JPH1158954A - Heat sensitive multiple duplicating sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sensitive multiple duplicating sheet excellent in water resistant retention properties of recorded images. SOLUTION: In a heat sensitive multiple duplicating sheet at least having an upper sheet base material sheet, on one side of which a heat sensitive recording layer including a leuco dye and a coloring agent and on the other side of which a heat transfer layer including the leuco dye and a heat fusible organic compound, and a lower sheet base material sheet, on one side of which a coloring agent-containing beat transfer accepting layer, in at least either one layer between the heat sensitive recording layer and the heat transfer accepting layer, a compound representing by the formula such as a 2,2-bis[3,5-bis(hydroxy-5- methyl benzyl-4-hydroxy phenyl] propane or the like is included. In the formula, R represents a hydrogen atom or 1-8C alkyl group.

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-forming reaction between a leuco dye and a color former, and more particularly to a heat-sensitive multi-copy sheet capable of simultaneously performing heat-sensitive recording on two or more sheets. It is.

[0002]

2. Description of the Related Art Thermosensitive recording media utilizing a color-forming reaction between a leuco dye and a color former are well known. Such a thermosensitive recording medium is relatively inexpensive, has a compact recording device, and is easy to maintain. Therefore, it is used not only as a recording medium for facsimile machines and various computing devices but also in a wide range of fields. In particular, since the thermal recording medium is used as a receipt, there is an increasing demand for a thermal recording medium capable of recording on a number of sheets with a single thermal recording.

As a means for recording a plurality of sheets in one thermal recording, a thermal recording medium having a thermal recording layer formed on one surface of a support is subjected to thermal recording in a state where a plurality of thermal recording media are stacked. It is conceivable, however, that clear thermal recording images cannot be formed on a plurality of sheets by the thermal head.

Therefore, in order to obtain a clear thermal recording image on multiple sheets, a thermal recording layer containing a leuco dye and a coloring agent is provided on one surface of the upper leaf base sheet, and the leuco dye is provided on the other surface. An upper leaf recording sheet provided with a thermal transfer layer containing a heat-fusible organic compound, and a lower leaf recording sheet provided with a thermal transfer receiving layer containing a colorant and an adhesive on one surface of a lower leaf base sheet. Having a heat-sensitive multi-copy sheet is disclosed in
96895 and JP-A-57-96896. However, in order to use such a heat-sensitive multiplex copy sheet as a receipt, it is necessary to use a sheet that has little discoloration of a recorded image when immersed in water, that is, has high water-resistant storage characteristics.

Further, in a general thermosensitive recording medium having a thermosensitive recording layer containing a leuco dye and a color former on a support,
For the purpose of improving the storability of recorded images, heat-sensitive recording media containing a phenolic compound as a storability improving agent in the heat-sensitive recording layer are disclosed in JP-A-49-45747 and JP-A-49-54040. JP-A-58-57990, JP-A-58-87089, and the like, further improvement in water-resistant storage stability is demanded.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat-sensitive multiplex copy sheet which is excellent in the water resistance of a recorded image.

[0007]

Means for Solving the Problems At least a heat-sensitive recording layer containing a leuco dye and a coloring agent is provided on one surface of an upper leaf base material sheet, and a leuco dye and a heat-fusible organic compound are contained on the other surface. In order to solve the above-mentioned problem, in a heat-sensitive multiplex copying sheet having an upper leaf recording sheet provided with a thermal transfer layer and a lower leaf recording sheet provided with a thermal transfer receiving layer containing a colorant on one surface of a lower leaf base sheet. In one aspect of the present invention, at least one of the thermal recording layer and the thermal transfer receiving layer contains a compound represented by the following general formula (1).

[0008]

Embedded image [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. ]

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a heat sensitive recording layer containing a leuco dye and a color former on at least one surface of an upper leaf base sheet, and a leuco dye and a heat-fusible organic compound on the other surface. A heat-sensitive recording layer or a thermal transfer sheet in a heat-sensitive multiplex copying sheet having an upper leaf recording sheet provided with a thermal transfer layer containing the same and a lower leaf recording sheet provided with a thermal transfer receiving layer containing a colorant on one surface of a lower leaf base sheet. It is characterized in that the specific compound represented by the general formula (1) is contained in at least one of the receiving layers, and its content is not particularly limited.
It is preferably about 30% by weight, more preferably about 5 to 20% by weight.

The thermal multiplex copying sheet of the present invention is used in a state where the thermal transfer layer of the upper recording sheet and the thermal transfer receiving layer of the lower recording sheet are set in contact with each other. Further, between the upper leaf recording sheet and the lower leaf recording sheet, a heat transfer layer containing a colorant and an adhesive is provided on one surface of the middle leaf base sheet, and on the other surface of the base sheet, This includes a state in which at least one or more middle leaf recording sheets provided with a thermal transfer layer containing a leuco dye and a heat-fusible organic compound are set.

Specific examples of the specific compound contained in at least one of the heat-sensitive recording layer or the heat transfer receiving layer include:
For example, the following are mentioned. 2,2-bis [3,5
-Di (2-hydroxybenzyl) -4-hydroxyphenyl] propane, 2,2-bis [3,5-di (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] propane, 2,2-bis [3,5-di (2-hydroxy-5-ethylbenzyl) -4-hydroxyphenyl] propane, 2,2-bis [3,5-di (2-hydroxy-5-n-propylbenzyl) -4- Hydroxyphenyl] propane, 2,2-bis [3,5-di (2-hydroxy-5-isopropylbenzyl) -4-hydroxyphenyl] propane, 2,2-bis [3,5-di (2
-Hydroxy-5-n-butylbenzyl) -4-hydroxyphenyl] propane, 2,2-bis [3,5-di (2-hydroxy-5-tert-butylbenzyl) -4-
Hydroxyphenyl] propane, 2,2-bis [3,5
-Di (2-hydroxy-5-sec-butylbenzyl)
-4-hydroxyphenyl] propane, 2,2-bis [3,5-di (2-hydroxy-5-n-pentylbenzyl) -4-hydroxyphenyl] propane, 2,2-
Bis [3,5-di (2-hydroxy-5-isopentylbenzyl) -4-hydroxyphenyl] propane, 2,
2-bis [3,5-di (2-hydroxy-5-n-hexylbenzyl) -4-hydroxyphenyl] propane,
2,2-bis [3,5-di (2-hydroxy-5-n-
Heptylbenzyl) -4-hydroxyphenyl] propane, 2,2-bis [3,5-di (2-hydroxy-5-
n-octylbenzyl) -4-hydroxyphenyl] propane, 2,2-bis {3,5-di [2-hydroxy-
5- (2'-ethylhexyl) benzyl] 4-hydroxyphenyl} propane

Among them, 2,2-bis [3,5-di (2
-Hydroxy-5-methylbenzyl) -4-hydroxyphenyl] propane is preferred. Such specific compounds can of course be used in combination of two or more.

Examples of the leuco dye contained in the heat-sensitive recording layer and the heat transfer layer include the following compounds.
3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, 3- (4-diethylamino-2)
-Methylphenyl) -3- (4-dimethylaminophenyl) -6-dimethylaminophthalide, 3-diethylamino-7-dibenzylaminofluoran, 3-cyclohexylamino-6-chlorofluoran, 3-diethylamino-6 -Methyl-7-chlorofluorane, 3-diethylamino-7-chlorofluoran, 3-diethylamino-
7-anilinofluoran, 3- (N-ethyl-N-isoamyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-7- (m-trifluoromethylanilino) fluoran, 3- (N-methyl-N-cyclohexyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-6-methyl-7-anilinofluoran, 3-di (n-butyl) amino-6-methyl -7-anilinofluoran, 3-di (n-pentyl) amino-6-methyl-7-anilinofluoran, 3-diethylamino-7- (o-chloroanilino) fluoran,
3-di (n-butyl) amino-7- (o-chloroanilino) fluoran, 3-di (n-butyl) amino-7-
(O-fluoroanilino) fluoran, 3- (N-ethyl-p-toluidino) -6-methyl-7-anilinofluoran, 3-diethylamino-6-chloro-7-anilinofluoran, 3-pepyridino -6-methyl-7-anilinofluoran, 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, 3,6, -bis (dimethylamino) fluorene-9-spiro-3'-
(6′-dimethylamino) phthalide, 3- (N-ethyl-N-2-tetrahydrofurfuramino) -6-methyl-7-anilinofluoran, 3- (4-dimethylamino) anilino-5,7- Dimethylfluoran, etc.

Of course, it is not limited to these,
If necessary, two or more kinds can be used in combination. The amount of the leuco dye used is about 5 to 35% by weight based on the total solids of the heat-sensitive recording layer in the heat-sensitive recording layer, and 3 to 50% by weight based on the total solids of the heat-transfer layer in the thermal transfer layer.
% By weight.

Examples of colorants contained in the heat-sensitive recording layer and the heat transfer receiving layer include the following compounds.
Acid clay, activated clay, attapulgite, zeolite,
Acid clays such as bentonite, 4,4'-isopropylidene diphenol, bis (2-tert-butylphenol) 4,4'-sec-butylidene diphenol, 4-phenylphenol, 2,2-bis (4- (Hydroxyphenyl) -4-methylpentane, 4,4′-cyclohexylidenediphenol, 2,4′-dihydroxyphenylsulfone 4,4′-dihydroxydiphenylsulfone,
4-hydroxy-4'-isopropoxydiphenylsulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, 4-hydroxy-4'-methyldiphenylsulfone, 4-hydroxy-4'-benzyloxydiphenylsulfone, 3, 4-dihydroxyphenyl-4′methylphenylsulfone, hydroquinone monobenzyl ether, 4-hydroxybenzophenone, 1,1-bis (4
-Hydroxyphenyl) -1-phenylethane, 1,4
-[(4-hydroxyphenyl) isopropylidene] benzene, benzyl 4-hydroxybenzoate, p-methoxybenzyl 4-hydroxybenzoate, phenolic compounds such as novolak-type phenolic resins, phenolic polymers, and the like, zinc 3-isopropylsalicylate , 3-tert-butylsalicylic acid, zinc 3-benzylsalicylate, 3- (α
-Methylbenzyl) zinc salicylate, 3-chloro-5-
(Α-methylbenzyl) zinc salicylate, 3,5-di-
Zinc tert-butylsalicylate, zinc 3,5-di (α-methylbenzyl) salicylate, 3-phenyl-5- (α,
α-dimethylbenzyl) zinc salicylate, 3,5-di-
Zinc tert-octylsalicylate, zinc 3,5 di-tert-nonylsalicylate, zinc 3,5-di-tert-dodecylsalicylate, zinc 5-tert-dodecylsalicylate, zinc 5-cyclohexylsalicylate, 4- [2- (p -Methoxyphenoxy) ethyloxy] zinc salicylate, 4-
Zinc [3- (p-tolylsulfonylpropyloxy) salicylate, 5- [p- (2-p-methoxyphenoxyethoxy) cumyl] zinc salicylate, mono [poly (0
4) [ω-hydro [poly (1-7) α-methylbenz]
-Α-yl] benzyl] zinc salt of a salicylic acid derivative such as zinc salicylate, Np-tolylsulfonyl N'-phenylurea, 4,4'-bis (p-tolylsulfonylaminocarbonylamino) diphenylmethane Among the compounds having a sulfoamide bond, a zinc salt of a salicylic acid derivative is preferable as the coloring agent for the thermal transfer receiving layer.

Of course, it is not limited to these,
If necessary, two or more kinds can be used in combination. The amount of the coloring agent used is about 10 to 70% by weight based on the total solids of the heat-sensitive recording layer in the heat-sensitive recording layer, and 1 to 70% by weight based on the total solids in the heat-transfer receiving layer.
It is about 0 to 60% by weight.

The heat fusible organic compound contained in the thermal transfer layer is not particularly limited as long as it is an organic compound having a melting point of about 35 to 150 ° C., for example, carnauba wax, montan wax, paraffin wax, microcrystalline wax, Polyethylene wax, palmitic acid, stearic acid, behenic acid, stearic acid amide, ethylenebisstearic acid amide, methyl stearate,
Higher aliphatic compounds such as stearic acid anilide are preferred because of their excellent pressure-sensitive recording properties. The amount of the heat-fusible organic compound used is about 30 to 90% by weight based on the total solid content of the thermal transfer layer. Preferably, it is about 40 to 80% by weight.

If necessary, pigments such as kaolin, calcium carbonate, amorphous silica, titanium oxide, aluminum hydroxide, calcined kaolin, zinc oxide, stearic acid amide, ethylenebisstearic acid amide, etc. m-terphenyl, di-p-methylbenzyl oxalate, di-p-chlorobenzyl oxalate, dibenzyl terephthalate, phenyl 1-hydroxynaphthoate, 1,2-di (3-methylphenoxy) Ethane, 1,2-diphenoxyethane,
Sensitizers such as 1-phenoxy-2-naphthoxyethane and p-benzylbiphenyl, 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3-tris (2 -Methyl-4-hydroxy-5-tert-butylphenyl) butane, N, N'-di-2-naphthyl-p-phenylenediamine, 2,2'-
Preservative improvers such as sodium methylenebis (4,6-di-tertbutylphenyl) phosphate, waxes such as carnauba wax, montan wax, paraffin wax, microcrystalline wax, polyethylene wax, and lubricants such as zinc stearate and calcium stearate. And a fluorescent dye, a coloring dye, a surfactant, a waterproofing agent, and the like.

The heat-sensitive recording layer is generally composed of water as a medium, a leuco dye finely dispersed to an average particle diameter of about 0.1 to 3 μm, a color former and a specific compound, an adhesive, and, if necessary, a sensitizer. The coating amount for the heat-sensitive recording layer obtained by mixing and stirring is dried on one surface of the upper leaf base sheet, and the coated amount is 2 to 7 g.
/ M ² by coating and drying.

Examples of the adhesive contained in the coating solution for the heat-sensitive recording layer include emulsion-polymerized acrylic resins, urethane resins, styrene-butadiene resins, vinyl acetate resins, vinylidene chloride resins, and vinyl acetate. Hydrophobic resins such as vinyl chloride resins, or completely (partially) saponified polyvinyl alcohol, carboxy-modified polyvinyl alcohol, acetoacetyl-modified polyvinyl alcohol, silicon-modified polyvinyl alcohol, styrene-maleic acid copolymer salts, ethylene-acryl Water-soluble resins such as salts of acid copolymers and salts of isobutylene-maleic acid copolymers are exemplified. The content of the adhesive is about 5 to 35% by weight based on the total solid content of the heat-sensitive recording layer.

The thermal transfer receiving layer is obtained by mixing and stirring a colorant and an adhesive which are finely dispersed to have an average particle diameter of about 0.1 to 3 μm using water or an organic solvent as a medium. The coating liquid for application is formed on one surface of the lower leaf base sheet or the middle leaf base sheet by applying and drying such that the applied amount after drying is about 1 to 7 g / m ² . As the adhesive contained in the thermal transfer receiving layer, for example, the above-mentioned adhesive which can be used for the heat-sensitive recording layer can be used. Further, an auxiliary agent that can be added to the heat-sensitive recording layer may be added to the thermal transfer receiving layer.

Examples of the method of applying the coating liquid for the heat-sensitive recording layer and the coating liquid for the thermal transfer receiving layer include an air knife method, a Meyer bar method, a pure blade method, a rod blade method, a reverse roll method, a gravure method, a slit die method and the like. Is mentioned.

The thermal transfer layer is generally formed by applying a thermal transfer coating solution obtained by adding a leuco dye to a heat-soluble heat-soluble organic compound on the other surface of the upper leaf or middle leaf base sheet at 1 to 8 g / m ^2.
For example, it is formed by applying by a hot melt method so as to have a degree.

The upper leaf base sheet and the middle leaf base sheet
For example, a basis weight of 20 to 45 g / m ^TwoHigh quality paper,
Lance paper and the like. Also, as a base sheet for the lower leaves
For example, a basis weight of 40 to 100 g / m^TwoQuality fine paper,
Films, non-woven fabrics and the like can be mentioned.

[0025]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should be understood that the present invention is by no means restricted thereto. Unless otherwise specified, parts and% in the examples are parts by weight and% by weight, respectively.

Example 1 (1) Preparation of Solution A 10 parts of 3-di (n-butyl) amino-6-methyl-7-anilinofluoran, sulfone-modified polyvinyl alcohol (trade name: Goselan L-3266, Nippon Gosei) A composition consisting of 5 parts of a 10% aqueous solution of water and 25 parts of water (manufactured by Chemical Industry Co., Ltd.) was pulverized with a sand mill until the average particle diameter became 0.8 μm to obtain a liquid A.

(2) Preparation of Solution B 10 parts of 4-hydroxy-4'-isopropoxydiphenylsulfone, sulfone-modified polyvinyl alcohol (trade name: Goselan L-3266, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
A composition comprising 5 parts of a 10% aqueous solution of water and 25 parts of water was pulverized with a sand mill until the average particle diameter became 1.5 μm to obtain a liquid B.

(3) Preparation of Solution C 10 parts of 1,2-di (3-methylphenoxy) ethane, 5 parts of a 10% aqueous solution of sulfone-modified polyvinyl alcohol (trade name: Goselan L-3266, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) And a composition comprising water and 25 parts of water were pulverized with a sand mill until the average particle diameter became 1.0 μm to obtain a liquid C.

(4) Preparation of Solution D 10 parts of 2,2-bis [3,5-di (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] propane (melting point: 233 ° C.), 10 parts of sulfone-modified polyvinyl alcohol Liquid D was obtained by pulverizing a composition comprising 5 parts of a 10% aqueous solution and 25 parts of water (trade name: Goceran L-3266, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) with a sand mill until the average particle diameter became 1.0 μm. Was.

(5) Preparation of coating solution for heat-sensitive recording layer 40 parts of liquid A, 80 parts of liquid B, 40 parts of liquid C, 20 parts of liquid D, amorphous silica (trade name: Mizuka Seal P-527, Mizusawa Chemical Industries, Ltd.) 15 parts by weight, light calcium carbonate 10 parts,
Completely saponified polyvinyl alcohol (trade name: PVA-1)
05, manufactured by Kuraray Co., Ltd.), 100 parts of a 10% aqueous solution, 2 parts of a 20% aqueous glyoxal solution and 30 parts of water were mixed and stirred to obtain a coating solution for a heat-sensitive recording layer.

(6) Preparation of Coating Solution for Thermal Transfer Layer Ten parts of 3-piperidino-6-methyl-7-anilinofluoran, 30 parts of carnauba wax and 15 parts of stearamide were melted at 120 to 130 ° C. and thermally transferred. Layer obtained.

(7) Preparation of coating liquid for thermal transfer receiving layer 20 parts of solution D, 65 parts of aluminum hydroxide, 20 parts of zinc oxide
Part, 30% of a mixed melt of zinc 3,5-di (α-methylbenzyl) salicylate and α-methylstyrene / styrene copolymer (mixed melt weight ratio = 80/20, average particle diameter 2.3 μm) 50 parts of an aqueous dispersion, 50 parts by weight of a 10% aqueous solution of a carboxy-modified polyvinyl alcohol, 10 parts of a 20% aqueous solution of a polyamide epichromidone resin as a waterproofing agent, styrene-butadiene resin latex (solid concentration: 50%)
40 parts by weight, 20% aqueous solution of sodium polyacrylate 5
Parts and 100 parts of water were mixed and stirred to obtain a coating liquid for a thermal transfer receiving layer.

(8) Preparation of Upper Leaf Recording Sheet The coating solution for the heat-sensitive recording layer was dried on one surface (front side) of 35 g / m ² basis weight, 35 μm thick glassine paper (upper leaf base sheet). After coating and drying so that the coating amount is 4.0 g / m ² , a super calender treatment is performed to provide a heat-sensitive recording layer, and a coating for a heat transfer layer at a temperature of 70 to 80 ° C. is applied to the other surface (back surface side). After applying 3.2 g / m ² , cooling was performed to form a thermal transfer layer to obtain an upper leaf recording sheet.

(9) Preparation of Middle-Leaf Recording Sheet On one surface (front side) of glassine paper (middle-leaf base sheet) having a basis weight of 35 g / m ² and a tension of 1.05, a coating solution for a heat transfer receiving layer was dried. After coating and drying so that the subsequent coating amount is 5.4 g / m ² , a super calender treatment is performed to provide a thermal transfer receiving layer, and the other side (back side) is coated with a thermal transfer layer at 70 to 80 ° C. After applying 3.2 g / m ^{2 of the} solution, the solution was cooled to form a thermal transfer layer to obtain a midleaf recording sheet.

(10) Preparation of lower leaf recording sheet A coating liquid for a heat transfer receiving layer is applied to one surface (front side) of neutral high-quality paper (lower leaf base sheet) having a basis weight of 64 g / m ² after drying. After coating and drying so as to have an amount of 5.4 g / m ² to form a thermal transfer receiver, a super calender treatment was performed to obtain a lower leaf recording sheet.

(11) Preparation of Thermal Multiplexed Copy Sheet The back side of the upper leaf recording sheet and the front side of the middle leaf recording sheet cut to A4 size, and the back side of the middle leaf recording sheet and the front side of the lower leaf sheet are in contact with each other. To form a thermosensitive multiple copy sheet.

Example 2 In the preparation of solution D in Example 1, 2,2-bis [3,5-
Except that 2,2-bis [3,5-di (2-hydroxybenzyl) -4-hydroxyphenyl] propane was used instead of di (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] propane. In the same manner as in Example 1, a thermosensitive multiple copy sheet was obtained.

Example 3 In the preparation of solution D in Example 1, 2,2-bis [3,5-
2,2-bis [3,5-di (2-hydroxy-5-tert-butylbenzyl) -4-hydroxyphenyl] instead of di (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] propane A heat-sensitive multiple copy sheet was obtained in the same manner as in Example 1 except that propane was used.

Comparative Example 1 In the preparation of the coating solution for the heat-sensitive recording layer and the coating solution for the thermal transfer receiving layer in Example 1, a heat-sensitive multiple copy sheet was obtained in the same manner as in Example 1, except that the solution D was not added. Was.

Comparative Example 2 In the preparation of solution D in Example 1, 2,2-bis [3,5-
Except that 4,4′-thiobis (6-tert-butyl-m-cresol) was used in place of di (2-hydroxy-5-methylbenzyl) 4-hydroxyphenyl] propane, A thermosensitive recording medium was obtained.

Comparative Example 3 In the preparation of solution D in Example 1, 2,2-bis [3,5-
Di (2-hydroxy-5-methylbenzyl) 4-hydroxyphenyl] propane was replaced by 2,2′-methylenebis (4-methyl-6-tert-butylphenol) in the same manner as in Example 1. A thermosensitive recording medium was obtained.

Comparative Example 4 In the preparation of solution D in Example 1, 2,2-bis [3,5-
Di (2-hydroxy-5-methylbenzyl) 4-hydroxyphenyl] propane was replaced by 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, A thermosensitive recording medium was obtained in the same manner as in Example 1.

Comparative Example 5 In the preparation of solution D in Example 1, 2,2-bis [3,5-
Example 1 except that 1,1,3-tris (2-methyl-4-hydroxy-5-cyclohexylphenyl) butane was used in place of di (2-hydroxy-5-methylbenzyl) 4-hydroxyphenyl] propane. In the same manner as in Example 1, a thermosensitive recording medium was obtained.

The following evaluation test was carried out on the thus obtained heat-sensitive multiplex copy sheet, and the obtained results are shown in Table 1.

[Coloring property] Thermal evaluation machine [Product name: TH-P]
MD, manufactured by Okura Electric Co., Ltd.]
The recording was performed at mJ / dot, and the unrecorded portion and the recorded portion in the heat-sensitive recording layer of the upper leaf recording sheet, and the recorded portion in the thermal transfer receiving layer of the middle leaf recording sheet were measured by a Macbeth densitometer [trade name: 9].
24, Macbeth Co.] visual mode.

[Water-resistant storage stability] Thermal evaluation machine [Product name: TH
-PMD, manufactured by Okura Electric Co., Ltd.
Recording was performed at 45 mJ / dot, and the recording was immersed in tap water for 24 hours, and the unrecorded portion and the recorded portion after drying were measured in a visual mode using a Macbeth densitometer (trade name: Model 924, manufactured by Macbeth).

[0047]

[Table 1]

[0048]

As shown in Table 1, the heat-sensitive multiplex copy sheet of the present invention has excellent effects on the water-resistant storage stability and heat-sensitive recording property of the recording portion.

Claims (2)

[Claims] 1. A heat-sensitive recording layer containing a leuco dye and a colorant is provided on at least one surface of an upper leaf base sheet, and a thermal transfer layer containing a leuco dye and a heat-fusible organic compound is provided on the other surface. The upper lobe recording sheet and the lower lobe base sheet, a thermal multiplex copying sheet having a lower lobe recording sheet provided with a thermal transfer receiving layer containing a colorant on one surface thereof, wherein at least one of the thermosensitive recording layer or the thermal transfer receiving layer is provided. And a compound represented by the following general formula (1). Embedded image [In the formula, R represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. ] 2. The compound represented by the general formula (1) is 2,2
2. The heat-sensitive multiplex copying sheet according to claim 1, wherein the sheet is -bis [3,5-di (2-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] propane.