JPH0470381A - Thermal recording medium - Google Patents

Abstract

PURPOSE:To eliminate the color fading phenomenon fo a recorded image and minimize a fog in a blank part, if a thermal recording medium is exposed to high temperature or high humidity condition by using a specific dye as a chloric dye selectively and using a specific compound concurrently. CONSTITUTION:3-di(n-butyl) amino-6-mehtyl-7-phenylaminofuruoran and/or 3-di(n- benthyl) amino-6-methyl-7-phenylaminofuruoran are added to a recording layer as a chloric dye. In addition, at least, one kind of compound expressed by formulae I or II is added. In the formulae 1,2, R is a C1-20 alkyl group, a halo gen atom, a C1-6 alkyl group and a C5-10 cycloalkyl group which can be substituted with a C1-6 alkoxy group; X,Y are a hydrogen atom, a C1-20 alkyl group and a C6-10 cycloalkyl group respectively; A is directly bonded C1-20 alkylene group, -O-, -S-, -SO2-, -O-Z-O-, -S-Z-S-, or -SO2 -Z-SO2. However, Z is a C1-20 alkylene group.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a heat-sensitive recording material, and particularly to a heat-sensitive recording material that has excellent storage stability of recorded images and can maintain high whiteness.

``Prior Art'' Conventionally, heat-sensitive recording materials utilize a coloring reaction between a colorless or light-colored basic dye and an organic or inorganic coloring agent to obtain a recorded image by bringing both coloring substances into contact with each other using heat. well known.

However, such heat-sensitive recording materials generally have the disadvantage that the storage stability of the recorded images is not sufficient and the colors tend to fade over time. In particular, since the recorded image disappears in a relatively short time under high temperature conditions or under high temperature conditions, there is a strong demand for improvement.

``Problems to be Solved by the Invention'' In order to improve the storage stability of recorded images, heat-sensitive recording materials to which various storage improvers are added have been proposed, but the improvement causes a decrease in whiteness. At present, it is not always possible to obtain satisfactory effects because of new drawbacks such as these.

In view of the current situation, the present inventors have extensively studied not only the field of storage improvers to be added to the recording layer, but also the field of color-forming substances to be used in combination.

As a result, 3-di(n-butyl)amino-6-methyl-7-phenylaminofluorane and/or
or 3-di(n-pentyl)amino-6-methyl-7-
By selectively using phenylaminofluorane and also using a compound represented by the following general formula (II or (If)), excellent storage stability of recorded images was achieved without a decrease in whiteness. It was discovered that a heat-sensitive recording material can be obtained, and the present invention was completed.

"Means for Solving the Problems" The present invention provides a heat-sensitive recording material having a recording layer on a support that contains a colorless or light-colored basic dye and a coloring agent that can change color when it comes into contact with the dye. , 3-di(n-butyl)amino-6-methyl-7~ as a basic dye in the recording layer.
contains phenylaminofluorane and/or 3-di(n-pentyl)amino-6-methyl-7-phenylaminofluorane, and has the following general formula CI) or (III
This is a heat-sensitive recording material characterized by containing at least one of the compounds represented by:

[In the formula, R is an alkyl group of 01 to 2°; a halogen atom,
cs+l, which may be substituted with an alkyl group in 01~ and an alkoxyl group in CI~6. cycloalkyl group; halogen atom, C5~, alkyl group, 01~. a phenyl group which may be substituted with an alkoxyl group; a halogen atom, a C
l-6 alkyl group, naphthyl group optionally substituted with CI~6 alkoxyl group; 07~IO phenylalkyl optionally substituted with halogen atom, C3~6 alkyl group, CI~, alkoxyl group Group; halogen atom, C
C11-1. which may be substituted with 1-6 alkyl group, Cl-6 alkoxyl group; represents a naphthylalkyl group, and x and Y each represent a hydrogen atom HCI-to alkyl kM
;Cs~,. cycloalkyl group; halogen atom, CI
-b alkyl group, phenyl group optionally substituted with CI~6 alkoxyl group; halogen atom, CI~6 alkyl group, naphthyl group optionally substituted with C1~6 alkoxyl group; halogen atom, CI ~6 alkyl groups, 0
C? which may be substituted with 1 to 6 alkoxyl groups? -11
+ phenylalkyl group; indicates a naphthylalkyl group of CI I to 1° which may be substituted with a halogen atom, an alkyl group of 01 to 6, or an alkoxyl group of C0 to 6;

A is a direct bond, 01-2° alkylene group, -〇--3
- -3o, -0-Z-o- -S-Z-S-1 or -so, -z-so□.

However, Z is 01~. represents an alkylene group. Further, n represents 1 or 2. ] "Action" Specific examples of the compound represented by the general formula CI) include the following.

1-(β-naphthylsulfonyloxy)-2-cyclohexylcyclohexane, 1-(β-naphthylsulfonyloxy)-2-methylcyclohexane, 1-(β-naphthylsulfonyloxy)-2゜6-dimethylcyclohexane, 1-(α-naphthylsulfonyloxy)-2-methylcyclohexane, 1-(methanesulfonyloxy)
-2-cyclohexylcyclohexane, 1-(p-)luenesulfonyloxy)-2-benzylcyclohexane, l-(benzenesulfonyloxy)-2-cyclohexylcyclohexane, 1,4-bis(benzenesulfonyloxy)cyclohexane , 1゜4-bis(p-toluenesulfonyloxy)cyclohexane, ■, 4-bis(
p-methoxyphenylsulfonyloxy)cyclohexane, 1,4-bis(p-toluenesulfonyloxy)-
2-methylcyclohexane, 1-(phenylmethanesulfonyloxy)-2-methylcyclohexane, 1-(methanesulfonyloxy)-2-benzylcyclohexane, 1-(methanesulfonyloxy)-2-ethylcyclohexane, 1-(cyclohexane) xylsulfonyloxy)
-4-tert-butylcyclohexane, 1-(4-chlorocyclohexylsulfonyloxy)-2-methylcyclohexane, 1-(4-methoxycyclohexylsulfonyloxy)-2-phenylcyclohexane, 4-ethoxyphenylsulfonyloxycyclohexane, 1-
(p-chlorobenzenesulfonyloxy)2-(β-naphthyl)cyclohexane, 1-(p-bromobenzenesulfonyloxy)-2-(β-naphthylmethyl)cyclohexane, I-(n-propylsulfonyloxy)-4
-(p-chlorophenyl)cyclohexane, 1 (
tert-butylsulfonyloxy)-4-(p-)luene)cyclohexane, 4-benzenesulfonyloxy-4-(p-ethoxyphenyl)cyclohexane, 1-
Chloronaphthalen-2-ylsulfonyloxycyclohexane, 1-ethoxynaphthalen-2-ylsulfonyloxycyclohexane, 4-methylcyclohexylsulfonyloxy-4-(1-ethoxynaphthalen-2-yl)cyclohexane, 1-(pentadecane) sulfonyloxy)-4-phenylcyclohexane, etc.

Furthermore, specific examples of the compound represented by general formula (II) include the following.

2.2-bis(4-(p-)luenesulfonyloxy)
cyclohexyl]propane, 2,2-bis(4-(p-
methoxyphenylsulfonyloxy)cyclohexyl]
Propane, 2,2-bis(4methanesulfonyloxycyclohexyl)propane, 2,2-bisC4-(benzenesulfonyloxy)cyclohexyl]propane, bis(4-(benzenesulfonyloxy)cyclohexyl)
Sulfone, bis(4-(p-4 luenesulfonyloxy)cyclohexyl)sulfone, bis(4-(P-methoxyphenylsulfonyloxy)cyclohexyl)sulfone, bis(4-(benzenesulfonyloxy)cyclohexyl cothioether, bis[4 -(p-toluenesulfonyloxy)cyclohexyl cothioether, bis(
4-(p-methoxyphenylsulfonyloxy)cyclohexylcothioether, 4,4'-dimethanesulfonyloxybicyclohexane, bis[4-(benzenesulfonyloxy)cyclohexyl]ether, 2,2-bis[3-(p- 1 luenesulfonyloxy)cyclohexyl]propane, 1,2-bis(4-(p-)luenesulfonyloxy)cyclohexyl]ethane, 2,2-bis(4-methanesulfonyloxy-3-methylcyclohexyl)propane, 2. 2-bis(4-methanesulfonyloxy-3-cyclohexylcyclohexyl)propane, 2,2-bis(4-methanesulfonyloxy-3-
phenylcyclohexyl)propane, 2,2-bis[4
-methanesulfonyloxy-3-(β-naphthyl)cyclohexyl]propane, bis(4-methanesulfonyloxy-3-benzylcyclohexyl)sulfone, bis[
4-methanesulfonyloxy-3-(α-naphthylmethyl)cyclohexyl]sulfone, bis[4-methanesulfonyloxy-3-(p-methylphenyl)cyclohexylsulfonylth[4-methanesulfonyloxy-3]
-(p-methoxyphenyl)cyclohexyl]sulfone, 2,2-bis[4-methanesulfonyloxy-3-(
p-chlorophenyl)cyclohexyl]propane, bis[4-methanesulfonyloxy-3-(1-chloronaphthalen-2-yl)cyclohexyl]sulfone, bis[
4-Methanesulfonyloxy-3-(1-methoxynaphthalen-2-yl)cyclohexyl]sulfone, 2,2
-bis(4-(p-tert-butylphenylsulfonyloxy)cyclohexyl)propane, bis(4-pentadodecylsulfonyloxycyclohexyl)sulfone, 2,2-bis(4-methanesulfonyloxycyclohexyloxy)propane, l, 2-bis(4-methanesulfonyloxycyclohexyloxy)ethane, 2゜2-bis(4-(p-toluenesulfonyloxy)cyclohexyloxy)propane, 2.2-bis(4-methanesulfonyloxycyclohexyloxy) hexylthio)propane, bis(4-benzenesulfonyloxycyclohexylthio)methane, 2,2-bis(4-methanesulfonyloxycyclohexylsulfonyl)propane, 1,2-bis(
4-(p-toluenesulfonyloxy)cyclohexylsulfonyl]ethane, 1,1-bis(4-benzenesulfonyloxycyclohexylsulfonyl)propane, and the like.

Note that the compounds represented by the general formulas (I) and (II) are not limited to these, and it is of course possible to use two or more kinds of compounds in combination as necessary.

The amount of the compound represented by the above general formula (1) or (I[) is not particularly limited, but is usually 1 to 300 parts by weight, preferably 5 to 300 parts by weight, per 100 parts by weight of the basic dye. It is desirable to adjust the amount within a range of 200 parts by weight.

As mentioned above, the present invention relates to a specific compound represented by general formula [I] or (II) and 3-di(n-butyl)amino-6
-methyl-7-phenylaminofluorane and/or 3
- Di(n-pentyl)amino-6-methyl-7-phenylaminofluorane is selectively combined with this dye, but if necessary, other basic dyes may be added. They can also be used together. In that case, 3-di(n-butyl)amino-6-methyl-7-phenylaminofluorane and/or 3-di(n-pentyl)amino-
It is necessary to blend 6-methyl-7-phenylaminofluorane so that it accounts for 50% by weight or more of the total basic dye.

Examples of basic dyes that can be used in combination include the following various known dyes.

3.3-Bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis(P-dimethylaminophenyl)phthalide, 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-:L-th)lecarbazol-3-yl)-6-dimethylaminophthalide, 3,
3-bis(2-phenylindol-3-yl)-6-
Triallylmethane dyes such as dimethylaminophthalide, 3-P-dimethylaminophenyl-3-(1-methylvirol-3-yl)-6-dimethylaminophthalide, 4
, 4'-bis-dimethylaminobenzhydrylbenzyl ether, N-halophenyl-leucoolamine, N-
Diphenylmethane dyes such as 2,4,5-trichlorophenylleucoolamine, thiazine dyes such as benzoylleucomethylene blue and p-nitrobenzoylleucomethylene blue, 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3 - Spiro dyes such as phenyl-spirodinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho(6'-methoxybenzo)spiropyran, 3-propyl-spiro-dibenzopyran, rhodamine-B-anilino lactam, rhodamine (P-nitroanilino) lactam, rhodamine (0-chloroanilino) lactam and other lactam dyes, 3-dimethylamino-7-methoxyfluoran, 3-diethylamino-6-methoxyfluoran, 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-diethylamino-7-N-acetyl-N-methylaminofluorane, 3-diethylamino-7-N-methylaminofluorane, 3-diethylamino-7-dibenzylaminofluoran Oran, 3-diethylamino-7-N-methyl-N-benzylaminofluorane, 3-diethylamino-7-N-
Chloroethyl-N-methylaminofluorane, 3-diethylamino-7-N-diethylaminofluorane, 3-(
N-ethyl-p-)luidino)-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-P-toluidino)-6-methyl-7-(p-toluidino)fluorane, 3-diethylamino- 6-Methyl-7phenylaminofluorane, 3-diethylamino-7-(2-carbomethoxyphenylamino)fluoran, 3-(N-ethyl-N-isoamyl)amino-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-diethylamine-6 -Methyl-7-xylidinofluorane, 3-diethylamino-7-(o-chlorophenylamino)fluoran, 3-
Dibutylamino 7-(0-chlorophenylamino)fluoran, 3-(N-ethyl-N-tetrahydrofurfuryl)amino-6-methyl-7-phenylaminofluoran, 3-(N-methyl-N-n-propyl) ) Amino-6
-Methyl-7-phenylaminofluorane, 3-pyrrolidino-6-methyl-7-P-butylphenylaminofluorane, 3-(N-methyl-N-n-propyl)amino-6-methyl-7-phenyl Aminofluorane, 3-(
N-ethyl N-isobutyl)amino-6-methyl-7-
Phenylaminofluorane, 3-(N-methyl-Nn-
hexyl)amino-6-methyl-phenylaminofluorane, 3-(N-ethyl-Nnhexyl)amino-6-methyl-7-phenylaminofluorane, 3-(N-hexyl)amino-6-methyl-7-phenylaminofluorane,
-ethyl-N-cyclopentyl)amino-6-methyl-
Fluoran dyes such as 7-phenylaminofluorane, etc. Of course, the dyes are not limited to these dyes, and it is also possible to use two or more dyes in combination.

Various known compounds can be used as the coloring agent used in the present invention, examples of which include the following.

Inorganic acidic substances such as activated clay, acid clay, acpulgite, bentonite, colloidal silica, aluminum silicate, 4-tert-butylphenol, 4-hydroxyphenoxide, α-naphthol, β-naphthol, 4
-Hydroxyacetophenol, 4 tert-octylcatechol, 2,2' dihydroxydiphenol,
2.2'-methylenebis(4-methyl-5-tert-
butylphenol), 4.4'-isopropylidene bisphenol, 4゜4'-isopropylidene bis(2-t
ert-butylphenol), 4.4'-5ec-butylidenediphenol, 4-phenylphenol, 2.2
'Methylenebis(4-chlorophenol), hydroquinone, 4.4'-cyclohexylidene diphenol,
Benzyl 4-hydroxybenzoate, dimethyl 4-hydroxyphthalate, hydroquinone monobenzyl ether, 4-
Hydroxy-4'-isopropoxydiphenylsulfone 3r,4r-tetramethylene-4-hydroxydiphenylsulfone, 4.4'-(1,3-dimethylbutylidene)bisphenol, 4.4'-(1-phenylethylidene)bisphenol , 4.4'-(p-phenylene diisopropylidene) diphenol, 4°4'-(m-
phenylene diisopropylidene) diphenol, novolak type phenolic resin, phenolic compounds such as phenol polymers, benzoic acid, p-tert-butylbenzoic acid, trichlorobenzoic acid, terephthalic acid, 3-sec-
Butyl-4-hydroxybenzoic acid, 3-cyclohexyl-4-hydroxybenzoic acid, 3.5-dimethyl-4-hydroxybenzoic acid, salicylic acid, 3-isopropylsalicylic acid, 3 tert-butylsalicylic acid, 4(3-
p-Tolylsulfonylpropyloxy) salicylic acid, 4
-(2-p-methoxyphenoxyethoxy)salicylic acid, 5-(p-(2-p-methoxyphenoxyethoxy)
cumyl] salicylic acid, 3-benzylsalicylic acid, 3-(
α-Methylbenzyl)salicylic acid, 3-0-5-(
α-methylbenzyl)salicylic acid, 3,5-diter
t-Butylsalicylic acid, 3-phenyl-5-(α, α
Aromatic carboxylic acids such as dimethylbenzyl)salicylic acid, 3,5-bis(α-methylbenzyl)salicylic acid, and these phenolic compounds, aromatic carboxylic acids such as zinc, magnesium, aluminum, calcium, titanium, manganese, Salts with polyvalent metals such as tin and nickel, as well as zinc, magnesium, aluminum,
Examples include organic acidic substances such as complex compounds of polyvalent metal salts such as calcium, titanium, manganese, tin, and nickel, and organic compounds such as antipyrine, pyridine, and dimethylaminoantipyrine.

The proportion of the basic dye and coloring agent used in combination is not necessarily limited, but is usually 100 to 700 parts by weight, preferably 150 to 700 parts by weight, per 100 parts by weight of the basic dye.
It is desirable to incorporate 400 parts by weight of a coloring agent.

Coating liquids containing these are generally prepared by using water as a dispersion medium and using a stirring/pulverizing machine such as a ball mill, attritor, or sand mill to remove the dye, coloring agent, general formula (1), and/or [
It is prepared by dispersing the compounds represented by (2) together or separately.

Such coating liquids usually contain binders such as various starches, hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohol, styrene/maleic anhydride copolymer salt, styrene/acrylic acid copolymer salt, etc. The polymer salt, styrene-butadiene copolymer emulsion, etc. accounts for 10 to 40% by weight of the total solids, preferably 15 to 40% by weight.
It is blended in an amount of about 30% by weight.

Furthermore, various auxiliary agents can be added to the coating liquid, such as dispersants such as sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl alcohol sulfate, fatty acid metal salts, and other antifoaming agents. agents, fluorescent dyes, colored dyes, etc.

In addition, dispersions or emulsions of stearic acid, polyethylene, carnauba wax, paraffin wax, zinc stearate, calcium stearate, ester wax, etc. are added to prevent sticking of the heat-sensitive recording material due to contact with recording equipment or recording heads. You can also do that.

Furthermore, fatty acid amides such as stearic acid amide, stearic acid methylene bisamide, oleic acid amide, valmitic acid amide, coconut fatty acid amide, 1,2-bis(phenoxy), etc., may be added to the extent that the desired effects of the present invention are not inhibited.
Ethane, 1,2-bis(4-methylphenoxy)ethane, 1,2-bis(3-methylphenoxy)ethane, 2-
Benzyloxynaphthalene, benzyl-4-methylthiophenyl ether, 4-methylbenzyl-4'methylthiophenyl ether, 2-naphthylbenzyl ether,
1-(2-methylphenoxy)2-(4-methoxyphenoxy)ethane, p-biphenyl-p-tolyl ether, 1.4-bis(2-vinyloxyethoxy)benzene, 1.5-bis(p-methoxy) Ethers such as phenoxy)-3-oxa-penkune, esters such as dibenzyl terephthalate, 1-hydroxy-2-naphthoic acid phenyl ester, dibenzyl oxalate, and bis(4-methylbenzyl) oxalate. 2-methyl-4-
hydroxy-5-tert-butylphenyl)butane,
1. 1. 3-)IJX (2-methyl-4-hydroxy-5-tert-butylphenyl)butane, bis(
2-Hydroxy-3tert-butyl-5-methylphenyl)methane, 1゜1.3-1-lis(2-methyl-
4-Hydroxy-5-cyclohexylphenyl)butane, tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)methylpropionate]methane, 1.3.5-)lis(3, Hindered phenols such as 5-di-tert-butyl (4-hydroxybenzyl)-2,4,6-)listylbenzene, and various known thermofusible substances such as p-benzylbiphenyl may also be used in combination. can.

In addition, kaolin is used to improve the adhesion of debris to the recording head.
Inorganic pigments such as clay, talc, calcium carbonate, calcined resin, titanium oxide, diatomaceous earth, fine particulate anhydrous silica, and activated clay can also be added.

On the other hand, as the support, paper, plastic film, synthetic paper, etc. can be used, and paper is preferably used in terms of cost, coating suitability, etc. The coating amount of the coating liquid forming the recording layer on the support is not particularly limited, and is usually 1 to 12 g/s'' in terms of dry weight, preferably 1.5 to 10 g/s.
It can be adjusted within a range of approximately 100 m.

Note that it is also possible to provide an overcoat layer on the recording layer for the purpose of protecting the recording layer, and it is of course also possible to provide a protective layer on the back side of the support or an undercoat layer on the support. Various known techniques in the field of heat-sensitive recording material manufacturing can be added.

"Example" The present invention will be described in more detail with reference to Examples below, but the present invention is of course not limited to these.

Further, unless otherwise specified, parts and % in the examples indicate parts by weight and % by weight, respectively.

Example work [Formation of undercoat layer] Baked G (trade name: Ansilex) 100 parts styrene-butadiene copolymer latex (solid content = 5
0%) 14 parts polyvinyl alcohol 10% aqueous solution 3 (1 water
200 parts of the above composition were mixed and the coating amount after drying was 10 g/m2 on high-quality paper with a basis weight of 50 g/m.
An undercoat layer was formed by coating and drying to form an undercoat layer.

[Formation of recording layer] ■ Preparation of liquid A 3-di(n-butyl)amino-6-methyl-7-phenylaminofluorane 10 parts 1.2-bis(3-methylphenoxy)ethane
20 parts methylcellulose 5% aqueous solution 15 parts water
120 parts of this composition was ground in a sand mill until the average particle size was 3 μm.

■ Preparation of Solution B 4. 20 parts of 4'-isopropylidene bisphenol 5% aqueous solution of methylcellulose 30 parts of water
70 parts of this composition was ground in a sand mill until the average particle size was 3 μm.

■ Preparation of liquid C 2.2-bis(4-methanesulfonyloxycyclohexyl)propane 6.7 parts methylcellulose
5% aqueous solution 10 parts water
23.3 parts This composition was ground in a sand mill until the average particle size was 3 μm.

165 parts of liquid A, 120 parts of liquid B, 40 parts of liquid C obtained above,
Silicon oxide pigment (oil absorption 180+1/100 g) 30
150 parts of 20% oxidized starch aqueous solution and 55 parts of water were mixed.
The mixture was stirred to form a coating liquid. The resulting coating liquid was applied onto the undercoat layer to a dry weight of 5.0 gems and dried to obtain a heat-sensitive recording paper.

Example 2 In preparing liquid A, 3-di(n-butyl)amino-6-
Instead of methyl-7-phenylaminofluorane, 3
A thermosensitive recording paper was obtained in the same manner as in Example 1 except that -di(n-pentyl)amino-6-methyl-7-phenylaminofluoran was used.

Example 3 In the preparation of Solution B of Example 2, 4-hydroxy-4' was used instead of 4,4'-isopropylidene bisphenol.
A thermosensitive recording paper was obtained in the same manner as in Example 2 except that -isopropoxydiphenyl sulfone was used.

Examples 4 to 10 Seven types were prepared in the same manner as in Example 1, except that the following compounds were used instead of 2,2-bis(4-methanesulfonyloxycyclohexyl)propane in the C wave preparation of Example 1. A thermosensitive recording paper was obtained.

Example 4: 1-(β-naphthylsulfonyloxy)-2
-Cyclohexylcyclohexane Example 5: 1-(methanesulfonyloxy)2-cyclohexylcyclohexane Example 11 & Example 6: 1. 4-bis(p-)luenesulfonyloxy)cyclohexane Example 7: 1,4-bis(p-toluenesulfonyloxy)-2-methylcyclohexane Example 8: 1-phenylmethanesulfonyloxy-
2-Methylcyclohexane Example 9: 4,4'-dimethylsulfonyloxybicyclohexane Example 10: Bis[4-(benzenesulfonyloxychlorohexyl)ether Comparative Example 1 In the preparation of Solution A of Example 1, 2,2- A thermosensitive recording paper was obtained in the same manner as in Example 1 except that bis(4-methanesulfonyloxycyclohexyl)propane was not used.

Comparative Examples 2 to 3 Same as Example 1 except that the following compound was used instead of 3-di(n-butyl)amino-6-methyl-7-phenylaminofluoran in the AI preparation of Example 1. Two types of thermal recording paper were obtained.

Comparative example 2: 3-(N-ethyl-N-isoamyl)amino-6-methyl-7-phenylaminofluoran Comparative example 3: 3-diethylamino-6-methyl 7-phenylaminofluoran Comparative example 4 Example 1 In the preparation of Ai, 4,4'-thiobis(2-methyl-6-tert-
A thermosensitive recording paper was obtained in the same manner as in Example 1, except that 1-butylphenol was used.

The 14 types of thermal recording paper obtained in this way were recorded using a thermal facsimile (Hitachi HIFAX-400 model 1 manufactured by Hitachi ■), and the density of the printed portion and blank paper portion was measured using a Macbeth densitometer (model RD-100R using an amber filter). ), and the results are shown in Table 1.

After recording, heat-sensitive recording paper was heated at 40°C, 190%R, )I.

After being left for 24 hours under the high humidity condition of 100° C. and the high temperature drying condition of 60° C., the density of each printed portion and blank paper portion was measured using a Macbeth densitometer, and the results are shown in Table 1.

"Effects" As is clear from Table 1, the heat-sensitive recording material of the present invention does not cause fading of recorded images even when exposed to high temperature conditions.
Moreover, it was a recording medium with extremely excellent storage stability, with little fogging in blank areas.

Claims (1)

[Claims] (1) In a heat-sensitive recording material in which a recording layer containing a colorless or light-colored basic dye and a coloring agent that can change color upon contact with the dye is provided on a support, the basic dye is contained in the recording layer. Contains 3-di(n-butyl)amino-6-methyl-7-phenylaminofluorane and/or 3-di(n-pentyl)amino-6-methyl-7-phenylaminofluorane, and the following general 1. A heat-sensitive recording material containing at least one compound represented by formula [I] or [II]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼[I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼[II] [In the formula, R is an alkyl group of C_1_ to _2_0; a halogen atom, an alkyl group of C_1_ to _6, C_1_ ~_6
C_5_~_1_ which may be substituted with an alkoxyl group of
0 cycloalkyl group; halogen atom, C_1_ to_6
an alkyl group, a phenyl group which may be substituted with an alkoxyl group of C_1_ to_6; a halogen atom, a C_1_ to__
6 alkyl group, naphthyl group which may be substituted with C_1_~_6 alkoxyl group; halogen atom, C_1_~
_6 alkyl group, C_7_-_1_0 phenylalkyl group which may be substituted with C_1_-_6 alkoxyl group; halogen atom, C_1_-_6 alkyl group, C
C_ which may be substituted with an alkoxyl group of _1_ to _6
1_1 to _1_5 naphthylalkyl group, X, Y
are respectively hydrogen atoms; alkyl groups of C_1_ to_2_0; cycloalkyl groups of C_5_ to_1_0; halogen atoms, alkyl groups of C_1_ to_6, phenyl groups which may be substituted with alkoxyl groups of C_1_ to_6; halogen atoms, C_1_ to Alkyl group at _6, naphthyl group optionally substituted with alkoxyl group at C_1_-_6; halogen atom, alkyl group at C_1_-_6, C_1_-_6
C_7_-_1_ which may be substituted with an alkoxyl group of
0 phenylalkyl group; halogen atom, C_1_～_
6, and a naphthylalkyl group of C_1_1_ to_1_5 which may be substituted with an alkoxyl group of C_1_ to_6. A is a direct bond, C_1 to_2_0 alkylene group, -O
-, -S-, -SO_2-, -O-Z-O-, -S-Z-S-, or -SO_2-Z-SO_2-. However, Z is C_1
Indicates an alkylene group from _ to _2_0. Further, n represents 1 or 2. ]