JPH06179287A - Color forming recording material - Google Patents

Abstract

PURPOSE:To provide a color forming recording material having high absorption within the range from a visible region to a near infrared region and having a high light resistance by providing a recording layer containing a azo compd. represented by a specific general formula and an acidic substance on a support. CONSTITUTION:A predetermined amt. of an azo compd. represented by formula I (wherein X is H, an amino group, an alkyl group or an acyl group, Y is H, halogen, an alkyl group or an aryl group, m is a natural number of 4 or less and A and B are H, an alkyl group or an aralkyl group) and a predetermined amt. of an acidic substance are mixed. The obtained mixture is compounded with an aqueous soln. of a binder such as polyvinyl alcohol and ground to prepare a coating soln. This coating soln. is applied to a support such as fine paper and dried to form a recording layer, thus obtaining a color forming recording material. As a concrete example of the azo compd., there is 4-aminoazobenzene or 4-(N-methylamino)azobenzene and, as examples of the acidic substance, there are phenol, naphthol, acid clay, kaolin and the like.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a color forming recording material,
More specifically, the present invention relates to a color forming recording material which is useful for a recording / reading device using visible light and / or near infrared rays.

[0002]

2. Description of the Related Art A dye precursor (hereinafter referred to as a color-forming dye), which is almost colorless in itself but is capable of exhibiting a certain color by a chemical reaction, is combined with a color-developing agent. Therefore, it has been widely put to practical use as a color-forming recording material such as heat-sensitive pressure-sensitive recording paper. On the other hand, in recent years, optical character reading devices and bar code reading devices using semiconductor laser light and the like have been rapidly spread, and images read by these devices often have absorption in the near infrared region of 700 nm or more. Is required.

However, in the fluoran type color-forming dye which is generally used in the conventional heat-sensitive pressure-sensitive recording paper,
Since the colored image has an absorption characteristic only in the visible portion, it cannot be used as a recording / display material for a near infrared ray reader. Therefore, in recent years, a method of giving absorption in the near infrared region by a lactone compound such as fluorene phthalide or vinyl phthalide having an extended π-electron conjugated system has been disclosed in JP-A-59-199757 and JP-A-62-24365.
No. 3, etc., but such a compound has a large molecular weight, its production is not easy, and the formed colorant is unstable, so that it has poor storage stability such as light resistance and is practically used. It has a problem of poor sex.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the conventional color-forming recording material, and the color-forming material has strong absorption from the visible region to the near infrared region. In addition, it is an object of the present invention to provide a color forming recording material which has high stability such as light resistance and moisture resistance and is useful as a recording material.

[0005]

The color-forming recording material according to the present invention comprises (a) a general formula (I).

[0006]

[Chemical 2]

(In the formula, X is hydrogen, halogen, amino group,
Alkylamino group, arylamino group, aralkylamino group, alkyl group, hydroxyl group, acyl group, alkoxy group,
It represents an aryl group, an aralkyl group, an acylamino group, an acyloxy group, an arylsulfonyl group, an arylsulfonamide group or a silyloxy group, n represents a natural number of 5 or less, and Y represents hydrogen, halogen, an alkyl group, a hydroxyl group, an acyl group, an alkoxy group. Group, aryl group, aralkyl group, acylamino group, acyloxy group, arylsulfonyl group,
Represents an aryl sulfonamide group or a silyloxy group,
m represents a natural number of 4 or less, and A and B each independently represent hydrogen, an alkyl group, an aryl group or an aralkyl group. ), And an (b) acidic substance.

That is, the color-forming recording material according to the present invention comprises the above-mentioned two elements, and the color-forming material produced from these elements has a strong absorption in a wide range from the visible region to the near infrared region and has a light resistance. Since it has extremely high storage stability such as resistance and moisture resistance, it is an excellent color forming recording material useful for a recording / reading apparatus using visible light and / or near infrared.

The azo compound used in the present invention is represented by the above general formula (I), and X is hydrogen, halogen, amino group, alkylamino group, arylamino group, aralkylamino group, alkyl group, hydroxyl group, acyl group. , An alkoxy group, an aryl group, an aralkyl group, an acylamino group, an acyloxy group, an arylsulfonyl group, an arylsulfonamide group or a silyloxy group, n represents a natural number of 5 or less, Y represents hydrogen, a halogen, an alkyl group, a hydroxyl group,
Acyl group, alkoxy group, aryl group, aralkyl group,
It represents an acylamino group, an acyloxy group, an arylsulfonyl group, an arylsulfonamide group or a silyloxy group, m represents a natural number of 4 or less, and A and B each independently represent hydrogen, an alkyl group, an aryl group or an aralkyl group.

Examples of the above-mentioned azo compound used in the present invention include 4-aminoazobenzene and 4
-(N-methylamino) azobenzene, 4- (N-ethylamino) azobenzene, 4- (N-propylamino)
Azobenzene, 4- (N, N-dimethylamino) azobenzene, 4- (N, N-diethylamino) azobenzene, 4- (N, N-dipropylamino) azobenzene,
4- (N, N-diphenylamino) azobenzene, 4-
(N-methyl-N-ethylamino) azobenzene, 4-
(N-methyl-N-propylamino) azobenzene, 4
-(N-methyl-N-phenylamino) azobenzene,
4- (N-ethyl-N-phenylamino) azobenzene, 4- (N-propyl-N-phenylamino) azobenzene and the like can be mentioned.

Examples of the azo compound used in the present invention include 4- (N, N-dimethylamino) -2.
-Methylazobenzene, 4- (N, N-dimethylamino) -2'-methylazobenzene, 4- (N, N-dimethylamino) -3-methylazobenzene, 4- (N, N)
-Dimethylamino) -3'-methylazobenzene, 4-
(N, N-Dimethylamino) -4'-methylazobenzene, 4- (N, N-dimethylamino) -4'-methoxyazobenzene, 4- (N, N-dimethylamino) -4 '
-Phenoxyazobenzene, 4- (N, N-dimethylamino) -3,3'-dimethylazobenzene, 4- (N,
N-dimethylamino) -2,2'-dimethylazobenzene, 4- (N, N-dimethylamino) -2,4'-dimethylazobenzene, 4- (N, N-dimethylamino)-
2,5-dimethylazobenzene, 4- (N, N-dimethylamino) -2,6-dimethylazobenzene and the like can be mentioned.

In addition to the above, for example, 4- (N,
N-dimethylamino) -2-chloroazobenzene, 4-
(N, N-Dimethylamino) -2'-chloroazobenzene, 4- (N, N-dimethylamino) -3-chloroazobenzene, 4- (N, N-dimethylamino) -3'-chloroazobenzene, 4- (N, N-dimethylamino)-
3,3'-dichloroazobenzene, 4- (N, N-dimethylamino) -2,2'-dichloroazobenzene, 4-
Examples thereof include (N, N-dimethylamino) -2,5-dichloroazobenzene and 4- (N, N-dimethylamino) -2,6-dichloroazobenzene.

Further, for example, 4- (N, N-dimethylamino) azonaphthalene, 4- (N, N-diethylamino) azonaphthalene, bis (4,4'-amino) azobenzene, bis (4,4'-). Methylamino) azobenzene, bis (4,4′-ethylamino) azobenzene, bis (4,4′-propylamino) azobenzene, bis [4,4 ′-(N, N-dimethylamino)] azobenzene, 4-amino -4 '-(N-methylamino) azobenzene, 4-amino-4'-(N-ethylamino) azobenzene, 4-amino-4 '-(N-propylamino) azobenzene, 4-amino-4'-( N, N-dimethylamino) azobenzene, 4-amino-4 ′-(N, N-ethylamino) azobenzene, 4-amino-4 ′-(N,
N'-dipropylamino) azobenzene, bis [4,
4 '-(N, N-diethylamino) azobenzene, bis [4,4'-(N, N-dipropylamino)] azobenzene, bis (4,4'-diphenylamino) azobenzene, bis [4,4'- (N-phenyl-N-methylamino)] azobenzene, bis [4,4 ′-(N-methyl-
N-ethylamino)] azobenzene, bis [4,4′-
(N-phenyl-N-ethylamino) -azobenzene,
Bis [4,4 '-(N-phenyl-N-propylamino)] azobenzene, bis [4,4'-(N, N-dimethylamino)] azonaphthalene, bis [4,4'-
(N, N-diethylamino)] azonaphthalene, bis [4,4 ′-(N, N-dimethylamino) -2-methyl] azobenzene, bis [4,4 ′-(N, N-dimethylamino) -2 , 2'-Dimethyl] azobenzene, bis [4,4 '-(N, N-dimethylamino) -2,6-dimethyl] azobenzene, bis [4,4'-(N, N-dimethylamino) -2, 2 ', 6,6'-tetramethyl]
Azobenzene, bis (4,4'-amino) -2-methyl-azobenzene, bis (4,4'-amino) -2,2 '
-Dimethylazobenzene etc. can be mentioned.

Further, for example, bis [4,4 '-(N, N
-Dimethylamino) -2-chloro] azobenzene, bis [4,4 '-(N, N-dimethylamino) -2,2'-
Dichloro) azobenzene, bis [4,4 '-(N, N-
Dimethylamino) -2,6-dichloro] azobenzene,
Bis [4,4 ′-(N, N-dimethylamino) -2,
2 ', 6,6'-tetrachloro] azobenzene, bis (4,4'-amino) -2-chloroazobenzene, bis (4,4'-amino) -2,2'-dichloroazobenzene and the like can be mentioned. it can.

Further, for example, bis (3,4'-amino)
Azobenzene, bis (3,4'-methylamino) azobenzene, bis (3,4'-ethylamino) azobenzene, bis (3,4'-propylamino) azobenzene,
Bis [3,4 ′-(N, N-dimethylamino)] azobenzene, 3-amino-4 ′-(N-methylamino) azobenzene, 3-amino-4 ′-(N-ethylamino) azobenzene, 3- Amino-4 ′-(N-propylamino) azobenzene, 3-amino-4 ′-(N, N-dimethylamino) azobenzene, 3-amino-4 ′-(N,
N-ethylamino) azobenzene, 3-amino-4′-
(N, N'-dipropylamino) azobenzene, bis [3,4 '-(N, N-diethylamino] azobenzene, bis [3,4'-(N, N-dipropylamino)]
Azobenzene, bis [3,4'-diphenylamino] azobenzene, bis [3,4 '-(N-phenyl-N-methylamino)] azobenzene, bis [3,4'-(N-
Methyl-N-ethylamino)] azobenzene, bis [3,4 ′-(N-phenyl-N-ethylamino)] azobenzene, bis [3,4 ′-(N-phenyl-N-propylamino)] azobenzene, Screw [3,4'-
(N, N-Dimethylamino)] azonaphthalene, bis [3,4 ′-(N, N-diethylamino)] azonaphthalene, bis [3,4 ′-(N, N-dimethylamino)-
2-methyl] -azobenzene, bis [3,4 '-(N,
N-dimethylamino) -2,2'-dimethyl] azobenzene, bis [3,4 '-(N, N-dimethylamino)-
2,6-Dimethyl] azobenzene, bis [3,4'-
(N, N-Dimethylamino) -2,2 ', 6,6'-tetramethyl] azobenzene, bis (4,4'-amino)
-2-methyl-azobenzene, bis (3,4'-amino) -2,2'-dimethyl-azobenzene, bis [3,3
4 '-(N, N-dimethylamino) -2-chloro) azobenzene, bis [3,4'-(N, N-dimethylamino) -2,2'-dichloro] azobenzene, bis [3,3 '
4 '-(N, N-dimethylamino) -2,6-dichloro] azobenzene, bis [3,4'-(N, N-dimethylamino) -2,2 ', 6,6'-tetrachloro] azobenzene , Bis [3,4′-amino] -2-chloroazobenzene, bis (3,4′-amino) -2,2′-dichloro-azobenzene and the like.

Further, for example, bis (2,4'-amino)
Azobenzene, bis (2,4'-methylamino) azobenzene, bis (2,4'-ethylamino) azobenzene, bis (2,4'-propylamino) azobenzene,
Bis [2,4 ′-(N, N-dimethylamino)] azobenzene, 2-amino-4 ′-(N-methylamino) azobenzene, 2-amino-4 ′-(N-ethylamino) azobenzene, 2- Amino-4 ′-(N-propylamino) azobenzene, 2-amino-4 ′-(N, N-dimethylamino) azobenzene, 2-amino-4 ′-(N,
N-ethylamino) azobenzene, 2-amino-4′-
(N, N'-dipropylamino) -azobenzene, bis [2,4 '-(N, N-diethylamino)] azobenzene, bis [2,4'-(N, N-dipropylamino)]
Azobenzene, bis (2,4'-diphenylamino) azobenzene, bis [2,4 '-(N-phenyl-N-methylamino)] azobenzene, bis [2,4'-(N-
Methyl-N-ethylamino)] azobenzene, bis [2,4 ′-(N-phenyl-N-ethylamino)] azobenzene, bis [2,4 ′-(N-phenyl-N-propylamino)] azobenzene, Screw [2,4'-
(N, N-Dimethylamino)] azonaphthalene, bis [2,4 ′-(N, N-diethylamino)] azonaphthalene, bis [2,4 ′-(N, N-dimethylamino)-
4-methyl] azobenzene, bis [2,4 '-(N, N
-Dimethylamino) -4,2'-dimethyl] azobenzene, bis [2,4 '-(N, N-dimethylamino)-
4,6-Dimethyl] azobenzene, bis [2,4'-
(N, N-Dimethylamino) -4,6,2 ', 6'-tetramethyl] azobenzene, bis (2,4'-amino)
-4-methyl-azobenzene, bis (2,4'-amino) -4,2'-dimethylazobenzene, bis [2,2
4 '-(N, N-dimethylamino) -4-chloro] azobenzene, bis [2,4'-(N, N-dimethylamino) -4,2'-dichloro] azobenzene, bis [2,2
4 '-(N, N-dimethylamino) -4,6-dichloro] azobenzene, bis [2,4'-(N, N-dimethylamino) -4,6,2 ', 6'-tetrachloro] azobenzene , Bis (2,4'-amino) -4-chloroazobenzene, bis (2,4'-amino) -4,2'-dichloroazobenzene and the like.

Further, for example, bis (2,2'-amino)
Azobenzene, bis (2,2'-methylamino) azobenzene, bis (2,2'-ethylamino) azobenzene, bis (2,2'-propylamino) azobenzene,
Bis [2,2 ′-(N, N-dimethylamino)] azobenzene, 2-amino-2 ′-(N-methylamino) azobenzene, 2-amino-2 ′-(N-ethylamino) azobenzene, 2- Amino-2 '-(N-propylamino) azobenzene, 2-amino-2'-(N, N-dimethylamino) azobenzene, 2-amino-2 '-(N,
N-ethylamino) azobenzene, 2-amino-2'-
(N, N'-dipropylamino) azobenzene, bis [2,2 '-(N, N-diethylamino)] azobenzene, bis [2,2'-(N, N-dipropylamino)]
Azobenzene, bis (2,2'-diphenylamino)-
Azobenzene, bis [2,2 '-(N-phenyl-N-
Methylamino)] azobenzene, bis [2,2 ′-(N
-Methyl-N-ethylamino)] azobenzene, bis [2,2 '-(N-phenyl-N-ethylamino)] azobenzene, bis [2,2'-(N-phenyl-N-propylamino)] azobenzene , Screw [2,2'-
Examples include (N, N-dimethylamino)] azonaphthalene and bis [2,2 ′-(N, N-diethylamino)] azonaphthalene.

Further, as another specific example, for example, bis (2,3'-amino) azobenzene, bis (2,3'-).
Methylamino) azobenzene, bis (2,3′-ethylamino) azobenzene, bis (2,3′-propylamino) azobenzene, bis [2,3 ′-(N, N-dimethylamino)] azobenzene, 2-amino -3 '-(N-
Methylamino) azobenzene, 2-amino-3 ′-(N
-Ethylamino) azobenzene, 2-amino-3'-
(N-propylamino) azobenzene, 2-amino-
3 '-(N, N-dimethylamino) azobenzene, 2-
Amino-3 ′-(N, N-ethylamino) azobenzene, 2-amino-3 ′-(N, N′-dipropylamino) azobenzene, bis [2,3 ′-(N, N-diethylamino)] azobenzene , Bis [2,3 '-(N, N
-Dipropylamino)] azobenzene, bis (2,3 '
-Diphenylamino) azobenzene, bis [2,3'-
(N-phenyl-N-methylamino)] azobenzene,
Bis [2,3 '-(N-methyl-N-ethylamino)]
Azobenzene, bis [2,3 '-(N-phenyl-N-
Ethylamino)] azobenzene, bis [2,3 ′-(N
-Phenyl-N-propylamino)] azobenzene, bis [2,3 '-(N, N-dimethylamino)] azonaphthalene, bis [2,3'-(N, N-diethylamino)] azonaphthalene and the like. be able to.

Further, for example, bis (3,3'-amino)
Azobenzene, bis (3,3′-methylamino) azobenzene, bis (3,3′-ethylamino) azobenzene, bis (3,3′-propylamino) azobenzene,
Bis [3,3 ′-(N, N-dimethylamino)] azobenzene, 3-amino-3 ′-(N-methylamino) azobenzene, 3-amino-3 ′-(N-ethylamino) azobenzene, 3- Amino-3 ′-(N-propylamino) azobenzene, 3-amino-3 ′-(N, N-dimethylamino) azobenzene, 3-amino-3 ′-(N,
N-ethylamino) azobenzene, 3-amino-3′-
(N, N'-dipropylamino) azobenzene, bis [3,3 '-(N, N-diethylamino)] azobenzene, bis [3,3'-(N, N-dipropylamino)]
Azobenzene, bis (3,3'-diphenylamino) azobenzene, bis [3,3 '-(N-phenyl-N-methylamino)] azobenzene, bis [3,3'-(N-
Methyl-N-ethylamino)] azobenzene, bis [3,3 ′-(N-phenyl-N-ethylamino)] azobenzene, bis [3,3 ′-(N-phenyl-N-propylamino)] azobenzene, Screw [2,3'-
(N, N-Dimethylamino)] azonaphthalene, bis [3,3 ′-(N, N-diethylamino)] azonaphthalene, bis [3,3 ′-(N, N-dimethylamino)-
4-methyl] azobenzene, bis [3,3 '-(N, N
-Dimethylamino) -4,4'-dimethyl] azobenzene, bis [3,3 '-(N, N-dimethylamino)-
4,6-Dimethyl] azobenzene, bis [3,3'-
(N, N-Dimethylamino) -4,4 ', 6,6'-tetramethyl] azobenzene, bis (3,3'-amino)
-4-methylazobenzene, bis (3,3'-amino)
-5,5'- dimethylazobenzene etc. can be mentioned.

However, the azo compounds that can be used in the present invention are not limited to the above examples.
On the other hand, the acidic substance used in the present invention may be either an organic compound or an inorganic compound, and examples of the organic acidic substance include phenol, alkylphenol, bisphenol A, naphthol, dihydroxynaphthalene, bisphenol S and ether thereof, phenyl. Phenols such as phenol-formalin resin and butylphenol-acetylene resin, benzoic acid, toluic acid, naphthoic acid, oxalic acid, malonic acid, maleic acid, cinnamic acid, naphthoic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene Examples thereof include carboxylic acids such as dicarboxylic acid and metal salts thereof, hydroxycarboxylic acids such as salicylic acid and hydroxynaphthoic acid, and metal salts thereof.

Examples of the inorganic acidic substance include acid clay, activated clay, clay minerals such as kaolin and montmorillonite, metal oxides such as titania, zirconia and alumina, and composite oxides such as silica alumina and silica titania. Examples thereof include heteropoly compounds such as phosphomolybdic acid, phosphotungstic acid, and silicotungstic acid, crystalline aluminosilicates such as zeolite, and metal salts such as zinc chloride.

The color-forming recording material according to the present invention can be made into a heat-sensitive pressure-sensitive recording material by a conventionally known method. When the color-forming recording material according to the present invention is used as, for example, a heat-sensitive recording material, the azo compound and the acidic substance are dispersed in an appropriate solvent together with an additive and a binder as necessary to prepare a dispersion liquid. Then, this may be applied on a substrate such as paper and dried. The coating amount of the above dispersion liquid is usually in the range of 1 to 15 g / m ² in terms of dry weight. Examples of the binder include water-soluble polymers such as polyvinyl alcohol, hydroxyethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone, and isobutylene-maleic anhydride copolymer, as well as polyvinyl acetate, polyurethane, and styrene-butadiene copolymer. Examples thereof include latexes such as polyacrylic acid and polyacrylic acid ester.

The heat-sensitive recording material according to the present invention may contain, as necessary, a sensitizer, a fluorescent dye, a pigment, an anti-adhesive agent, etc. as additives. As the sensitizer, for example,
Stearic acid amide, benzamide, dibenzyl oxalate, benzyl biphenyl, dimethyl terephthalate, dibenzyl terephthalate, catechol benzoate, terphenyl, benzyl p-hydroxybenzoate, diphenyl carbonate, phenyl hydroxynaphthoate, benzyloxynaphthalene, benzyloxybenzoic acid Examples thereof include benzyl, bis (methylphenyloxy) ethane, dimethoxydiphenyl sulfone and the like. Further, as the fluorescent dye, for example, diaminostilbene-based, benzimidazole-based, benzidine-based, imidazolone-based, coumarin-based compounds, as the pigment, titanium dioxide, clay, talc, calcium carbonate, aluminum hydroxide, silica, polystyrene resin Examples of the anti-adhesive agent such as urea-formalin resin include zinc stearate, calcium stearate, and paraffin wax.

In order to use the color-forming recording material according to the present invention as a pressure-sensitive recording material, for example, one component of the azo compound and the acidic substance is microencapsulated, and this is prepared as described above. It may be applied to a base material such as paper together with a binder to obtain an upper leaf paper, and the remaining components not microencapsulated may be applied together with a binder onto a base material such as paper to form a lower leaf paper. As another method, the microcapsules as described above and the remaining components that have not been microencapsulated may be coated on the same paper surface together with the binder. Examples of the polymer for forming microcapsules include polyurethane, polyamide, polyurea, polystyrene, styrene-methacrylate copolymer, urea-formaldehyde resin, and melamine resin. Such a polymer is preferably produced by an interfacial polymerization method or an internal polymerization method.

Various microcoacervation methods can be used to form microcapsules from the water-soluble polymer. In this method, as the water-soluble polymer, for example, gelatin, gum arabic, sodium alginate, carboxymethyl cellulose, polyvinylbenzenesulfonic acid, etc. can be used. The color-forming recording material produced by such a method has an overcoat layer on the surface for the purpose of protecting the recording layer, or an undercoat layer for smoothing the surface and increasing the thermal conductivity, An adhesive layer may be provided on the back surface so that it can be used as a label.

[0026]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

Examples 1, 2, 5 and 6 Bis [4,4 '-(N, N-dimethylamino)] azobenzene (Examples 1 and 5) or bis [4,4'-(N,
N-diethylamino)] azobenzene (Examples 2 and 6) 0.070 g, 1-hydroxy-2-naphthoic acid 0.2
26 g, stearamide 0.10 g, zinc stearate 0.100 g and 3% polyvinyl alcohol aqueous solution 2.
70 g was mixed and treated with a pulverizer for 10 minutes to obtain a coating liquid.

This coating solution was applied to a high-quality paper using a bar coater (Tester Sangyo, PI1210), air-dried, and then heat-colored (color-developed) using a thermal paper color tester (Okura Denki, TH-PMD). test). Table 1 shows the reflectance at 780 nm measured by a UV measuring device (Shimadzu, UV-3101). In Table 1, R indicates the reflectance of the background portion, and R ′ indicates the reflectance of the colored portion. Here, the larger the reflectance R of the background portion and the smaller the reflectance R ′ of the color-developing portion, the better the characteristics of the heat-sensitive material.

Similarly, NEC printer (PC-PR
The barcode was printed using a thermal head of 102 TL). This bar code is used as a semiconductor laser (780n
m) Bar code reader (Symbol Technologies, Inc.
, LS8200). The results of the reading test are shown in Table 1. Table 2 (Examples 3 and 4) shows the reading test results of this bar code after irradiation with a xenon lamp for 24 hours using a light resistance tester (Shimadzu, XF-180) (light resistance test).

Examples 3 and 7 A thermal paper was prepared in the same manner as in Example 1 except that 0.40 g of activated clay was used in place of 1-hydroxy-2-naphthoic acid. , Color development and light fastness test were conducted. The obtained results are shown in Tables 1 and 2.

Examples 4 and 8 In Example 1, instead of bis [4,4 '-(N, N-dimethylamino)] azobenzene and 1-hydroxy-2-naphthoic acid, 4-N, N-, respectively. Dimethyl
A thermal paper was prepared and a color development and light fastness test were conducted in the same manner as in Example 1 except that 0.070 g of 4'-aminoazobenzene and 0.300 g of 1-naphthoic acid were used.
The obtained results are shown in Tables 1 and 2.

Comparative Examples 1 to 4 As a comparative example, in Example 1, bis [4,4'-
(N, N-Dimethylamino)] azobenzene 0.070 g
Instead of 0.226 g of 1-hydroxy-2-naphthoic acid, a color forming dye (3,6-bis (dimethylamino) fluorene-9-spiro proposed in JP-A-59-199757 shown below is used. -3 '-(6'-dimethylamino) phthalide, Comparative Examples 1 and 3)

[0033]

[Chemical 3]

Alternatively, a color-forming dye (3,3-bis [(2'-p-
N, N'-Dimethylaminophenyl-2'-p-methoxyphenyl) ethylene-1'-yl] 4,5,6,7-
Tetrachlorophthalide, Comparative Examples 2 and 4)

[0035]

[Chemical 4]

0.070 g and bisphenol A 0.226
A thermal paper was prepared in the same manner as in Example 1 except that g was used, and color development and light fastness tests were conducted. The obtained results are summarized in Tables 1 and 2.

[0037]

[Table 1]

[0038]

[Table 2]

From the above, it is clear that the color forming body of the color forming dye of the present invention has high color strength and high stability.

[0040]

INDUSTRIAL APPLICABILITY The novel color-forming dye according to the present invention has a strong absorption in the visible region to the near-infrared region and high stability such as light resistance and moisture resistance, and therefore, as a recording material. Extremely useful.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical indication location B41M 5/30 6956-2H B41M 5/18 102 6956-2H 108 (72) Inventor Yoshihisa Kiso Yamaguchi Prefecture Kuwa-gun 6-1-2 Waki Kimachi Mitsui Petrochemical Industry Co., Ltd.

Claims (1)

[Claims] 1. (a) General formula (I): (In the formula, X is hydrogen, halogen, amino group, alkylamino group, arylamino group, aralkylamino group, alkyl group, hydroxyl group, acyl group, alkoxy group, aryl group,
Represents an aralkyl group, an acylamino group, an acyloxy group, an arylsulfonyl group, an arylsulfonamide group or a silyloxy group, n represents a natural number of 5 or less, and Y represents hydrogen, halogen, an alkyl group, a hydroxyl group, an acyl group, an alkoxy group, aryl Group, aralkyl group, acylamino group,
It represents an acyloxy group, an arylsulfonyl group, an arylsulfonamide group or a silyloxy group, m represents a natural number of 4 or less, and A and B each independently represent hydrogen, an alkyl group, an aryl group or an aralkyl group. ) And an azo compound represented by the formula (b), and (b) an acidic substance.