JPH0593982A - Color developing recording material - Google Patents

Abstract

PURPOSE:To obtain the color developing recording material capable of developing color in a practicablly sufficient intensity soon after color development operation and having absorption in a wide region from the visible region to a near infrared region in its color developing part by incorporating a specified compound, an oxidant, and an acidic material. CONSTITUTION:This recording material contains the compound of formula I, the oxidant, and the acidic material. In formula I, A is a univalent aromatic group; each of B and X is, an independently divalent aromatic group; Y is -O-, -NH-, -N (lower alkyl)-, -N(,aryl)-, or -N(aralkyl)=; Z is H, alkyl, aryl, aralkyl, alkoxy, aryloxy, aralkyloxy, alkylated amino, or arylated amino; each of R<1> and R<2> is, independently to each other, H, lower alkyl, aryl, or aralkyl. The oxidant is a quinoid type electron acceptor, and the acidic material is an aromatic carboxylic acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a color forming recording material. More specifically, it relates to a color-forming recording material which is useful for a recording / reading device using visible light and / or near infrared light.

[0002]

2. Description of the Related Art Conventionally, a dye precursor (hereinafter, referred to as a color-forming dye), which is almost colorless in itself but can develop a certain color by a chemical reaction, is combined with a color-developing agent to develop the color. As a color-forming recording material, it has been widely put to practical use on heat-sensitive and pressure-sensitive recording paper and the like.

By the way, in recent years, a bar code has been actively used as a means for more advanced information processing, and a semiconductor laser device is advantageous as a device for reading the bar code because of its advantages such as small size, low cost and long life. -There is a tendency that devices utilizing the "Z-" are frequently used. Since the semiconductor laser emits light in the near infrared region, the dye forming the bar code must absorb the light in the region. However, in the fluoran-based color-forming dye that has been generally used for the conventional heat-sensitive / pressure-sensitive recording paper, the dye formed by the color-forming reaction does not have a practical absorption in the region. In addition, a method of extending the π-electron conjugated system to have absorption in this region is also adopted, but the compound has a high molecular weight and its production is not easy.
The formed dye is unstable and easily discolors, and has poor light resistance.

Therefore, in recent years, a compound having a structure greatly different from that of the conventional one has been proposed as a color forming dye which produces a dye absorbing the light in the region.

JP-A-62-181361 proposes a color forming recording material containing a phenylenediamine derivative or a naphthylenediamine derivative and an acidic substance. This color-forming recording material has a drawback that the change with time after color development is remarkable.

JP-A-63-256486 proposes a color-forming recording material containing a phenylenediamine derivative or a naphthylenediamine derivative and a quinoid type electron-accepting compound. According to the study of the present inventor, it is difficult for this color forming recording material to cause substantial color development, and it seems that practical application is not easy.

Further, JP-A-63-94880 discloses a color-forming recording material containing a phenylenediamine derivative or a naphthylenediamine derivative and an organic halogen compound which generates a halogen radical by the action of heat and / or light. It is disclosed. The generated organic halogen radicals such as chlorine radicals abstract hydrogen radicals from surrounding compounds to generate a strong acid such as hydrohalic acid such as hydrochloric acid. Therefore, when this recording paper is used for copying books, documents, etc., the durability of the paper is impaired for a long period of time.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel color forming recording material. Another object of the present invention is to provide a color forming recording material which gives a color having a practically sufficient intensity immediately after the color forming operation and has a strong absorption in a wide range from the visible region to the near infrared region. is there.

Still another object of the present invention is to provide a novel color forming recording material which can solve the above-mentioned problems in the conventional color forming recording materials. Other objects and advantages of the present invention will be apparent from the following description.

[0010]

According to the present invention, the above objects and advantages of the present invention are: (a) the following formula (I):

[0011]

[Chemical 2]

The present invention is achieved by a color-forming recording material characterized by containing a compound represented by the formula (b), an oxidizing agent and (c) an acidic substance.

The color-forming recording material according to the present invention comprises the above-mentioned three elements, and these elements react with each other by a color-forming operation to produce an aminium salt having a strong absorption in a wide range from the visible region to the near infrared region. According to the present invention, it is possible to provide an excellent color forming recording material which is useful for a recording / reading apparatus using visible light and / or near infrared rays.

The above component (a) used in the present invention is represented by the formula (I). In formula (I), A is a monovalent aromatic group. As the monovalent aromatic group, for example, a phenyl group,
A naphthyl group and the like can be mentioned as preferable ones.

B and X are, independently of each other, a divalent aromatic group. Examples of the divalent aromatic group include 1,3
-Phenylene, 1,4-phenylene, 2,6-naphthylene, 1,4-naphthylene, 1,5-naphthylene and the like can be mentioned as preferable ones.

These monovalent and divalent aromatic groups can have a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group, an aryl group, an aralkyl group, a hydroxyl group, an alkoxy group, an aryloxy group, an aralkyloxy group, an acyl group, a carboxyl group and an alkoxycarbonyl group. , Aryloxycarbonyl group, alkyl-substituted carbamoyl group, aryl-substituted carbamoyl group, sulfonic acid group, alkylsulfonyl group, arylsulfonyl group, amino group, alkyl-substituted amino group, aryl-substituted amino group, pyrrolidino Group, piperidino group and the like. One or more of these substituents may be substituted on the aromatic group. The plurality of substituents may be the same or different.

Preferred examples of the halogen atom include fluorine, chlorine, bromine and iodine.

The alkyl group is preferably a linear or branched one having 1 to 8 carbon atoms, such as methyl,
Ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, t-butyl, n
-Amyl, iso-amyl, n-hexyl, n-octyl and the like can be mentioned as preferable ones.

Preferred examples of the aryl group include phenyl, tolyl, naphthyl, biphenyl and the like. Preferred examples of the aralkyl group include benzyl and phenethyl.

The alkoxy group is preferably a straight-chain or branched-chain alkoxy group having 1 to 4 carbon atoms, for example, methoxy, ethoxy, n-propoxy, iso-propoxy,
n-butoxy, iso-butoxy, sec-butoxy,
Preferable examples are t-butoxy and the like.

Preferable examples of the aryloxy group include phenoxy, methylphenoxy and naphthoxy. Preferred examples of the aralkyloxy group include benzyloxy, phenethyloxy and the like.

As the acyl group, for example, a linear or branched aliphatic acyl group having 1 to 4 carbon atoms and an alkyl portion or an alkyl group having an aryl portion of 7 to 12 carbon atoms is used. An optionally substituted aromatic acyl group is preferable, and examples thereof include formyl, acetyl, propionyl, butyryl, benzoyl, toluoyl and naphthoyl.

As the alkoxycarbonyl group, those having the same alkoxy moiety as those described above are preferable, and examples thereof include methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, iso-propoxycarbonyl and n-.
Butoxycarbonyl, sec-butoxycarbonyl, t
-Butoxycarbonyl and the like can be mentioned as preferable ones.

As the aryloxycarbonyl group, those having the same aryloxy moiety as those described above are preferable, and preferable examples include phenoxycarbonyl, methylphenoxycarbonyl, naphthoxycarbonyl and the like.

The alkyl-substituted carbamoyl is preferably a carbamoyl group mono- or di-substituted by a linear or branched alkyl group having 1 to 4 carbon atoms,
For example, methylcarbamoyl, dimethylcarbamoyl, ethylcarbamoyl, methylethylcarbamoyl, diethylcarbamoyl, n-propylcarbamoyl, n-propylmethylcarbamoyl, di (n-propyl) carbamoyl, iso-propylcarbamoyl, n-butylcarbamoyl, di (n- Butyl) carbamoyl, iso-butylcarbamoyl, sec-butylcarbamoyl, t-
Butylcarbamoyl and the like can be mentioned as preferable ones.

The aryl-substituted carbamoyl includes, for example, a carbamoyl group mono- or di-substituted with an aryl group such as phenyl, tolyl, and naphthyl, or carbamoyl in which an aryl group and an alkyl group are simultaneously substituted. A group is preferable, and preferable examples thereof include phenylcarbamoyl, diphenylcarbamoyl, phenylmethylcarbamoyl, phenylethylcarbamoyl, tolylcarbamoyl, and naphthylcarbamoyl.

The alkylsulfonyl group is preferably one in which the alkyl portion has a straight or branched chain having 1 to 4 carbon atoms, and preferred examples thereof include methanesulfonyl, ethanesulfonyl, propanesulfonyl, butanesulfonyl and the like. it can.

The arylsulfonyl group is preferably one having the same aryl moiety as described above, and preferred examples thereof include benzenesulfonyl, toluenesulfonyl, naphthalenesulfonyl and the like.

The alkyl-substituted amino group has 1 carbon atom.
An amino group mono- or di-substituted by a linear or branched alkyl group of 4 to 4 is preferable, and examples thereof include methylamino, dimethylamino, ethylamino, methylethylamino, diethylamino, n-propylamino and n-.
Propylmethylamino, di (n-propyl) amino, i
Examples include so-propylamino, n-butylamino, di (n-butyl) amino, iso-butylamino, sec-butylamino, t-butylamino and the like.

The aryl-substituted amino group is, for example, an amino group mono- or di-substituted with an aryl group such as phenyl, tolyl, and naphthyl, or an aryl group and an alkyl group are simultaneously substituted. An amino group is preferable, and preferable examples thereof include phenylamino, diphenylamino, phenylmethylamino, phenylethylamino, tolylamino, and naphthylamino.

In the above formula (I), Y is --O.
It is-, -NH-, -N (lower alkyl)-, -N (aryl)-or -N (aralkyl)-. Examples of the lower alkyl group, aryl group and aralkyl group bonded to the nitrogen atom include the following groups.

The lower alkyl group is preferably a straight chain or branched chain having 1 to 4 carbon atoms, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-. Butyl, t-butyl and the like can be mentioned as preferable ones.

Preferable examples of the aryl group include phenyl, tolyl, naphthyl, biphenyl and the like. Preferred examples of the aralkyl group include benzyl and phenethyl.

In the above formula (1), Z is a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an aralkyloxy group, an alkyl-substituted amino group or an aryl-substituted amino group. Preferable specific examples of these groups include the same groups as those mentioned above.

Further, in the above formula (I), R ¹ and R ² are each independently a hydrogen atom, a lower alkyl group, an aryl group or an aralkyl group. Preferable specific examples of these groups include the same groups as those mentioned above.

As is clear from the above specific examples, in the above formula (I), the -Y-CO-Z- moiety is a ureido group, a carbamate group, a carbonate group, an amide group or an acyloxy group. It will be understood to represent.

Examples of the compound represented by the above formula (I) include N- (4-acetylaminophenyl)-
N'-phenyl-p-phenylenediamine, N- (4-
Acetylaminophenyl) -N'-phenyl-m-phenylenediamine, N- (4-acetylaminophenyl)
-N'-phenyl-N, N ', N "-trimethyl-p-phenylenediamine, N- (4-acetylaminophenyl) -N'-phenyl-N, N'-diphenyl-p-phenylenediamine, N- (3-Acetylaminophenyl) -N'-phenyl-p-phenylenediamine, N-
(3-Acetylaminophenyl) -N'-phenyl-
N, N ', N "-trimethyl-p-phenylenediamine,
N- (3-acetylaminophenyl) -N'-phenyl-N, N'-diphenyl-p-phenylenediamine, N
-(4-propionylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (4-benzoylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (3-benzoylaminophenyl) -N '-
Phenyl-p-phenylenediamine, N- (3-β-naphthoylaminophenyl) -N′-phenyl-p-phenylenediamine,

N- (4-acetoxyphenyl) -N'-
Phenyl-p-phenylenediamine, N- (4-acetoxyphenyl) -N'-phenyl-N, N'-dimethyl-p-phenylenediamine, N- (4-acetoxyphenyl) -N'-phenyl-N, N '-Diphenyl-p-
Phenylenediamine, N- (3-acetoxyphenyl)
-N'-phenyl-p-phenylenediamine, N- (3
-Acetoxyphenyl) -N'-phenyl-N, N'-
Dimethyl-p-phenylenediamine, N- (3-acetoxyphenyl) -N'-phenyl-N, N'-diphenyl-p-phenylenediamine, N- (2-acetoxyphenyl) -N'-phenyl-p-phenylene Diamine,
N- (4-propionyloxyphenyl) -N'-phenyl-p-phenylenediamine, N- (4-benzoyloxyphenyl) -N'-phenyl-p-phenylenediamine, N- (3-benzoyloxyphenyl)- N '
-Phenyl-p-phenylenediamine, N- (3-β-
Naphthoyloxyphenyl) -N'-phenyl-p-phenylenediamine, N- (4-methoxycarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (3-methoxycarbonylaminophenyl)-
N'-phenyl-p-phenylenediamine, N- (2-
Methoxycarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (4-ethoxycarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (3-ethoxycarbonylaminophenyl) -N ' -Phenyl-p-phenylenediamine, N
-(4-t-butoxycarbonylaminophenyl)-
N'-phenyl-p-phenylenediamine, N- (3-
t-butoxycarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (4-phenoxycarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (3-phenoxycarbonylaminophenyl)- N'-phenyl-p-phenylenediamine, N- (4-methoxycarbonyloxyphenyl)
-N'-phenyl-p-phenylenediamine,

N- (3-methoxycarbonyloxyphenyl) -N'-phenyl-p-phenylenediamine, N
-(4-Ethoxycarbonyloxyphenyl) -N'-
Phenyl-p-phenylenediamine, N- (3-ethoxycarbonyloxyphenyl) -N'-phenyl-p-
Phenylenediamine, N- (4-t-butoxycarbonyloxyphenyl) -N'-phenyl-p-phenylenediamine, N- (3-t-butoxycarbonyloxyphenyl) -N'-phenyl-p-phenylenediamine,
N- (4-phenoxycarbonyloxyphenyl)-
N'-phenyl-p-phenylenediamine, N- (3-
Phenoxycarbonyloxyphenyl) -N'-phenyl-p-phenylenediamine, N- (4-methylaminocarbonyloxyphenyl) -N'-phenyl-p-phenylenediamine, N- (4-dimethylaminocarbonyloxyphenyl)- N'-phenyl-p-phenylenediamine, N- (4-phenylaminocarbonyloxyphenyl) -N'-phenyl-p-phenylenediamine, N- (4-tolylaminocarbonyloxyphenyl) -N'-phenyl-p -Phenylenediamine,

N- (4-methylaminocarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (4-dimethylaminocarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N-
(4-Ethylaminocarbonylaminophenyl) -N '
-Phenyl-p-phenylenediamine, N- (4-diethylaminocarbonylaminophenyl) -N'-phenyl-p-phenylenediamine, N- (4-phenylaminocarbonylaminophenyl) -N'-phenyl-p-
Examples thereof include phenylenediamine and N- (4-tolylaminocarbonylaminophenyl) -N'-phenyl-p-phenylenediamine.

The compound represented by the above formula (I) has the following formula (II)

[0042]

[Chemical 3]

The compound represented by the formula (1) can be produced by reacting, for example, isocyanate, carbamic acid chloride, chlorocarbonic acid ester, dicarbonic acid diester, carboxylic acid, acid chloride and the like. That is, ureido or carbamate can be obtained by reacting isocyanate or carbamic acid chloride.
Carbamates or carbonates can be obtained by reacting chlorocarbonic acid esters or dicarbonic acid diesters, and amides or esters can be obtained by reacting carboxylic acids or acid chlorides.

The reaction can be carried out in the presence of a base as an acid scavenger or a dehydrating agent, if necessary.

The oxidizing agent (b) used in the present invention may be either an organic or an inorganic oxidizing agent. As the organic oxidant, quinoid type electron accepting compound, organic halogen compound, peracid, phosphine oxide, sulfoxide,
Examples thereof include disulfide and N-oxide. Further, examples of the inorganic oxidizing agent include oxygen, halogen, halides, metal oxides and the like. In the present invention, among them, the MNDO-PM3 molecular orbital method (JJ Stewart, J. Comp. Chem. 10 209; Mo) is particularly preferable.
A quinoid type electron-accepting compound having an LUMO energy level of -2.80 to -1.30 eV calculated by pac 6 ver. 6.0) is preferable.

As specific examples, silver perchlorate, silver hexafluoroantimonate, silver oxide, lead oxide, benzoquinone,
Naphthoquinone, chloranil, dichlorodicyanobenzoquinone, tetracyanoquinodimethane, N, N'-diphenylquinonediimine, N-chlorosuccinimide, diphenyldisulfide, tripromomethylphenylsulfone,
Benzoyl per-oxide, N-methylmorpholine-N
-Oxide, m-chloroperbenzoic acid and the like can be mentioned.

The oxidizing agent (b) is a compound represented by the above formula (I): oxidizing agent (b) in a molar ratio of preferably 1: 1.
In the range of 100 to 100: 1, more preferably 1:20 to 2
Used in the range of 0: 1.

The acidic substance (c) used in the present invention
For example, phenol, carboxylic acid, sulfonic acid, phenol resin and the like can be preferably used.
Of these, carboxylic acids, especially aromatic carboxylic acids, are particularly desirable.

As specific examples, naphthol, bisphenol A, 4,4'-sulfonyldiphenol, nitrophenol, oxalic acid, malonic acid, maleic acid, benzoic acid,
Chlorobenzoic acid, nitrobenzoic acid, salicylic acid, cinnamic acid, naphthoic acid, phthalic acid, isophthalic acid, terephthalic acid, hydroxynaphthoic acid, benzenesulfonic acid, toluenesulfonic acid, phenylphenol-formalin resin, butylphenol- An acetylene resin etc. can be mentioned.

The acidic substance (c) is a molar ratio of the compound represented by the above formula (I) to the acidic substance (c), preferably 1
The range is 0: 1 to 1:10, and more preferably 5: 1 to 1: 1.
Used in the range of 10.

The color-forming recording material of the present invention comprises the components (a), (b) and (c) as described above. Each of these components can be used alone or in combination of two or more. The color-forming recording material of the present invention, if necessary, other known color-forming dyes, binders,
A sensitizer, a fluorescent dye, a pigment, an antiblocking agent, etc. can be contained. Examples of other color forming dyes include fluorane compounds, fluorene compounds, and phthalide compounds. By using these other color forming dyes in combination, it is possible to enhance absorption in the near infrared region and adjust the hue in the visible region. Examples of the near infrared absorption dye include 3- (4′-anilinophenyl) amino-6-methyl-7-anilinofluorane and 3- [4′-
(4 "-anilinophenyl) aminophenyl] amino-
6-methyl-7-chlorofluorane, 3-diethylamino-7-dibenzylaminothiofluorane, 3-diethylamino-7-ethylaminothiofluorane, 3,6-
Bis (dimethylamino) fluorene-9-spiro-3 '
-(6'-Dimethylamino) phthalide, 3,6-bis (diethylamino) fluorene-9-spiro-3 '-(6'-
Dimethylamino) phthalide, 3'3-bis [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl]
Phthalide, 3,3-bis [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl] -4,5,6,7-
Tetrachlorophthalide, 3- (4-dimethylaminophenyl) -3- [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl] phthalide, 3- (4-dimethylaminophenyl) -3- [1,1-bis (4-dimethylaminophenyl) ethylene-2-yl] -6-dimethylaminophthalide and the like can be mentioned.

As the visible region absorbing dye, for example, blue color forming dyes such as crystal violet lactone, benzoyl leuco methylene blue, pyridine blue and the like; 3-diethylamino-7-octylaminofluorane, 3-diethylamino-7-dibenzylamino Green coloring dye such as fluorane; Red coloring dye such as 3-cyclohexylamino-6-chlorofluorane and 3-diethylamino-6-methyl-7-chlorofluorane; 3-diethylamino-
6-methyl-7-anilinofluorane, 3-di-n-butylamino-6-methyl-7-anilinofluorane, 3
-Diethylamino-7- (o-chloroanilino) fluorane, 3-dibutylamino-7- (o-chloroanilino) fluorane, 3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3- Pyrrolidino-6-methyl-7-anilinofluorane, 3-
Diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N-isoamylamino-6-methyl-7-anilinofluorane, 3- (Np-tolyl-
Black color-forming dyes such as N-ethylamino) -6-methyl-7-anilinofluorane can be mentioned.

These other color forming dyes are represented by the above formula (I).
Compound: other color forming dye in a molar ratio of preferably 1:
It is used in the range of 100 to 100: 1, and more preferably in the range of 1:20 to 20: 1.

Examples of the binder include polyvinyl alcohol, hydroxyethyl cellulose, sodium polyacrylate, polyvinylpyrrolidone and isobutylene.
In addition to water-soluble polymers such as maleic anhydride copolymer, latexes such as polyvinyl acetate, polyurethane, styrene-butadiene copolymer, polyacrylic acid, polyacrylic acid ester and the like can be mentioned.

Examples of the sensitizer include stearic acid amide, benzamide, dibenzyl terephthalate, diphenyl carbonate, phenyl 1-hydroxy-2-naphthoate, 1-benzyloxynaphthalene and 4,4'-dimethoxydiphenyl. Examples thereof include sulfone. Examples of fluorescent dyes include diaminostilbene-based dyes,
Benzimidazole-based, benzidine-based, imidazolone-based, coumarin-based compounds, pigments include titanium dioxide, clay, talc, calcium carbonate, aluminum hydroxide, silica, polystyrene resin, urea-formalin resin, etc. Examples thereof include zinc stearate, calcium stearate, and paraffin wax.

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. For example, when used as a heat-sensitive recording material, the color-forming recording material of the present invention may be dispersed in a solvent, and this may be coated on a substrate such as paper and dried. The amount applied is generally in the range of 1 to 15 g / m ² dry weight.

The color-forming recording material produced by such a method has an overcoat on the surface for the purpose of protecting the recording layer.
A coat layer may be provided, an undercoat layer may be provided for smoothing the surface and increasing heat transfer efficiency, and an adhesive layer may be provided on the back surface so that it can be used as a label.

[0058]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. The number in parentheses after the oxide is MNDO.
-LUMO energy level value calculated by the PM3 molecular orbital method.

Reference Example 1 N- (4-aminophenyl) -N'-phenyl-p-phenylenediamine 1.4 g, acetic acid 50 g, zinc powder 0.1
g was stirred under reflux for 5 hours. After cooling, the mixture was filtered, and the filtrate was concentrated to give N- (4-acetylaminophenyl) -N'-phenyl-p-phenylenediamine in a yield of 98%.

Reference Example 2 N- (4-aminophenyl) -N'-phenyl-p-phenylenediamine 1.0 g, di-t-butyl dicarbonate 1.2
g and 10 ml of methanol were stirred indoors for 1 hour. The reaction solution was concentrated to obtain N- (4-t-butoxycarbonylaminophenyl) -N'-phenyl-p-phenylenediamine with a yield of 95%.

Reference Example 3 N- (4-hydroxyphenyl) -N'-phenyl-p
-Phenylenediamine 1.0 g, methyl chlorocarbonate 0.4
g, triethylamine 1.5 g, dichloromethane 10 m
1 was stirred at room temperature for 5 hours. The reaction solution is filtered and the filtrate is concentrated to give N- (4-methoxycarbonyloxyphenyl).
Yield 98% of -N'-phenyl-p-phenylenediamine.
Earned in%.

Reference Example 4 N- (4-hydroxyphenyl) -N'-phenyl-p
-Phenylenediamine 1.1 g, phenyl isocyanate 0.5 g, tetrahydrofuran 10 ml at room temperature 12
Stir for hours. The reaction solution is filtered and the filtrate is concentrated to N-
(4-phenylaminocarbonyloxyphenyl)-
85% yield of N'-phenyl-p-phenylenediamine
Got with.

Reference Example 5 N- (4-aminophenyl) -N'-phenyl-p-phenylenediamine 0.8 g, phenylisocyanate 0.9.
4 g and 5 ml of dichloromethane were stirred at room temperature for 30 minutes.
The reaction solution was filtered, the filter cake was washed with acetone and N- (4-
Phenylaminocarbonylaminophenyl) -N'-phenyl-p-phenylenediamine was obtained with a yield of 90%.

Reference Example 6 N- (3-aminophenyl) -N'-phenyl-p-phenylenediamine 1.2 g, acetic acid 10 g, zinc powder 0.1
g was stirred under reflux for 6 hours. After cooling, the mixture was filtered, and the filtrate was concentrated to give N- (3-acetylaminophenyl) -N'-phenyl-p-phenylenediamine in a yield of 99%.

Examples 1 to 6 Compounds of the formula (1) synthesized in the above Reference Examples.
05 g, chloranil (-2.17 eV) 0.0472 g,
1-hydroxy-2-naphthoic acid 0.2178 g, stearic acid amide 0.20 g, zinc stearate 0.10 g
g, 10% polyvinyl alcohol aqueous solution 0.75 g and water 1.75 g were treated with a pulverizer for 10 minutes to obtain a coating solution.

This coating solution was applied to a high quality paper using a bar coater (Tester Sangyo, P11210) and air dried to prepare a color forming recording material. The compounds represented by the formula (1) used in each example are as follows. Example 1 N- (4-acetylaminophenyl) -N '
-Phenyl-p-phenylenediamine Example 2 N- (4-t-butoxycarbonylaminophenyl) -N'-phenyl-p-phenylenediamine Example 3 N- (4-methoxycarbonyloxyphenyl) -N'-phenyl -P-phenylenediamine Example 4 N- (4-phenylaminocarbonyloxyphenyl) -N'-phenyl-p-phenylenediamine Example 5 N- (4-phenylaminocarbonylaminophenyl) -N'-phenyl-p -Phenylenediamine Example 6 N- (3-acetylaminophenyl) -N '
-Phenyl-p-phenylenediamine

The prepared chromogenic recording material was heated and color-developed by using a thermal paper color tester (Okura Denki, TH-PRD), and the reflectance before and after color development was measured by a UV measuring device (Shimadzu, UV).
-3101) at 300-1300 nm. With respect to the color-forming recording materials of Examples 1 to 6, reflection spectra before and after coloring are shown in FIGS. 1, 2, 3, 4, 5, and 6, respectively. In the figure, the vertical axis is the reflectance (%)
And the horizontal axis is the wavelength (nm). Also, the solid line shows before coloring and the broken line shows after coloring.

Further, NEC printer- (PC-PR1
(02 TL) thermal head was used to print a bar code on the color forming recording material. This bar code
Semiconductor laser (780 nm) bar code reader (Symb
olTechnologies, Inc., LS8200) and LEDs (6
60nm) Bar-co-dreader (Mechano Systems, To
When the reading test was conducted with both uch7-PC-M10), good reading was possible with any of them.

Example 7 Example 1 except that 2-naphthoic acid was used as the acidic substance.
A color-forming recording material was prepared in the same manner as in (1) and a bar code was printed. This bar code is a semiconductor laser bar code lead.
Good reading was possible with both the reader and the LED bar cord reader.

Example 8 Benzoic acid was used as the acidic substance, and 2,5-
A color-forming recording material was prepared in the same manner as in Example 2 except that dichlorobenzoquinone (-1.99 eV) was used.
Printed. This bar code is a semiconductor laser bar.
Good reading was possible with both the cord reader and the LED bar cord reader.

Example 9 A color-forming recording material was prepared in the same manner as in Example 6 except that benzoquinone (-1.71 eV) was used as an oxidizing agent.
The code was printed. This bar code is a semiconductor laser
Good reading was possible with both the bar cord reader and the LED bar cord reader.

Example 10 A color-forming recording material was prepared in the same manner as in Example 3 except that salicylic acid was used as the acidic substance and benzoquinone was used as the oxidizing agent, and a bar code was printed. This bar code could be satisfactorily read by both a semiconductor laser bar cord reader and an LED bar cord reader.

[0073]

As described above, the color-forming recording material according to the present invention gives a color having a practically sufficient intensity immediately after the color-forming operation, and the color-forming portion is strong in a wide range from the visible region to the near infrared region. Since it has absorption, it is advantageous for reading information by instruments at all wavelengths such as a bar code reader using a semiconductor laser for reading in the near infrared region and a device for reading in the visible region.

[Brief description of drawings]

FIG. 1 shows reflection spectra before and after color development of a color forming recording material of Example 1.

FIG. 2 shows reflection spectra before and after color development of the color forming recording material of Example 2.

FIG. 3 shows reflection spectra before and after color development of the color forming recording material of Example 3.

FIG. 4 shows reflection spectra before and after color development of the color forming recording material of Example 4.

5 shows reflection spectra before and after color development of the color forming recording material of Example 5. FIG.

FIG. 6 shows reflection spectra before and after color development of the color forming recording material of Example 6.

Front page continuation (72) Masato Kawamura 6-1-2 Waki, Waki-machi, Kuga-gun, Yamaguchi Prefecture Mitsui Petrochemical Industry Co., Ltd. 1-2 Mitsui Petrochemical Industry Co., Ltd. (72) Inventor Hisaya Miki 6-1-2 Waki, Waki-machi, Kuga-gun, Yamaguchi Prefecture Mitsui Petrochemical Industry Co., Ltd.

Claims (4)

[Claims] 1. (a) The following formula (I): A color-forming recording material containing a compound represented by the formula (b), an oxidizing agent and (c) an acidic substance. 2. The color-forming recording material according to claim 1, wherein the oxidizing agent (b) is a quinoid type electron-accepting compound. 3. The LUMO energy level of the oxidant (b) calculated by the MNDO-PM3 molecular orbital method-2.8.
The chromogenic recording material according to claim 1, which is a quinoid type electron-accepting compound of 0 to -1.30 eV. 4. The color-forming recording material according to claim 1, wherein the acidic substance (c) is an aromatic carboxylic acid.