JPH02293185A - Thermal recording material - Google Patents

Abstract

PURPOSE:To improve high speed recording properties by providing a thermal color forming layer containing 3-di-n-pentylamine-6-methyl-7-phenylaminofluorane and a specific phenol compound on a support. CONSTITUTION:3-di-n-pentylamino-6-methyl-7-phenylaminofluorane as a basic dye and a phenol compound represented by formula I(wherein R is a 2 - 10C divalent group and X and Y are hydrogen, a lower alkyl group, a lower alkoxyl group, a lower alkenyl group, a hydroxyl group or a halogen atom) developing a color upon the contact with said dye are mixed and dispersed by a ball mill using water as a dispersing medium to prepare a coating solution. This coating solution is applied to a support such as paper or a plastic film in a coating amount (on a dry wt. basis) of about 2 - 12g/m<2> and dried to obtain a thermal recording material having a thermal color forming layer formed thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to a heat-sensitive recording medium, and in particular to a heat-sensitive recording medium that is free from background fog, has excellent high-speed recording suitability, and has excellent storage stability of recorded images.

``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.

Recently, with remarkable progress in thermal recording methods, thermal faxes, thermal printers, etc. can all be faster.
Thermal fax machines can record A4 size documents in less than 10 seconds, and thermal printers can record at over 120 characters/sec.

With the speed increase in the hardware field, there is a demand for heat-sensitive recording bodies that are excellent in suitability for high-speed recording.

However, in order to enable high-speed recording, it is necessary to increase the sensitivity of the heat-sensitive recording medium, but in general, the higher the sensitivity of the recording medium, the more likely it is that discoloration (fogging phenomenon) of blank areas will occur due to long-term storage. In addition, the present situation is that recorded images do not have sufficient storage stability.

``Problem to be Solved by the Invention J'' Up to this point, the present inventors have conducted extensive research into improving such defects observed in heat-sensitive recording materials, and have found that 3-di-n-pentyl acetate is a basic dye. Minnow 6
- By using methyl-7-phenylaminofluorane and at least one specific phenol compound as a coloring agent, the whiteness is high, the suitability for high-speed recording and the preservability of recorded images are excellent, and it can be stored for a long time. The present inventors have discovered that it is possible to obtain a heat-sensitive recording material with extremely high commercial value that does not cause a decrease in whiteness even when exposed to heat, and has completed the present invention. ``Means for Solving the Problems'' The present invention provides a thermosensitive recording material that uses a reaction between a colorless or light-colored basic dye and a coloring agent that can change color when it comes into contact with the basic dye. It is characterized by using 3-di-n-pentylamino-6-methyl-7-phenylaminofluoran as a dye and at least one selected from the compounds represented by the following general formula [I] as a coloring agent. This is a heat-sensitive recording medium.

In formula C, R represents a divalent group having 2 to 10 carbon atoms, and X, Y
each represents a hydrogen atom, a lower alkyl group, a lower alkoxyl group, a lower alkenyl group, a hydroxyl group or a halogen atom. [Function] In the above general formula (1), R represents a divalent group having 2 to IO carbon atoms, preferably an alkylene group, an alkylene group having a carbonyl group, an alkylene group having a hydroxyl group, or a halogen atom. R is preferably an alkylene group having an unsaturated bond or an aromatic ring, an alkylene group having an ether bond, an alkylene group having a thioether bond, an alkylene group having an ester bond, or an alkylene group having an amide bond, and particularly when R is alkylene Compounds having an alkylene group, an alkylene group having a hydroxyl group, an alkylene group having an ether bond, and an alkylene group having an ester bond are more preferably used because they yield a heat-sensitive recording material particularly excellent in high-speed recording suitability and storage stability of recorded images. It will be done.

Furthermore, the melting point of the compound represented by the general formula ([) is 70°C.
If the temperature is lower than 250°C, the fogging phenomenon tends to occur, whereas if the temperature is higher than 250°C, the fogging phenomenon may become insufficient. Therefore, compounds with a melting point of 70 to 250°C are preferable, and in particular, compounds with a melting point of 70 to 250°C are preferable. Compounds with a temperature of 80 to 200°C are more preferred.

Specific examples of the compound represented by the 1S formula [I] include the following compounds.

1.2-bis(4-hydroxyphenylthio)ethane,
1.3-bis(4-hydroxyphenylthio)propane, 1.4-bis(4-hydroxyphenylthio)butane, 1,5-bis(4-hydroxyphenylthio)pentane, 1.6-bis(4 -hydroxyphenylthio)hexane, 1,3bis(4-hydroxyphenylthio)acetone, 1,5-bis(4-hydroxyphenylthio)2
．． 4-pentanedione, 1.7-bis(4-hydroxyphenylthio)-3.5-heptanedione, 1,2-bis(4-hydroxyphenylthio)ethanol, 1.3
-bis(4-hydroxyphenylthio)-2-propanol, 1. 4-bis(4-hydroxyphenylthio)-2-butanol, 1,4-bis(4-hydroxyphenylthio)2,3-butanediol, l 5-bis(
4-hydroxyphenylthio)-3-pentanol, 1
,6-bis(4-hydroxyphenylthio)-2.4-
Hexanediol, 1,3-bis(4-xyphenylthio)-2-chloropropane, 1,5-bis(4-
hydroxyphenylthio)-3chloropentane, 1,4
-bis(4-hydroxyphenylthio)-2-butene,
3.4-bis(4-hydroxyphenylthio)-1-butene, 1,4-bis(4-hydroxyphenylthio)-
2 butin, α. α'-bis(4-hydroxyphenylthio)-o-xylene, α,α'-bis(4-hydroxyphenylthio)-1m-xylene, αα'-bis(4-hydroxyphenylthio)-1p-xylene, 1.5-bis(
4-hydroxydiphenylthio)-3-oxapentane,
1,7-bis(4-hydroxyphenylthio)-3.5
-dioxahebutane, 1,8-bis(4-hydroxyphenylthio)-3,6-dioxaoctane, 1,9-bis(4-hydroxydiphenylthio)-5oxanonan,
1,3-bis(2-(4-hydroxyphenylthio)
ethoxy]benzene, 1. 4bisC2-<4-hydroxydiphenylthio)ethoxy]benzene, 1,5-bis(4-hydroxyphenylthio)-3-thiapencune, (4-hydroxyphenylthio)acetate-2-(4-hydroxyphenyl) thio)ethyl ester, (4-hydroxyphenylthio)acetic acid-3-(4-hydroxyphenylthio)probyl ester, 2-(4-hydroxyphenylthio)ethyl 2-(4-hydroxyphenylthio)propionate Ester, 3-(4-hydroxyphenylthio)probionic acid-2-(4-hydroxyphenylthio)ethyl ester, 4-(4-hydroxyphenylthio)mM-2-<4-hydroxyphenylthio)ethyl ester , 2-(4-hydroxyphenylthio)N-
[2-(4-hydroxyphenylthio)ethyl]acetamide, 2-(4-hydroxyphenylthio)-N
-(1(4-hydroxyphenylthio)probyl)acetamide, 3-(4-hydroxyphenylthio)-N-
(2-(4-hydroxyphenylthio)ethyl)propionamide, 3-(4-hydroxyphenylthio)
-N- (3(4-hydroxyphenylthio)probyl)probionamide, 1,3-bis(4-hydroxy=
3-methylphenylthio)propane, 1,3bis(4-
Hydroxy-3-methoxyphenylthio)propane, ■
,3-bis(4-hydroxy3-chlorophenylthio)
Propane, 1 5-bis(4-hydroxy-3-methylphenylthio)pentane, 1,5-bis(4-hydroxy-3methoxyphenylthio)pentane, 1,5-bis(4-hydroxy-3-chlorophenyl) thio)pentane, 1,5-bis(3,4-dihydroxyphenylthio)
Pentane, 1,3-bis(4-hydroxy-3-methylphenylthio)acetone, 1,3-bis(4-hydroxy-3-methoxyphenylthio)acetone, 1,3-bis(4-hydroxy-3 -chlorophenylthio)acetone, 1,3-bis(4-hydroxy-3-allylphenylthio)acetone, l,5-bis(4-hydroxy 3-
methylphenylthio)-3-oxabentane, 1.5-
Bis(4-hydroxy-3-methoxyphenylthio)-
3-oxapentane, 1,5-bis(4-hydroxy-
3-chlorophenylthio)3-oxapentane, 1.8
-bis(3.4dihydroxyphenylthio)-3.6-
Dioxaoctane, 1,8-bis(4-hydroxydi-3
Allyl phenylthio)-3,6-dioxaoctane, (
4-Hydroxy-3-methylphenylthio)acetic acid-2-
(4-hydroxy-3-methylphenylthio)ethyl ester, (4-hydroxy-3-methoxyphenylthio)acetic acid-2-(4-hydroxy-3-methoxyphenylthio)ethyl ester, (4-hydroxy-3-chlorophenylthio) enylthio)acetic acid-2-(4-hydroxy-3-chlorophenylthio)ethyl ester, etc.

The proportion of these coloring agents and 3-di-n-pentylamino 6-methyl-7-phenylaminofluoran is not necessarily limited, but is 100 to 700 parts by weight per 100 parts by weight of the basic dye. parts by weight, more preferably 15
It is desirable to blend about 0 to 600 parts by weight of a coloring agent.

In addition, in the thermosensitive recording material of the present invention, 3-
An important feature is that di-n-pentylamino-6-methyl 7-phenylaminofluorane is used in combination with a coloring agent having a specific structure, and the desired effect of the present invention can be achieved. One or more other colorless or light-colored basic dyes can be used in combination as long as they do not inhibit the effect. Examples of basic dyes that can be used in combination include the following compounds.

3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(4-dimethylaminophenyl)-3-(4- Dimethylamine-2-methylphenyl)-6-(dimethylamino)phthalide, 3-(p
-dimethylaminophenyl)-3- (1,2-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-3-(2-methylindole-3
-yl) phthalide, 3,3-bis(l,2-dimethylindol-3-yl)-5-dimethylaminophthalide,
3.3-bis(1,2-dimethylindol-3-yl)-6-dimethylaminophthalide, 3.3-bis(9-
Ethyl Rubazol-3-yl)-6-dimethylaminophthalide, 3,3-bis(2-phenylindole-3-
triarylmethane dyes such as 6-dimethylaminophthalide and 3-P-dimethylaminophenyl-3-(1-methylpyrrol-3-yl)-6-dimethylaminophthalide. 4. Diphenylmethane dyes such as 4'-bis-dimethylaminobenzhydryl benzyl ether, N-halophenyl leuco auramine, N-2.4.5-trichlorophenyl leuco auramine, etc. 14; 3,3-His [1. 1bis(4-pyrrolidinophenyl)ethylene-2yl>4.5,6.7-tetrabromophthalide, 3
,3-bis(1-(4-methoxyphenyl)1-(4-
dimethylaminophenyl)ethylene 2-yl)-4.5
．． 6.7-tetrachophthalide, 3.3-bis(1-
Divinylphthalide dyes such as (4-methoxyphenyl)-1-(4-pyrrolidinophenyl)ethylene-2-yl)-4.5,6.7-tetrachlorophthalide; benzoylleucomethylene blue, p-nitrohen Thiazine dyes such as icomethylene blue; 3-methyl-spirodinaphthopyran, 3-ethyl-spirodinaphthopyran, 3-phenyl-spirodinaphthopyran, 3-
Spiro dyes such as pendylose spirodinaphthopyran, 3-methylnaphtho(6'-methoxybenzo)spiropyran, and 3-propylose dibenzopyran; rhodamine B-anilinolactam, rhodamine (p-nitroanilino)lactam, rhodamine (0- Lactam dyes such as chloroanilino)lactam; 3-dimethylamino-7-
Methoxyfluoran, 3-jethylamino-6-methoxyfluoran, 3-diethylamino-7-methoxyfluoran, 3-jethylamino-7-chlorofluoran,
3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamine-6,7-dimethylfluorane, 3-(N-ethyl-p-}luidino)-7-methylfluorane, 3-diethylamino-7-N-acetyl N-methylaminofluorane, 3-diethylamino-7-N-
Methylaminofluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-
N-methyl-N-pendylaminofluorane, 3
-diethylamino-7-N-chloroethyl-N-methylaminofluorane, 3-diethylamino-7-N-diethylaminofluorane, 4-pendylamino-8-diethylaminobenzo(a) fluorane, 3- (4-
(4-dimethylaminoanilino)anilino]-7-chloro-6-methylfluorane, 8-(4-(4-dimethylaminoanilino)anilino)-benzo(a)fluorane, 3-(N-ethyl- p-1-luidino)-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-p-toluidino)-6-methyl-7-(p-}luidino)fluoran, 3-diethylamino-6-methyl- 7-phenylaminofluorane, 3-dibutylamino-
6-Methyl-7-phenylaminofluorane, 3-diethylamine-7-(2-carbomethoxyphenylamino)fluorane, 3-(N-ethyl-N-isoamylamino)-6-methyl-7-phenylamino Fluoran, 3-(N-cyclohexyl-N-methylamine)-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-dibutylamino-7-
(o-chlorophenylamino)fluoran, 3-(N-ethyl-N=tetrahydrofurfurylamino)-6-methyl 7-phenylaminofluoran, 3-(N-methyl-N-n-propylamino)-6-methyl 7-phenylaminofluorane, 3-(N-ethyl-N-i-butylamino)-6-methyl-7phenylaminofluorane,
3-(N-methylN-n-hexylamino)-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-N101hexylamino)-6-methyl-7-phenylaminofluoran Oran... 3-(N-ethyl-N-cyclobentylamino)-6-methyl-7-phenylaminofluorane, 3-(N-(3-ethoxypupyl)-N-
methylamino]-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-N-(3-ethoxypropyl)amino)6-methyl-7-phenylaminofluorane, 3-diethylamino-7-(m - (Trifluoromethyl)phenylamino]fluoran, 3-jethylamino-7-(o-fluorophenylamino)fluoran, 3-dibutylamino-7-(o-fluorophenylamino)fluoran, 3-jethylamino-6-chloro-7-phenyl Fluoran dyes such as amino) fluorane; 3,6-bis(dimethylamino)fluorene-9-
Spiro-3'(6'-dimethylamino)phthalide, 3-
Jethylamino-6-(N-aryl-N-methylaminofluorene-9-subiro-3'-(6'-dimethylamino)phthalide, 3,6-bis(dimethylamino)
Isubiro [fluorene-9.6'-6'H-chromeno (
4.3-b) indole], 3.6-bis(dimethylamino)-3'-methyl-subiro[fluorene-9.6'
-6'H-chromeno(4,3-b)indole L
3,6-bis(diethylamino)-3'-methylspiro[fluorene-9.6'-6'H-chromeno(4.
3-b) Fluorene dyes such as indole]. Of course,
It is not limited to these dyes.

Coating liquids containing these heat-sensitive materials are generally prepared by using water as a dispersion medium and using a stirring/pulverizing machine such as a ball mill, attritor, or sand grinder to mix each of the above-mentioned heat-sensitive materials separately or in combination of two or more. It is prepared by mixing and dispersing.

Such coating liquids usually contain starches and binders as binders.
Hydroxyethylcellulose, methylcellulose, carboxymethylcellulose, gelatin, casein, gum arabic, polyvinyl alcohol, styrene/maleic anhydride copolymer salt, styrene/acrylic acid copolymer salt, styrene/putadiene copolymer emulsion, etc. are total solids. It is blended in an amount of about 10 to 40% by weight, preferably about 15 to 30% by weight.

Furthermore, various auxiliary agents can be added to the coating liquid.
For example, dispersants such as sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium salt of lauryl alcohol sulfate, fatty acid metal salt; ultraviolet absorbers such as triadur; other antifoaming agents;
Examples include fluorescent dyes; colored dyes, etc. In addition, in order to prevent sticking of the heat-sensitive recording medium due to contact with recording equipment or recording heads, dispersions of stearic acid, polyethylene, carnauba wax, paraffin wax, zinc stearate, calcium stearate, ester wax, etc. are added to the coating liquid. Emulsions and the like can also be added.

Furthermore, fatty acid amides such as stearic acid amide, stearic acid methylene bisamide, oleic acid amide, valmitic acid amide, coconut fatty acid amide, p-penzylbiphenyl,
Aromatic compounds such as m-terphenyl; 1.2-diphenoxyethane, 1.2-bis(4-methylphenoxy)ethane, 1.2-bis(3-methylphenoxy)ethane,
Ethers such as 1.5-bis(p-methoxyphenoxy)-3-oxahentane and 2-naphtholbenzyl ether; esters such as dibenzyl terephthalate and 1-hydroxydi-2-naphthoic acid phenyl ester; and various known thermoplastics. A fusible substance can also be used in combination.

Further, in the heat-sensitive recording material of the present invention, various anti-fading agents can be contained in the angry heat coloring layer in order to prevent the recorded image from fading and to make the generated image more robust. The anti-fading agent is preferably a phenol derivative, particularly a hindered phenol compound, and specific examples include 4,4'-butylidenebis(2 tert-butyl-5-methylphenol), 4,4'-butylidenebis( 2-tert-butyl-6-methylphenol),
4,4'-cyclohexylidene bis(2 jerk-
(butyl-5-methylphenol), 4,4'-thiobis(2-tert-butyl-5-methylphenol),
4,4'-thiobis(2 tert-butyl-6-methylphenol), 4,4'-isopropylidene bis(2,6-dichlorophenol), 4,4'-isopropylidene bis(2,6-dibromophenol) ), 4.4'
-Cyclohexylidene bis(2,6-dibromophenol), bis(4-hydroxydi-3,5-dichlorophenyl)sulfone, bis(4-hydroxydi-3,5-dibromophenyl)sulfone, 2.2' -methylenebis(4-
methyl-6-tert-butylphenol), 2.2'
1 methylenebis(4-ethyl-6-tert-butylphenol), 2,2'-methylenebis(4,6-tert-butylphenol)
erL-butylphenol), 2,2'-methylenebis(4,6-dichlorophenol), 22'-thiobis(4-methyl-6-tert-butylphenol),
Bis(2-hydroxydi-3 tertbutyl-5-methylphenyl)sulfone, 1.3-1-lis(2-
Methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1.3 tris(2-ethyl-4-hydroxy-5-tert-butylphenyl)butane, I.
1.3-tris(5-cyclohexyl-4-hydroxy-2methylphenyl)butane, l-(1.1-bis(4
-hydroxyphenyl)ethyl)-4-(1methyl-1
-(4-hydroxyphenyl)ethyl]benzene and the like. Of course, two or more of the above compounds can also be used in combination.

In addition, in order to improve the adhesion of debris on the recording head, kaolin, clay, talc, calcium carbonate, calcined clay,
Inorganic pigments such as titanium oxide, diatomaceous earth, particulate anhydrous silica, and activated clay may also be added.

As the support, paper, plastic film, synthetic paper, etc. can be used, but paper is most preferably used in terms of cost, coatability, etc. Further, the amount of the coating liquid to be applied to the support for forming the recording layer is not particularly limited, and is usually 2 to 1 on dry weight.
It is adjusted within a range of about 2 g/rrf, preferably about 3 to 10 g/rd.

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.

The thermal recording medium of the present invention thus obtained has suitability for high-speed recording, has no tendency for recorded images to fade, has no capri phenomenon in blank areas, and is free from debris adhesion to the recording head (piling).
It also exhibits excellent characteristics in terms of.

"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 1 ■ Preparation of Solution A 3-di-n-petylamino-6-methyl-7phenylaminofluorane 10 parts 4,4'-butylidene bis(2 tert-butyl-5-methylphenol) 5 parts 5% methylcellulose aqueous solution 20 parts water
50 parts of this composition was ground with a sand grinder until the average particle size was 2 μm.

■ Preparation of Solution B (4-hydroxyphenylthio)acetic acid-2-(4-hydroxyphenylthio)ethyl ester 40 parts Methylcellulose 5% aqueous solution? Fi 3 0
Department water
70 parts of this composition was ground with a sand grinder until the average particle size was 2 μm.

■ Formation of recording layer 85 parts of liquid A, 140 parts of liquid B, silicon oxide pigment (oil absorption 18
0 m/100 g) 30 parts, 150 parts of a 20% oxidized starch aqueous solution, and 255 parts of water were mixed and stirred to prepare a coating liquid. The obtained coating liquid was applied to 50 g/board of base paper with a dry weight of 6.0 g/r.
A heat-sensitive recording paper was obtained by coating and drying the mixture to give the following properties.

Examples 2 to 7 In Be3m, (4-hydroxyphenylthio)
Six types of thermal recording paper were obtained in the same manner as in Example 1, except that the following compound was used instead of acetic acid-2-(4-hydroxyphenylthio)ethyl ester.

Actual Jf5 Example 2: 1,5-bis(4-hydroxyphenylthio)pentane Example 3: 1. 5-bis(4-hydroxyphenylthio)-3-oxapencune 31 examples 4: 1. 7-bis(4-hydroxydiphenylthio)-3,5-dioxabencune Example 5: 1. 8-bis(4-hydroxyphenylthio)-3,6-dioquinaoctane Example 6: 1. 3-bis(4-hydroxyphenylthio)-2-propanol Example 1: 2-(4-hydroxyphenylthio)-N-(2-(4-hydroxyphenylthio)
Ethyl] Acetamide Comparative Examples 1 to 2 Examples except that the following compound was used in place of (4-hydroxyphenylthio)acetic acid-2-(4-hydroxyphenylthio)ethyl ester in B fiill. Two types of thermal recording paper were obtained in the same manner as in Example 1.

Comparative Example 1: 4,4'-isopropylidene bisphenol Comparative Example 2: Benzyl p-hydroxybenzoate Comparative Example 3 A (in night preparation, 3-di-n-pentylamino-6
-Instead of methyl-7-phenylaminofluorane,
Except that 3-(N-ethyl-N-isopentylamino)-6-methyl-7-phenylaminofluorane was used.
A thermosensitive recording paper was obtained in the same manner as in Example 1.

Comparative Example 4 A: In night preparation, 3-di-n-pentylamino-6
-Instead of methyl-7-phenylaminofluorane,
3-(N-cyclohexyl-N-methylamino)-6-
A thermosensitive recording paper was obtained in the same manner as in Example 3 except that methyl-7-phenylaminofluorane was used.

The 11 types of thermal recording paper obtained in this way were recorded using a thermal facsimile (Hitachi H T FAX-700 model), and the color density and the recording paper after color development were evaluated at 60%.
The density of the recorded image was measured using a Macbeth densitometer (Model RD-100R, using an amber filter) after being left for 24 hours under high temperature dry conditions at 40°C and 24 hours under high humidity conditions at 40°C and 90% RH. ), and the results are shown in Table 1.

In addition, the whiteness of the surface of the recording layer of the recording paper, after leaving the recording paper under high temperature drying conditions of 60°C for 3 days, and after leaving the recording paper under high temperature conditions of 40°C and 90% Rl1 for 3 days. The whiteness of the surface of the recording layer was measured using a Hunter whiteness meter, and the results are shown in Table 1.

"Effects" As is clear from the results in Table 1, the heat-sensitive recording paper of the present invention had high whiteness, excellent high-speed recording characteristics, and was also excellent in blank paper storage properties and recording storage properties.

Claims (1)

[Scope of Claims] A thermosensitive recording material utilizing a reaction between a colorless or light-colored basic dye and a coloring agent capable of forming a color when it comes into contact with the basic dye, in which 3-di-n is used as the basic dye. - A thermosensitive recording material characterized by using pentylamino-6-methyl-7-phenylaminofluorane and at least one type of compound selected from the following general formula [I] as a coloring agent. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, R represents a divalent group having 2 to 10 carbon atoms, and X, Y
each represents a hydrogen atom, a lower alkyl group, a lower alkoxyl group, a lower alkenyl group, a hydroxyl group or a halogen atom. ]