JPH0532046A - Thermal recording material - Google Patents

Abstract

PURPOSE:To provide a thermal recording material excellent in heat stability, reduced in background fog and having good color forming properties by adding a compound having two or more ethyleneimino groups being a storage stabilizer and a specific diphenylsulfone derivative being a developer to a recording layer. CONSTITUTION:A compound represented by formula II containing two or more ethyleneimino groups as a storage stabilizer and at least one kind of a diphenylsulfone derivative represented by formula I as a developer are added to the recording layer containing a colorless or light-colored basic dye and a developer provided on a support. In the formulae I, II, R1 and 2 are a 1-4C alkyl group, a 2-4C alkenyl group, a 1-4C alkoxyl group, a benzyloxy group or a halogen atom, m is 0 or an integer of 1-2, n is an integer of 1-3, p and q are 0 or an integer of 1-4 and R3 is a cycloalkylene group which may have a substituent, an arylene group, an aralkyl group or a group represented by formula III.

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, and more particularly to a heat-sensitive recording material which is excellent in storage stability of recorded images, has less background fog and is excellent in color development.

[0002]

2. Description of the Related Art A thermosensitive recording medium is known in which a color or color reaction between a colorless or pale basic dye and an organic or inorganic coloring agent is used to bring a recording image by contacting both coloring substances with heat. Has been. Such thermal recording materials are used in various fields and forms in association with the remarkable progress of thermal recording systems, and are used not only as recording media for thermal facsimiles and thermal printers but also as POS (Point of Sales) labels. The use for new applications is also rapidly increasing.

However, such a heat-sensitive recording material generally has insufficient storage stability of a recorded image and has a drawback of fading over time. In particular, if it is exposed to high humidity or high temperature conditions, or if it comes into contact with plasticizers, cosmetics, or chemicals such as alcohol contained in the vinyl chloride film, the recorded image will disappear in a relatively short time. Therefore, the improvement is strongly requested.

Therefore, for the purpose of improving the storage stability of a recorded image, a thermal recording material to which various storability improving agents are added has been proposed, but no sufficient effect can be obtained or the thermal recording material is improved. Therefore, satisfactory results have not always been obtained because new defects such as a decrease in whiteness are accompanied.

[0005]

In view of the above situation, the inventors of the present invention have conducted various studies on techniques for improving the preservation of recorded images, and as a result, the ethyleneimino group of 2 When a compound having two or more compounds is used in combination with a specific diphenylsulfone derivative as a color former, the thermal stability of the recorded image is excellent, especially the chemical resistance, and moreover there is little background fog and the thermal recording material is excellent in color development. They have found that they can be obtained and have completed the present invention.

[0006]

SUMMARY OF THE INVENTION The present invention comprises:
In a thermosensitive recording medium provided with a recording layer containing a colorless or light-colored basic dye and a coloring agent, at least one compound having two or more ethyleneimino groups is contained in the recording layer as a storage stability improving agent, and A heat-sensitive recording material containing at least one diphenylsulfone derivative represented by the following general formula [Chemical Formula 1] as a coloring agent.

[0007]

[Chemical 1]

[In the formula, R ₁ and R ₂ are each C _{1 to} C ₄
Alkyl group, an alkenyl group of C ₂ -C ₄ of, C ₁ -C ₄
Represents an alkoxyl group, a benzyloxy group, or a halogen atom. In addition, m represents 0 or an integer of 1 to 2, and n
Represents an integer of 1 to 3, p and q are 0 or 1 to 4, respectively.
Indicates an integer. ]

[0009]

In the present invention, a compound having two or more ethyleneimino groups in the molecule is used as a preservative improving agent. Among these compounds, the compound represented by the following general formula [Chemical Formula 2] is It is preferably used.

[0010]

[Chemical 2]

[In the formula, R ₃ is an alkylene group which may have a substituent, a cycloalkylene group which may have a substituent,
An arylene group which may have a substituent, an aralkylene group which may have a substituent, or [Chemical Formula 3] is shown.

[0012]

[Chemical 3]

Here, R ₆ is a direct bond, -O-, -S.
-, - SO ₂ -, or an alkylene group, R _7, R
₈ represents an alkyl group, an alkoxyl group, or a halogen atom, and r and s each represent 0 or an integer of 1 to 4. R ₄ and R ₅ each represent an alkyl group or a hydrogen atom. ]

Among the compounds represented by the general formula [Chemical Formula 2], R ₃ is a C ₁ -C ₂₀ alkylene group which may have a substituent, or a C ₅ -C which may have a substituent. A C ₆ cycloalkylene group, a phenylene group which may have a substituent, a naphthylene group which may have a substituent, a xylylene group which may have a substituent, or the following formula [Chemical Formula 4], R ₄ , R
_A compound in which ₅ is a C ₁ -C ₄ alkyl group or a hydrogen atom is more preferable because it exerts a particularly remarkable effect.

[0015]

[Chemical 4]

[Wherein R ₉ is a direct bond, -O-, -S
-, - SO ₂ -, or an alkylene group of C ₁ -C _6, alkyl group R _10, R ₁₁ each C ₁ ~C _4, C
₁ -C ₄ alkoxyl group or a halogen atom. Further, t and u each represent 0 or an integer of 1 to 4. ]

In the general formula [Chemical Formula 2], a C ₁ -C ₄ alkyl group is used as a substituent further added to the alkylene group, cycloalkylene group, phenylene group, naphthylene group, and xylylene group represented by R _3. , C ₁ -C ₄ alkoxyl groups, and halogen atoms are preferred.

Specific examples of the compound having two or more ethyleneimino groups used in the present invention include the following. 1,4-bis (ethyleneiminocarbonylamino) butane, 1,6-bis (ethyleneiminocarbonylamino) hexane, 1,8-bis (ethyleneiminocarbonylamino) octane, 1,12-bis (ethyleneiminocarbonylamino) Dodecane, 1,18-bis (ethyleneiminocarbonylamino) octadecane, 1,4
-Bis (ethyleneiminocarbonylamino) cyclohexane, 1,2-bis (ethyleneiminocarbonylamino) cyclohexane, 1,3-bis (ethyleneiminocarbonylamino) cyclohexane, 1,4-bis (ethyleneiminocarbonylamino) benzene, 1 , 2-bis (ethyleneiminocarbonylamino) benzene, 1,3
-Bis (ethyleneiminocarbonylamino) benzene,
1,3-bis (ethyleneiminocarbonylamino) -4
-Chlorobenzene, 1,3-bis (ethyleneiminocarbonylamino) -4-methylbenzene, 1,5-bis (ethyleneiminocarbonylamino) naphthalene, 1,
8-bis (ethyleneiminocarbonylamino) naphthalene, 4,4'-bis (ethyleneiminocarbonylamino) biphenyl, 4,4'-bis (ethyleneiminocarbonylamino) -3,3'-dimethylbiphenyl, 4,
4'-bis (ethyleneiminocarbonylamino) -3,
3'-di-tert-butylbiphenyl, 4,4'-bis (ethyleneiminocarbonylamino) -3,3'-dimethoxybiphenyl, 4,4'-bis (ethyleneiminocarbonylamino) -3,3'-dichloro Biphenyl, bis (4-ethyleneiminocarbonylaminophenyl) ether, bis (4-ethyleneiminocarbonylaminophenyl) sulfide, bis (4-ethyleneiminocarbonylaminophenyl) sulfone, bis (4-ethyleneiminocarbonylamino-3,5 -Dibromophenyl) sulfone, bis (4-ethyleneiminocarbonylamino-
3,5-dichlorophenyl) sulfone, bis (4-ethyleneiminocarbonylamino-3,5-di-tert-butylphenyl) sulfone, bis (4-ethyleneiminocarbonylaminophenyl) methane, bis (4-ethyleneiminocarbonylamino) -3-methylphenyl) methane,
Bis (4-ethyleneiminocarbonylamino-3-methoxyphenyl) methane, bis (4-ethyleneiminocarbonylamino-3,5-dimethoxyphenyl) methane,
1,2-bis (4-ethyleneiminocarbonylaminophenyl) ethane, 1,1-bis (4-ethyleneiminocarbonylaminophenyl) ethane, 2,2-bis (4-
Ethyleneiminocarbonylaminophenyl) propane,
2,2-bis (4-ethyleneiminocarbonylaminophenyl) butane, 2,2-bis (4-ethyleneiminocarbonylaminophenyl) -4-methylpentane, 1,
4-bis (ethyleneiminocarbonylaminomethyl) benzene, 1,3-bis (ethyleneiminocarbonylaminomethyl) benzene, 1- (ethyleneiminocarbonylamino) -4- (N-ethyleneiminocarbonyl-N-)
Methylamino) benzene, 1- (ethyleneiminocarbonylamino) -4- (N-ethyleneiminocarbonyl-
N-ethylamino) benzene, 1,3,5-tris (ethyleneiminocarbonylamino) benzene, 1,3,5
-Tris (ethyleneiminocarbonylamino) -4-methylbenzene, bis (4-ethyleneiminocarbonylphenyl) ether, 1,3-bis (ethyleneiminosulfonyl) benzene, 1,3,5-tris (ethyleneiminocarbonyl) benzene 1,4-bis [2- (ethyleneiminocarbonyloxy) ethoxycarbonyl] benzene, 1,3-bis (ethyleneiminocarbonyloxyphenyl) propane and the like. Of course, it is not limited to these, and two or more kinds can be used in combination as required.

The amount of the compound having two or more ethyleneimino groups used is not necessarily limited, but generally 5 to 500 parts by weight, preferably 10 to 100 parts by weight of the basic dye. It is desirable to adjust the amount within the range of about 200 parts by weight.

In the present invention, in the heat-sensitive recording material using the above-mentioned preservability improving agent, ethylene is obtained by selectively combining the diphenylsulfone derivative represented by the general formula [Chem. The characteristics of the compound having an imino group are fully exhibited, and specific examples of such a diphenylsulfone derivative include the following. 4,4'-dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone,
3,3'-diallyl-4,4'-dihydroxydiphenyl sulfone, 3,3 ', 5,5'-tetrabromo-4,
4'-dihydroxydiphenyl sulfone, 3,3 ',
5,5'-tetrachloro-4,4'-dihydroxydiphenyl sulfone, 4-hydroxydiphenyl sulfone,
4-hydroxy-4'-methyldiphenyl sulfone, 4
-Hydroxy-3 ', 4'-trimethylene diphenyl sulfone, 4-hydroxy-3', 4'-tetramethylene diphenyl sulfone, 4-hydroxy-4'-methoxydiphenyl sulfone, 4-hydroxy-4'-ethoxydiphenyl sulfone , 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxy-4'-n
-Butoxydiphenyl sulfone, 4-hydroxy-4 '
-Benzyloxydiphenyl sulfone, 3,4-dihydroxydiphenyl sulfone, 3,4-dihydroxy-
4'-methyldiphenyl sulfone, 3,4,4'-trihydroxydiphenyl sulfone, 3,4,3 ', 4'-
Tetrahydroxydiphenyl sulfone, 2,3,4-trihydroxydiphenyl sulfone and the like. Of course, it is not limited to these, and two or more kinds may be used in combination as required. Among these diphenyl sulfone derivatives, 2,4'-dihydroxydiphenyl sulfone and 4-hydroxy-4'-isopropoxydiphenyl sulfone are capable of obtaining a heat-sensitive recording material which is not only preservative of a recorded image but also particularly has less background fog. Therefore, it is more preferably used. In the present invention, the specific diphenylsulfone derivative as described above is selectively used as a color-developing agent, but other known color-developing agents are used in combination within a range that does not inhibit the desired effect of the present invention. It is also possible to do so.

In the present invention, various known dyes can be used as a colorless or light-colored basic dye which constitutes a color-forming system together with the above-mentioned specific color-forming agent, but the color-forming system is constituted by a dye having a lactone ring in the molecule. Then, a particularly remarkable effect is exhibited, which is more preferable. Specific examples of such dyes include the following. 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3,3-bis (p-dimethylaminophenyl) phthalide, 3- (4-dimethylaminophenyl) -3- (4
-Diethylamino-2-methylphenyl) -6-dimethylaminophthalide, 3- (p-dimethylaminophenyl) -3- (1,2-dimethylindol-3-yl)
Phthalide, 3- (p-dimethylaminophenyl) -3-
(2-Methylindol-3-yl) phthalide, 3,3
-Bis (1,2-dimethylindol-3-yl) -5
-Dimethylaminophthalide, 3,3-bis (1,2-dimethylindol-3-yl) -6-dimethylaminophthalide, 3,3-bis (9-ethylcarbazole-3-
Yl) -6-Dimethylaminophthalide, 3,3-bis (2-phenylindol-3-yl) -6-dimethylaminophthalide, 3-p-dimethylaminophenyl-3
Triarylmethane dyes such as-(1-methylpyrrol-3-yl) -6-dimethylaminophthalide, 3,3-
Bis [1,1-bis (4-pyrrolidinophenyl) ethylene-2-yl] -4,5,6,7-tetrabromophthalide, 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,
Divinylphthalide dyes such as 6,7-tetrachlorophthalide, 3-dimethylamino-7-methoxyfluorane,
3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-
6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3- (N-ethyl-
p-toluidino) -7-methylfluorane, 3-dimethylamino-7- (N-acetyl-N-methylamino) fluorane, 3-diethylamino-7-N-methylaminofluorane, 3-diethylamino-7-di Benzylaminofluorane, 3-diethylamino-7- (N-methyl-N-benzylamino) fluorane, 3-diethylamino-7- (N-chloroethyl-N-methylamino) fluorane, 3-diethylamino-7-diethylaminofluorane , 4-benzylamino-8-diethylamino-benzo [a] fluorane, 3- [4- (4-dimethylaminoanilino) anilino] -7-chloro-6-methylfluorane, 3- [4- (4- Phenylanilino) anilino] -7-chloro-6-methylfluorane, 8- [4-
(4-Dimethylaminoanilino) anilino] -benzo [a] fluorane, 3- (N-ethyl-p-toluidino) -6-methyl-7-phenylaminofluorane, 3
-(N-ethyl-p-toluidino) -6-methyl-7-
(P-Toluidino) fluorane, 3-diethylamino-
6-methyl-7-phenylaminofluorane, 3-di-
n-Butylamino-6-methyl-7-phenylaminofluorane, 3-di-n-pentylamino-6-methyl-
7-phenylaminofluorane, 3-diethylamino-
7- (2-carbomethoxy-phenylamino) fluorane, 3- (N-ethyl-N-isoamylamino) -6-
Methyl-7-phenylaminofluorane, 3- (N-cyclohexyl-N-methylamino) -6-methyl-7-
Phenylaminofluorane, 3-pyrrolidino-6-methyl-7-phenylaminofluorane, 3-piperidino-
6-methyl-7-phenylaminofluorane, 3-diethylamino-6-methyl-7-xylidinofluorane,
3-diethylamino-7- (o-chlorophenylamino) fluorane, 3-di-n-butylamino-7- (o
-Chlorophenylamino) fluorane, 3- (N-ethyl-N-tetrahydrofurfuryl) amino-6-methyl-7-phenylaminofluorane, 3- (N-methyl-)
N-n-propylamino) -6-methyl-7-phenylaminofluorane, 3-pyrrolidino-6-methyl-7-
p-Butylphenylaminofluorane, 3- (N-methyl-Nn-propyl) amino-6-methyl-7-phenylaminofluorane, 3- (N-ethyl-N-isobutylamino) -6-methyl -7-Phenylaminofluorane, 3- (N-methyl-Nn-hexylamino)-
6-methyl-7-phenylaminofluorane, 3- (N
-Ethyl-N-n-hexylamino) -6-methyl-7
-Phenylaminofluorane, 3- (N-ethyl-N-
Cyclopentylamino) -6-methyl-7-phenylaminofluorane, 3- [N- (3-ethoxypropyl)
-N-methylamino] -6-methyl-7-phenylaminofluorane, 3- [N-ethyl-N- (3-ethoxypropyl) amino] -6-methyl-7-phenylaminofluorane, 3-diethylamino -7- [m- (trifluoromethyl) phenylamino] fluorane, 3-diethylamino-7- (o-fluorophenylamino) fluorane, 3-di-n-butylamino-7- (o-fluorophenylamino) fluorane , 3-diethylamino-
6-chloro-7-phenylaminofluorane, 3- (N
-Ethyl-N-isoamylamino) -7- (o-chlorophenylamino) fluorane, 3- (N-ethyl-N-
Fluorane dyes such as n-hexylamino) -7- (o-chlorophenylamino) fluorane, 3,6-bis (dimethylamino) fluorene-9-spiro-3'-
(6'-Dimethylamino) phthalide, 3-diethylamino-6- (N-allyl-N-methylamino) fluorene-9-spiro-3 '-(6'-dimethylamino) phthalide, 3,6-bis (dimethyl) Amino) -spiro [fluorene-9,6'-6'H-chromeno (4,3-b) indole], 3,6-bis (dimethylamino) -3'-methyl-spiro [fluorene-9,6 ' -6H-chromeno (4,3-b) indole], 3,6-bis (diethylamino) -3'-methyl-spiro [fluorene-9,
6'-6H-chromeno (4,3-b) indole] and other fluorene dyes. Of course, the dyes are not limited to these dyes, and two or more dyes may be used in combination as required.

The use ratio of the basic dye and the above specific coloring agent is not particularly limited, but generally 100 to 700 parts by weight, preferably 150 to 400 parts by weight, relative to 100 parts by weight of the basic dye. Some colorants are used. In the heat-sensitive recording material of the present invention, a recording sensitivity improving agent can be added to the recording layer for the purpose of obtaining high speed recording suitability. Examples of the recording sensitivity improving agent include the following compounds. Caproic acid amide, capric acid amide,
Palmitic acid amide, stearic acid amide, oleic acid amide, erucic acid amide, linoleic acid amide, linolenic acid amide, N-methylstearic acid amide, stearic acid anilide, N-methyloleic acid amide, benzanilide, linoleic acid anilide, N- Ethylcapric acid amide, N-butyllauric acid amide, N-octadecylacetamide, N-oleinacetamide, N-oleylbenzamide, N-stearylcyclohexylamide, polyethylene glycol, 1-benzyloxynaphthalene, 2-benzyloxynaphthalene, 1-hydroxynaphthoic acid phenyl ester, 1,2-diphenoxyethane, 1,4-diphenoxybutane, 1,2-bis (3-methylphenoxy) ethane, 1,2-bis (4-
Methoxyphenoxy) ethane, 1-phenoxy-2-
(4-chlorophenoxy) ethane, 1-phenoxy-2
-(4-methoxyphenoxy) ethane, 1- (2-methylphenoxy) -2- (4-methoxyphenoxy) ethane, terephthalic acid dibenzyl ester, oxalic acid dibenzyl ester, oxalic acid di (4-methylbenzyl) ester , P-benzyloxybenzoic acid benzyl ester,
p-benzylbiphenyl, 1,5-bis (p-methoxyphenoxy) -3-oxa-pentane, 1,4-bis (2-vinyloxyethoxy) benzene, p-biphenyl-p-tolyl ether, benzyl-p- Methylthiophenyl ether, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2-hydroxy-4
-Benzyloxybenzophenone and the like. The amount of the recording sensitivity improver used is not particularly limited, but is generally 50 to 10 with respect to 100 parts by weight of the basic dye.
It is desirable to adjust the amount in the range of 00 parts by weight, preferably 100 to 500 parts by weight.

The coating liquid containing these generally contains water as a dispersion medium and has a basic dye, a specific coloring agent, and an ethyleneimino group by an agitator / pulverizer such as a ball mill, an attritor, or a vertical or horizontal sand mill. It is prepared by dispersing the compound or the like together or separately. In such coating liquid, starch, hydroxyethyl cellulose, methyl cellulose, carboxyethyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohol, styrene / maleic anhydride copolymer salt, styrene / acrylic acid copolymer salt as a binder, A styrene / butadiene copolymer emulsion or the like is added in an amount of about 2 to 40% by weight, preferably about 5 to 25% by weight, based on the total solid content.

Further, various auxiliary agents may be added to the coating liquid, for example, dispersant such as sodium dioctylsulfosuccinate, sodium dodecylbenzene sulfonate, sodium lauryl alcohol sulfate, fatty acid metal salt, and the like. Other examples include defoaming agents, fluorescent dyes, and coloring dyes. Further, in order to improve the adhesion of dust to the recording head, it is possible to add an inorganic pigment such as kaolin, clay, talc, calcium carbonate, calcined clay, titanium oxide, diatomaceous earth, fine anhydrous silica, and activated clay. It is also possible to add a dispersion or emulsion of stearic acid, polyethylene, carnauba wax, paraffin wax, zinc stearate, calcium stearate, ester wax or the like so that sticking does not occur due to contact with the recording head.

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 known and commonly used technique. For example, the coating liquid for the heat-sensitive recording layer is air knife coater, blade coater, bar coater. ,
It is formed by a method such as coating on a support using an appropriate coating device such as a gravure coater or a curtain coater.
Also, the coating amount is not particularly limited,
Generally, the dry weight is about 1 to 12 g / m ² , preferably 2
It is adjusted within the range of about 10 g / m ² . As the support, paper, plastic film, synthetic paper or the like is appropriately selected and used.

In the present invention, a protective layer may be provided on the thermosensitive recording layer for the purpose of protecting the recording layer, or an intermediate layer may be provided between the support and the recording layer. Various publicly known techniques in the field of manufacturing a thermosensitive recording medium, such as providing a protective layer on the backside of the body and applying an adhesive process to the backside of the recording medium, can be appropriately added.

[0027]

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 the examples, parts and% are parts by weight and% by weight, respectively, unless otherwise specified.

Example 1 Preparation of liquid A 10 parts of 3-di-n-butylamino-6-methyl-7-phenylaminofluorane, 25 parts of 1,2-bis (3-methylphenoxy) ethane, 5% of methylcellulose A composition consisting of 5 parts of an aqueous solution and 50 parts of water was pulverized with a horizontal sand mill until the average particle size became 1.0 μm. Solution B Preparation 2,4'-Dihydroxydiphenyl sulfone 20 parts, a composition consisting of 5% 5% aqueous solution of methylcellulose, and 55 parts of water, the average particle size was 1.5μ in a horizontal sand mill.
It was crushed until it reached m.

Solution C Preparation Bis (4-ethyleneiminocarbonylaminophenyl)
A composition consisting of 10 parts of methane, 5 parts of a 5% aqueous solution of methyl cellulose, and 35 parts of water was pulverized with a horizontal sand mill until the average particle diameter became 1.5 μm. Formation of thermosensitive recording layer 90 parts of liquid A, 80 parts of liquid B, 20 parts of liquid C, 7 parts of silicon oxide pigment (oil absorption: 180 ml / 100 g), 8 parts of light calcium carbonate (oil absorption: 90 ml / 100 g), 20% A coating solution was obtained by mixing and stirring 50 parts of an aqueous polyvinyl alcohol solution, 15 parts of a 30% zinc stearate aqueous dispersion, and 10 parts of water.
The coating amount of obtained dried coating liquid on a base paper of 45 g / m ² was obtained a heat-sensitive recording paper by coating and drying so that 3 g / m ^2.

Examples 2 to 5 Four kinds of compounds were prepared in the same manner as in Example 1 except that the following compounds were used in place of bis (4-ethyleneiminocarbonylaminophenyl) methane in the preparation of liquid C in Example 1. A thermosensitive recording paper was obtained. Example 2: 1,3-bis (ethyleneiminocarbonylamino) benzene Example 3: 1- (ethyleneiminocarbonylamino)-
4- (N-ethyleneiminocarbonyl-N-methylamino) benzene Example 4: 1,4-bis (ethyleneiminocarbonylaminomethyl) benzene Example 5: 1,12-bis (ethyleneiminocarbonylamino) dodecane

Example 6 In the preparation of solution B of Example 1, 4-hydroxy-4'- was used instead of 2,4'-dihydroxydiphenyl sulfone.
A thermal recording paper was obtained in the same manner as in Example 1 except that isopropoxydiphenyl sulfone was used.

Example 7 In the preparation of solution C of Example 6, 1,4 was used instead of bis (4-ethyleneiminocarbonylaminophenyl) methane.
A thermal recording paper was obtained in the same manner as in Example 6 except that -bis (ethyleneiminocarbonylaminomethyl) benzene was used.

Example 8 In the preparation of solution B of Example 1, 3,3'-diallyl- was used instead of 2,4'-dihydroxydiphenyl sulfone.
A thermal recording paper was obtained in the same manner as in Example 1 except that 4,4'-dihydroxydiphenyl sulfone was used.

Comparative Example 1 A thermosensitive recording paper was obtained in the same manner as in Example 1 except that the liquid C was not used in forming the thermosensitive recording layer.

Comparative Example 2 In the preparation of liquid C of Example 1, bis (4-ethyleneiminocarbonylaminophenyl) methane was replaced with 4,
A thermosensitive recording paper was obtained in the same manner as in Example 1 except that 4'-thiobis (3-methyl-6-tert-butylphenol) was used.

Comparative Example 3 Thermal recording was carried out in the same manner as in Example 1 except that 4,4'-isopropylidenediphenol was used in place of 2,4'-dihydroxydiphenylsulfone in the preparation of solution B of Example 1. Got the paper.

The 11 kinds of heat-sensitive recording papers thus obtained were recorded by a heat-sensitive facsimile (Hitachi HIFAX-400 type), and the density of the recorded image and the blank area was measured by a Macbeth densitometer (RD).
-100R type, using amber filter),
The results are shown in Table 1. After recording, the thermosensitive recording paper is left for 72 hours under a high humidity condition of 40 ° C. and 90% RH (moisture resistance test), or a vinyl chloride film containing a plasticizer on the color development surface is overlapped with the recording paper at 40 ° C. for 24 hours. After standing for a period of time (plasticizer resistance test), the densities of the recorded image and the blank area were measured again with a Macbeth densitometer, and the results are shown in Table 1.

[0038]

[Table 1]

[0039]

As is clear from the results shown in Table 1, the thermosensitive recording medium of the present invention is excellent in storage stability of recorded images, particularly in chemical resistance, and has excellent high-sensitivity thermosensitive recording with little background fog in the blank area. It was a body.

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 coloring agent, wherein the recording layer contains two or more ethyleneimino groups as a storage stability improver. Containing at least one of the compounds having,
A heat-sensitive recording material containing at least one diphenylsulfone derivative represented by the following general formula [Chemical Formula 1] as a coloring agent. [Chemical 1] [In the formula, R ₁ and R ₂ each represent a C _{1 to} C ₄ alkyl group, a C _{2 to} C ₄ alkenyl group, a C _{1 to} C ₄ alkoxyl group, a benzyloxy group, or a halogen atom. Moreover, m shows 0 or the integer of 1-2, n is 1-3.
, And p and q each represent 0 or an integer of 1 to 4. ] 2. The heat-sensitive recording material according to claim 1, wherein the compound having an ethyleneimino group is a compound represented by the following general formula [Chemical formula 2]. [Chemical 2] [In the formula, R ₃ is an alkylene group which may have a substituent, a cycloalkylene group which may have a substituent, an arylene group which may have a substituent, and an aralkylene which may have a substituent. A group or [Chemical Formula 3] is shown. [Chemical 3] Wherein, R ₆ is a direct bond, -O -, - S -, - SO
_2- or an alkylene group, R ₇ and R ₈ each represent an alkyl group, an alkoxyl group, or a halogen atom, and r and s each represent 0 or an integer of 1 to 4. R ₄ and R ₅ each represent an alkyl group or a hydrogen atom. ]