JP3429851B2 - Thermal recording material - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermal recording material. More specifically, it relates to a heat-sensitive recording material having improved storage stability of uncolored part (background) and colored image.

[0002]

2. Description of the Related Art Conventionally, a heat-sensitive recording material utilizing a color reaction between an electron-donating color-forming compound and an electron-accepting compound (developing agent) is well known (for example, Japanese Patent Publication No. 43-4).
160, JP-B-45-14039). The heat-sensitive recording material is relatively inexpensive and has the advantage that the recording device is compact and maintenance-free, and thus is widely used in the fields of facsimile, recorder and printer. In recent years, the fields of use of thermal recording materials have further expanded and diversified, and have expanded to applications for use in harsh environments (eg, labels, prepaid cards, etc.). However, the known 2,
A heat-sensitive recording material containing 2-bis (4′-hydroxyphenyl) propane [“bisphenol A”], 4-hydroxybenzoic acid benzyl ester or the like as an electron-accepting compound is used in a harsh environment (for example, oil, solvent, oil and fat). When in contact with a writing instrument such as a highlighter pen or in a humid environment), there are drawbacks such that the uncolored part is significantly contaminated (ground stain) and the color image is discolored.

In order to improve such a defect, a heat-sensitive recording material containing a salicylic acid derivative having a substituted amino group or a metal salt thereof as an electron-accepting compound has been proposed (JP-A-63-95979). But,
JP-A-63-95979 does not disclose the salicylic acid derivative having an imide group as a substituent and the metal salt of the derivative according to the present invention at all. As described in JP-A-63-95979, for example,
A heat-sensitive recording material containing 4-phenylacetylaminosalicylic acid or a metal salt of the compound (for example, a zinc salt) as an electron-accepting compound still has poor storage stability (for example, heat and moisture resistance and oil resistance) of a color image. Further, it has a low color-developing sensitivity and cannot be said to be a heat-sensitive recording material suitable for practical high-speed recording. Further, a heat-sensitive recording material containing 4-benzoylaminosalicylic acid or a metal salt of the compound (for example, a zinc salt) disclosed in the publication as an electron-accepting compound also has storage stability of a color image (for example, moist heat resistance, It has the disadvantages of poor oil resistance) and low color development sensitivity. Against this background, there is a strong demand for a heat-sensitive recording material in which the storage stability of the uncolored portion and the color-developed image are further improved and the color sensitivity is good.

Regarding the salicylic acid derivative represented by the general formula (1), some compounds are already known [eg, Pharm. Acta. Helv. , 55 , 50
(1980), US Pat. No. 3,808,230, German Patent No. 1111635, British Patent No. 1533068, JP-A-55-24127], but a salicylic acid derivative represented by the general formula (1) or a metal of the derivative. The applicability of salt to heat-sensitive recording materials is completely unknown.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-sensitive recording material which is remarkably improved in storage stability of an uncolored portion (background) and a colored image.

[0006]

Means for Solving the Problems The present inventors have arrived at the present invention as a result of earnest studies on a heat-sensitive recording material, particularly an electron-accepting compound, in order to meet the above-mentioned demand. That is, the present invention provides a thermosensitive recording material containing an electron-donating color-forming compound and an electron-accepting compound, wherein the electron-accepting compound is a salicylic acid derivative represented by the general formula (1) The present invention relates to a heat-sensitive recording material containing at least one selected from metal salts.

[Chemical 2] (In the formula, A represents a divalent aliphatic group or a divalent aromatic group, and X1 and X2 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aralkyl group or an aryl group.)

In the salicylic acid derivative represented by the general formula (1) according to the present invention, A represents a divalent aliphatic group or a divalent aromatic group, and preferably has a substituent. It represents a divalent saturated or unsaturated aliphatic group or a divalent aromatic group which may have a substituent. More preferably, A has a total carbon number of 2 to 16 which may have a substituent.
Is a divalent saturated or unsaturated aliphatic group, or a divalent aromatic group having 6 to 20 total carbon atoms which may have a substituent. The divalent aliphatic group may be a divalent chain-like aliphatic group or a divalent cyclic aliphatic group. Furthermore, one carbon atom in the divalent aliphatic group may be replaced with an oxygen atom or a sulfur atom.

Specific examples of the divalent aliphatic group or the divalent aromatic group include, for example, 1,2-ethylene group and 1,3-
Propylene group, 1,4-butylene group, 1,5-pentylene group, 1,6-hexylene group, 1,7-heptylene group,
1,8-octylene group, 1,10-decylene group, 1,1
2-dodecylene group, 1,2-cyclopentylene group, 1,
2-cyclohexylene group, 1,2-cycloheptylene group, 1,2-cyclooctylene group, 1,2-cyclodecylene group, 1,2-cyclododecylene group, 2,3-norbornylene group ["1,2-3, 6-endomethylene-hexahydrophenylene group "], 2,3-bicyclo [2.
2.2] Octylene group ["1,2,3,6-endoethano-hexahydrophenylene group"],

1,2-vinylene group, 1,2-1-cyclohexenylene group ["1,2-3,4,5,6-tetrahydrophenylene group"], 1,2-4-cyclohexenylene group ["1,2-1,2,3,6-tetrahydrophenylene group"], 2,3-5-norbornenylene group ["1,
2-3,6-Endomethylene-1,2,3,6-tetrahydrophenylene group "], 9,10-tricyclo [4.
2.2.0 ^2,5 ] deca-3,7-dienylene group ["1,
2-4,5-Cyclobuteno-3,6-endoetheno-hexahydrophenylene group "], 1,2,3,6-epoxy-1,2,3,6-tetrahydrophenylene group, 1,
A 2-phenylene group, a 1,2-naphthylene group, a 2,3-naphthylene group, a 1,8-naphthylene group, a 2,2′-biphenylene group and the like can be mentioned, but not limited thereto. Furthermore, these groups may have a substituent.

Particularly preferred as A is a 1, ω-alkylene group having 2 to 10 carbon atoms which may have a substituent,
A 1, ω-alkenylene group having 2 to 10 carbon atoms which may have a substituent, a 1,2-hexahydrophenylene group which may have a substituent, and an optionally substituted 1 ，
2-1,2,3,6-tetrahydrophenylene group, optionally substituted 1,2,3,6-endomethylene-1,2,3,6-tetrahydrophenylene group, optionally substituted 1,2,3,6-epoxy-1, which may be
2,3,6-Tetrahydrophenylene group, 1,2-phenylene group which may have a substituent, 2,3-naphthylene group which may have a substituent, and which may have a substituent Examples thereof include a good 1,8-naphthylene group and a 1,4,5-cyclobuteno-3,6-endoetheno-hexahydrophenylene group which may have a substituent.

The substituent is not particularly limited, but for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, se
c-butyl group, n-pentyl group, isopentyl group, n-
Hexyl group, 2-ethylbutyl group, n-heptyl group, n
-Octyl group, 2-ethylhexyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and other alkyl groups having 1 to 8 carbon atoms, for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, Alkoxy groups having 1 to 8 carbon atoms such as n-butoxy group, isobutoxy group, n-pentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group and cyclohexyloxy group, for example, benzyl group,
7 to 10 carbon atoms such as α-methylbenzyl group and cumyl group
Aralkyl group of, for example, phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 3-ethylphenyl group, 4-tert-butylphenyl group, 4-methoxyphenyl group, 4-ethoxy An aryl group having 6 to 10 carbon atoms such as a phenyl group, a 4-chlorophenyl group, a 1-naphthyl group, a 2-naphthyl group, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and a nitro group. You can Particularly preferred substituents are an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and a chlorine atom. When the group A has geometrical isomers (cis isomer, trans isomer, endo isomer, exo isomer), these geometrical isomers may be used alone, and further, these geometrical isomers may be used. It may be a mixture of bodies.

In the general formula (1), X1 and X2 are a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group,
Represents an aralkyl group or an aryl group, preferably a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or a carbon number of 1 to 2.
A chain alkyl group having 0 to 5, a cyclic alkyl group having 5 to 14 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and more preferably hydrogen. Atom, fluorine atom, chlorine atom,
It is a chain alkyl group having 1 to 4 carbon atoms, a cyclohexyl group, an alkoxy group having 1 to 4 carbon atoms, a benzyl group, an α-methylbenzyl group, a cumyl group or a phenyl group, and a hydrogen atom is particularly preferable.

The compound represented by the general formula (1) has an imide group in the salicylic acid skeleton, and the substitution position of the imide group is at the 3-position, 4-position, 5-position or 6-position in the salicylic acid skeleton. Is more preferable, and the substitution at the 3-position, 4-position or 5-position is more preferable, and the substitution at the 4-position or 5-position is particularly preferable. That is, the general formula (1-a) (formula 3) or the general formula (1-
b) The salicylic acid derivative represented by Chemical formula 4 is particularly preferable.

[Chemical 3] (In the formula, A, X1 and X2 are the same as above)

[Chemical 4] (In the formula, A, X1 and X2 are the same as above)

Specific examples of the salicylic acid derivative represented by the general formula (1) and the metal salt of the derivative according to the present invention include the salicylic acid derivative and the metal salt of the derivative described below. Of course, the present invention is not limited to these.

Exemplified Compound No. 1) 3-succinimido salicylic acid 2) 3-glutarimide salicylic acid 3) 3-maleimido-5-methylsalicylic acid 4) 3-phthalimido-5-chlorosalicylic acid 5) 3- (cis-hexahydrophthalimide ) -5
Cumyl salicylic acid 6) 3- (4'-methylphthalimido) salicylic acid 7) 3- (2 ', 3'-naphthalimido) salicylic acid 8) 4-succinimidosalicylic acid 9) 4- (3'-methyl-3'- Phenyl succinimide) salicylic acid 10) 4- (3'-methyl-3'-benzyl succinimide) salicylic acid 11) 4-glutarimide salicylic acid 12) 4-adipimido salicylic acid 13) 4-pimelimido salicylic acid 14) 4- Sebacimidosalicylic acid 15) 4- (cis-hexahydrophthalimide) salicylic acid 16) 4- (mixture of cis, trans -4'-methylhexahydrophthalimide) salicylic acid 17) 4- (cis-3 ', 6'-endo Methylene-hexahydrophthalimide) salicylic acid 18) 4-maleimidosalicylic acid 19) 4- (2 ', 3'-dimethylmaleic De) salicylic acid 20) 4- (2 ', 3'-difluoro-maleimide) -5
-Ethylsalicylic acid 21) 4- (2 ', 3'-dichloromaleimido) salicylic acid 22) 4- (3', 4 ', 5', 6'-tetrahydrophthalimido) salicylic acid 23) 4- (cis-1 ', 2 ', 3', 6'-Tetrahydrophthalimido) salicylic acid 24) 4- (cis-3 ', 6'-endomethylene-
1 ', 2', 3 ', 6'-tetrahydrophthalimide)
Salicylic acid 25) 4- (cis-3 ′, 6′-endomethylene-hexahydrophthalimide) salicylic acid

26) 4- (cis-3 ', 6'-epoxy-1', 2 ', 3', 6'-tetrahydrophthalimide) salicylic acid 27) 4-phthalimidosalicylic acid 28) 4- (4'-methylphthalimide ) Salicylic acid 29) 4- (4'-tert-butylphthalimido) salicylic acid 30) 4- (4'-n-hexylphthalimido) salicylic acid 31) 4- (3'-methoxyphthalimido) salicylic acid 32) 4- (3'- n-Propoxyphthalimido) salicylic acid 33) 4- (4'-methoxyphthalimido) salicylic acid 34) 4- (4'-n-butoxyphthalimido) salicylic acid 35) 4- (3'-fluorophthalimido) -5-phenylsalicylic acid 36) 4- (4'-chlorophthalimido) salicylic acid 37) 4- (3 ', 6'-dichlorophthalimido) salicylic acid 38) 4- 4 ', 5'-dichloro phthalimide) salicylic acid 39) 4- (4', 5'-dibromo-phthalimido) -5
-Ethoxysalicylic acid 40) 4- (3 ', 4', 5 ', 6'-tetrachlorophthalimido) -5-benzyl salicylic acid 41) 4- (3'-nitrophthalimido) salicylic acid 42) 4- (4'-nitro Phthalimido) salicylic acid 43) 4- (1 ', 2'-naphthalimido) salicylic acid 44) 4- (2', 3'-naphthalimido) salicylic acid 45) 4- (5'-methyl-2 ', 3'-na Phthalimido) salicylic acid 46) 4- (1 ', 8'-naphthalimido) salicylic acid 47) 4- (4'-chloro-1', 8'-naphthalimido) salicylic acid 48) 4- (2 ', 2 "-biphenyl Imido) salicylic acid 49) 5-succinimidosalicylic acid 50) 5- (3'-methyl-3'-phenylsuccinimide) salicylic acid

51) 5- (3'-methyl-3'-benzylsuccinimide) salicylic acid 52) 5-glutarimidosalicylic acid 53) 5-adipimidosalicylic acid 54) 5-pimelimidosalicylic acid 55) 5-sebac Imidosalicylic acid 56) 5- (cis-hexahydrophthalimido) salicylic acid 57) 5- (mixture of cis, trans -4'-methylhexahydrophthalimido) salicylic acid 58) 5- (cis-3 ', 6'-endomethylene- Hexahydrophthalimide) salicylic acid 59) 5-maleimidosalicylic acid 60) 5- (2 ', 3'-dimethylmaleimido) salicylic acid 61) 5- (2', 3'-difluoromaleimido) salicylic acid 62) 5- (2 ', 3 '-Dichloromaleimido) salicylic acid 63) 5- (3', 4 ', 5', 6'-tetrahydrophthalimido) salicy Acid 64) 5- (cis-1 ', 2', 3 ', 6'- tetrahydrophthalimide) salicylate 65) 5- (cis-3', 6'- endomethylene -
1 ', 2', 3 ', 6'-tetrahydrophthalimide)
Salicylic acid 66) 5- (cis-3 ′, 6′-endoethano-
1 ', 2', 3 ', 6'-tetrahydrophthalimide)
Salicylic acid 67) 5- (cis-4 ′, 5′-cyclobuteno-
3 ', 6'-endoetheno-hexahydrophthalimido) salicylic acid 68) 5-phthalimidosalicylic acid 69) 5- (4'-methylphthalimido) salicylic acid 70) 5- (4'-tert-butylphthalimido) salicylic acid 71) 5- ( 4'-n-hexylphthalimido) salicylic acid 72) 5- (3'-methoxyphthalimido) salicylic acid 73) 5- (3'-n-propoxyphthalimido) salicylic acid 74) 5- (4'-methoxyphthalimido) salicylic acid 75) 5 -(4'-Ethoxyphthalimido) salicylic acid

76) 5- (3'-Fluorophthalimide) salicylic acid 77) 5- (4'-chlorophthalimido) salicylic acid 78) 5- (3 ', 6'-dichlorophthalimido) salicylic acid 79) 5- (4', 5'-dichlorophthalimido) salicylic acid 80) 5- (4 ', 5'-dibromophthalimido) salicylic acid 81) 5- (3', 4 ', 5', 6'-tetrachlorophthalimido) salicylic acid 82) 5- (3 '-Nitrophthalimide) -4-methoxysalicylic acid 83) 5- (4'-nitrophthalimide) salicylic acid 84) 5- (1', 2'-naphthalimide) salicylic acid 85) 5- (2 ', 3'-naphthalimide ) Salicylic acid 86) 5- (5'-methyl-2 ', 3'-naphthalimide) salicylic acid 87) 5- (1', 8'-naphthalimide) salicylic acid 88) 5- (4'-chloro 1 ', 8'-Naphthalimido) salicylic acid 89) 5- (2', 2 "-biphenylimido) salicylic acid 90) 6-glutarimide salicylic acid 91) 6-adipimidosalicylic acid 92) 6-pimelimidosalicylic acid 93) 6-Sebacimidosalicylic acid 94) 6- (cis-hexahydrophthalimide) salicylic acid 95) 6-phthalimido-4-methoxysalicylic acid 96) 6- (4'-methylphthalimido) salicylic acid 97) 6- (4'-chlorophthalimide ) Salicylic acid 98) 6- (4 ', 5'-dichlorophthalimido) salicylic acid 99) 6- (4'-nitrophthalimido) salicylic acid 100) 6- (2', 3'-naphthalimido) salicylic acid

The salicylic acid derivative represented by the general formula (1) according to the present invention can be prepared by a method known per se [eg Phar.
m. Acta. Helv. , 55 , 50 (1980),
British Patent No. 1533068, German Patent No. 111163
5, the method described in JP-A-55-24127]. That is, typically, by reacting the aminosalicylic acid derivative represented by the general formula (2) (formula 5) with the acid anhydride derivative represented by the general formula (3) (formula 6), The salicylic acid derivative represented by 1) can be produced.

[Chemical 5] (In the formula, X1 and X2 are the same as above)

[Chemical 6] (In the formula, A is the same as above)

In the metal salt of the salicylic acid derivative represented by the general formula (1) according to the present invention, the metal salt includes monovalent metal salts such as sodium, potassium and lithium, and is more preferable. Is a polyvalent metal salt, more preferably a divalent, trivalent or tetravalent metal salt, and particularly preferably a divalent metal salt. Specific examples of the polyvalent metal salt include, for example, zinc, magnesium,
Calcium, barium, nickel, tin, copper, molybdenum, tungsten, zirconium, manganese, cobalt, titanium, aluminum, salts of iron can be mentioned, preferably zinc, magnesium, calcium, barium, nickel, manganese, cobalt, It is an aluminum salt, more preferably a zinc, magnesium or calcium salt, and particularly preferably a zinc salt.

The metal salt of the salicylic acid derivative represented by the general formula (1) according to the present invention, for example, an alkali metal salt such as monovalent sodium, potassium or lithium salt is usually represented by the general formula (1). 0.8 to 1.2 equivalents, preferably 1.0 to 1.
Activating 1 equivalent of alkali metal hydroxide compound, alkali metal carbonate compound, alkali metal hydrogen carbonate compound (eg, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate) in an aqueous solution Can be manufactured. In the metal salt of the salicylic acid derivative represented by the general formula (1), the divalent, trivalent and tetravalent metal salts are usually the salicylic acid derivative represented by the general formula (1) in the presence of water. 0.8 to 1.5 equivalents, preferably 1.0 to 1.2 equivalents of water-soluble corresponding 2 to 1 equivalent of the alkali metal salt of
It is produced as a metal salt of a sparingly water-soluble or water-insoluble salicylic acid derivative by reacting a trivalent, trivalent or tetravalent metal compound. The equivalent weight in this case means that the polyvalent metal compound is, for example, a divalent metal compound (for example, zinc sulfate) with respect to 1 mol of the alkali metal salt of the salicylic acid derivative represented by the general formula (1). Is equivalent to 1 equivalent of 0.5 mol of the divalent metal compound. At this time, heating may be performed or an organic solvent may coexist as desired. As the alkali metal salt of the salicylic acid derivative represented by the general formula (1), a plurality of different alkali metal salts of the salicylic acid derivative represented by the general formula (1) may be used, for example, 4-phthalimidosalicylic acid. And poly (2 ′, 3′-naphthalimide) salicylic acid mixed with respective alkali metal salts, or 4-phthalimidosalicylic acid mixed with 5-phthalimidosalicylic acid mixed salts with polyvalent metal compound The divalent, trivalent or tetravalent metal salt thus prepared can also be used as the electron-accepting compound for the heat-sensitive recording material of the present invention.

Examples of the water-soluble polyvalent metal compounds include sulfates such as zinc sulfate, magnesium sulfate, calcium sulfate and aluminum sulfate, zinc chloride, magnesium chloride, calcium chloride, barium chloride, nickel chloride and cobalt chloride. , Chlorides such as aluminum chloride, and acetates such as zinc acetate and manganese acetate. The metal salt of the salicylic acid derivative represented by the general formula (1) produced as described above may vary depending on the production conditions, the type of salicylic acid derivative represented by the general formula (1), the type of metal salt, or the production conditions. Sometimes, a solvate such as a hydrate may be formed, and the solvate can also be preferably used as the electron-accepting compound for the heat-sensitive recording material of the invention. Of course, a metal salt of the salicylic acid derivative represented by the general formula (1) in which a solvent such as water is removed from the solvate can also be used in the heat-sensitive recording material of the present invention. The heat-sensitive recording material of the present invention is manufactured as follows using at least one selected from the salicylic acid derivative represented by the general formula (1) and the metal salt of the derivative as the electron-accepting compound. In the heat-sensitive recording material of the present invention, the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative as the electron-accepting compound may be used alone or in combination.
Furthermore, one or more salicylic acid derivatives represented by the general formula (1) and a metal salt of one or more salicylic acid derivatives represented by the general formula (1) may be used in combination. In the heat-sensitive recording material of the present invention, the amount of the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative is not particularly limited, but is usually 100 parts by weight of the electron-donating color forming compound. It is desirable to use about 50 to 700 parts by weight, preferably about 100 to 500 parts by weight, based on parts.

The heat-sensitive recording material of the present invention has the general formula (1) as an electron-donating color-forming compound and an electron-accepting compound.
It is characterized by containing at least one selected from salicylic acid derivatives represented by and a metal salt of the derivative, and the present invention is further characterized by adding a metal compound to the heat-sensitive recording material of the present invention. The characteristics of the heat-sensitive recording material can be further improved. The metal compound is not particularly limited, but is preferably divalent,
It is a compound of trivalent or tetravalent metal. Examples of the metal compound include zinc, magnesium, barium, calcium, aluminum, tin, titanium, nickel, cobalt, manganese, iron, and other metal oxides, hydroxides, sulfides, halides, carbonates, and the like. Phosphates, silicates, sulfates, nitrates, acetylacetonate complexes, organic carboxylates and the like can be mentioned, and zinc compounds are particularly preferable. Specific examples of the metal compound include, for example,
Zinc oxide, zinc hydroxide, zinc aluminate, zinc sulfide, zinc carbonate, zinc phosphate, zinc silicate, zinc sulfate, zinc chloride, zinc nitrate, magnesium sulfate, magnesium aluminate, magnesium hydroxide, magnesium oxide, magnesium carbonate Inorganic metal compounds such as barium carbonate, calcium sulfate, calcium chloride, calcium carbonate, aluminum oxide, aluminum hydroxide, aluminum silicate, aluminum phosphate, tin oxide, titanium oxide, zinc, magnesium, barium, calcium, aluminum, etc. Silica, surface acetylacetonate zinc, acetylacetonate calcium, nickel acetylacetonate, zinc stearate, magnesium stearate, calcium stearate, steari And organic metal compounds such as aluminum and the like, may be their hydrates. These metal compounds may be used alone or in combination. A particularly preferable metal compound is an inorganic metal compound, and zinc oxide is particularly preferable.

The amount of the metal compound is not particularly limited, but is usually 1 to 5 with respect to 100 parts by weight of the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative.
00 parts by weight, preferably 3 to 300 parts by weight, more preferably 5 to 200 parts by weight, particularly preferably 7 to 15 parts by weight.
It is desirable to use 0 part by weight.

The method for incorporating the metal compound into the heat-sensitive recording material of the present invention is not particularly limited.
For example, a salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative and, if desired, a heat-fusible compound are mixed in a solid state, and then a coating liquid for a heat-sensitive recording layer is prepared. The method of applying to a support, or the salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative and a metal compound, and a heat-fusible compound, if desired, are combined together in the presence of water. Or separately, and then dispersed and mixed to prepare a coating solution for the heat-sensitive recording layer, and a method of coating on a support can be applied. When mixing in the presence of water, it may be carried out in the presence of a binder, a surfactant and the like.

The dispersion and mixing treatment temperature is not particularly limited, but is preferably 20 ° C. to a temperature below the melting point of the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative, and water. When dispersed and mixed in the presence of, the temperature is about 20 to 100 ° C. Dispersion, mixing method is not particularly limited, suitable stirring, mixing device [for example, mortar, propeller type agitator, turbine type agitator, paddle type agitator, homogenizer, homomixer, line mixer, line homomixer media Stirrer without using a mixing device, or a stirring tank type mill such as an attritor or a Sentry mill, a flow tube type mill such as a sand grinder, a grain mill, a pearl mill, a matter mill, a dyno mill, an annular type continuous wet type such as a conical ball mill or an annular mill. It is preferable to use a stirring / mixing device filled with a medium such as a stirring mill (for example, glass beads, ceramic balls, steel balls, etc.).

The colorless or light-colored electron-donating color-forming compound used in the heat-sensitive recording material of the present invention is not particularly limited, but triarylmethane compounds, vinylphthalide compounds, diarylmethane compounds, rhodamine-type compounds. Lactam compounds, thiazine compounds, fluorane compounds, pyridine compounds, spiro compounds, various known electron-donating color-forming compounds such as fluorene compounds, and more preferably fluoran compounds, among which the general formula The fluoran compound represented by (A) (Chemical Formula 7) is preferable.

[Chemical 7] (In the formula, A and B are an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkoxyalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a tetrahydrofurfuryl group. Further, A and B may form a heterocycle together with the adjacent nitrogen atom, and Z1 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a halogen atom. , Z2 and Z3 represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a halogen atom or a trifluoromethyl group).

Specific examples of the electron-donating color forming compound include triarylmethane compounds such as, for example,
3,3-bis (4-dimethylaminophenyl) -6-dimethylaminophthalide ["crystal violet lactone"], 3,3-bis (4-dimethylaminophenyl) phthalide, 3- (4-dimethylaminophenyl) −
3- (4-diethylamino-2-methylphenyl) -6
-Dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- (1,2-dimethylindole-3-
Yl) phthalide, 3- (4-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-ethylcarbazol-3-yl) -6-dimethylaminophthalide,
3,3-bis (2-phenylindol-3-yl)-
6-dimethylaminophthalide, 3- (4-dimethylaminophenyl) -3- (1-methylpyrrol-3-yl)
-6-Dimethylaminophthalide and the like.

Examples of vinylphthalide compounds include 3,3-bis [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, , 3-bis [1,1-bis (4
-Pyrrolidinophenyl) ethylene-2-yl] -4,
5,6,7-Tetrabromophthalide, 3,3-bis [1
-(4-Dimethylaminophenyl) -1- (4-methoxyphenyl) ethylene-2-yl] -4,5,6,7-
Tetrachlorophthalide, 3,3-bis [1- (4-pyrrolidinophenyl) -1- (4-methoxyphenyl) ethylene-2-yl] -4,5,6,7-tetrachlorophthalide, etc. is there.

Examples of the diarylmethane compound include 4,4-bis-dimethylaminobenzhydrin benzyl ether, N-halophenyl-leuco auramine,
N-2,4,5-trichlorophenyl leuco auramine and the like. As the rhodamine-lactam compound,
For example, rhodamine-B-anilinolactam, rhodamine- (4-nitroanilino) lactam, rhodamine-B
-(4-chloroanilino) lactam and the like. Examples of thiazine compounds include 3,7-bis (diethylamino) -10-benzoylphenoxazine, benzoylleuco methylene blue, and 4-nitrobenzoylmethylene blue.

Examples of fluoran compounds include:
3,6-dimethoxyfluorane, 3-dimethylamino-
7-methoxyfluorane, 3-diethylamino-6-methoxyfluorane, 3-diethylamino-7-methoxyfluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-diethylamino-6,7-dimethylfluorane, 3-N-cyclohexyl-Nn-butylamino-7-methylfluorane, 3-diethylamino-7-dibenzylaminofluorane, 3-diethylamino-7-
Octylaminofluorane, 3-diethylamino-7-
Di-n-hexylaminofluorane, 3-diethylamino-7-anilinofluorane, 3-diethylamino-7
-(2'-fluorophenylamino) fluorane, 3-
Diethylamino-7- (2'-chlorophenylamino)
Fluorane, 3-diethylamino-7- (3'-chlorophenylamino) fluorane, 3-diethylamino-7
-(2 ', 3'-dichlorophenylamino) fluorane, 3-diethylamino-7- (3'-trifluoromethylphenylamino) fluorane, 3-di-n-butylamino-7- (2'-fluorophenylamino) Fluorane, 3-di-n-butylamino-7- (2'-chlorophenylamino) fluorane,

3-N-isopentyl-N-ethylamino-7- (2'-chlorophenylamino) fluorane, 3
-N-n-hexyl-N-ethylamino-7- (2'-
Chlorophenylamino) fluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-di-n
-Butylamino-6-chloro-7-anilinofluorane, 3-diethylamino-6-methoxy-7-anilinofluorane, 3-di-n-butylamino-6-ethoxy-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 3-piperidino-6-methyl-7-anilinofluorane, 3-morpholino-6-
Methyl-7-anilinofluorane, 3-dimethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-di-n-butylamino-6 -Methyl-7-anilinofluorane, 3-di-n-pentylamino-6-methyl-7-
Anilinofluorane, 3-N-ethyl-N-methylamino-6-methyl-7-anilinofluorane, 3-Nn
-Propyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-n-propyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-
n-Butyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-n-butyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl- N-methylamino-6-methyl-7-anilinofluorane, 3-N-isobutyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-isopentyl-N-ethylamino-6 -Methyl-7-anilinofluorane, 3-Nn-hexyl-N-methylamino-6-methyl-7-anilinofluorane,

3-N-cyclohexyl-N-ethylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-N-n-propylamino-6-methyl-
7-anilinofluorane, 3-N-cyclohexyl-N
-N-butylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn-hexylamino-6-methyl-7-anilinofluorane, 3-N-cyclohexyl-Nn -Octylamino-6-methyl-
7-anilinofluorane, 3-N-2'-methoxyethyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-2'-methoxyethyl-N-ethylamino-6- Methyl-7-anilinofluorane, 3-N-
2'-methoxyethyl-N-isobutylamino-6-methyl-7-anilinofluorane, 3-N-2'-ethoxyethyl-N-methylamino-6-methyl-7-anilinofluorane, 3- N-2'-ethoxyethyl-N-ethylamino-6-methyl-7-anilinofluorane, 3
-N-3'-methoxypropyl-N-methylamino-6
-Methyl-7-anilinofluorane, 3-N-3'-methoxypropyl-N-ethylamino-6-methyl-7-
Anilinofluorane, 3-N-3'-ethoxypropyl-N-methylamino-6-methyl-7-anilinofluorane, 3-N-3'-ethoxypropyl-N-ethylamino-6-methyl- 7-anilino fluoran,

3-N-2'-tetrahydrofurfuryl-
N-ethylamino-6-methyl-7-anilinofluorane, 3-N- (4'-methylphenyl) -N-ethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6- Ethyl-7-anilinofluorane, 3
-Diethylamino-6-methyl-7- (3'-methylphenylamino) fluorane, 3-diethylamino-6-
Methyl-7- (2 ', 6'-dimethylphenylamino)
Fluorane, 3-di-n-butylamino-6-methyl-
7- (2 ', 6'-dimethylphenylamino) fluorane, 3-di-n-butylamino-7- (2', 6'-dimethylphenylamino) fluorane, 2,2-bis [4 '-(3 -N-cyclohexyl-N-methylamino-6-methylfluorane) -7-ylaminophenyl]
Propane, 3- [4 '-(4-phenylaminophenyl) aminophenyl] amino-6-methyl-7-chlorofluorane, and the like.

Examples of pyridine compounds include 3-
(2-Ethoxy-4-diethylaminophenyl) -3-
(1-octyl-2-methylindol-3-yl)-
4 or 7-azaphthalide, 3- (2-ethoxy-4-
Diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4 or 7-azaphthalide, 3- (2-hexyloxy-4-diethylaminophenyl) -3- (1-ethyl-2- Methylindole-
3-yl) -4 or 7-azaphthalide, 3- (2-ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7-azaphthalide, 3- ( 2-butoxy-4-diethylaminophenyl) -3- (1-ethyl-2-phenylindol-3-yl) -4 or 7-azaphthalide.

Examples of the spiro compound include 3-methyl-spiro-dinaphthopyran, 3-ethyl-spiro-
Dinaphthopyran, 3-phenyl-spiro-dinaphthopyran, 3-benzyl-spiro-dinaphthopyran, 3-methyl-naphtho- (3-methoxybenzo) spiropyran, 3
-Propyl-spiro-dibenzopyran and the like. Examples of the fluorene compound include 3,6-bis (dimethylamino) fluorene-9-spiro-3 ′-(6′-
Examples include dimethylamino) phthalide and 3,6-bis (diethylamino) fluorene-9-spiro-3 ′-(6′-dimethylamino) phthalide. Of course, it is not limited to these electron donating color forming compounds, and these electron donating color forming compounds may be used alone or in combination.

The heat-sensitive recording material of the present invention is characterized by containing at least one salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative as an electron-accepting compound. Other electron-accepting compounds may be used in combination within the range that does not impair the desired effects of the present invention. In this case, the proportion of the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative in the total electron-accepting compound is usually 10% by weight or more, preferably,
It is desirable to adjust to 20% by weight or more, more preferably 30% by weight or more. The electron-accepting compound other than the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative is not particularly limited, but is a phenol derivative or a metal salt thereof, an organic acid derivative or a metal salt or complex thereof. Examples thereof include various known electron-accepting compounds such as organic electron-accepting compounds such as urea derivatives and inorganic electron-accepting compounds.

Specific examples of the electron-accepting compound other than the salicylic acid derivative represented by the general formula (1) or the metal salt of the derivative include 4-tert-butylphenol and 4
-Tert-octylphenol, 4-phenylphenol, 1-naphthol, 2-naphthol, hydroquinone, resorcinol, 4-tert-octylcatechol,
2,2'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 2,2-bis (4'-hydroxyphenyl) propane ["bisphenol A"],
1,1-bis (4′-hydroxyphenyl) cyclohexane, 2,2-bis (4′-hydroxy-3′-methylphenyl) propane, 1,3-bis (4′-hydroxycumyl) benzene, 1, 4-bis (4'-hydroxycumyl) benzene, 1,3,5-tris (4'-hydroxycumyl) benzene, 2,2-bis (4'-hydroxyphenyl) acetic acid ethyl ester, 4,4- (4'-Hydroxyphenyl) pentanoic acid-n-butyl ester, 4
-Hydroxybenzoic acid benzyl ester, 4-hydroxybenzoic acid phenethyl ester, 2,4-dihydroxybenzoic acid phenoxyethyl ester, 4-hydroxyphthalic acid dimethyl ester, gallic acid-n-propyl ester, gallic acid-n-octyl ester, Gallic acid-n
-Dodecyl ester, gallic acid-n-octadecyl ester,

Hydroquinone monobenzyl ether, bis (3-methyl-4-hydroxyphenyl) sulfide, bis (2-methyl-4-hydroxyphenyl) sulfide, bis (3-phenyl-4-hydroxyphenyl) sulfide, bis (3 -Cyclohexyl-4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfone, bis (3-allyl-4-hydroxyphenyl) sulfone, bis (3-phenyl-4-hydroxy) Phenyl) sulfone, 4-hydroxy-4'-methyldiphenyl sulfone, 4-hydroxy-4'-te
rt-Butyldiphenylsulfone, 4-hydroxy-
4'-chlorodiphenyl sulfone, 4-hydroxy-
4'-methoxydiphenyl sulfone, 4-hydroxy-4'-n-propoxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4-hydroxy-4'-n-butoxydiphenyl sulfone, 4-hydroxy-4 '-Benzyloxydiphenyl sulfone, 3,4-dihydroxy-4'-methyldiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone,

2-methoxy-4'-hydroxydiphenyl sulfone, 2-ethoxy-2'-hydroxydiphenyl sulfone, 4-hydroxy-3-methyl-4'-
n-propoxydiphenyl sulfone, bis (2-hydroxy-5-tert-butylphenyl) sulfone, bis (2-hydroxy-5-chlorophenyl) sulfone,
Bis [4- (3'-hydroxyphenyloxy) phenyl] sulfone, 4-hydroxybenzophenone, 2,
4-dihydroxybenzophenone, 2,4'-dihydroxybenzophenone, 4,4'-dihydroxybenzophenone, 1,7-di (4'-hydroxyphenylthio)
Phenol derivatives such as -3,5-dioxaheptane and 1,5-di (4'-hydroxyphenylthio) -3-oxapentane, or metal salts of these phenol derivatives (for example, nickel, zinc, aluminum, calcium) Metal salts such as),

For example, 4- (2'-phenoxyethoxy) salicylic acid, 4- [2 '-(4-methoxyphenoxy) ethoxy] salicylic acid, 5- [4'-(2- [4-
Methoxyphenoxy] ethoxy) cumyl] salicylic acid,
4- [3 '-(4-methylphenylsulfonyl) propoxy] salicylic acid, 4-n-butyloxycarbonylaminosalicylic acid, 4-n-octyloxycarbonylaminosalicylic acid, 4-n-nonyloxycarbonylaminosalicylic acid, 4-n -Decyloxycarbonylaminosalicylic acid, 5-cyclohexyloxycarbonylaminosalicylic acid, 1-naphthoic acid, 2-naphthoic acid, 1-
Hydroxy-2-naphthoic acid, 2-hydroxy-3-naphthoic acid, 2-hydroxy-6-naphthoic acid, 1-acetyloxy-2-naphthoic acid, 2-acetyloxy-1
-Naphthoic acid, 2-acetyloxy-3-naphthoic acid,
Phthalic acid monobenzyl ester, phthalic acid monophenyl ester, isophthalic acid, terephthalic acid, 4-methylbenzoic acid, 2-benzoylbenzoic acid, 2- (4'-chlorobenzoyl) benzoic acid, 4-nitrobenzoic acid, 4- Chlorobenzoic acid, 4-trifluoromethylbenzoic acid, 4-formylbenzoic acid, 4-cyanobenzoic acid, organic acid derivatives such as stearic acid, or metal salts of these organic acid derivatives (for example, nickel, zinc, aluminum, Metal salts such as calcium),

For example, complexes such as zinc thiocyanate antipyrine complex and molybdic acid acetylacetone complex, such as N, N'-diphenylthiourea, N, N'-di (3-trifluoromethylphenyl) thiourea, N,
N'-di (3-chlorophenyl) thiourea, 1,4-di (3'-chlorophenyl) -3-thiosemicarbazide,
Organic electron-accepting compounds such as urea derivatives such as N-phenyl-N ′-(4-methylphenylsulfonyl) urea and 4,4′-bis (4 ″ -methylphenylsulfonylcarbonylamino) diphenylmethane, for example, acid clay, Examples thereof include inorganic electron-accepting compounds such as attapulgite, activated clay, aluminum chloride, zinc chloride, and zinc bromide, but are not limited to these compounds. You can also

Furthermore, by adding a heat-fusible compound (a compound having a melting point of about 70 to 150 ° C., more preferably a melting point of about 80 to 130 ° C.) as a sensitizer to the heat-sensitive recording material of the present invention, It is possible to obtain a heat-sensitive recording material compatible with higher speed recording. In this case, the amount of the heat-fusible compound used is not particularly limited, but is usually 10 to 700 parts by weight, relative to 100 parts by weight of the electron-donating color forming compound.
It is preferable to use 20 to 500 parts by weight.

Specific examples of the heat-fusible compound include caproic acid amide, capric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, erucic acid amide, linoleic acid amide, linolenic acid amide, and N- Ethyl capric acid amide, N-butyl lauric acid amide, N-methyl stearic acid amide, N-methyl oleic acid amide, N-stearyl cyclohexyl amide, N-octadecyl acetamide, N-olein acetamide, stearyl urea, stearic acid anilide, benzanilide , Linoleic acid anilide, acetoacetic acid anilide, o-acetoacetic acid toluidide, p-acetoacetic acid anisidide, N-ethylcarbazole, 4-methoxydiphenylamine, N-hydroxymethylstearic acid amide,
Nitrogen-containing compounds such as ethylenebisstearic acid amide,
For example, 4-benzyloxybenzoic acid benzyl ester, 2-naphthoic acid phenyl ester, 1-hydroxy-2-naphthoic acid phenyl ester, oxalic acid dibenzyl ester, oxalic acid di (4-methylbenzyl) ester, oxalic acid di ( 4-chlorobenzyl) ester, adipic acid diphenyl ester, glutaric acid diphenacyl ester, di (4-methylphenyl) carbonate, terephthalic acid dibenzyl ester, and the like, for example, 4-benzylbiphenyl, m-terphenyl, Hydrocarbon compounds such as fluorene, fluoranthene, 2,6-diisopropylnaphthalene and 3-benzylacenaphthene,

For example, 2-benzyloxynaphthalene,
2- (4'-methylbenzyloxy) naphthalene, 1,
4-diethoxynaphthalene, 1,2-diphenoxyethane, 1,2-bis (3′-methylphenoxy) ethane,
1-phenoxy-2- (4'-methylphenoxy) ethane, 1-phenoxy-2- (4'-ethylphenoxy)
Ethane, 1- (4'-methoxyphenoxy) -2-phenoxyethane, 1- (4'-methoxyphenoxy) -2
-(3'-methylphenoxy) ethane, 1- (4'-methoxyphenoxy) -2- (2'-methylphenoxy)
Ethane, 1,2-bis (4'-methoxyphenylthio)
Ethane, 1,5-bis (4'-methoxyphenoxy)-
3-oxapentane, 1,4-bis (2′-vinyloxyethoxy) benzene, 4- (4′-methylphenoxy) biphenyl, 1,4-bis (2′-chlorobenzyloxy) benzene, 4,4 ′ -Di-n-butoxydiphenyl sulfone, 1,2-diphenoxybenzene, 1,
4-bis (2'-chlorophenoxy) benzene, 1,4
-Bis (4'-methylphenoxy) benzene, 1,4-
Bis (3'-methylphenoxymethyl) benzene, 4-
Chlorobenzyloxy- (4'-ethoxybenzene),
4,4'-bis (phenoxy) diphenyl ether,
Ether compounds such as 4,4′-bis (phenoxy) diphenylthioether, 1,4-bis (4′-benzylphenoxy) benzene and 1,4-bis [(4′-methylphenyloxy) methoxymethyl] benzene,

For example, 1,4-diglycidyloxybenzene, 4-benzyloxy-4 '-(2-methylglycidyloxy) diphenylsulfone, 4- (4-methylbenzyloxy) -4'-glycidyloxydiphenylsulfone, Epoxy compounds such as N-glycidyl phthalimide, for example, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-butylphenyl) benzotriazole, 2- ( 2'-hydroxy-3 ', 5'-di-tert
-Butylphenyl) benzotriazole, 2- (2'-
Hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)-
5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole and the like. Examples thereof include, but are not limited to, triazole compounds. These heat-fusible compounds may be used alone or in combination.

The heat-sensitive recording material of the present invention can be manufactured by a known method without using a special method. Generally, in the presence of water, an electron-donating color-forming compound, a salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative, and, if desired, a metal compound,
The heat-fusible compound, etc., together or separately, is usually 3 μm by a ball mill, sand mill (vertical type, horizontal type), attritor, colloidal mill, etc., and a pulverizer.
Hereinafter, the coating liquid for the recording layer can be prepared by pulverizing and dispersing to a particle size of 2 μm or less and mixing them.
In such a coating liquid, the binder is usually 5 to 5 of the total solid content.
About 50% by weight is blended. As the binder, a water-soluble binder is generally used, for example, polyvinyl alcohol, carboxy modified polyvinyl alcohol, sulfonated modified polyvinyl alcohol, polyvinyl alcohol derivatives such as alkyl modified polyvinyl alcohol,
Cellulose derivatives such as methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, epichlorohydrin modified polyamide, ethylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer, isobutylene-maleic anhydride copolymer, polyacrylic acid , Polyacrylamide, methylol-modified polyacrylamide, starch, starch derivatives (oxidized starch, etherified starch, etc.), casein, gelatin, gum arabic, etc., but are not limited thereto.

Further, if necessary, a pigment,
A water-insoluble binder, metal soap, wax, surfactant, ultraviolet absorber, ultraviolet stabilizer, crosslinking agent, hindered phenol, phosphorus compound, defoaming agent, etc. are added. As the pigment, for example, calcium carbonate, barium carbonate,
Inorganic pigments such as magnesium carbonate, zinc carbonate, zinc oxide, aluminum oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide, barium sulfate, talc, wax, kaolin, clay, diatomaceous earth, silica, styrene microballs, nylon particles , Urea-formalin fillers, polyethylene particles, cellulose fillers, starch particles and other organic pigments are used.

As the water-insoluble binder, synthetic rubber latex or synthetic resin emulsion is generally used.
Examples thereof include styrene-butadiene rubber latex, acrylonitrile-butadiene latex, methyl acrylate-butadiene rubber latex, vinyl acetate emulsion and the like, and they are used as necessary. Examples of the metal soap include metal salts of higher fatty acids such as zinc stearate, calcium stearate, aluminum stearate and zinc oleate. As the wax, for example, paraffin wax,
Microcrystalline wax, carboxy-modified paraffin wax, carnauba wax, polyethylene wax, polystyrene wax, candelia wax,
Examples include montan wax and higher fatty acid esters.

As the surfactant (dispersant), for example,
Sulfosuccinic acid-based alkali metal salts [for example, di (n-
Hexyl) sulfosuccinic acid, di (2-ethylhexyl)
Sodium salt of sulfosuccinic acid and the like], sodium salt of dodecylbenzene sulfonic acid, sodium salt of lauryl alcohol sulfate, fatty acid metal salt, fluorine-containing surfactant and the like. Examples of the ultraviolet absorber and the ultraviolet stabilizer include cinnamic acid derivatives, benzophenone derivatives, triazole derivatives, salicylic acid derivatives, hindered amine derivatives and the like.

Examples of the cross-linking agent include aldehyde derivatives such as glyoxal, epoxy compounds, polyamide resins, diglycidyl compounds, aziridine compounds, magnesium chloride and ferric chloride.

The hindered phenol is preferably a phenol derivative in which at least one of the ortho positions of the phenolic hydroxyl group is substituted with a branched alkyl group.
2,6-diisopropyl-4-methylphenol, 2,
6-di-tert-butyl-4-methylphenol, 2-te
rt-Butyl-4-methoxyphenol, 2,5-di-te
rt-octyl-4-methoxyphenol, 2,5-di-
tert-butylhydroquinone, 2,5-di-tert-octylhydroquinone, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (2 -Methyl-4-hydroxy-5-cyclohexylphenyl) butane, 1,1,3-
Tris (2-ethyl-4-hydroxy-5-tert-butylphenyl) butane, 1,1,3-tris (3,5-di-tert-butyl-4-hydroxyphenyl) butane,
1,1,3-tris (2-methyl-4-hydroxy-5)
-Tert-butylphenyl) propane, 1,1-bis (2
-Methyl-5-tert-butyl-4-hydroxy) butane, tetrakis [methylene-3- (3 ', 5'-di-te
rt-Butyl-4'-hydroxyphenyl) propionate] methane, 2,2'-methylene-bis (6-tert-butyl-4-methylphenol), 2,2'-methylene-
Bis (6-tert-butyl-4-ethylphenol),
1,3,5-Trimethyl-2,4,6-tris (3,5
-Di-tert-butyl-4-hydroxybenzyl) benzene, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanuric acid,
1,3,5-tris (4-tert-butyl-3-hydroxy-2-methyl-6-ethylbenzyl) isocyanuric acid, bis (2-methyl-4-hydroxy-5-tert-butylphenyl) sulfide, etc. Can be mentioned.

As the phosphorus compound, a phosphate compound is preferable, for example, 2,2'-methylenebis (4-
Methyl-6-tert-butylphenyl) phosphate,
2,2'-methylenebis (4-ethyl-6-tert-butylphenyl) phosphate, 2,2'-methylenebis (4,6-di-tert-butylphenyl) phosphate,
Diphenyl phosphate, bis (4-tert-butylphenyl) phosphate, bis (2,4-ditert-butylphenyl) phosphate, bis (4-chlorophenyl)
Mention may be made of phosphates, bis (2-phenylphenyl) phosphates, bis (4-phenylphenyl) phosphates and the like, or salts of these metals (eg potassium, sodium, zinc, calcium, magnesium, aluminum).

In the heat-sensitive recording material of the present invention, the method for forming the recording layer is not particularly limited, and the recording layer can be formed according to a conventionally known technique. For example, the coating liquid for the heat-sensitive recording layer is coated on a support with an appropriate coating device such as an air knife coater, a blade coater, a bar coater, a short dwell coater, a gravure coater, a curtain coater, and a wire bar, and dried. Can form a recording layer. The coating amount of the coating liquid is not particularly limited, but is generally about 1.5 to 12 g / m ^{2 in} dry weight, preferably 2.5 to
It is adjusted at about 10 g / m ² . The support is not particularly limited, but, for example, paper, plastic sheet, synthetic paper, or a composite sheet or a non-woven sheet in which these are combined, a molded product, or a metal deposition product is used.

If necessary, a protective layer (overcoat layer) may be provided on the front surface and / or the back surface of the heat-sensitive recording layer, or a single-layer or multi-layer pigment (for example, between the support and the heat-sensitive recording layer). Providing an undercoat layer (undercoat layer) made of kaolin, calcium carbonate) or synthetic resin (for example, plastic spherical particles, plastic spherical hollow particles), between the heat-sensitive recording layer and the undercoat layer,
Alternatively, it is of course possible to provide an intermediate layer composed of a pigment, a binder, etc. between the heat-sensitive recording layer and the protective layer, and further, the back surface of the support is subjected to an adhesive treatment to form an adhesive label. Various known techniques in the manufacturing method of can be applied. Further, after forming the heat-sensitive recording layer and / or the protective layer, super calendering treatment can be performed.

[0056]

EXAMPLES The present invention will be described in more detail with reference to production examples and examples, but the present invention is not limited to these production examples and examples. Production Example 1 (Production of Compound of Exemplified Compound No. 8) 100 g of succinic anhydride and 7 g of concentrated sulfuric acid in toluene (200
0 ml) solution was heated to 110 ° C., and 153 g of 4-aminosalicylic acid dimethylacetamide (600 m) was added to the solution.
l) The solution was added dropwise over a period of 1 hour. After the dripping, the Dean-Stark water eliminator was used to remove the by-product water, and the mixture was further stirred at 110 to 115 ° C. for 10 hours. Then, it cooled at 70 degreeC, 500 ml of water was added, the water layer was isolate | separated, and it left at room temperature. The precipitated crystals were filtered, recrystallized from a methanol-water solution, and dried to obtain 57 g of 4-succinimidosalicylic acid. Melting point 232-234 ° C

Production Example 2 (Production of Exemplified Compound No. 15) cis-Hexahydrophthalic anhydride 150 g, concentrated sulfuric acid 7
g of toluene (2000 ml) was heated to 110 ° C,
A solution of 153 g of 4-aminosalicylic acid in dimethylacetamide (600 ml) was added dropwise to the solution over 1 hour. After dripping, the Dean-Stark water remover was used to remove the water formed as a byproduct, and further 110 to 115
Stirred at 10 ° C for 10 hours. Then, cool to 70 ° C. and add water 5
00 ml was added and the toluene layer was separated and left at room temperature.
Precipitated crystals were filtered, washed with methanol and dried to obtain 165 g of 4- (cis-hexahydrophthalimide) salicylic acid. Melting point 206-208 ° C

Production Example 3 (Production of Compound of Exemplified Compound No. 23) Except that cis-1,2,3,6-tetrahydrophthalic anhydride was used in place of cis-hexahydrophthalic anhydride in Production Example 2. According to the method described in Example 2, 4- (cis-1 ′, 2 ′, 3 ′, 6′-tetrahydrophthalimido) salicylic acid was produced. Melting point 193
~ 195 ° C

Production Example 4 (Production of Compound of Exemplified Compound No. 24) In Production Example 2, instead of cis-hexahydrophthalic anhydride, cis--3,6-endomethylene-1,
According to the method described in Example 2, except that 2,3,6-tetrahydrophthalic anhydride was used, 4- (cis-
3 ', 6'-endomethylene-1', 2 ', 3', 6 '
-Tetrahydrophthalimide) salicylic acid was prepared.
Melting point 245-248 ° C

Production Example 5 (Production of Compound of Exemplified Compound No. 26) In Production Example 2, instead of cis-hexahydrophthalic anhydride, cis--3,6-epoxy-1,2,2.
4- (cis-3 ′, 6 ′ was prepared according to the method described in Example 2 except that 3,6-tetrahydrophthalic anhydride was used.
-Epoxy-1 ', 2', 3 ', 6'-tetrahydrophthalimido) salicylic acid was prepared. Melting point 258-26
1 ° C

Production Example 6 (Production of Compound of Exemplified Compound No. 27) Phthalic anhydride 150 g, concentrated sulfuric acid 7 g of toluene (200
0 ml) solution was heated to 110 ° C., and 153 g of 4-aminosalicylic acid dimethylacetamide (600 m) was added to the solution.
l) The solution was added dropwise over 4 hours. After the dropwise addition, the Dean-Stark water remover was used to remove water by-product, and the mixture was further stirred at 110 to 115 ° C. for 2 hours.
Then, the mixture was cooled to room temperature, the precipitated crystals were filtered, washed with isopropanol, and dried to obtain 200 g of 4-phthalimidosalicylic acid. Melting point 284-287 ° C

Production Example 7 (Production of Zinc Salt of Exemplified Compound No. 27) 42.5 g of 4-phthalimidosalicylic acid was dissolved in an aqueous solution (1000 ml) of 12.6 g of sodium hydrogen carbonate at room temperature. 24 g of water (100 g of zinc sulfate heptahydrate) was added to the solution.
(ml) solution was added dropwise after 30 minutes. After the dropping, the mixture was stirred at room temperature for 30 minutes, and the mixture was further stirred at 50 ° C. for 1 hour. After cooling to room temperature, the solid is filtered, washed with water and dried to obtain the desired 4
-44 g of zinc salt of phthalimidosalicylic acid are obtained. Melting point 300 ° C or more

Production Example 8 (Production of Compound of Exemplified Compound No. 28) According to the method described in Example 6, except that 4-methylphthalic anhydride was used in place of phthalic anhydride in Production Example 6, -(4'-Methylphthalimido) salicylic acid was prepared. Melting point 278-281 ° C

Production Example 9 (Production of Compound of Exemplified Compound No. 36) According to the method described in Example 6, except that 4-chlorophthalic anhydride was used in place of phthalic anhydride in Production Example 6, -(4'-Chlorophthalimido) salicylic acid was prepared. Melting point 294-297 ° C

Production Example 10 (Production of Compound of Exemplified Compound No. 44) In Production Example 6, instead of phthalic anhydride, 2,3-
4- (2 ', 3'-Naphthalimido) salicylic acid was produced according to the method described in Example 6 except that naphthalenedicarboxylic acid anhydride was used. Melting point 300 ° C or more

Production Example 11 (Production of Compound of Exemplified Compound No. 56) cis-Hexahydrophthalic anhydride 150 g, concentrated sulfuric acid 7
g of toluene (2000 ml) was heated to 110 ° C,
A solution of 153 g of 5-aminosalicylic acid in dimethylacetamide (600 ml) was added dropwise to the solution over 1 hour. After dripping, the Dean-Stark water remover was used to remove the water formed as a byproduct, and further 110 to 115
Stirred at 10 ° C for 10 hours. Then, cool to 70 ° C. and add water 5
00 ml was added and the toluene layer was separated and left at room temperature.
The precipitated crystals were filtered, washed with methanol and dried to obtain 180 g of 5- (cis-hexahydrophthalimide) salicylic acid. Melting point 275-278 ° C

Production Example 12 (Production of Compound of Exemplified Compound No. 64) Except that cis-1,2,3,6-tetrahydrophthalic anhydride was used in place of cis-hexahydrophthalic anhydride in Production Example 11. According to the method described in Example 11, 5- (cis-1 ′, 2 ′, 3 ′, 6′-tetrahydrophthalimido) salicylic acid was produced. Melting point 3
00 ° C or higher

Production Example 13 (Production of Compound of Exemplified Compound No. 65) In Production Example 11, instead of cis-hexahydrophthalic anhydride, cis-3,6-endomethylene-1,
According to the method described in Example 11, except that 2,3,6-tetrahydrophthalic anhydride was used, 5- (cis-
3 ', 6'-endomethylene-1', 2 ', 3', 6 '
-Tetrahydrophthalimide) salicylic acid was prepared.
Melting point 253-256 ° C

Production Example 14 (Production of Compound of Exemplified Compound No. 68) 150 g of phthalic anhydride and 7 g of concentrated sulfuric acid in toluene (200
0 ml) solution was heated to 110 ° C., and 153 g of 5-aminosalicylic acid dimethylacetamide (600 m) was added to the solution.
l) The solution was added dropwise over 4 hours. After the dropwise addition, the Dean-Stark water remover was used to remove water by-product, and the mixture was further stirred at 110 to 115 ° C. for 2 hours.
Then, the mixture was cooled to room temperature, the precipitated crystals were filtered, washed with isopropanol, and dried to obtain 200 g of 5-phthalimidosalicylic acid. Melting point 283-286 ° C

Production Example 15 (Production of Compound of Exemplified Compound No. 85) In Production Example 14, 2,3 instead of phthalic anhydride was used.
-5- (2 ', 3'-Naphthalimido) salicylic acid was prepared according to the method described in Example 14 except that naphthalenedicarboxylic acid anhydride was used. Melting point 300 ° C or more

Hereinafter, a thermal recording paper was prepared using a salicylic acid derivative represented by the general formula (1) or a metal salt of the derivative as an electron-accepting compound, and the results of evaluating its performance are shown as examples. In the following,% means% by weight. In each of the examples, the following composition A was used to prepare a thermosensitive recording paper.
The liquid, the liquid B, the liquid C and the liquid D were dispersed by a sand grinding mill so that the average particle diameter was 1.5 μm, and the dispersion liquid was prepared and used. (Liquid A composition) Electron-donating color forming compound 10 g 10% polyvinyl alcohol aqueous solution (Kuraray-117) 10 g Water 80 g Total 100 g (Liquid B composition) Electron-accepting compound 20 g Light calcium carbonate (Okutama industry, TP-123) 40 g 10 % Polyvinyl alcohol aqueous solution (Kuraray-117) 60 g Water 130 g Total 250 g (C liquid composition) Electron-accepting compound 20 g Light calcium carbonate (Okutama industry, TP-123) 10 g Zinc oxide 30 g 10% Polyvinyl alcohol aqueous solution (Kuraray-117) 60 g Water 130 g Total 250 g (D liquid composition) Thermofusible compound (2-benzyloxynaphthalene) 20 g 10% polyvinyl alcohol aqueous solution (Kuraray-117) 10 g Water 220 g Total 250 g

The performance of the obtained thermal recording paper was evaluated as follows. (Storage stability test of uncolored part) The whiteness of the uncolored part (background) immediately after application of each thermal recording paper prepared in Examples and Comparative Examples was measured by using a color difference meter (Σ-80, manufactured by Nippon Denshoku Co., Ltd.). Measured. The thermal recording papers prepared in Comparative Examples 3 and 4 were already stained in gray immediately after coating. As the storage stability test, a moist heat resistance test and an oil resistance test were conducted, and the whiteness of the uncolored portion of each thermosensitive recording paper after each test was examined. Moisture and heat resistance test was carried out by using each thermal recording paper at 40 ° C and 90% relative humidity for 24 hours.
The whiteness after storage for a period of time was measured using a color difference meter. The oil resistance test was carried out by overlaying each thermosensitive recording paper with capsule coating paper containing dioctyl phthalate, passing through a pressure roll, and then storing the whiteness of the uncolored portion with a color difference meter after storing at 25 ° C for 1 week. It was measured using. The larger the value, the higher the whiteness and the better the storage stability of the uncolored part. In addition, as a writing resistance test, after writing the uncolored portion with a highlighter pen, the whiteness of the uncolored portion was visually observed after standing at 25 ° C. for 72 hours. ⊚ indicates a state with no stain and high whiteness, ∘ indicates a state in which gray is slightly stained, and x indicates a state in which black gray is stained. The results are shown in Table 4.

(Colored Image Storage Stability Test) Each of the thermosensitive recording papers prepared in Examples and Comparative Examples was subjected to a Macbeth densitometer (T) using a thermosensitive paper coloring device (TH-PMD manufactured by Okura Electric Co., Ltd.).
R-524) was used to form a color image having a color density of 1.0, and then a storage stability test was conducted.
As the storage stability test, a moist heat resistance test and an oil resistance test were conducted to examine the image storage stability of each thermal recording paper after each test. In the moist heat resistance test, each of the thermosensitive recording papers was stored at 60 ° C. and 90% relative humidity for 24 hours, and the color image density was measured using a Macbeth densitometer to obtain the residual ratio of the color image. The oil resistance test was carried out by using a Macbeth densitometer for the color image density after each thermosensitive recording paper was overlaid with a dioctyl phthalate-containing capsule coated paper, passed through a pressure roll and stored at 25 ° C for 1 week. And the residual rate of the color image was determined. The larger the value, the better the storage stability of the color image. In addition, as a writing resistance test, after writing the colored portion with a highlighter pen, the degree of residual rate of the colored portion was visually observed after standing at 25 ° C. for 72 hours. ◎ indicates that there is no color fading, ○ indicates that the color is a little decolored, ×
Indicates the state of being erased. The results are shown in Table 5.

Examples 1 to 4 Liquid A 100 g, liquid B 250 g and liquid D 250 g dispersion were mixed with 30% paraffin wax 23 g, and the dry coating amount was 5.0 ± 0.5 g / A thermosensitive recording paper was prepared by coating and drying so as to be m ² . The electron-donating color-forming compound in the solution A and the electron-accepting compound in the solution B used in each example are shown in Table 1 (Table 1). In the table,% represents% by weight. Table 4 (Table 5) shows the result of the storage stability test of the uncolored part of the obtained thermal recording paper, and Table 5 (Table 6) shows the result of the storage stability test of the color image.

[0075]

[Table 1]

Examples 5 to 24 A liquid 100 g, C liquid 250 g, and liquid D 250 g dispersion liquid and 30% paraffin wax 23 g were mixed, and the dry coating amount was 5.0 ± 0.5 g / A thermosensitive recording paper was prepared by coating and drying so as to be m ² . The electron-donating color-forming compound in solution A and the electron-accepting compound in solution C used in each example are shown in Table 2 [(Table 2) and (Table 3)]. Table 4 (Table 5) shows the result of the storage stability test of the uncolored part of the obtained thermal recording paper, and Table 5 (Table 6) shows the result of the storage stability test of the color image.

[0077]

[Table 2]

[0078]

[Table 3]

Comparative Examples 1 to 6 Dispersions of 100 g of A liquid, 250 g of B liquid and 250 g of D liquid were mixed with 23 g of 30% paraffin wax, and a dry coating amount of 5.0 ± 0.5 g / A thermosensitive recording paper was prepared by coating and drying so as to be m ² . The electron-donating color-forming compound in solution A and the electron-accepting compound in solution B used in each comparative example are shown in Table 3 (Table 4). The result of the storage stability test of the uncolored part of the obtained thermal recording paper is shown in No. 4
Table (Table 5) and the storage stability test results of the color image are shown in Table 5 (Table 6).

[0080]

[Table 4]

[0081]

[Table 5]

[0082]

[Table 6] As is clear from Tables 4 and 5, the general formula (1)
The heat-sensitive recording material of the present invention in which the salicylic acid derivative represented by or / and the metal salt of the derivative is used as an electron-accepting compound is not as good as a heat-sensitive recording material prepared using a conventional electron-accepting compound. The storage stability (moisture heat resistance, oil resistance, and writing instrument resistance) of the color-developed part and the color-developed image is very excellent.

Example 25 (Coloring performance test against temperature) Examples 4 and 18
The color-developing characteristics of the thermal recording papers produced in Examples 19 and 20 and the thermal recording papers produced in Comparative Examples 5 and 6 were compared with each other. In the color development performance test with respect to temperature, each thermosensitive recording paper was brought into contact with a metal block heated to each temperature for 5 seconds, and the color image density was measured using a Macbeth densitometer (TR-524 type). The results are shown in Table 6 (Table 7). The larger the value, the deeper the color.

[0084]

[Table 7] As is clear from Table 6, the heat-sensitive recording material of the present invention is
It can be said that it is a thermal recording material suitable for high-speed recording, which develops color rapidly at a lower temperature as compared with a conventional thermal recording material using a metal salt of a salicylic acid derivative having an amide group as a substituent as an electron-accepting compound. .

[0085]

According to the present invention, it has become possible to provide a heat-sensitive recording material which is very excellent in the storage stability of the uncolored portion and the color-developed image and has improved color-developing sensitivity.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumi Yoshikawa 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Kiyoharu Hasegawa 1190, Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Kagaku Incorporated (72) Inventor Naomasa Koike 3-4-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Paper Mills (56) Reference JP-A-55-24127 (JP, A) JP-A-7-96677 (JP , A) JP-A-59-33189 (JP, A) JP-A-1-101188 (JP, A) JP-A-6-239031 (JP, A) JP-A-63-34178 (JP, A) JP-A 64-87292 (JP, A) JP 6-199785 (JP, A) JP 3-45617 (JP, A) JP 53-9320 (JP, A) JP 57-16804 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B4 1M 5/28-5/34 CAPLUS (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. A thermosensitive recording material containing an electron-donating color-forming compound and an electron-accepting compound, wherein the electron-accepting compound is a salicylic acid derivative represented by the general formula (1) A heat-sensitive recording material containing at least one selected from salts. [Chemical 1] (In the formula, A represents a divalent aliphatic group or a divalent aromatic group, and X1 and X2 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aralkyl group or an aryl group.) 2. In the general formula (1), A has 2 to 5 carbon atoms.
The heat-sensitive recording material according to claim 1, which is an aliphatic group having 16 or an aromatic group having 6 to 20 carbon atoms. 3. The heat-sensitive recording material according to claim 1, further comprising a metal compound.