JPS63137889A - Thermal recording material - Google Patents

Abstract

PURPOSE:To obtain a recording material having an excellent high speed recording performance, an excellent whiteness, an excellent anti-platicizer performance and an excellent anti-diazo suitability, by combining a specific coloring agent and a specific compound. CONSTITUTION:A thermal recording layer containing a colorless or faint color basic dye, at least one kind of coloring agent shown by formula I and at least one kind of compound shown by formula II is provided on a supporting material. In formula I, X, Y represent a hydrogen atom, a halogen atom, an alkyl group, etc. respectively and (m) represents 1 or 2. R1-R5 represent a hydrogen atom, a halogen atom, an alkyl group, vinyl group, etc. R1 and R2 or R2 and R3 may form a naphthalene ring together with an adjoining benzene ring. In formula II, R6-R11 represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, etc. and (n) represents an integer of 1-10.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a heat-sensitive recording medium, which has particularly excellent suitability for high-speed recording and storage stability of recorded images, and which is stable and does not cause a decrease in whiteness in blank areas. The present invention relates to a heat-sensitive recording medium that can maintain a recorded image.

``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 a recoloring substance into contact with heat. well known.

Recently, with the remarkable progress of thermal recording methods, thermal facsimiles, thermal printers, etc. have all become faster.
Facsimiles can record in 20 seconds on A4 size paper, and printers can record at over 120 characters/sec. Therefore, there is a demand for a thermal recording medium to be used that has excellent suitability for high-speed recording.

In addition, with the rapid spread of thermal facsimiles, thermal printers, etc., the usage of these thermal recording media has become more widespread, such as being used in contact with plastic films, or stacked with other recording media such as diazo copy paper. An increasing number of cases are being stored together.

However, in general, when thermal recording materials come into contact with plastic film, the recorded image fades significantly, or when stored in contact with diazo copy paper, especially diazo copy paper immediately after copying, discoloration of the white paper area (fogging phenomenon) occurs. ) has the disadvantage that it is extremely easy to occur, and improvement of this problem (
It has been requested.

Therefore, various proposals have been made regarding methods of improving the coloring ability and storage stability of coloring agents, but at present, satisfactory results have not always been obtained.

"Problems to be Solved by the Invention" In view of the current situation, the inventors of the present invention have conducted extensive research and have found that, in particular, the coloring agent represented by the general formula [I] and the following -i formula (II)
When used in combination with the compound shown in , it not only exhibits extremely excellent high-speed recording suitability, but also exhibits excellent plasticizer resistance and diazo developer resistance, and has excellent storage stability of recorded images and does not cause a decrease in whiteness. The present inventors have discovered that it is possible to obtain a highly sensitive heat-sensitive recording material that does not require high sensitivity, and have completed the present invention.

"Means for Solving the Problems" The present invention provides a colorless or light-colored basic dye, at least one coloring agent represented by the following general formula [1], and a compound represented by the following general formula (I [)]. This is a heat-sensitive recording material characterized in that a heat-sensitive recording layer containing at least one of the following is provided on a support.

[In the formula, X and Y each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxyl group, or an allyl group, and the sum is l
Or not showing 2. R1, R2, R3, R4 and R2 are each a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, a vinyl group, an allyl group, a cycloalkyl group, an aralkyl group, an aryl group, an alkoxyl group, a cycloalkyloxy group, an aralkyl group It represents an oxy group, an aryloxy group, an alkylthio group, an aralkylthio group, an arylthio group, an alkoxyalkoxyl group, or an aryloxyalkoxyl group. Further, R1 and R2, Rz and R1 may form a naphthalene ring, a tetrahydronaphthalene ring, or an indane ring together with the benzene ring adjacent to each other.

[In the formula, R6''-R11 are each a hydrogen atom, a halogen atom, a nitro group, a cyano group, a C1-4 alkyl group,
Aralkyl group, aryl group, C7-, alkoxyl group, C1-4 alkylthio group, acetyl group, propionyl group, methoxycarbonyl group, cyclohexenyl group,
Indicates an aralkyloxy group or an aryloxy group, n
represents an integer from 1 to 10. ] "Action" Although it is not clear why suitability for high-speed recording and storage stability are obtained by the combined use of the coloring agent represented by the above general formula [I] and the compound represented by the general formula (II), -
i The compound represented by formula (II) has excellent compatibility with the coloring agent represented by general formula (I), and has the effect of promoting contact between the basic dye and the coloring agent. It is presumed that the diazo resistance is improved, and since both of them are difficult to dissolve in a diazo developer, the diazo resistance is also excellent. General formula [l
) Specific examples of the color former include the following.

3.4-dihydroxydiphenylsulfone, 3゜4-dihydroxy-4'-methyldiphenylsulfone, 3,4
-dihydroxy-4'-ethyldiphenylsulfone, 3
, 4-dihydroxy-4'-propyldiphenylsulfone, 3,4-dihydroxy-4'-isopropyldiphenylsulfone, 3,4-dihydroxy-4'-butyldiphenylsulfone, 3,4-dihydroxy-2',4 '
-dimethyldiphenylsulfone, 3,4-dihydroxy-4'-chlordiphenylsulfone, 3,4゜4'-trihydroxydiphenylsulfone, 3゜4-dihydroxy-4'-cyclohexyldiphenylsulfone, 3.4
-dihydroxy-4'-methoxydiphenyl sulfone,
3.4-dihydroxy-4'-nidoxydiphenylsulfone, 3,4-dihydroxy-4'-phenoxydiphenylsulfone, 3.4-dihydroxy-4'-benzyloxydiphenylsulfone, 3.4-dihydroxy-4
'-Benzyldiphenylsulfone, 3,4-dihydroxy-4'-phenethyldiphenylsulfone, 3,4-dihydroxydi4'-methylthiodiphenylsulfone, 3
, 4-dihydroxy-4'-ethylthiodiphenylsulfone, 3,4-dihydroxy-4'-phenylthiodiphenylsulfone, 3,4-dihydroxy-4'-benzylthiodiphenylsulfone, 3,4-dihydroxyphenyl-1- Naphthylsulfone, 3,4-dihydroxyphenyl-2-naphthylsulfone, 3゜4-dihydroxy-3',4'-1-rimethylenediphenylsulfone, 3
．． 4-dihydroxy-3'.

4'-tetramethylene diphenyl sulfone, 3'.

4'-trimethylene-4-hydroxydiphenylsulfone, 3', 4'-1-rimethylene-2-methyl-4-hydroxydiphenylsulfone, 3'.

4'-trimethylene-3-methyl-4-hydroxydiphenylsulfone, 3',4'-)dimethylene-2-methoxy-4-hydroxydiphenylsulfone, 3',4'
-) Dimethylene-2-chloro-4-hydroxydiphenylsulfone, 3',4'-trimethylene-2,3-dimethyl-1-hydroxydiphenylsulfone, 3',4
'-trimethylene-2,6-dimethyl-4-hydroxydiphenylsulfone, 3',4'-)rimethylene-2゜4-dihydroxydiphenylsulfone, 3',4'-tetramethylene-4-hydroxydiphenylsulfone, 3
', 4'-tetramethylene-2-methyl-4-hydroxydiphenylsulfone, 3'.

4'-tetramethylene-3-methyl-4-hydroxydiphenylsulfone, 3',4'-tetramethylene-
2-methoxy-4-hydroxydiphenylsulfone, 3
',4'-tetramethylene-2-chloro-4-hydroxydiphenylsulfone, 3',4'-tetramethylene-
2,3-dimethyl-4-hydroxydiphenylsulfone, 3',4'-tetramethylene-2,6-dimethyl-4
-Hydroxydiphenylsulfone, 3',! '-tetramethylene-2,4-dihydroxydiphenylsulfone, 3-allyl-4-hydroxydiphenylsulfone, 3
-Allyl-4-hydroxy-4'-methyldiphenylsulfone, 3-allyl-4-hydroxy-4'-ethyldiphenylsulfone, 3-allyl-4-hydroxy-4'
-isobutyldiphenylsulfone, 3-allyl-4-hydroxy-4'-tert-butyldiphenylsulfone, 3-allyl-4-hydroxy-2', 4'-dimethyldiphenylsulfone, 3-allyl-4-hydroxy-4
'-Cyclohexyldiphenylsulfone, 3-allyl-
4-hydroxy-4'-benzyldiphenyl sulfone,
3-Hydroxy-4'-phenethyldiphenylsulfone, 3-allyl-4-hydroxy-4'-phenyldiphenylsulfone, 3-allyl-4-hydroxy-4'-vinyldiphenylsulfone, 3-allyl- 4
-Hydroxy-4'-methoxydiphenylsulfone, 3
．． 3'-Diallyl-4-hydroxy-4'-methoxydiphenylsulfone, 3-allyl-4-hydroxy-4'
-Ethoxydiphenylsulfone, 3,3'-diallyl-
4-hydroxy-4'-ethoxydiphenyl sulfone,
3-allyl-4-hydroxy-4'-propoxydiphenylsulfone, 3-allyl-4-hydroxy-4'-isopropoxydiphenylsulfone, 3,3'-diallyl-4-hydroxy-4'-isopropoxydiphenylsulfone, 3-allyl-4-hydroxy-4'-butoxydiphenylsulfone, 3-allyl-4-hydroxy-4
'-isobutoxydiphenylsulfone, 3-allyl-4
-Hydroxy-4'-cyclohexyloxydiphenylsulfone, 3-allyl-4-hydroxy-4'-benzyloxydiphenylsulfone, 3-allyl-4-hydroxy-4'-phenethyloxydiphenylsulfone, 3
-Allyl-4-hydroxy-4'-phenoxydiphenylsulfone, 3-allyl-4-hydroxy-4'-(2
-methoxyethoxy)-diphenylsulfone, 3-allyl-4-hydroxy-4'-(2-ethoxyethoxy)
-diphenylsulfone, 3-allyl-4-hydroxy-
4'-(2-phenoxyethoxy)-diphenylsulfone, 3-allyl-4-hydroxy-4'-methylthiodiphenylsulfone, 3-allyl-4-hydroxy-4'
-Ethylthiodiphenylsulfone, 3-allyl-4-hydroxy-4'-propylthiodiphenylsulfone, 3
-Allyl-4-hydroxy-4'-phenylthiodiphenylsulfone, 3-allyl-4-hydroxy-4'-benzylthiodiphenylsulfone, 3-allyl-4-hydroxy-42-phenethylthiodiphenylsulfone, 3
-Allyl-4-hydroxy-2t, 3r F rimethylene diphenyl sulfone, 3-allyl-4-hydroxy-
3'4'-)rimethylene diphenyl sulfone, 3-allyl-4-hydroxy-2', 3'-tetramethylene diphenyl sulfone, 3-allyl-4-hydroxy-3',
4'-tetramethylenediphenylsulfone, 3-allyl-4-hydroxyphenyl-1-naphthylsulfone, 3
-71J Ru 4-hydroxyphenyl-2-naphthylsulfone, 4-hydroxy-4'-isopropyloxydiphenylsulfone, 4-hydroxy-4'-butoxydiphenylsulfone, 4-hydroxy-4'-hexyloxydiphenylsulfone, 4- Hydroxy-4'-octyloxydiphenylsulfone, 4-hydroxy-4'
-benzyloxydiphenylsulfone, 4-hydroxy-4'-(2-ethoxyethoxy)diphenylsulfone, 4-hydroxy-4'-methyldiphenylsulfone, 4,4'-dihydroxy-2,2'-diallyldiphenylsulfone, etc. Of course, two or more of these compounds can be used in combination.

Among the coloring agents represented by the above general formula (I), the following general formula (
The coloring agent represented by Ia], (Ib) or (Ic), when used in combination with the compound represented by the general formula Cl0), provides a heat-sensitive recording material particularly excellent in high-speed recording suitability and storage stability. Therefore, it is more preferably used.

[In the formula, Z represents a hydrogen atom, a halogen atom, an alkyl group, or an alkoxyl group. RI2 to R21 are each a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, a vinyl group, an allyl group, a cycloalkyl group, an aralkyl group, an aryl group, an alkoxyl group, a cycloalkyloxy group, an aralkyloxy group, an aryloxy group , an alkylthio group, an aralkylthio group, an arylthio group, an alkoxyalkoxyl group, or an alkoxyalkoxyl group. R2□ represents an alkoxyl group. Also, R1
2 and RB, RI, and Rz, RI7 and RlB, RIB and R
19 may form a naphthalene ring, a tetrahydronaphthalene ring, or an indane ring together with adjacent benzene rings. ]-i Among the compounds represented by formula (II), when a compound in which n is 2 to 6 is used, a heat-sensitive recording material having better high-speed recording suitability and high whiteness can be obtained;
It is more preferable to use a compound having 2 or 4 because a heat-sensitive recording material with the best balance between high-speed recording suitability and whiteness can be obtained.

Specific examples of the compound represented by the general formula (I[) include di(4-biphenylthio)methane, di(4-bromophenylthio)methane, di(3-nitrophenylthio)
Methane, 1,2-diphenylthioethane, 1,2-di(
4-tolylthio)ethane, 1,2-di(3-tolylthio)ethane, 1゜2-di(t-fluorophenylthio)ethane, 1゜2-cy(2-chlorophenylthio)ethane,
1゜2-di(4-chlorophenylthio)ethane, 1゜2
-di(3-nitrophenylthio)ethane, 1゜2-di(
4-2i-lophenylthio)ethane, 1゜2-di(2,
5-dichlorophenylthio)ethane, ■-(4-benzyloxyphenylthio)-3-phenylthiopropane,
1.4-diphenylthiobutane, 1.4-di(4-chlorophenylthio)butane, 1-(4-methoxyphenylthio)-4-phenylthiobutane, 1.4-di(4-tolylthio)butane, 1 -(4-hensylphenylthio)
-5-phenylthiopentane, 1,5-di(4-bromophenylthio)pentane, 1,6-cyphenylthiohexane and the like.

The ratio of the color former represented by the general formula (I) and the compound represented by the general formula CI) is not necessarily limited, but usually the color former represented by the general formula [I] 1
It is desirable to adjust the amount of the compound represented by the general formula (It) to 1 to 1000 parts by weight, more preferably 10 to 300 parts by weight.

In the present invention, various types of colorless or light-colored basic dyes are known as the colorless or light-colored basic dyes constituting the recording layer of the thermosensitive recording material, and the following are exemplified.

3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophenylde, 3,3-bis(p-dimethylaminophenyl)phthalide, 3-(p-dimethylaminophenyl)-3-(1,2 -dimethylindol-3-yl)phthalide 1,3-(p-dimethylaminophenyl)
-3-(2-methylindol-3-yl)phthalide,
3.3-bis(l,2-dimethylindol-3-yl)=5-dimethylaminotuclide, 3.3-bis(1°2-dimethylindol-3-yl)-6-dimethylaminotuclide 1 .3.3-bis(9-ethylcarbazol-3-yl)-6-dimethylaminotuclide, 3,3
-Bis(2-phenylindol-3-yl)-6-dimethylaminophenyl, 3-p-dimethylaminophenyl-3-(1-methylpyrrol-3-yl)-6-dimethylaminol, etc. Allylmethane dye, 4.
4'-bis-dimethylaminobenzhydrylbenzyl ether, N-herophenyl leukoolamine, N-2
, diphenylmethane dyes such as 4,5-trichlorophenylleucoolamine, thiazine dyes such as benzoylleucomethylene blue and p-nitrobenzoylleucomethylene blue, 3-methyl-spiro-dinaphthopyran,
3-ethyl-spiro-dinaphthopyran, 3-phenyl-
Spiro dyes such as spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho (6'-methoxybenzo) spiropyran, 3-propyl-spiro dihenzopyran, rhodamine-B-anilinolactam, rhodamine ( p-nitroanilino)lactam,
Lactam dyes such as rhodamine (0-chloroanilino)lactam, 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-7N-acetyl-N-methylaminofluorane, 3-diethylamino-7-N-methylaminofluorane, 3-diethylamino-7-dihendylaminofluorane, 3-diethylamino-7-N-methyl-
N-hensylaminofluorane, 3-diethylamino-
7N-chloroethyl-N-methylaminofluorane, 3
-diethylamino-7-diethylaminofluorane, 3
-(N-ethyl-p-toluidino)-6-methyl-7-
Phenylaminofluorane, 1-(N-ethyl-1)-
)luidino)-6-methyl-7-(p-toluidino)fluoran, 3-diethylamino-6-methyl-7-phenylaminofluoran, 3-dibutylamino-6-methyl-7-phenylaminofluoran, 3- Diethylamino-7-(2-carbomethoxy-phenylamino)fluoran, 3-(N-ethyl-N-isoamyl)amino-
6-Methyl-7-phenylaminofluorane, 3-(N
-cyclohexyl-N-methylamino)-6-methyl-
7-phenylaminofluorane, 3-pyro°nodino 6
-Methyl-7-phenylaminofluorane, 3-piperidino-6-methyl-7-phenylaminofluorane, 3
-diethylamino-6-methyl-7-xylidinofluorane, 3-diethylamino-7-(0-chlorophenylamino)fluoran, 3-dibutylamino-7-(o-
chlorophenylamino)fluorane, 3-pyrrolidino-
6-Methyl-7-p-butylphenylaminofluorane, 3-(N-methyl-Nn-amyl)amino-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-N-n -Amino-6-methyl-7-phenylaminofluorane, 3-(N-methyl-Nn-hexyl)amino-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-N -n-hexyl)amino-
6-Methyl-7-phenylaminofluorane, 3-(N
-Ethyl-N-β-ethylhexyl)amino-6-methyl-7-phenylaminofluoran and other fluoran dyes.

Of course, the dyes are not limited to these dyes, and two or more types of dyes can be used in combination. In addition, the ratio of the basic dye to the coloring agent represented by the general formula [I] is generally 1:1 for the dye.
Coloring agent represented by general formula [I] 1 to 50 parts by weight
It is desirable to adjust the box size by parts by weight, more preferably from 1 to 10 parts by weight.

To prepare a heat-sensitive coating solution containing these, dyes, coloring agents, and general formula [II
It is prepared by dispersing the compounds shown in ] together or separately.

Such i4 liquid usually contains starches, hydroxyethyl cellulose, methyl cellulose,
Carboxomethyl cellulose, gelatin, casein, gum arabic, polyvinyl alcohol, styrene/maleic anhydride copolymer salt, styrene/acrylic acid copolymer salt, styrene/butadiene copolymer emulsion, etc. have a total solid content of 10 to 40% 4%, preferably 15-30% by weight
It is mixed to some extent.

Furthermore, various auxiliary agents can be added to the coating liquid.
For example, dispersants such as sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium lauryl alcohol sulfate, fatty acid metal salts, ultraviolet absorbers such as triazoles, and other antifoaming agents,
Examples include fluorescent dyes and colored dyes. Further, a dispersion or emulsion of stearic acid, polyethylene, carnauba wax, paraffin wax, zinc stearate, calcium stearate, ester wax, etc. may be added to prevent sticking from contact with a recording device or a recording head.

Further, fatty acid amides such as stearic acid amide, stearic acid methylene bisamide, oleic acid amide, palmitic acid amide, coconut fatty acid amide, 1,1,3-tris(2-methyl -4-hydroxy-5-tert-butylphenyl)butane, 2,2'-methylene-bis(4-methyl-6
-tert-butylphenol), 1゜2-bis(phenoxy)ethane, 1.2-
Bis(4-methylphenoxy)ethane, 1,2-bis(
Various known thermofusible substances such as ethers such as 3-methylphenoxy)ethane and 2-naphthol benzyl ether, esters such as dibenzyl terephthalate and 1-hydroxy-2-naphthoic acid phenyl ester, and bisphenol A, p -Hydroxybenzoic acid hensyl ester, 4-
Various known coloring agents such as hydroxyphthalic acid dimethyl ester can also be used in combination.

In addition, kaolin, clay, talc, calcium carbonate, calcined clay,
Inorganic pigments such as titanium oxide, diatomaceous, fine 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 coating liquid forming the recording layer applied to the support is not particularly limited, and is usually 2 to 12
g/m, preferably adjusted within a range of about 3 to 10 g/m.

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

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

"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 do not indicate parts by weight and % by weight, respectively.

Example 1 ■ Preparation of Solution A 3-(N-ethyl-N-4-pentylamino)-6-methyl-7-phenylaminofluorane 10 parts 1.4-diphenylthiobutane 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 B solution 3.4-dihydroxy-4'-ethyldiphenylsulfone 30 parts Methylcellulose 5% aqueous solution 30 parts water
70 parts of this composition was ground in a sand mill until the average particle size was 3 μm.

■ Formation of recording layer 165 parts of liquid A, 130 parts of liquid B, silicon oxide pigment (oil absorption 1
80 m1/100 g), 150 parts of a 20% oxidized starch aqueous solution, and 55 parts of water were mixed and stirred to prepare a coating liquid. The resulting coating liquid was applied to 50 g/lri of base paper with a dry weight of 7.5
The coating was applied and dried to obtain a heat-sensitive recording paper of g/m.

Example 2 Thermosensitive recording paper was obtained in the same manner as in Example 1, except that 1,2-di(4-tolylthio)ethane was used instead of 1,4-diphenylthiobutane in preparing liquid A. .

Example 3 Thermosensitive recording paper was obtained in the same manner as in Example 1, except that 1,2-di(4-chlorophenylthio)ethane was used instead of 1,4-diphenylthiobutane in preparing liquid A. Ta.

Example 4 3,4-dihydroxy-4 was used instead of 3,4-dihydroxy-4'-ethyldiphenylsulfone in the preparation of Solution B.
Example 1 except that '-methyldiphenylsulfone was used.
A thermosensitive recording paper was obtained in the same manner as above.

Example 5 Same as Example 1 except that 3',4'-tetramethylene-4-hydroxydiphenylsulfone was used instead of 3,4-dihydroxy-4'-ethyldiphenylsulfone in preparing Solution B. A thermosensitive recording paper was obtained.

Example 6 Thermal sensitivity was carried out in the same manner as in Example 1, except that 3-allyl-4-hydroxy-4'-methoxydiphenyl sulfone was used instead of 3,4-dihydroxy-4'-ethyldiphenyl sulfone in the preparation of liquid B. I got the recording paper.

Example 7 Thermosensitive recording paper was prepared in the same manner as in Example 1 except that 4-hydroxy-4'-isopropyloxydiphenyl sulfone was used in place of 3,4-dihydroxy-4'-ethyldiphenyl sulfone in preparing liquid B. Obtained.

Example 8 Thermosensitive recording paper was obtained in the same manner as in Example 1, except that 4-hydroxy-4'-methyldiphenylsulfone was used instead of 3,4-dihydroxy-4'-ethyldiphenylsulfone in preparing liquid B. Ta.

Example 9 Heat-sensitive recording paper was prepared in the same manner as in Example 1, except that 1,5-di(4-bromophenylthio)pentane was used instead of 1,4-diphenylthiobutane in preparing Liquid A. Obtained.

Comparative Example I In preparing liquid A, stearic acid amide was used instead of 1,4-diphenylthiobutane, and in preparing liquid B, bisphenol A was used instead of 3,4-dihydroxy-4'-ethyldiphenylsulfone. Example 1 except that
A thermosensitive recording paper was obtained in the same manner as above.

Comparative example 2 B? A thermosensitive recording paper was obtained in the same manner as in Example 1, except that bisphenol A was used instead of 3,4-dihydroxy-4'-ethyldiphenylsulfone in the 1J31 formation.

Comparative Example 3 A thermosensitive recording paper was obtained in the same manner as in Example 1 except that stearic acid amide was used instead of 1,4-diphenylthiobutane in preparing liquid A.

The 12 types of thermal recording papers obtained were recorded using a thermal facsimile (Hitachi HIFAX-700 model),
The color development; the agricultural degree (Do) is measured using the Macbeth Densitometer (RD-10).
The results are shown in Table 1.

Next, the recorded heat-sensitive recording paper was layered on a vinyl chloride film, and the density (D) of the recorded image after one hour was measured using a Macbeth agricultural meter, and the results are shown in Table 1.

In addition, the whiteness of the surface of the recording layer before recording was measured using a Hunter whiteness meter, and the whiteness was also measured after the heat-sensitive recording paper was overlaid with high-quality paper impregnated with a diazo developer and left to stand for 5 minutes. The results were also shown in Table 1.

"Effect" As is clear from the results in Table 1 (, the thermal recorder tTh of the present invention
The paper has high-speed recording characteristics, excellent whiteness, and is resistant to plasticizers.
It was a recording medium with excellent diazo resistance.

Table 1

Claims (1)

[Scope of Claims] A colorless or light-colored basic dye, at least one coloring agent represented by the following general formula [I], and the following general formula [I]
A heat-sensitive recording material comprising a heat-sensitive recording layer containing at least one of the compounds represented by I] on a support. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, X and Y each represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxyl group, or an allyl group, and m is 1
or 2. R_1, R_2, R_3, R_4 and R_5 are each a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, a vinyl group, an allyl group, a cycloalkyl group, an aralkyl group, an aryl group, an alkoxyl group,
cycloalkyloxy group, aralkyloxy group, aryloxy group, alkylthio group, aralkylthio group,
Indicates an arylthio group, an alkoxyalkoxyl group, or an aryloxyalkoxyl group. Also, R_1 and R_2
, R_2 and R_3 may form a naphthalene ring, a tetrahydronaphthalene ring or an indane ring together with the benzene ring adjacent to each other. ] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] [In the formula, R_6 to R_1_1 are hydrogen atoms, halogen atoms, nitro groups, cyano groups, C_1_ to _4 alkyl groups, aralkyl groups, aryl groups, C_1_ ~＿４
alkoxyl group, C_1_ to_4 alkylthio group,
Acetyl group, propionyl group, methoxycarbonyl group,
It represents a cyclohexenyl group, an aralkyloxy group, or an aryloxy group, and n represents an integer of 1 to 10. ]