, p-chlorobenzoic acid and other aromatic carboxylic acids, and aromatic carboxylic acids such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin and nickel. Examples thereof include salts with valent metals, and organic acid substances such as antipyrine complexes of zinc thiocyanate.

In the heat-sensitive recording material of the present invention, a sensitizer can be added to the recording layer according to the purpose. Specific examples of the sensitizer include stearic acid amide and methoxycarbonyl-
N-stearic acid benzamide, N-benzoylstearic acid amide, N-eicosanoic acid amide, ethylenebistearic acid amide, behenic acid amide, methylenebisstearic acid amide, N-methylolstearic acid amide,
Dibenzyl terephthalate, dimethyl terephthalate, dioctyl terephthalate, benzyl p-benzyloxybenzoate, phenyl 1-hydroxy-2-naphthoate, dibenzyl oxalate, oxalate-di-p-methylbenzyl,
Oxalic acid-di-p-chlorobenzyl, 2-naphthylbenzyl ether, m-terphenyl, p-benzylbiphenyl, tolylbiphenyl ether, 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, p-
Methylthiophenyl benzyl ether, 1,4-di (phenylthio) butane, p-acetotoluidide, p-acetophenetide, N-acetoacetyl-p-toluidine, di (β-biphenylethoxy) benzene, p-di (vinyloxy) Examples include ethoxy) benzene and 1-isopropylphenyl-2-phenylethane. The amount of these sensitizers used is not particularly limited, but it is generally desirable to adjust the amount within the range of about 4 parts by weight or less relative to 1 part by weight of the color developing agent.

Further, in order to suppress the background fog caused by heat, tetrakis (1,2,2,6,6-pentamethyl-4)
It is desirable to use a hindered amine stabilizer such as -piperidinyl) -1,2,3,4-butanetetracarboxylate together. Further, a preservative improving agent may be used in combination for the purpose of further enhancing preservability of a recorded image as long as the effect is not impaired. Specific examples of the preservability improving agent include, for example, 1,4-diglycidyloxybenzene, 4,4'-diglycidyloxydiphenyl sulfone, diglucidyl terephthalate, epoxy compounds such as 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-tert-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-te
rt-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-
Hindered phenol compounds such as bis (4-hydroxy-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-
Examples thereof include naphthyl-p-phenylenediamine and 2,2'-methylenebis (4,6-di-tert-butylphenyl) sodium phosphate.

In order to prepare a coating liquid for a recording layer containing these substances, generally, water is used as a dispersion medium and a basic dye, a color developer, and further a basic dye, a color developer, and the like are required by a stirring / grinding machine such as a ball mill, an attritor or a sand mill. A sensitizer or the like added according to the above is dispersed together or separately to prepare a coating liquid.
In the coating liquid, starch, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, arabic gum as an adhesive,
Polyvinyl alcohol, diisobutylene / maleic anhydride copolymer salt, styrene / maleic anhydride copolymer salt,
The ethylene / acrylic acid copolymer salt, the styrene / acrylic acid copolymer salt, the styrene / butadiene copolymer emulsion, etc. are 10 to 40% by weight of the total solid content, preferably 15
It is used in an amount of about 30% by weight.

It is also possible to use various pigments in combination in the coating liquid, for example, kaolin, clay, calcium carbonate, calcined clay, calcined kaolin, titanium oxide, diatomaceous earth,
Inorganic pigments such as fine particulate anhydrous silica and activated clay, styrene microballs, nylon powder, polyethylene powder, urea / formalin resin filler, and organic pigments such as raw starch particles can be used.

Further, various auxiliary agents can be added to the coating solution, for example, sodium dioctylsulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl alcohol sulfate / sodium salt, alginate, fatty acid metal salt and the like. Dispersant, benzophenone type,
Examples thereof include UV absorbers such as triazole type, defoaming agents, fluorescent dyes, and coloring dyes.

In the present invention, the method for forming the heat-sensitive recording layer is not particularly limited, and the heat-sensitive recording layer can be formed according to a conventionally well-known and conventional technique. For example, air knife coating, varibar blade coating, pure blade coating. It can be formed by a method of coating and drying the coating liquid on the support by short dwell coating, curtain coating or the like. The coating amount of the coating liquid is also not particularly limited, and is usually ² to 12 g / m ² in dry weight, preferably 3 to 10 g.
The range is / m ² . As the support, paper, synthetic paper, plastic film or the like is appropriately selected and used.

In the present invention, it is possible to further improve the storability of a recorded image by providing a resin layer on the heat-sensitive recording material and / or on the back surface side, if necessary.
Further, in the field of heat-sensitive recording material manufacturing, such as providing an undercoat layer on the support to improve image quality and sensitivity, processing the back surface of the recording material into an adhesive label by processing with an adhesive, and providing a magnetic layer on the back surface of the recording material. Various known techniques can be added. Further, the image quality and the image density can be improved by performing a super calendering process after forming the recording layer.

[0020]

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. In addition, "part" and "%" in an example show "weight part" and "weight%", respectively, unless there is particular notice.

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 40 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 bis (3-allyl-4-hydroxyphenyl) sulfone [trade name: TG-SA, manufactured by Nika Kagaku], 5 parts of a 5% aqueous solution of methylcellulose, and 80 parts of water was sand-milled. And pulverized until the average particle diameter became 1.5 μm. Preparation of liquid C A composition consisting of 20 parts of 1,2-di (3-methylphenoxy) ethane, 5 parts of a 5% aqueous solution of methylcellulose, and 55 parts of water was pulverized with a sand mill until the average particle diameter became 1.5 μm. Preparation of solution D 4-benzyloxy-4 '-(2-methyl-2,3-epoxypropyloxy) diphenyl sulfone 10 parts, 5% 5% aqueous solution of methylcellulose, and 40 parts of water It was pulverized until the diameter became 1.5 μm. Formation of recording layer 55 parts of solution A, 115 parts of solution B, 80 parts of solution C, 55 parts of solution D,
A recording layer coating liquid obtained by mixing and stirring 160 parts of a 10% polyvinyl alcohol aqueous solution and 25 parts of calcium carbonate,
45 g / m ² of high-quality paper coated on one side with a coating amount of 4 g /
A recording layer was formed by coating and drying so that the recording layer had a thickness of m ² .

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

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

Example 4 Preparation of Solution E 4- [3- (p-tolylsulfonyl) propyloxy]
A composition consisting of 30 parts of a zinc salt of salicylic acid, 5 parts of a 5% aqueous solution of methylcellulose, and 80 parts of water was ground by a sand mill until the average particle size became 1.5 μm. Formation of recording layer 55 parts of solution A, 80 parts of solution B, 80 parts of solution C, 55 parts of solution D, E
Liquid 35 parts, 10% polyvinyl alcohol aqueous solution 160
Parts, and recording the recording layer coating solution obtained by mixing and stirring 25 parts of calcium carbonate, the coating amount after drying on one surface of woodfree paper of 45 g / m ² is then applied and dried so as to 4g / m ² Layers were formed.

Example 5 Preparation of liquid F Tetrakis (1,2,2,6,6-pentamethyl-4-)
Piperidinyl) -1,2,3,4-butanetetracarboxylate 5 parts, 5% aqueous solution of methylcellulose 2 parts,
A composition comprising 20 parts of water and water was pulverized with a sand mill until the average particle size became 1.5 μm. Formation of recording layer 55 parts of solution A, 80 parts of solution B, 80 parts of solution C, 55 parts of solution D, E
Liquid 35 parts, Liquid F 27 parts, 10% polyvinyl alcohol aqueous solution 160 parts, and calcium carbonate 25 parts were mixed and stirred to obtain a recording layer coating liquid, which was applied to one side of a fine paper of 45 g / m ² after drying. A recording layer was formed by coating and drying so that the amount was 4 g / m ² .

Example 6 A thermosensitive recording medium was prepared in the same manner as in Example 1 except that 2-naphthylbenzyl ether 20 was used in place of 20 parts of 1,2-di (3-methylphenoxy) ethane in the preparation of solution C. Got

Example 7 Preparation of liquid G A composition consisting of 100 parts of calcined clay [trade name: Ansilex, manufactured by EMC, oil absorption: 110 ml / 100 g], 100 parts of a 10% aqueous solution of polyvinyl alcohol, and 200 parts of water was prepared. By mixing and stirring, a coating liquid for the undercoat layer was obtained. On one surface of woodfree paper of Preparation 45 g / m ² of the heat-sensitive recording material, after coating and drying the solution G so that the coating amount after drying of 8 g / m ^2, coating the recording layer was prepared as in Example 1 Coating amount after drying is 4 g /
After coating and drying so as to be m ² , super calender treatment was carried out to obtain a heat-sensitive recording material.

Comparative Example 1 Example 1 was repeated except that 30 parts of 4,4'-isopropylidenediphenol was used instead of 30 parts of bis (3-allyl-4-hydroxyphenyl) sulfone in the preparation of solution B.
A thermosensitive recording medium was obtained in the same manner as described above.

Comparative Example 2 Example 1 was repeated except that 30 parts of 4-hydroxy-4'-isopropoxydiphenyl sulfone was used in place of 30 parts of bis (3-allyl-4-hydroxyphenyl) sulfone in the preparation of solution B. A thermosensitive recording medium was obtained in the same manner as described above.

Comparative Example 3 55 parts of solution A, 115 parts of solution B, 80 parts of solution C, 160 parts of 10% aqueous polyvinyl alcohol solution in the formation of the recording layer,
And a recording layer coating solution obtained by mixing and stirring 25 parts of calcium carbonate, the coating dried to a recording layer as the coating amount after drying on one surface of woodfree paper of 45 g / m ² is 4g / m ² Formed.

Comparative Example 4 Example 3 was repeated except that 30 parts of 4,4'-isopropylidenediphenol was used in place of 30 parts of bis (3-allyl-4-hydroxyphenyl) sulfone in the preparation of solution B.
A thermosensitive recording medium was obtained in the same manner as described above.

Comparative Example 5 4-benzyloxy-4 '-(2-
Methyl-2,3-epoxypropyloxy) diphenylsulfone was replaced with 10 parts of 4,4′-dihydroxy-
A thermosensitive recording medium was obtained in the same manner as in Example 1 except that 10 parts of 3,3 ', 5,5'-tetrabromodiphenyl sulfone was used.

The 12 types of thermal recording materials thus obtained were subjected to the following evaluation tests, and the results are shown in [Table 1].

1. [Whiteness] To evaluate the degree of color fog, the whiteness of the recording layer was measured with a Hunter whiteness meter. 2. [Coloring Density] Each thermal recording material was colored with an applied voltage of 24 V and a pulse time of 2 ms using a thermal recording material evaluation device [trade name: TH-PMD, manufactured by Okura Electric Co., Ltd.] The color density was measured in a visual mode with a Macbeth densitometer [RD-914 type, manufactured by Macbeth Co.]. 3. [Oil resistance] The edible oil is dropped on the heat-sensitive recording body on which the color has been printed, and 24
The state of printing after being left for a time was visually evaluated. 4. [Hand cream resistance] A hand cream was applied on the heat-sensitive recording material on which the print color was developed, and the state of the print after that was visually evaluated. 5. [Plasticizer resistance] A vinyl chloride wrap film (manufactured by Mitsui Toatsu Kagaku Co., Ltd.) is wound three times on a polypropylene pipe (40 mmφ pipe),
A thermosensitive recording material with printed color was sandwiched on it so that the printed color surface was on the outside, and a vinyl chloride wrap film was wrapped around it in three layers. The drug properties were evaluated.

[Evaluation Criteria] Evaluation criteria for oil resistance, hand cream resistance and plasticizer resistance are as follows. ◎ −−−−− ○ −−−−− △ −−−−− × Excellent Excellent Inferior

[0036]

[Table 1]

[0037]

As is clear from the results of [Table 1], all of the thermosensitive recording materials of the present invention are excellent in storage stability of recorded images, particularly in oil resistance and plasticizer resistance, and also in recording sensitivity. It was a thermosensitive recording medium.

Claims (2)

[Claims] 1. A thermosensitive recording medium comprising a support and a recording layer containing a colorless or light-colored basic dye and a color developer, wherein bis (3-allyl-4-hydroxyphenyl) is contained in the recording layer. Sulfone and 4-benzyloxy-4 '-(2-
A heat-sensitive recording material containing methyl-2,3-epoxypropyloxy) diphenyl sulfone. 2. The heat-sensitive recording material according to claim 1, wherein the recording layer contains a zinc salt of 4- [3- (p-tolylsulfonyl) propyloxy] salicylic acid.