JPH02297486A - Thermally sensitive recording medium - Google Patents

Abstract

PURPOSE:To stabilize the degree of whiteness of a thermally sensitive recording medium best suited to high-speed recording by using 3-di-n-pentyleamino-6- methyl-7-phenylaminofluorane as a basic dye and adding one type of specific thermally fusable material to a thermally sensitive, recording layer. CONSTITUTION:3-di-n-pentylamino-6-methyl-7-phenylaminofluorene is used as a basic dye, and further one type of thermally fusable material represented by formula I is added to a thermally sensitive recording layer. In the formula I, R is a divalent group with 2 to 8 carbons, R1 to R4 are a hydrogen atom, a low alkyl group, a cycloalkyl group respectively or a halogen atom. R1 and R2, R3 and R4 are bonded to each other to form an aromatic ring. X, Y represent an oxygen atom or a sulfur atom respectively. Thus the thermally sensitive recording medium is obtained which is best suited to rapid recording, has a high degree of whiteness of a thermally sensitive recording medium itself, and in addition, has no deterioration of the degree of whiteness, if stored for a long time.

Description

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

□ "Prior Art" Conventionally, heat-sensitive recording materials utilize a color 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. is well known. Recently, with the remarkable progress of thermal recording method,
Thermal faxes, thermal printers, etc. can all be faster, and thermal faxes and printers can be used at 10 times faster on A4 size paper.
recording speed of 120 characters/sec or more is possible with thermal printers. 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.

In order to enable high-speed recording, it is necessary to increase the sensitivity of the heat-sensitive recording medium, and various thermofusible substances are included in the heat-sensitive recording layer to increase the sensitivity. however,
In general, such high-sensitivity thermosensitive recording materials tend to undergo discoloration (fogging phenomenon) in blank areas due to long-term storage, and there is a strong demand for improvement.

``Problems to be Solved by the Invention'' In view of the current situation, the present inventors have conducted extensive research into improving the defects observed in heat-sensitive recording materials, and have found that 3-di-n-pentylamino is a basic dye. -6
- By using methyl-7-phenylaminofluorane in combination with a specific thermofusible substance, not only is it excellent in high-speed recording suitability, but the heat-sensitive recording material itself has a high whiteness and can be stored for a long time. It was discovered that a heat-sensitive recording material without a decrease in whiteness could be obtained, and the present invention was completed.

"Means for Solving the Problems" The present invention provides a heat-sensitive recording layer containing a colorless or light-colored basic dye and a coloring agent capable of coloring when it comes into contact with the basic dye, on a support. In the thermosensitive recording medium, 3-di-n-pentylamino-6-methyl-7-
This is a heat-sensitive recording material characterized by using phenylaminofluorane and further containing at least one type of thermofusible substance represented by the following general formula 4 (I) in the heat-sensitive recording layer.

[In the formula, R represents a divalent group having 2 to 8 carbon atoms, and R3-R
4 is a hydrogen atom, a lower alkyl group, a cycloalkyl group, a phenyl group, a lower alkoxyl group, a cycloalkoxyl group, a lower alkylthio group, an aralkyloxy group,
Aralkylthio group, lower alkyloxycarbonyl group,
Indicates an aralkyloxycarbonyl group or a halogen atom. Furthermore, R and Rz, and Rs and R4 may be bonded to each other to form an aromatic ring. X and Y each represent an oxygen atom or a sulfur atom. [Function] The heat-sensitive recording material of the present invention has 3 as a basic dye as described above.
By using -di-n-pentylamino-16-methyl-7-phenylaminofluorane and a specific thermofusible substance, it has excellent high-speed recording suitability and the whiteness of the heat-sensitive recording material itself. To provide a heat-sensitive recording material having extremely high commercial value, which has a high degree of brightness and does not suffer from a decrease in whiteness even when stored in an external environment for a long time.

In the general formula [■], R represents a divalent group having 2 to 8 carbon atoms, and among the divalent groups, alkylene groups, alkylene groups having a carbonyl group, alkylene groups having a halogen atom, and ether bonds An alkylene group having a thioether bond, an alkylene group having an ester bond, an alkylene group having an amide bond, and an alkylene group having an unsaturated bond are preferable, and an alkylene group and an alkylene group having an ether bond are particularly preferable.

Furthermore, the melting point of the compound represented by general formula [I] is 50
~150°C is preferable, and moreover, a melting point of 70~13
A temperature of 0°C is more preferable.

Specific examples of the compound represented by general formula [I] include the following.

1.2-diphenoxyethane, 1.2-bis(2-methylphenoxy)ethane, ■, 2-bis(3-methylphenoxy)ethane, ■, 2-bis(4-methylphenoxy)ethane, 1-phenoxy -2-(2-methylphenoxy)ethane, ■-phenoxy-2-(3-methylphenoxy)ethane, 1-phenoxy-2-(4-methylphenoxy)ethane, 1-phenoxy-2-(4-ethylphenoxy) ) ethane, 1-phenoxy-2-(4-isopropylphenoxy)ethane, ■-phenoxy=2-(4
-tert-butylphenoxy)ethane, 1-phenoxy-2-(2,3-dimethylphenoxy)ethane, 1-
Phenoxy-2-(2,4-dimethylphenoxy)ethane, 1-phenoxy-2-(3,4-dimethylphenoxy)ethane, 1-phenoxy-2-(3,5-dimethylphenoxy)ethane, 1-(2 -methylphenoxy)-
2-(4-methylphenoxy)ethane, 1-(3-methylphenoxy)-2-(4-methylphenoxy)ethane, 1-phenoxy-2-(2-phenylphenoxy)ethane, 1-phenoxy- 2-(α-naphthyloxy)ethane, 1-phenoxy-2-(2-chlorophenoxy)ethane, ■-phenoxy-2-(3-
chlorophenoxy)ethane, 1-phenoxy-2-(4
-chlorophenoxy)ethane, 1,2-bis(2-chlorophenoxy)ethane, 1,2-bis(3-chlorophenoxy)ethane, 1,2-bis(4-chlorophenoxy)ethane, ■-phenoxy 3 -(β-naphthyloxy)propane, ■-(4-methylphenoxy)-3-(β
-naphthyloxy)propane, 1-phenoxy-3-(
4-Phenylphenoxy)propane, ■-(4-methylphenoxy)-,3-(4-phenylphenoxy)propane, 1,4-diphenoxybutane, 1,4-bis(4
-methylphenoxy)butane, 1,4-bis(4-methoxyphenoxy)butane, 1,4-bis(4-cyclohexylphenoxy)butane, 1,4-bis(4-chlorophenoxy)butane, 1,4-bis (2-methylphenoxy)butane, 1,6-diphethoxyhexane, 1-phenoxy-6-(β-naphthyloxy)hexane, ■,
2-bis[4-(methylthio)phenoxy]ethane, 1
．． 3-bis[4-(methylthio)phenoxy]propane, 1,4-bis[4-(methylthio)phenoxycobutane, 1,2-bis(4-(benzylthio)phenoxy)
Ethane, 1.2-bis(4-benzyloxyphenoxy)ethane, ■, 2-bis(4-methoxycarbonylphenoxy)ethane, 1.2-bis(4-ethoxycarbonylphenoxy)ethane, 1°2-bis( 4-hensyloxycarbonylphenoxy)ethane, 1,5-bis(4
-methoxyphenoxy)-3-oxapencune, 1,5
-Bis[4-(methylthio)phenoxy]-3-oxapencune, 1,5-bis(4-methoxyphenoxy)-
3-Thiabencune, 1,5-bis[4-(methylthio)
phenoxy]-3-thiapencune, 1゜3-diphenoxyacetone, 1,3-diphenoxy-2-hydroxypropane, ■, 3-diphenoxy-2-chloropropane,
1,4-diphenoxy-2-chlorobutane, 1,4-diphenoxy-2-butene, 1.4=diphenoxy-2-
Butyne, phenoxyacetic acid-2-phenoxyethyl ester, 1-phenoxy-N-(2-phenoxyethyl)acetamide, 1-phenoxy-N-(3-phenoxypropyl)acetamide, 1.2-bis(phenylthio)
Ethane, 1,3-bis(phenylthio)propane, 1,
4-bis(phenylthio)butane, 1,2-bis(4-
Chlorophenylthio)ethane, 1,3-bis(4-chlorophenylthio)propane, ■, 4-bis(4-chlorophenylthio)butane, 1,2-bis(4-methylphenylthio)ethane, 1,3-bis (4-Methylphenylthio)propane, 1,4-bis(4-methylphenylthio)butane, 1,2-bis(4-methoxyphenylthio)ethane, 1,3-bis(4-methoxyphenylthio)
Propane, 1,4-bis(4-methoxyphenylthio)
Butane, 1,5-bis(4-methoxyphenylthio)-
3-oxapentane, 1,3-bis(phenylthio)acetone, 1-phenoxy-2-(phenylthio)ethane, 1-phenoxy-4-(phenylthio)butane, 1-
phenoxy-2-(4-methylphenylthio)ethane,
1-phenoxy-2-(4-chlorophenylthio)ethane, 1-phenoxy-2-(4-methoxyphenylthio)ethane, and the like.

Of course, the present invention is not limited to these compounds, and it is also possible to use two types of compounds in combination, if necessary. .

These thermofusible substances and 3-di-n-pentylamino-
The proportion of the combined use with 6-methyl-7-phenylaminofluorane is not necessarily limited, but 1, 50 to 700 parts by weight, preferably 100 to 500 parts by weight of heat per 100 parts by weight of the basic dye. It is desirable to incorporate a fusible substance.

Furthermore, in the present invention, the following general formula (Il
) to (V) is a more preferable embodiment, since the solidity of the recorded image can be further improved.

[In the formula, R3 represents a branched alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a halogen atom, and Rt represents a hydrogen atom, a branched alkyl group having 3 to 8 carbon atoms, or Indicates a halogen atom, R3, R5-R8
each represents a hydrogen atom or a lower alkyl group. R4 represents a hydrogen atom, a halogen atom, or an alkyl group having 8 or less carbon atoms. X is 10-2-S-1-S-S-1 each represents a hydrogen atom or an alkyl group having 8 or less carbon atoms. Furthermore, R7 and R1° may be combined with each other to form a ring.

Z represents a linear or branched alkylene group having 8 or less carbon atoms. ] Specific examples of the compounds represented by general formulas [II] to [V] include the following compounds.

[Compound represented by general formula (Il)]

4.4'-Butylidene bis(2tert-butyl-5-
methylphenol), 4,4'-butylidene bis(2-
tert-butyl-6-methylphenol), 4.4'
-butylidene bis(2,6-di-tert-butylphenol), 4.4'-butylidene bis(2-cyclohexylphenol L4゜4'-butylidene bis(2-
phenylphenol), 4,4'-cyclohexylidenebis(2tert-butyl-5-methylphenol),
4,4'-cyclohexylidene bis(2-tert-phthyl-5-methylphenol) 4,4'-cyclohexylidene bis(2,6-di-tert-butylphenol), 4,4'-cyclohexylidene bis(2-tert-butylphenol) −
cyclohexylphenol), 4,4'-cyclohexylidenebis(2-phenylphenol L 4,4'-
Thiobis(2tert-butyl-5-methylphenol L 4,4'-thiobis(2tert-butyl-6-methylphenol), 4,4'-thiobis(2,6-di-tert-butylphenol), 4°4' -thiobis(2-cyclohexylphenol), 4.4'-thiobis(2-phenylphenol), 4.4'-isopropylidenebis(2,6-dichlorophenol), 4.4
'-isopropylidene bis(2,6-dibromophenol), 4.4'-cyclohexylidene bis(2,6-dichlorophenol) 4.4'-cyclohexylidene bis(2,6-dibromophenol), bis (4-hydroxy-3,5-dichlorophenyl)sulfone, bis(
4-hydroxy-3,5-dibromophenyl) sulfone, bis(4-hydroxy-3,5-dichlorophenyl)
Sulfide, bis(4-hydroxy-3,5-dibromophenyl) sulfide, bis(4-hydroxy-3,5
-dichlorophenyl) ether, bis(4-hydroxy-3,5-dibromophenyl) ether, bis(4-hydroxy-3,5-dichlorophenyl) disulfide,
Bis(4-hydroxy-3,5-dibromophenyl) disulfide and the like.

[Compound represented by general formula (1]) 2.2'-methylenebis(4-methyl-6tert-butylphenol), 2.2'-methylenebis(4-ethyl-6-tert-butylphenol), 2.2 ′−
Methylenebis(4,6-di-tert-butylphenol), 2,2'-methylenebis(4゜6-dichlorophenol) 2,2'-ethylidenebis(4,6-di-tert-butylphenol), 2.2' -thiobis(4-methyl-5-tert-butylphenol), 2
．． 2'-thiobis(4-ethyl-5-Lert-butylphenol), 2,2'monothiobis(4,6-dite
r t-Butylphenol L 2,2'-dithiobis(
4-methyl-6-tert-butylphenol), bis(2-hydroxy-3-tert-butyl-5-methylphenyl)sulfone, bis(2-hydroxy-3-tert-butylphenol), bis(2-hydroxy-3-tert-butyl-5-methylphenyl)
ert-butyl-5-ethylphenyl) sulfone, bis(2-hydroxy-3,5-dichlorophenyl) sulfone, and the like.

[Compound represented by general formula (IV)]

1.1.3-) Lis(2-methyl-4-hydroxy-5
-tert-butylphenyl)butane, 1゜1.3-tris(3-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,1.3-tris(3,5-
di-tert-butyl-4-hydroxyphenyl)butane, 1,1.3-)lis(3,5-dichloro-4-hydroxyphenyl)butane, 1,1.3-tris(3,
5-dibromo-4-hydroxyphenyl)butane, 1,
1,3-tris(3-cyclohexyl-4-hydroxy-6-methylphenyl)butane, 1,1,3-)lis(
3-phenyl-4-hydroxyphenyl)butane, 2-
Methyl-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 2-ethyl-1,1,3-1-lis(2-methyl-4-hydroxy-5 -tert-butylphenyl)butane, 1.1
．． 3-) Lis(2-methyl-4-hydroxy-5-te
rt-butylphenyl)hexane, 1,1.3-)lis(2-methyl-4-hydroxy-5-tert-butylphenyl)hebutane, 2-ethyl-1,1,3-tris(2-methyl- 4-hydroxy-5-tert-butylphenyl)hexane, etc.

[Compound represented by general formula [V]] 1-[bis(4-hydroxyphenyl)methyl]-3-
(1-(4-hydroxyphenyl)ethyl)benzene,
1-[bis(4-hydroxyphenyl)methyl]-4-
(1-(4-hydroxyphenyl)ethyl)benzene,
1-(bis(4-hydroxyphenyl)methyl)-3-
(1-methyl-1-(4-hydroxyphenyl)ethyl]benzene, 1-[bis(4-hydroxyphenyl)methyl]-4-[1-methyl-1-(4-hydroxyphenyl)ethyl]benzene, 1 -(1,1-bis(4-hydroxyphenyl)ethyl)-3-(1-(4-hydroxyphenyl)ethyl)benzene, 1-(1,'1-bis(4-hydroxyphenyl)ethyl)-4 -(1-(
4-hydroxyphenyl)ethyl]benzene, 1-(1
,1-bis(4-hydroxyphenyl)ethyl) -3
-(1-methyl-1-(4-hydroxyphenyl)ethyl)benzene, 1-(1,1-bis(4-hydroxyphenyl)ethyl)-4-(1-methyl-1-(4-hydroxyphenyl) [ethyl]benzene etc.

Of course, two or more of the compounds represented by the above general formulas (Il) to [V] can also be used in combination.

Note that the amount of phenolic compounds with these specific structures to be used is not necessarily limited, but
It is desirable to blend the phenolic compound in an amount of about 5 to 300 parts by weight, preferably about 10 to 200 parts by weight, per 100 parts by weight of 3-di-n-pentylamino-6-methyl-7-phenylaminofluorane.

Various coloring agents are known, including the following compounds.

4.4'-isopropylidene diphenol, 4゜4'-
Cyclohexylidene diphenol, 4,4'-(1,3
-dimethylbutylidene) diphenol, 1,3-bis(
p-hydroxy-α-cumyl)benzene, 1,4-bis(p-hydroxy-α-cumyl)benzene, p, p'-
Biphenol, 4-phenylphenol, 4-α-cumilfumorinor, 4-hydroxydiphenyl ether, 4
．． 4'-dihydroxydiphenyl ether, 4.4'
-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxybenzophenone, bis(3-allyl-4-hydroxyphenyl) sulfone,
4-hydroxydiphenylsulfone, 4-hydroxy-
4'-methyldiphenylsulfone, 4-hydroxy-
4'-chlorodiphenylsulfone, 3,4-dihydroxy-41-methyldiphenylsulfone, 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-3',4'-tetramethylenediphenylsulfone, methyl-4- Hydroxybenzoate, benzyl-4-hydroxybenzoate, methyl-bis(4-hydroxyphenyl)acetate, ethyl-bis(4-hydroxyphenyl)acetate, butyl-bis(4-hydroxyphenyl)acetate, benzyl-bis(4-hydroxyphenyl)acetate
Hydroxyphenyl) acetate, bis(4-hydroxyphenyl)acetic acid-2-phenoxyethyl ester, p
-Hydroxy-N-(2-phenoxyethyl)benzenesulfonamide, dimethyl 4-hydroxyphthalate, 1
．． 5-bis(4-hydroxyphenylthio)-3-oxapentane, 1゜7-bis(4-hydroxyphenylthio)-3゜5-dioxahebutane, 1.8-bis(4-
Phenolic compounds such as hydroxyphenylthio)-3,6-thioxaoctane, (4-hydroxyphenylthio)acetic acid-2-(p-hydroxyphenylthio)ethyl ester; benzoic acid, 4-tert-butylbenzoic acid,
4-chlorobenzoic acid, 4-nitrobenzoic acid, phthalic acid monoethyl ester, tetrachlorophthalic acid mo2(2-hydroxyethyl) ester, salicylic acid, 3-isopropylsalicylic acid, 3-phenylsalicylic acid, 3-cyclohexylsalicylic acid, 3 .5-di-tert-butylsalicylic acid, 3-methyl-5-benzylsalicylic acid, 3-
Phenyl-5-α-cumylsalicylic acid, 3゜5-di(
α-Methylbenzyl)salicylic acid, 4-(2-phenoxyethoxy)salicylic acid, 4-(2-(p-methoxyphenoxy)ethoxy)salicylic acid, 2-hydroxy-1
- Aromatic carboxylic acids such as benzyl-3-naphthoic acid, and furthermore, these organic coloring agents such as zinc, magnesium,
aluminum, calcium, titanium, manganese, tin,
Salts with polyvalent metals such as nickel, metal complex compounds such as antipyrine complexes of zinc thiocyanate, and 1°=22-3-diphenylthiourea, ■, 3-bis(m-chlorophenyl)thiourea, 1,3 -bis(m-)lyl)thiourea, 1,3-bis(m~trifluoromethylphenyl)
Urea derivatives such as thiourea.

Among these, 4,4'-isopropylidene diphenol is more preferred because it is industrially inexpensive and has excellent coloring ability.

The proportion of these coloring agents and 3-di-n-pentylamino-6-methyl-7-phenylaminofluorane is as follows:
Although not necessarily limited, 100 to 700 parts by weight, more preferably 1 part by weight, per 100 parts by weight of basic dye.
It is desirable to blend about 50 to 600 parts by weight of a coloring agent.

In addition, in the thermosensitive recording material of the present invention, 3-
An important characteristic lies in the use of di-n-pentylamino-6-methyl-7-phenylaminofluorane, but other colorless or light-colored fluoranes may be used as long as they do not impede the desired effects of the present invention. One or more kinds of basic dyes can be used in combination. 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-diethylamino -2~methylphenyl)-6-(dimethylamino)phthalide, 3-(p-
dimethylaminophenyl)-3-(1,2-dimethylindol-3-yl)phthalide, 3-(p-dimethylaminophenyl)-1-(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-ethylcarbazol-3-yl)-6-dimethylaminophthalide, 3゜3-bis(2-phenylindol-3-yl)-〇-dimethylaminophthalide 3-p-dimethylaminophenyl-1-(1-methylpyrrol-3-yl)
-Triarylmethane dyes such as 6-dimethylaminophthalide; 4,4'-bis-dimethylaminobenzhydrylbenzyl ether, N-herophenyl leucoauramine, N-2,4°5-trichlorophenyl Diphenylmethane dyes such as leucoauramine; 3,3-bis(1
, l-bis(4-pyrrolidinophenyl)ethylene-2-
yl)-4,5,6,7-titrabromophthalide, 3.
3-bis(1-(4-methoxyphenyl)-1-(4-
dimethylaminophenyl)ethylene-2-yl)-4,
5,6,7-titrachlorophthalide, 3,3-bis(1
Divinylphthalide dyes such as -(4-methoxyphenyl)-1 to (4-pyrrolidinophenyl)ethylene-2-yl)-4,5,6,7-titrachlorophthalide; benzoylleucomethylene blue, p- Thiazine dyes such as nitrobenzoylleucomethylene blue; 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-
Spiro dyes such as benzyl-spiro-dinaphthopyran, 3-methyl-naphtho(6'-methoxyhenzo)spiropyran, 3-propyl-spiro-dibenzopyran; 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-methoxyfluoran, 3-diethylamino-7-chlorofluoran, 3-diethylamino-6-methyl-7-chlorofluoran, 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, 3-diethylamino-7-N-methyJL/-N-benzylaminofluorane, 3-diethylamino-? -N-chloroethyl-N-
Methylaminofluorane, 3-diethylamino-7-N
-=26- diethylaminofluorane, 4-benzylamino-8-
diethylamino-benzo(alfluorane, 3-(4-
'(4-dimethylaminoanilino)anilino]-7-chloro-6-methylfluorane, 8-(4-(4-dimethylaminoanilino)anilino)-benzo(a]lfluorane 3-(N-ethyl -p-)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-diethylamino-7-(2-carbomethoxy-phenylamino)fluorane, 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-diethylamino-6-methyl-7-xylidinofluorane, 3-diethylamino-7-(o-chlorophenylamino)fluorane, 3-dibutylamino-7
-(o-chlorophenylamino)fluorane, 3-(N
-ethyl-N-tetrahydrofurfurylamino)-6-
Methyl-phenylaminofluorane, 3-(N-methyl-N-n-propylamino)-6-methyl-7-phenylaminofluorane, 3-(N-ethyl-N-i-
butylamino)-6-methyl-7-phenylaminofluorane, 3-(N-methyl-Nn-hexylamino)
-6-methyl-7-phenylaminofluorane, 3-(
N-ethyl-N-n-hexylamino)-6-methyl-
7-phenylaminofluorane, 3-(N-ethyl-N
-cyclopentylamino)-6-methyl-7-phenylaminofluorane, 3-(N-(3-ethoxypropyl)-N-methylaminoco-6-methyl-fuphenylaminofluorane, 3-[N-ethyl-N -(3-ethoxypropyl)aminoco-=27- 6-methyl-7-phenylaminofluorane, 3-diethylamino-7-(m-()lifluoromethyl)phenylamino-l fluorane, 3-diethylamino-7-( o
Fluoran dyes such as -fluorophenylamino)fluoran, 3-dibutylamino-7-(o-fluorophenylamino)fluoran, and 3-diethylamino-6-chloro-7-phenylaminofluorane; 3,6-bis(
dimethylamino)fluorene-9-spiro-3'-(6
'-dimethylamino)phthalide, 3-diethylamino-
6-(N-allyl-N-methylamino)fluorene-9
-spiro-3'-(6'-dimethylamino)phthalide, 3,6-bis(dimethylamino)-spiro[fluorene-9,6'-6'H-chromeno(4,3-b)
indole), 3,6-bis(dimethylamino)-3'
-Methyl-spiro[fluorene-9゜6'-6' H
-chromeno(4,3-b)indole), 3,6-bis(diethylamino)-3'-methylspiro [fluorene-9,6'-6'H-chromeno(4,3-b)indole], etc. Examples include dyes such as dyes, but the dyes are not limited to these dyes.

Coating liquids containing these heat-sensitive materials are generally prepared by using water as a dispersion medium and using an agitating/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/butadiene 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.
Examples include sodium dioctyl sulfosuccinate, sodium dodecylbenzenesulfonate, sodium salt of lauryl alcohol sulfate, dispersants such as fatty acid metal salts, ultraviolet absorbers such as triazoles, other antifoaming agents, and 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.

In addition, in order to improve the adhesion of debris on the recording head, we have added kaolin, clay, talc, calcium carbonate, fired 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 the range of 2ε/bo, 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 heat-sensitive recording material of the present invention thus obtained has suitability for high-speed recording, and is free from the tendency of recorded images to fade or fogging of blank areas, and does not cause residue 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 do not indicate parts by weight and % by weight, respectively.

Example 1 ■ Overcoat 1-sided polygonal firing relay (trade name: Ansilex, manufactured by Engelhard) 100 parts styrene-butadiene copolymer latex (solid content: 50%)
15 parts polyvinyl alcohol 10% aqueous solution 30 m water
A coating solution for undercoating was prepared by mixing 200 parts of the above composition. The obtained coating liquid was applied and dried to form an undercoat layer on high-quality paper at a rate of 50 g/n so that the coated amount after drying was Log/n.

■ 3-di-n-pentylamino-6-methyl-7-phenylaminofluorane made in a phlegm dish 10 parts 1,2-bis(3
-Methylphenoxy)ethane 20 parts Methylcellulose 5% aqueous solution $20 parts Water
110 parts of this composition was ground to an average particle size of 2 μm using a sand grinder.
It was crushed until it was.

■ 4.4'-Isopropylidene diphenol manufactured by Kanseiho 30 parts Methyl cellulose 5% aqueous solution 30 parts water
70 parts of this composition was ground with a sand grinder until the average particle size was 2 μm.

■ 160 parts of liquid A, 130 parts of liquid B, silicon oxide pigment (oil absorption 1
80ml/100g) 30 parts, 20% oxidized starch aqueous solution 1
50 parts and 160 parts of water were mixed and stirred to prepare a coating liquid. The obtained coating liquid was applied onto the undercoat layer to a dry weight of 5.0 g/m and dried to obtain a heat-sensitive recording paper.

Examples 2 to 5 In preparing liquid A, the following compounds were used instead of 1,2-bis(3-methylphenoxy)ethane.
Four types of thermal recording paper were obtained in the same manner as in Example 1.

Example IL2-Diphenoxyethane Example 3: 1,4-bis(phenylthio)butane Example 4: 1,5-bis(4-methoxyphenoxy)-
3-Oxapenkune Example 5: 1,2-bis(4-benzyloxycarbonylphenoxy)ethane Example 6 Example 1 except that in the formation of the recording layer of Example 1, the following liquid C was used instead of liquid A. A thermosensitive recording paper was obtained in the same manner as above.

3-di-n-pentylamino-6-methyl-7-phenylaminofluorane manufactured by Tategoho Co., Ltd. 10 parts 4,4'-butylidene bis(2tert-butyl-5-methylphenol)
5 parts 1,2-bis(3-methylphenoxy)
ethane
20 parts methylcellulose 5% aqueous solution
20 parts water
105 parts of this composition was ground with a sand grinder until the average particle size was 2 μm.

Examples 7-11 In the preparation of C lacquer, 4,4'-butylidene bis(2-t
ert-butyl-5-methylphenol) instead of
Five types of thermal recording papers were obtained in the same manner as in Example 6 except that the following compounds were used.

Example 1: 2.2'-methylenebis(4-methyl-5-
tert-butylphenol) Example 8: 4,4'-thiobis(2-tert-butyl-5-methylphenol) Example 9: 4,4'-isopropylidene bis(2,6-
Example 10: 1,1.3-1-lis(2-methyl-4
-Hydroxy-5-tert-butylphenyl)butane Example 11: 1-(1,1-bis(4-hydroxyphenyl)ethyl)-4-(1-methyl-1-(4-hydroxyphenyl)ethyl)benzene Comparative Example I A thermosensitive recording paper was obtained in the same manner as in Example 1 except that water was used instead of 1,2-bis(3-methylphenoxy)ethane in the preparation of lacquer.

Comparative Example 2 A thermosensitive recording paper was obtained in the same manner as in Example 1 except that stearic acid amide was used instead of 1,2-bis(3-methylphenol)ethane in the preparation of lacquer A.

Comparative Examples 3-4 AWl, in the preparation of 3-di-n-pentylamino-
Two types of thermal recording paper were obtained in the same manner as in Example 1, except that the following compound was used instead of 6-methyl-7-phenylaminofluorane.

Comparative example 3: 3-(N-cyclohexyl-N-methylamino)-6-methyl-7-phenylaminofluoran Comparative example 4: 3-(N-ethyl-N-isoamylamino)-6-methyl- 7-Phenylaminofluorane Comparative Examples 5-6 In the preparation of C lacquer, 3-di-n-pentylamino-6-
Two types of thermal recording paper were obtained in the same manner as in Example 6 except that the following compound was used instead of methyl-7-phenylaminofluorane.

Comparative Example 5: 3-(N-cyclohexyl-N-methylamino)-6-methyl-7-leynylaminofluoran Comparative Example 6: 3-(N-ethyl-N-isoamylamino)
-6-Methyl-7-phenylaminofluorane The 17 types of thermal recording paper thus obtained were placed in a Kyocera simulator (voltage: 16 V, pulse cycle: 5 m 5
ec) for 0.30 m sec and 0.30 m sec during the pulse.
The color density was measured using a Macbeth densitometer (model RD-100'R, using an amber filter), and the results are shown in Table 1.

In addition, the whiteness of the surface of the recording layer of the recording paper, and the conditions under which the recording paper was dried at a high temperature of 60°C and 190°C at 40°C.
The whiteness of the surface of the recording layer after being left for 3 days under high humidity conditions of %RH was measured using a Hunter whiteness meter, and the results are shown in Table 1.

Table 1 Heat resistance: Processed at 60°C for 3 days Humidity resistance: Processed at 40°C and 990% RH for 3 days "Results" As is clear from the results in Table 1, the heat-sensitive recording material of the present invention is suitable for high-speed recording. It was a recording medium with excellent whiteness and excellent whiteness retention.

Claims (2)

[Claims] (1) A colorless or light-colored basic dye on the support,
In a heat-sensitive recording material provided with a heat-sensitive recording layer containing a coloring agent capable of coloring upon contact with the basic dye, 3-di-n-pentylamino-6-methyl-7-phenylamino is used as the basic dye. 1. A heat-sensitive recording material characterized by using fluoran and further containing at least one kind of thermofusible substance represented by the following general formula [I] in the heat-sensitive recording layer. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, R represents a divalent group having 2 to 8 carbon atoms, and R_1 to
R_4 is a hydrogen atom, lower alkyl group, cycloalkyl group, phenyl group, lower alkoxyl group, cycloalkoxyl group, lower alkylthio group, aralkyloxy group, aralkylthio group, respectively.
Indicates a lower alkyloxycarbonyl group, an aralkyloxycarbonyl group, or a halogen atom. Furthermore, R_1 and R_2, and R_3 and R_4 may be bonded to each other to form an aromatic ring. X and Y each represent an oxygen atom or a sulfur atom. ] (2) In the heat-sensitive recording layer, the following general formulas [II] to [V
The heat-sensitive recording material according to claim (1), which contains at least one kind selected from the compounds represented by the following. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [III] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [IV] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [ V] [In the formula, R_1 represents a branched alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, a phenyl group, or a halogen atom, and R_2 represents a hydrogen atom, a branched alkyl group having 3 to 8 carbon atoms, or a halogen atom. Indicates atoms, R_3, R_
5 to R_8 each represent a hydrogen atom or a lower alkyl group. R_4 represents a hydrogen atom, a halogen atom, or an alkyl group having 8 or less carbon atoms. X represents -O-, -S-, -S-S-, -SO_2- or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, and R_9, R
_1_0 each represents a hydrogen atom or an alkyl group having 8 or less carbon atoms. Furthermore, R_9 and R_1_0 may be combined with each other to form a ring. Z represents a linear or branched alkylene group having 8 or less carbon atoms. ]