JPH10217614A - Heat-sensitive recording body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce fogging with time, and improve the shelf life of a recorded image by a method wherein for a heat-sensitive recording body, in the heat- sensitive recording layer, as a developer, the one containing one, or two kinds or more selected from a group comprising a specified sulfonyl compound and its polyvalent metallic salts, and wax, is used. SOLUTION: A developer which is used for a heat-sensitive recording layer contains one kind, or two or more kinds, which are selected from a group comprising a sulfonyl compound represented by the formula I (in the formula, (x) represents hydrogen atom or a low class alkyl group, R<1> , R<2> -R<5> and R<6> represent hydrogen atom, halogen atom, and a low class alkyl group, etc., and R<7> represents hydrogen atom or the formula II, and in this case, R<4> , R<5> and R<6> represent hydrogen atom, halogen atom, a low class alkyl group, etc.) and its polyvalent metallic salts, and wax. The wax is one kind or two or more kinds which are selected from a group comprising a candelilla wax, a paraffin wax, a montan wax derivative and a polyethylene wax derivative, etc. In addition, a specified hydration preventive agent may be contained in the heat- sensitive recording layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermosensitive recording medium,
More specifically, when the thermosensitive recording layer contains one or more selected from the group consisting of a specific sulfonyl compound and a polyvalent metal salt thereof as a color developer, and further contains a wax, high sensitivity is obtained. In addition, there is little background fogging,
The present invention relates to a heat-sensitive recording medium capable of obtaining recording stability excellent in storage stability of a recorded image, in particular, moisture resistance, heat resistance and plasticizer resistance.

[0002]

2. Description of the Related Art A thermosensitive recording material utilizing a thermal coloring reaction between an electron-donating basic dye precursor and an electron-accepting developer has been well known. Among them, 2,2-bis (4-hydroxy-phenyl) propane and 4-hydroxy-4'-
Isopropoxy-diphenyl sulfone is well known (for example, Japanese Patent Publication No. 3-54555).

However, heat-sensitive recording materials using these materials are required to be further improved with respect to the storage stability of a color image, particularly the moisture resistance, heat resistance and plasticizer resistance. In order to solve such a problem, the present inventors have previously used the general formula (1) as a color developer.

[0004]

Embedded image [In the general formula (1), X represents a hydrogen atom or a lower alkyl group, and R ₁ , R ₂ and R ₃ may be the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, or a lower alkyl group. Or a cycloalkyl group;
₄ , R ₅ and R ₆ may be the same or different and each represent a hydrogen atom, a halogen atom, a lower alkyl group or a cycloalkyl group, and R ₇ is a hydrogen atom or

[0005]

Embedded image Wherein R ₄ , R ₅ and R ₆ are as defined above. And a polyvalent metal salt thereof, and filed a patent for this compound.

However, in the present developer, the developer may be crushed into extremely fine particles, or the developer may be hydrated when the aqueous developer slurry is stored at 40 ° C. for a long period of time. When the developer thus hydrated is used, the resulting heat-sensitive recording medium causes background fog when stored at 60 ° C. The present inventors have conducted intensive studies to prevent hydration of the present color developer, and as a result, general formula (2)

[0007]

Embedded image [In the general formula (2), X, R ₁ , R ₂ , R ₃ , R
₄ , R ₅ and R ₆ have the same meaning as in formula (1), and Y is an alkyl group, an aralkyl group, an allyl group, a cyclohexyl group, an alkylaryl group, an alkylsulfonyl group, a benzenesulfonyl group, an alkylbenzenesulfonyl group. , An alkylloyl group, a benzoyl group, an alkylbenzoyl group, an acryloyl group, a methacryloyl group or a glycidyl group. ] Was found to be effective, and a patent was previously filed.

That is, when the developer represented by the general formula (1) is hydrated, the sulfonyl compound represented by the general formula (2) is added to the compound represented by the general formula (1) to form a developer. When used, hydration of the developer can be prevented, and occurrence of background fogging of the obtained heat-sensitive recording medium over time can be prevented.

However, after that, even if the recording medium is placed in a more severe environment, it is required that the background of the recording medium is less fogged with the passage of time.
From 1 day and 60 ° C. for 1 day at 0 ° C. and 90% humidity, the conditions are strictly changed to 1 day and 60 ° C. for 3 days at 50 ° C. and 90% humidity. I worked diligently to study a recording medium with less background fogging.

[0010]

As a result, the present inventors have developed a compound represented by the general formula (1) and a polyvalent metal salt thereof or a compound represented by the general formula (2) as a developer. By containing one or more selected from the group consisting of the compound represented by the general formula (1) and a polyvalent metal salt thereof, and further using a wax as a lubricant, the recording medium is heated at 50 ° C. 90% for 1 day and 60 ° C,
Even when exposed for 3 days, the recording medium has a characteristically low background fog, the recording medium has high sensitivity, and the storage stability of the color image is high.
In particular, they have found that they are excellent in moisture resistance, heat resistance, and plasticizer resistance, and have completed the present invention.

That is, the present invention relates to a heat-sensitive recording material utilizing a thermochromic reaction between an electron-donating basic dye precursor and an electron-accepting color developing agent. )

[0012]

Embedded image [In the general formula (1), X represents a hydrogen atom or a lower alkyl group, and R ₁ , R ₂ and R ₃ may be the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, or a lower alkyl group. Or a cycloalkyl group;
₄ , R ₅ and R ₆ may be the same or different and each represent a hydrogen atom, a halogen atom, a lower alkyl group or a cycloalkyl group, and R ₇ is a hydrogen atom or

[0013]

Embedded image Wherein R ₄ , R ₅ and R ₆ are as defined above. A heat-sensitive recording material comprising at least one selected from the group consisting of a sulfonyl compound represented by the formula (1) and a polyvalent metal salt thereof, and a wax as a lubricant.

Further, according to the present invention, in the above-mentioned heat-sensitive recording material, a general formula (2)

[0015]

Embedded image [In the general formula (2), X, R ₁ , R ₂ , R ₃ , R
₄ , R ₅ and R ₆ have the same meaning as in the general formula (1) according to claim 1, Y is an alkyl group, an aralkyl group,
Represents an allyl group, a cyclohexyl group, an alkylaryl group, an alkylsulfonyl group, a benzenesulfonyl group, an alkylbenzenesulfonyl group, an alkyloyl group, a benzoyl group, an alkylbenzoyl group, an acryloyl group, a methacryloyl group, or a glycidyl group. ] A heat-sensitive recording material containing a sulfonyl compound represented by the formula:

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The recording medium will be described in more detail.

Examples of the sulfonyl compound represented by the general formula (1) include 2,4-bis (phenylsulfonyl) phenol, 2,4-bis (4-methylphenylsulfonyl) phenol, and 2,4-bis (4 -Ethylphenylsulfonyl) phenol, 2,4-bis (4-isopropylphenylsulfonyl) phenol, 2,4-bis (2,5-dimethylphenylsulfonyl) phenol,
2,4-bis (2,4-dimethylphenylsulfonyl)
Phenol, 2,4-bis (3,4-dimethylphenylsulfonyl) phenol, 2,4-bis (4-chlorophenylsulfonyl) phenol, 2,4-bis (phenylsulfonyl) -5-methylphenol, 2,4- Bis (4-methylphenylsulfonyl) -5-methylphenol, 2,4-bis (phenylsulfonyl) -5-ethylphenol, 2,4-bis (4-methylphenylsulfonyl) -5-ethylphenol, 2- ( 4-methylphenylsulfonyl) -4- (phenylsulfonyl) phenol, 2- (4-ethylphenylsulfonyl) -4-
(Phenylsulfonyl) phenol, 2- (2,5-dimethylphenylsulfonyl) -4- (phenylsulfonyl) phenol, 2- (2,4-dimethylphenylsulfonyl) -4- (phenylsulfonyl) phenol,
-(3,4-dimethylphenylsulfonyl) -4- (phenylsulfonyl) phenol, 2- (4-chlorophenylsulfonyl) -4- (phenylsulfonyl) phenol, 2- (phenylsulfonyl) -4- (4-methylphenyl Sulfonyl) phenol, 2- (phenylsulfonyl) -4- (4-ethylphenylsulfonyl) phenol, 2- (phenylsulfonyl) -4- (2,5-
Dimethylphenylsulfonyl) phenol, 2- (phenylsulfonyl) -4- (2,4-dimethylphenylsulfonyl) phenol, 2- (phenylsulfonyl)-
4- (3,4-dimethylphenylsulfonyl) phenol, 2- (phenylsulfonyl) -4- (4-chlorophenylsulfonyl) phenol, 4,4'-dihydroxy-5- (phenylsulfonyl) diphenylsulfone,
4,4'-dihydroxy-5,5'-bis (phenylsulfonyl) diphenylsulfone, 2,4-bis (2,3
-Dimethylphenylsulfonyl) -5-methylphenol, 2,4-bis (2,4-dimethylphenylsulfonyl) -5-methylphenol, 2,4-bis (2,5-
Dimethylphenylsulfonyl) -5-methylphenol, 2,4-bis (3,4-dimethylphenylsulfonyl) -5-methylphenol, and the like. These may be used alone or in combination of two or more. Good.

In the polyvalent metal salt of the above compound, the metal is preferably zinc, magnesium, calcium, strontium, aluminum, iron, cobalt, nickel and titanium, and among them, zinc, magnesium, calcium and aluminum are preferred. Particularly preferred.

Specific examples of the compound represented by the general formula (2) include the following compounds.

1-methoxy-2,4-bis (phenylsulfonyl) benzene, 1-ethoxy-2,4-bis (phenylsulfonyl) benzene, 1-n-propoxy-
2,4-bis (phenylsulfonyl) benzene, 1-i
so-propoxy-2,4-bis (phenylsulfonyl) benzene, 1-n-butoxy-2,4-bis (phenylsulfonyl) benzene, 1-sec-butoxy-
2,4-bis (phenylsulfonyl) benzene, {2
4-bis (phenylsulfonyl) phenyl} benzyl ether, 2,4-bis (phenylsulfonyl) phenyl} allyl ether, 2,4-bis (phenylsulfonyl) phenyl} phenyl ether, 2,4-bis (phenyl) Sulfonyl) phenyl {methanesulfonate, {2,4-bis (phenylsulfonyl) phenyl}
Benzenesulfonate, {2,4-bis (phenylsulfonyl) phenyl} 4-methylbenzenesulfonate,
{2,4-bis (phenylsulfonyl) phenyl} 2
4-dimethylbenzenesulfonate, {2,4-bis (phenylsulfonyl) phenyl} 2,5-dimethylbenzenesulfonate, {2,4-bis (phenylsulfonyl) phenyl} 3,4-dimethylbenzenesulfonate, {2,4 -Bis (phenylsulfonyl) phenyl}
Acetate, 1-stearoyloxy-2,4-bis (phenylsulfonyl) benzene, {2,4-bis (phenylsulfonyl) phenyl} phenylcarboxylate, {2,4-bis (phenylsulfonyl) phenyl}
4-methylphenylcarboxylate, {2,4-bis (phenylsulfonyl) phenyl} acrylate,
{2,4-bis (phenylsulfonyl) phenyl} methacrylate, 1- {2,4-bis (phenylsulfonyl) phenoxy} -2,3-epoxypropane, {2
4-bis (phenylsulfonyl) phenyl} n-hexyl ether, {2,4-bis (phenylsulfonyl) phenyl} stearyl ether, {2,4-bis (phenylsulfonyl) phenyl} cyclohexyl ether, 1
-Iso-propoxy-2,4-bis (4-methylphenylsulfonyl) benzene, 1-methoxy-2,4-bis (4-methylphenylsulfonyl) benzene, {2
4-bis (4-methylphenylsulfonyl) phenyl}
Benzenesulfonate, {2,4-bis (4-methylphenylsulfonyl) phenyl} 4-methylbenzenesulfonate, {2,4-bis (4-methylphenylsulfonyl) phenyl} phenylcarboxylate, 1-methoxy-2,4 -Bis (2,5-dimethylphenylsulfonyl) benzene, {2,4-bis (2,5-dimethylphenylsulfonyl) phenyl} benzenesulfonate,
{2,4-bis (2,5-dimethylphenylsulfonyl) phenyl} 2,5-dimethylbenzenesulfonate, {2,4-bis (2,5-dimethylphenylsulfonyl) phenyl} phenylcarboxylate, 1-is
o-Propoxy-2,4-bis (phenylsulfonyl)
-5-methylbenzene, 1-ethoxy-2,4-bis (phenylsulfonyl) -5-methylbenzene, {2
4-bis (phenylsulfonyl) -5-methylphenyl} benzenesulfonate, {2,4-bis (phenylsulfonyl) -5-methylphenyl} phenylcarboxylate, 1-iso-propoxy-2,4-bis (phenylsulfonyl) ) -5-Ethylbenzene, 1-ethoxy-2,4-bis (phenylsulfonyl) -5-ethylbenzene, {2,4-bis (phenylsulfonyl) -5
-Ethylphenyl benzenesulfonate, ｛1-is
o-propoxy-2- (4-methylphenylsulfonyl) -4-phenylsulfonyl} benzene, {2- (4
-Methylphenylsulfonyl) -4- (phenylsulfonyl) phenyl} allyl ether, {2- (4-methylphenylsulfonyl) -4- (phenylsulfonyl) phenyl} benzenesulfonate, {2- (4-methylphenylsulfonyl)- 4- (phenylsulfonyl) phenyl} phenylcarboxylate, {1-methoxy-2}
-(4-methylphenylsulfonyl) -4-phenylsulfonyl} benzene, {1-iso-propoxy-2-
(2,5-dimethylphenylsulfonyl) -4-phenylsulfonyl} benzene, {2- (2,5-dimethylphenylsulfonyl) -4- (phenylsulfonyl) phenyl} benzenesulfonate, {2- (2,5-dimethyl) Phenylsulfonyl) -4- (phenylsulfonyl)
Phenyl phenyl carboxylate, ｛1-methoxy-2- (2,5-dimethylphenylsulfonyl) -4-
Phenylsulfonyl} benzene, 1-iso-propoxy-2,4-bis (3,4-dimethylphenylsulfonyl) benzene, {2,4-bis (3,4-dimethylphenylsulfonyl) phenyl} allyl ether, 4
-Bis (3,4-dimethylphenylsulfonyl) phenyl} benzenesulfonate, {2,4-bis (3,4-
Dimethylphenylsulfonyl) phenyl {3,4-dimethylbenzenesulfonate, {2,4-bis (3,4-
Dimethylphenylsulfonyl) phenyl} phenylcarboxylate, 1-methoxy-2,4-bis (3,4-
Dimethylphenylsulfonyl) benzene, 1-iso-
Propoxy-2,4-bis (4-chlorophenylsulfonyl) benzene, {2,4-bis (4-chlorophenylsulfonyl) phenyl} benzenesulfonate, {2
4-bis (4-chlorophenylsulfonyl) phenyl}
4-chlorobenzenesulfonate.

Further, the wax according to the present invention includes, as specific examples, candelilla wax, rice wax, wood wax, beeswax, lanolin, montan wax,
Natural waxes such as carnauba wax, ceresin wax, paraffin wax, microcrystalline wax, and tallow and coconut oil, and also natural waxes such as polyethylene wax, montan wax, carnauba wax, microcrystalline wax, and tallow and coconut oil, and further, polyethylene wax , Montan wax, carnauba wax, microcrystalline wax and the like, and Fischer-Tropsch wax.

These may be used alone or as a mixture. Further, as long as the effect is not impaired, a lubricant generally used for the thermosensitive recording medium, for example, a metal soap such as zinc stearate, calcium stearate, and aluminum stearate may be coexisted.

The total amount of the compound of the formula (1) and its polyvalent metal salt used as a color developer is 50 to 600 parts by weight, preferably 100 to 4 parts by weight, per 100 parts by weight of the basic dye.
00 parts by weight. Further, the amount of the compound represented by the general formula (2) as a hydration inhibitor of the present developer is 0.001 to 200 parts by weight, preferably 0.1 to 200 parts by weight, based on 100 parts by weight of the developer used. 002 to 100 parts by weight. or,
The total amount of the wax used is 2 to 1,000 parts by weight, preferably 5 to 5 parts by weight, per 100 parts by weight of the basic dye.
00 parts by weight.

Next, the basic dye, sensitizer, pigment, surfactant and dispersant used in the present invention will be described.

Examples of the basic dye include triarylmethane compounds, diarylmethane compounds, pyridine compounds, spiro compounds, rhodamine-lactam compounds,
Examples thereof include fluoran compounds, indolylphthalide compounds, and fluorene compounds. Among them, 3-N, N
-Dibutylamino-6-methyl-7-anilinofluoran, 3-N, N-diethylamino-6-methyl-7-anilinofluoran, 3- (N-isopentyl-N-ethyl) -6-methyl- 7-anilinofluoran, 3- (N
-Cyclohexyl-N-methyl) -6-methyl-7-anilinofluoran, 3-N, N-diethyl-6-chloro-7-anilinofluoran, crystal violet lactone and the like are exemplified as typical examples. You. These basic dyes may be used alone or as a mixture of two or more kinds for the purpose of adjusting the color tone of a color-developed image or obtaining a multicolor thermosensitive recording material.

Examples of the sensitizer include nitrogen-containing compounds, ester compounds, hydrocarbon compounds, ether compounds, and sulfone compounds. Among them, β-naphthylbenzyl ether, stearic acid amide, benzyl 4-benzyloxybenzoate, dibenzyl oxalate, di-P-methylbenzyl oxalate, bis (4-methylphenyl) carbonate, 4-benzylphenyl, m -T-phenyl, 1,2-bis (3-methylphenoxy) ethane, 1,2-bis (phenoxy) ethane, diphenylsulfone, 3,3 ', 4,4'-tetramethyl-diphenylethane and the like are typical. Is exemplified. These sensitizers may be used alone or in combination of two or more. The sensitizer is used in an amount of 50 to 800 parts by weight, preferably 1 to 100 parts by weight of the basic dye.
It is 00 to 400 parts by weight.

As the pigment, pigments generally used for thermosensitive recording media, for example, kaolin, silica, amorphous silica,
Fine inorganic powders such as calcined kaolin, zinc oxide, calcium carbonate, magnesium carbonate, titanium oxide, barium sulfate, and synthetic aluminum silicate; and fine organic resins such as styrene-methacrylic acid copolymer, polystyrene resin, and urea-formalin resin. You may make it coexist with a powder etc. The amount of the pigment used is 10 to 10 parts by weight of the basic dye.
It is 2,000 parts by weight, preferably 20 to 1,000 parts by weight.

Examples of the surfactant include a sulfosuccinic acid-based alkali metal salt, an alkali metal salt of alkylbenzenesulfonic acid, and a sodium salt of lauryl alcohol sulfate. Examples of the dispersant include sodium polyacrylate, polyvinyl alcohol (having various degrees of saponification, pH and polymerization degree), carboxymethylcellulose, hydroxyethylcellulose, polyacrylamide, starch, and ammonium salt of styrene-maleic anhydride copolymer. Is exemplified.

The heat-sensitive recording layer according to the present invention can be manufactured by a known method, and it is not necessary to adopt any special method. For example, a basic dye, a developer, a sensitizer, and a wax are usually mixed with a pigment, a metal soap, and the like, in an aqueous medium containing a surfactant, an antifoaming agent, a dispersant, and the like, by a ball mill, a sand mill, or the like. The coating liquid can be prepared by pulverizing and dispersing the particles to a particle size of preferably 1.5 μm or less. Next, the heat-sensitive recording layer can be formed according to a conventionally known technique, and the forming method is not particularly limited. For example, a coating solution for a heat-sensitive recording layer is coated on a support with an appropriate coating device such as an air knife coater, a blade coater, a bar coater, a rod coater, a gravure coater, a curtain coater, and a wire bar, and dried to form a recording layer. Can be formed. There is no particular limitation on the coating amount of the coating solution, and the dry weight is generally 0.5 to 50 g with respect to the support surface.
r / m ² , preferably in the range of 1.0 to 20.0 gr / m ² . As the support, paper, plastic sheet, synthetic paper and the like are used. Further, a protective layer may be provided on the heat-sensitive recording layer for the purpose of further improving the storage stability and the like.

[0030]

The present invention will be described below with reference to examples. Example 1 Preparation of Basic Dye Dispersion A solution of 20 g of 3-N, N-dibutylamino-6-methyl-7-anilinofluoran in 5% polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) ) Aqueous solution 80
gr gr sand grinder (Igarashi Kikai Co., Ltd. TS
G4H) to prepare a basic dye dispersion having an average particle size of 0.6 μm.

Preparation of sensitizer dispersion 1,2-bis (3-methylphenoxy) ethane 20 gr
With a concentration of 5% polyvinyl alcohol (PVA-117)
The mixture was pulverized in a 30 gr aqueous solution using a sand grinder to prepare a sensitizer dispersion having an average particle size of 0.6 μm.

Preparation of developer dispersion 2,4-bis (2,5-dimethylphenylsulfonyl)
20 gr of phenol was pulverized using a sand grinder in 30 gr of a 5% aqueous solution of methylcellulose (trade name: Metroose 60SH-03, manufactured by Shin-Etsu Chemical Co., Ltd.) using a sand grinder to prepare a developer dispersion having an average particle diameter of 1.1 μm.

Preparation of Pigment Dispersion Calcium Carbonate (Shiraishi Industry Co., Ltd .: UNIVER 70)
30 gr, water 69 gr and 40% strength aqueous sodium hexametaphosphate 1.0 gr were homogenized at a rotation speed of 5,000 rpm (TK homodisper L manufactured by Tokushu Kika Co., Ltd.).
(Mold) for 5 minutes to prepare a pigment dispersion.

Preparation of Lubricant Dispersion A 30% aqueous solution of montan wax (trade name: wax kp, manufactured by Hoechst Japan Co., Ltd.) was added to a 70% aqueous solution of a 5% modified polyvinyl alcohol (trade name: PVA-205, manufactured by Kuraray Co., Ltd.).
gr, and melted at 94 ° C .;
The mixture was pulverized with stirring at 000 RPM to prepare a lubricant dispersion having an average particle size of 1.0 μm.

Preparation of coating solution for thermosensitive recording layer 3 gr of the above basic dye dispersion, 3 gr of sensitizer dispersion,
Using 3 gr of a developer dispersion, 7 gr of a pigment dispersion, and 2.0 gr of the above-mentioned lubricant dispersion and 1.0 gr of hydrin P (trade name of Chukyo Yushi Co., Ltd.) having a paraffin wax emulsion concentration of 30% as a lubricant, 5% polyvinyl alcohol (PVA-117) aqueous solution 6g and water 9gr
Was mixed to obtain a thermosensitive recording layer coating solution.

Preparation of heat-sensitive recording paper The weight of the heat-sensitive recording layer after drying was 5 gr / m.
^{Then, the} coating solution for the heat-sensitive recording layer was applied using a wire bar to obtain a coating liquid of ² and dried in an oven at 60 ° C.
The calender processing was performed so that the time became 0 seconds (Beck method).

Example 2 In the preparation of the developer dispersion liquid of Example 1, instead of 2,4-bis (2,5-dimethylphenylsulfonyl) phenol 20gr, {2,4-
The same operation as in Example 1 was carried out except that 20 g of 2,4-bis (phenylsulfonyl) phenol containing 1.2% of bis (phenylsulfonyl) phenyl @ benzenesulfonate was used.

Example 3 In the preparation of the developer dispersion liquid of Example 1, instead of 20 gr of 2,4-bis (2,5-dimethylphenylsulfonyl) phenol, {2,4-
2,4-containing 5.0% bis (phenylsulfonyl) phenyl} -2,4-dimethylbenzenesulfonate
20 g of bis (2,5-dimethylphenylsulfonyl) phenol and 30 g of carnauba wax 1 (trade name of Toyo Petrolite Co.) instead of 30 g of montan wax (Hoechst wax kp) in the preparation of the lubricant dispersion Example 1 except that 3.0 g of the present carnauba wax dispersion was used in place of 2.0 g of the above-mentioned lubricant dispersion and 1.0 gr of 30% hydrin P as a lubricant in the preparation of the coating solution for the thermosensitive recording layer. The same operation was performed.

Example 4 In the preparation of the developer dispersion of Example 1, 2,4-bis (2,5-dimethylphenylsulfonyl) phenol was replaced with 2,4-bis (phenylsulfonyl) phenol 20 g. -5-methylphenol 20
Gr, and further, as a lubricant in the preparation of the heat-sensitive recording layer coating solution, as the lubricant, 2.0 g of the lubricant dispersion of Example 1 and 30% hydrin P; 0.5 g of the lubricant dispersion of Example 1 instead of 1.0 gr. The same operation was performed as in Example 1 except that 2.5 gr of hydrin P was used.

Example 5 In the preparation of the lubricant dispersion of Example 1, a polyethylene oxide wax (Hoechst wax-PED) 30 was used instead of the montan wax 30 gr.
The emulsification temperature was further increased from 94 ° C. to 130 ° C.
In place of 2.0 g of the lubricant dispersion of Example 1 and 1.0 gr of 30% hydrin P in the preparation of the coating solution for the heat-sensitive recording layer, the present polyethylene oxide dispersion was prepared in place of 2.0 g of the lubricant dispersion. The same operation as in Example 1 was performed except that 0 gr and 1.0 gr of 30% hydrin P were used.

[Comparative Example 1] Hydrin Z-having a zinc stearate emulsion concentration of 30% was used in place of the lubricant (2.0 g of a 30% montan wax dispersion) used in the preparation of the heat-sensitive recording layer coating solution of Example 2. 7 (product name of Chukyo Yushi Co., Ltd.) except that 2.0 gr was used.

Comparative Example 2 In the preparation of the developer dispersion of Comparative Example 1, 20 gr of 2,2-bis (4-hydroxyphenyl) propane was used instead of 20 gr of 2,4-bis (phenylsulfonyl) phenol. Comparative Example 1 except for using
The same operation was performed.

[Comparative Example 3] In the preparation of the coating solution for the heat-sensitive recording layer of Comparative Example 2, hydrin Z-7 having a concentration of 30%;
The same operation as in Comparative Example 2 was performed except that 2.0 gr of the 30% montan wax dispersion used in Example 1 was used instead of 0 gr.

Next, the heat-sensitive recording papers obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were used for the FUJITU fax FF1700.
A print test was performed under the copy mode conditions of the RX type machine, and the following performance comparison test was performed. Table 1 shows the results.

Performance comparison test Print density Measured using a Macbeth densitometer.

Heat Resistance Test Skin: Skin fogging after standing at 60 ° C. for 72 hours was visually observed according to the following criteria.

：: No change Δ: Slightly colored X: Colored Printing: After the printing paper was left at 60 ° C. for 24 hours, the remaining percentage of printing density (%) indicated by the following criteria was measured.

Print density residual rate (%) = (print density after storage / print density before storage) × 100

Moisture Resistance Test Background: The background fog after standing at 50 ° C. and 90% humidity for 24 hours was expressed in accordance with the standard of the heat resistance background fog test.

Printing: 24 hours at 40 ° C. and 90% humidity
After standing for a period of time, the print density residual ratio was expressed according to the heat-resistant print density residual ratio (%).

Plasticizer test A printing paper was wrapped around the outer periphery of a glass bottle, and a high wrap V-450 (trade name, manufactured by Mitsui Toatsu Chemicals Co., Ltd.) was wrapped three times thereon and left at 40 ° C. for 2 hours. And the print density residual ratio was expressed according to the heat-resistant print density residual ratio (%).

[0052]

[Table 1] As described above, the thermosensitive recording medium according to the present invention is excellent in color developability, has less background fogging over time, and is excellent in storage stability of recorded images, particularly, heat resistance, moisture resistance and plasticizer resistance. .

[0053]

According to the present invention, there is provided a heat-sensitive recording material having high sensitivity, less background fogging over time, and excellent in storage stability of a recorded image, particularly, heat resistance, moisture resistance and plasticizer resistance.

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[Procedure amendment]

[Submission date] February 26, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

Preparation of Lubricant Dispersion Solution A 30% aqueous solution of montan wax (manufactured by Hoechst Japan, Inc., product name: Wax KP ) is a 70% aqueous solution of 5% modified polyvinyl alcohol (manufactured by Kuraray, Inc., product name: PVA-205).
gr, and melted at 94 ° C .;
The mixture was pulverized with stirring at 000 RPM to prepare a lubricant dispersion having an average particle size of 1.0 μm.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction contents]

Preparation of coating solution for thermosensitive recording layer 3 gr of the above basic dye dispersion, 3 gr of sensitizer dispersion,
As the lubricant, 3 gr of the developer dispersion, 7 gr of the pigment dispersion, and 2.0 gr of the above-mentioned lubricant dispersion and 1.0 gr of hydrin P- 7 (trade name of Chukyo Yushi Co., Ltd.) having a paraffin wax emulsion concentration of 30% are used as lubricants. Then, 6 g of a 5% aqueous solution of polyvinyl alcohol (PVA-117) and 9 g of water
Gr was mixed to obtain a coating solution for the heat-sensitive recording layer.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0038

[Correction method] Change

[Correction contents]

Example 3 In the preparation of the developer dispersion liquid of Example 1, instead of 20 gr of 2,4-bis (2,5-dimethylphenylsulfonyl) phenol, {2,4-
2,4-containing 5.0% bis (phenylsulfonyl) phenyl} -2,4-dimethylbenzenesulfonate
20 g of bis (2,5-dimethylphenylsulfonyl) phenol and 30 g of carnauba wax 1 (trade name of Toyo Petrolite Co.) instead of 30 g of montan wax (Hoechst wax kp) in the preparation of the lubricant dispersion And the use of 3.0 g of the present carnauba wax dispersion in place of 2.0 g of the above-mentioned lubricant dispersion and 30% concentration of hydrin P- 7; 1.0 g as a lubricant in the preparation of the coating solution for the heat-sensitive recording layer. Is Example 1
The same operation was performed.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction contents]

Example 4 In the preparation of the developer dispersion of Example 1, 2,4-bis (2,5-dimethylphenylsulfonyl) phenol was replaced with 2,4-bis (phenylsulfonyl) phenol 20 g. -5-methylphenol 20
Further, 2.0 g of the lubricant dispersion of Example 1 and 30% hydrin P- 7 having a concentration of 30% were used as lubricants in preparing the coating solution for the heat-sensitive recording layer. The same operation as in Example 1 was performed except that 5 gr and hydrin P- 7 ; 2.5 gr were used.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

Example 5 In the preparation of the lubricant dispersion of Example 1, a polyethylene oxide wax (Hoechst wax-PED) 30 was used instead of the montan wax 30 gr.
The emulsification temperature was further increased from 94 ° C. to 130 ° C.
In place of 2.0 gr of the lubricant dispersion of Example 1 and a concentration of 30% hydrin P- 7 , the present polyethylene oxide wax was used in the preparation of the coating solution for the heat-sensitive recording layer. The same operation as in Example 1 was carried out except that 2.0 gr of the dispersion and 30% concentration of hydrin P- 7; 1.0 gr were used.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0041

[Correction method] Change

[Correction contents]

[0041] [Comparative Example 1] Instead of the lubricant (concentration 30% montan wax dispersion 2.0Gr) used in the preparation of the heat-sensitive recording layer coating solution in Example 2, zinc dispersion concentration of 30% stearic acid HYDRIN Z except for using -7 -30 (Chukyo Yushi Co., Ltd. product name) 2.0Gr was operated in the same manner as in example 2.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0043

[Correction method] Change

[Correction contents]

[0043] [Comparative Example 3] In the preparation of the heat-sensitive recording layer coating solution of Comparative Example 2, 30% strength HYDRIN Z-7 -3
0 ; concentration of 30% used in Example 1 instead of 2.0 gr
The same operation as in Comparative Example 2 was carried out except that 2.0 g of montan wax dispersion was used.

Claims (3)

[Claims] In a heat-sensitive recording material utilizing a thermal coloring reaction between an electron-donating basic dye precursor and an electron-accepting color developing agent, a general formula (1) is used as a color developing agent in a heat-sensitive recording layer. ] [In the general formula (1), X represents a hydrogen atom or a lower alkyl group, and R ₁ , R ₂ and R ₃ may be the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, or a lower alkyl group. Or a cycloalkyl group;
₄ , R ₅ and R ₆ may be the same or different and each represent a hydrogen atom, a halogen atom, a lower alkyl group or a cycloalkyl group, and R ₇ represents a hydrogen atom or Wherein R ₄ , R ₅ and R ₆ are as defined above. A heat-sensitive recording material characterized by containing one or more selected from the group consisting of the sulfonyl compound represented by the formula (1) and a polyvalent metal salt thereof, and further comprising a wax. 2. The heat-sensitive recording layer further comprises a hydration inhibitor represented by the general formula (2): [In the general formula (2), X, R ₁ , R ₂ , R ₃ , R
₄ , R ₅ and R ₆ have the same meaning as in the general formula (1) according to claim 1, Y is an alkyl group, an aralkyl group,
Represents an allyl group, a cyclohexyl group, an alkylaryl group, an alkylsulfonyl group, a benzenesulfonyl group, an alkylbenzenesulfonyl group, an alkyloyl group, a benzoyl group, an alkylbenzoyl group, an acryloyl group, a methacryloyl group, or a glycidyl group. The heat-sensitive recording material according to claim 1, which contains a sulfonyl compound represented by the formula: 3. The wax is one or two selected from the group consisting of candelilla wax, rice wax, carnauba wax, montan wax, ceresin wax, paraffin wax, Fischer-Tropsch wax, montan wax derivatives and polyethylene wax derivatives. The heat-sensitive recording material according to claim 1, which is at least one kind.