JPH04320882A - Color forming recording material - Google Patents

Abstract

PURPOSE:To provide a color forming recording material imparting a developed color of practically sufficient intensity immediately after color forming operation and having absorption in a long wavelength region from a visible light region to a near infrared region. CONSTITUTION:A color forming recording material contains an acyldiamine derivative (a) represented by general formula (I) A-NR<1>-B-NR<2>-CO-X (wherein A is an aryl group, B is an arylene group, X is an alkyl group, an aryl group or an aralkyl group and R<1> and R<2> are respectively independently hydrogen, a lower alkyl group, an aryl group or an aralkyl group), an oxidizing agent (b) and an acidic substance (c).

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to color-forming recording materials. More specifically, the present invention relates to a color-forming recording material that exhibits absorption in visible light to near infrared rays and is thus useful for reading information with equipment.

0002

2. Description of the Related Art Hitherto, color-forming recording materials made of dyes that are colorless per se and acidic substances have been widely put into practical use as heat-sensitive recording materials.

However, in recent years, with the development of electronic technology and information management systems, record reading devices that are sensitive to electromagnetic waves in the long wavelength range from the long wavelength range of visible light to the near infrared range have come into practical use. However, conventionally commonly used color-forming recording materials using phthalide compounds as color-forming dyes do not have practical absorption in such long wavelength regions.

That is, in order to shift the absorption wavelength of conventionally known phthalide compounds to the near-infrared region, it is necessary not only to utilize the substituent effect on the compound but also to extend the π-electron conjugated system. However, this method increases the molecular weight of the compound, making it difficult to manufacture, and the absorption in the near-infrared region is still insufficient. Also,
Colored images are unstable, easily fade, and have poor light fastness.

Therefore, in recent years, various color-forming dyes that form pigments that absorb electromagnetic waves in the long wavelength range have been proposed. JP-A-62-142681 and JP-A-62-18
No. 1361 proposes a color-forming recording material containing two elements: a phenylene diamine derivative or a naphthylene diamine derivative and an acidic substance.

However, according to experiments conducted by the present inventors, a follow-up test of the embodiment described in the above publication revealed that
It was difficult to achieve sufficient color development in the near-infrared region and readout at 780 nm. Furthermore, Unexamined Japanese Patent Publication No. 6
No. 3-256486 proposes a color-forming recording material containing two elements: a phenylenediamine derivative or a naphthylenediamine derivative, and a quinoid electron-accepting compound as an oxidizing agent. However, according to experiments conducted by the present inventors, in a recording paper containing a phenylenediamine derivative or a naphthylenediamine derivative and a quinoid-type electron-accepting compound, which was prepared by replicating the example described in the same publication, In some cases, even when heated, sufficient color development could not be achieved.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color-forming recording material. Another object of the present invention is to provide a color-forming recording material that produces a color of sufficient intensity for practical use immediately after a color-forming operation and that has absorption in the long wavelength range from the visible light region to the near-infrared region. .

[0008]

According to the present invention, the above objects and advantages of the present invention are achieved by (a) general formula (I) A-NR
1-B-NR2-CO-X where A represents an aryl group, B represents an arylene group, X represents an alkyl group, an aryl group, or an aralkyl group, and R1 and R2 are each independently hydrogen, lower alkyl group, aryl group or aralkyl group. This is achieved by a color-forming recording material containing an acyldiamine derivative represented by (b) an oxidizing agent and (c) an acidic substance.

The color-forming recording material according to the present invention has the above-mentioned (a)
), (b) and (c). Only by bringing these three components into contact can a dye with extremely strong absorption strength and fastness in the visible to near infrared region be obtained. Therefore, the present invention provides a practical color-forming recording material that can be read with a semiconductor laser.

The acyldiamine derivative (a) used in the present invention is represented by the above general formula (I).

General formula (I) A is an aryl group and B is an arylene group. These aryl groups and arylene groups include, for example, halogen atoms, cyano groups, hydroxyl groups, alkyl groups, aryl groups, alkoxy groups, aryloxy groups, aralkyloxy groups, alkylcarbonyloxy groups, arylcarbonyloxy groups, amino groups, and alkyl-substituted groups. It may have at least one substituent selected from the group consisting of an amino group, an aryl-substituted amino group, a pyrrolidino group, a piperidino group, and a carbamoyl group.

X is an alkyl group, an aryl group or an aralkyl group. Moreover, R1 and R2 are each independently hydrogen,
It is a lower alkyl group, an aryl group or an aralkyl group.

Examples of such acyldiamine derivatives (a) include N-acetyl-N'-phenyl-p-
Phenylenediamine, N-propanoyl-N'-phenyl-p-phenylenediamine, N-butanoyl-N'-
Phenyl-p-phenylenediamine, N-pentanoyl-N'-phenyl-p-phenylenediamine, N-formyl-N'-phenyl-p-phenylenediamine, N
-acryloyl-N'-phenyl-p-phenylenediamine, N-methacroyl-N'-phenyl-p-phenylenediamine, N-cinnamoyl-N'-phenyl-p
-phenylenediamine, N-crotonoyl-N'-phenyl-p-phenylenediamine, N-acetyl-N'-
(4-phenylamino)phenyl-p-phenylenediamine, N-acetyl-N'-(4-aminophenyl)-
p-phenylenediamine, N-acetyl-N'-(4-
(N,N-dimethylamino)phenyl)-p-phenylenediamine, N-phenylacetyl-N'-phenyl-
Examples include p-phenylenediamine. These compounds can be used alone or in combination of two or more, but the compounds are not limited to the above specific examples.

The oxidizing agent (b) used in the present invention may be either an organic oxidizing agent or an inorganic oxidizing agent. Suitable examples of the organic oxidizing agent include quinoid electron-accepting compounds, organic halogen compounds, phosphine oxides, sulfoxides, disulfides, N-oxides, radical compounds, and other organic oxides such as chloranil and p-benzoquinone. used for. Also,
Preferred examples of the inorganic oxidizing agent include oxygen, halogen, metal oxides, halides, and organic acid metal salts.

As the oxidizing agent, the above-mentioned compounds can be used alone or in combination of two or more.

Furthermore, in the present invention, both organic compounds and inorganic compounds can be used as the acidic substance (c). Examples of organic compounds include aromatic carboxylic acids such as benzoic acid and naphthoic acid; aromatic hydroxycarboxylic acids such as hydroxybenzoic acid and hydroxynaphthoic acid; organic sulfonic acids such as p-toluenesulfonic acid; and acids such as phenolic resins. Preferred examples include resins and the like.

[0017] Preferred examples of inorganic compounds include activated clay, kaolin, and clay.

As the acidic substance (c), the above-mentioned compounds can be used alone or in combination of two or more.

As is well known, conventional heat-sensitive recording materials are prepared by preparing an aqueous dispersion containing a coloring dye, a color developer such as bisphenol A, and other additives as necessary, as well as a binder. It is prepared by coating it on a substrate such as paper and drying it. When the color-forming recording material according to the present invention is used as a heat-sensitive recording material, an aqueous dispersion containing the acyl diamine derivative, an oxidizing agent, an acidic substance, and other additives used as necessary and a binder is prepared in the same manner as described above. It is prepared by coating this on a substrate such as paper and drying it.

As the binder, those conventionally used in the preparation of heat-sensitive recording materials can be suitably used. Preferred examples of such binders include polyvinyl alcohol, hydroxyethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic ester, polymethacrylic acid, polymethacrylic ester, etc. can be mentioned.

In the color-forming recording material of the present invention, the acyldiamine derivative (a) and the oxidizing agent (b) preferably have a molar ratio of acyldiamine derivative/oxidizing agent of 0.01 to 1.
00, more preferably in the range of 0.05 to 20. In addition, acyldiamine derivative (a) and acidic substance (c
) is used in an acyldiamine derivative/developer molar ratio of preferably 0.01 to 100, more preferably 0.05 to 21.

The color-forming recording material of the present invention may further contain a fluorescent dye or pigment. As a fluorescent dye,
For example, diaminostilbene type, benzimidazole type, benzidine type, imidazolone type, etc. can be mentioned. Examples of pigments include titanium dioxide, clay, talc, calcium carbonate, aluminum hydroxide, silica, and polystyrene resin.

Furthermore, the color-forming recording material of the present invention can also contain a sensitizer. Examples of the sensitizer include higher fatty acid amides such as stearamide, benzamide, stearanilide, cisetoacetanilide, thioacetanilide, dimethyl phthalate, dibenzyl oxalate, dibenzyl terephthalate, dibenzyl isophthalate,
Examples include 4,4'-dimethoxyphenyl sulfone. The materials of the invention may also contain or be overcoated with antiblocking agents such as stearic acid, calcium stearate, zinc stearate, carnauba wax, paraffin wax, and the like.

Pressure-sensitive recording paper is produced by using a conventional method, for example, by coating a top sheet paper with microcapsules containing a color-forming dye solution coated on its lower surface and carrying a color developer on its upper surface. Alternatively, the microcapsules and the color developer may be coated on the same paper surface.

[0025]

[Examples] The present invention will be explained below with reference to Examples.
The present invention is not limited in any way by these Examples.

Example 1 N-acetyl-N'-phenyl-p-phenylenediamine 0.0435g, chloranil 0.0472g, 1-hydroxy-2-naphthoic acid 0.2178g, stearamide 0.10g, zinc stearate 0.10g, 1
0.75g of 0% polyvinyl alcohol aqueous solution and 1 part of water
．． A coating solution was obtained by processing 75 g for 10 minutes in a planetary fine pulverizer (manufactured by FRITSCH).

Next, the obtained liquid was applied to high-quality paper using a bar coater (Tester Sangyo, P11210).
After air-drying, use a thermal paper color test device (T manufactured by Okura Electric Co., Ltd.).
H-PMD) to develop color by heating. The reflectance before and after coloring was measured using a UV measuring device (Shimadzu Corporation UV-3101)
) at 300 to 1300 nm.

Example 2 0.0555 g of N-benzoyl-N'-phenyl-p-phenylenediamine, 0.0472 g of chloranil, 1-
Hydroxy-2-naphthoic acid 0.2178g, stearamide 0.10g, zinc stearate 0.10g,
A coating solution was obtained by processing 0.75 g of a 10% polyvinyl alcohol aqueous solution and 1.75 g of water in a pulverizer for 10 minutes.

Next, the liquid obtained in the same manner as in Example 1 was applied to high-quality paper using a bar coater, air-dried, and then heated and colored using a thermal paper coloring test device.

Further, bar codes were printed on the thermal papers of Examples 1 and 2 using a thermal head of an NEC printer (PC-PR102TL). This barcode is scanned by a semiconductor laser (780nm) barcode reader (Sym).
bol Technologies Inc. , L.S.
8200) and an LED barcode reader (Meccano Systems, M10).

Example 3 0.0435 g of N-acetyl-N'-phenyl-p-phenylenediamine, 0.0207 g of p-benzoquinone,
1-hydroxy-2-naphthoic acid 0.2178g, stearamide 0.10g, zinc stearate 0.10
g, 0.75 g of a 10% polyvinyl alcohol aqueous solution, and 1.75 g of water were processed in a pulverizer for 10 minutes to obtain a coating liquid.

Next, the liquid obtained in the same manner was applied to high-quality paper using a bar coater, air-dried, and then heated and colored using a thermal paper coloring test device.

Example 4 0.0555 g of N-benzoyl-N'-phenyl-p-phenylenediamine, 0.0207 g of p-benzoquinone
, 1-hydroxy-2-naphthoic acid 0.2178g, stearamide 0.20g, zinc stearate 0.1
0g, 10% polyvinyl alcohol aqueous solution 0.75g,
and 1.73 g of water were treated in a pulverizer for 10 minutes to obtain a coating liquid.

Next, the liquid obtained in the same manner was applied to high-quality paper using a bar coater, air-dried, and then heated and colored using a thermal paper coloring test device.

In Examples 3 and 4, bar codes were also printed and could be read by both semiconductor laser and LED bar code readers.

[0036]

Effects of the Invention As described above, the color-forming recording material of the present invention contains an acyldiamine derivative, an oxidizing agent, and an acidic substance, and provides a practically sufficient color development after color-forming operation, and furthermore, it has a color-forming property that can be used in the visible light range and near range. Since it has absorption in the long wavelength range up to the infrared range, it is useful for reading information with equipment.

Claims (1)

[Claims] Claim 1: (a) General formula (I) A-NR1-B-NR2-CO-X where A represents an aryl group, B represents an arylene group, and X represents an alkyl group, an aryl group, or an aralkyl group. R1 and R2 each independently represent hydrogen, a lower alkyl group, an aryl group or an aralkyl group. A color-forming recording material comprising: an acyldiamine derivative represented by: (b) an oxidizing agent; and (c) an acidic substance.