JPH0890903A - Pressure-sensitive recording material - Google Patents

Abstract

PURPOSE: To enhance OCR reading apptitude by combining 3,3-bis(4- diethylamino-2-ethoxyphenyl)-4-azaphthalide and at least one kind of a specific monovinyl phthalide compd. and using a zinc salt of a salicylic acid derivative as a coupler. CONSTITUTION: In a pressure-sensitive recording material utilizing the color forming reaction of a colorless or light-colored basic dye and a coupler, 3,3-bis(4- diethylamino-2-ethoxyphenyl)-4-azaphthalide and at least one kind of a monovinyl phthalide compd. represented by the general formula (wherein R1 is a methyl group, an ethyl group, an n-propyl group or an n-butyl group and R2 is a hydrogen atom, a methyl group, an ethyl group, a methoxy group or an ethoxy group) are used in combination. As the coupler, at least one of 3,5-di(α-methylbenzyl) salicylic acid, a carboxylated terpene/phenol resin and a zinc salt of benzylated styrenated salicylic acid is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive recording material utilizing a color-forming reaction between a colorless or light-colored basic dye and a coloring agent, and more particularly to an optical character reader having a reading wavelength of 650 to 700 nm. The present invention relates to a pressure-sensitive recording material that exhibits excellent properties when applied.

[0002]

2. Description of the Related Art A pressure-sensitive recording medium is prepared by applying a microcapsule composition containing microcapsules containing droplets of a basic dye or the like as a main component to one side of a support and a paper or one side of the support. Is a color-developing composition containing an electron-accepting color-developing agent (hereinafter simply referred to as a color-developing agent) as a main component, which is colored when contacted with a basic dye to form a color-developing layer on the opposite surface. Includes a middle paper coated with a microcapsule composition and a lower paper coated with a colorant composition on one side of a support to form a color layer. These three types of sheets are used as upper paper and lower paper, or It is put into practical use as a copy set by combining upper paper, middle paper, and lower paper in this order. A self-coloring pressure-sensitive recording medium capable of pressure-sensitive recording with one sheet by coating a microcapsule containing a basic dye and a colorant on the same surface of the support is also a form of pressure-sensitive recording medium. Are known.

In recent years, office automation has been advanced along with the development of the information processing industry, and the rationalization of office work has been promoted. As one of the methods, OCR devices and OMR devices having a reading wavelength of 650 to 700 nm have become widespread. Various types of slips such as slips, sales slips, shipping slips, purchase slips, and input / output slips are becoming suitable for OCR and OMR devices.

By the way, in the case of the conventional pressure-sensitive recording material for OCR reading, although the color image has absorption at 650 to 700 nm, it is exposed to sunlight for a long time or is exposed to a vinyl chloride film containing a plasticizer for a long time. However, there are problems such as poor readability of OCR and poor desensitization to ordinary desensitizing ink, and satisfactory performance has not yet been obtained. Therefore, improvement is strongly desired.

[0005]

DISCLOSURE OF THE INVENTION The object of the present invention is 65
When applied to an optical character reading (OCR) device having a reading wavelength of 0 to 700 nm, it has excellent characteristics, that is, high density at the reading wavelength, and excellent performance in light resistance and plasticizer resistance. Moreover, it is to provide a pressure-sensitive recording material having desensitization suitability.

[0006]

The present invention provides a pressure-sensitive recording material utilizing a color reaction of a colorless or light-colored basic dye and a coloring agent, which is 3,3-bis (4-diethylamino-).
2-ethoxyphenyl) -4-azaphthalide and at least one monovinylphthalide compound represented by the following general formula (1) are used in combination, and a zinc salt of a salicylic acid derivative is used as a colorant. It is a pressure sensitive recording medium.

[0007]

[Chemical 2](In the formula, R₁Is a methyl group, an ethyl group, or an n-propyl group.
Or n-butyl group, R ₂Is a hydrogen atom, methyl group, ethi
Group, methoxy group or ethoxy group. )

[0008]

The specific examples of the monovinylphthalide compound represented by the above general formula (1) used in the present invention include, for example, 3
-[2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3- (4-dimethylaminophenyl) phthalide, 3- [2,2-bis (1-n-
Butyl-2-methylindol-3-yl) ethenyl]
-3- (4-diethylaminophenyl) phthalide, 3-
[2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3- (4-di-n-propylaminophenyl) phthalide, 3- [2,2-bis (1
-N-butyl-2-methylindol-3-yl) ethenyl] -3- (4-di-n-butylaminophenyl) phthalide, 3- [2,2-bis (1-n-butyl-2-methyl) Indole-3-yl) ethenyl] -3- (4-dimethylamino-2-methylphenyl) phthalide, 3-
[2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3- (4-dimethylamino-2-methoxyphenyl) phthalide, 3- [2,2-bis (1 -N-Butyl-2-methylindol-3-yl) ethenyl] -3- (4-diethylamino-2-methylphenyl) phthalide, 3- [2,2-bis (1-n-
Butyl-2-methylindol-3-yl) ethenyl]
-3- (4-diethylamino-2-methoxyphenyl)
Phthalide, 3- [2,2-bis (1-n-butyl-2-
Methylindol-3-yl) ethenyl] -3- (4-
Diethylamino-2-ethoxyphenyl) phthalide, 3
Examples include-[2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3- (4-di-n-butylamino-2-ethoxyphenyl) phthalide.

Among these compounds, 3- [2,2
-Bis (1-n-butyl-2-methylindole-3-
Il) ethenyl] -3- (4-diethylaminophenyl) phthalide is particularly preferably used because it exhibits particularly excellent color forming properties, light resistance, and plasticizer resistance. The compounds are not limited to these compounds, and any compound included in the general formula (1) can be used, and if necessary, two or more kinds can be used in combination. The use ratio of 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4-azaphthalide and the monovinylphthalide compound represented by the general formula (1) is not particularly limited, but is usually a weight ratio. Then, 50:20
It is preferably used in a ratio of 0 to 200: 50.

In the present invention, known basic dyes such as triarylmethane type compounds, diarylmethane type compounds, fluorane type compounds, phenothiazine type compounds, phenoxazine type compounds and rhodamine are used within a range that does not impair the desired effects. A lactam compound, a spiropyran compound, a leuco auramine compound, etc. can also be used together.

The basic dye used in the present invention is mixed with various known ultraviolet absorbers such as benzotriazole derivative, benzophenone derivative, cyanoacrylate derivative, salicylic acid derivative, cinnamic acid derivative, etc., if necessary, and then cottonseed oil, hydrogenated Terphenyl, hydrogenated terphenyl derivative,
Dissolved in a natural or synthetic hydrophobic medium such as dibasic acid ester such as alkylbiphenyl, alkylnaphthalene, diarylalkane, paraffin, naphthene oil, and phthalic acid ester, coacervation method, interfacial polymerization method, in-
It is encapsulated in microcapsules by a capsule manufacturing method such as an in situ polymerization method. The membrane material of the microcapsule is not particularly limited, but it does not generate color stains due to involuntary pressure or rubbing, and thus is made of a synthetic polymer such as aminoaldehyde resin, polyurea resin, polyurethane resin, or polyamide resin. Membrane materials are preferably used.

Aminoaldehyde resin wall membrane capsules include, for example, at least one amine such as urea, thiourea, alkylurea, ethyleneurea, acetoguanamine, benzoguanamine, melamine, guanidine, biuret, and cyanamide, and formaldehyde, acetaldehyde, para. It is produced by an in-situ polymerization method using at least one aldehyde such as formaldehyde, hexamethylenetetramine, glutaraldehyde, glyoxal and furfural, or an initial condensate obtained by condensing them.

Polyurethane resin and polyurea resin wall membrane capsules are made of, for example, polyvalent isocyanate and water, polyvalent isocyanate and polyol, isothiocyanate and water, isothiocyanate and polyol, polyvalent isocyanate and polyamine, isothiocyanate and polyamine, etc. It is manufactured by an interfacial polymerization method. The polyamide resin wall membrane capsule is manufactured by, for example, an interfacial polymerization method of acid chloride and amine.

The microcapsules thus prepared containing the specific basic dye are used in the conventional manner in addition to adhesives such as polyvinyl alcohols, starches, carboxymethyl cellulose and latexes, as well as stilts such as pulp powders and raw starch powders. Various auxiliaries such as agents are appropriately mixed and used as a capsule coating liquid for the production of upper paper, middle paper, self-coloring type pressure sensitive recording paper and the like.

In the present invention, a zinc salt of a salicylic acid derivative is selectively used as a color developing agent. By the way,
When an inorganic compound such as activated clay or an acidic organic polymer such as novolak resin of p-phenylphenol is used as a coloring agent, the color developability is low, and image storability, especially long-term light fastness and plasticizer There is a problem in that it is inferior in properties, and the obtained pressure-sensitive recording material itself tends to yellow with time.

Specific examples of such a coloring agent include, for example, 3
-Methyl-5- (α-methylbenzyl) salicylic acid, 3
-Methyl-5- (α, α-dimethylbenzyl) salicylic acid, 3,5-di-tert-butylsalicylic acid, 3,5-di-tert-butyl-6-methylsalicylic acid, 3,5-di-
tert-Butyl-6-phenylsalicylic acid, 3,5-di-
tert-amylsalicylic acid, 3,5-di-cyclohexylsalicylic acid, 3-cyclohexyl-5- (α-methylbenzyl) salicylic acid, 3-dodecylsalicylic acid, 3-methyl-5-dodecylsalicylic acid, 3-dodecyl-6-methylsalicylic acid , 3-phenyl-5- (α-methylbenzyl) salicylic acid, 3-phenyl-5- (α, α-dimethylbenzyl) salicylic acid, 3- (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl)- 5-methylsalicylic acid, 3- (α-methylbenzyl) -5-phenylsalicylic acid, 3- (α, 4-dimethylbenzyl)
-5-methylsalicylic acid, 3- (α, α-dimethylbenzyl) -5-methylsalicylic acid, 3- (α, α-dimethylbenzyl) -6-methylsalicylic acid, 3,5-di (α, α-dimethylbenzyl) ) Salicylic acid, 3,5-di (α-methylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5- (α, α-dimethylbenzyl) salicylic acid, 3- (α-methylbenzyl) -5-bromosalicylic acid , 3- (α-methylbenzyl) -4-methylsalicylic acid, 3- (α-methylbenzyl) -6-methylsalicylic acid, 3-nonylsalicylic acid, 3,5-dinonylsalicylic acid, 3-nonyl-5-methylsalicylic acid , 3-nonyl-6-methylsalicylic acid, 3-nonyl-5-phenylsalicylic acid, 3-methyl-5-nonylsalicylic acid, 5-
Examples thereof include zinc salts such as (4-mesitylmethylbenzyl) salicylic acid, carboxylated terpene phenol resin, and benzylated styrenated salicylic acid. If necessary, two or more kinds may be used in combination. Among these compounds, zinc salt of 3,5-di (α-methylbenzyl) salicylic acid, zinc salt of carboxylated terpene phenolic resin or zinc salt of benzylated styrenated salicylic acid exhibits excellent performance. The zinc salt of 5,5-di (α-methylbenzyl) salicylic acid is particularly preferably used because it is particularly excellent in color development and image storability.

The coloring agent coating liquid is usually prepared by a method in which a zinc salt of a salicylic acid derivative is dispersed in water together with an adhesive. Examples of the adhesive include starch, casein, gum arabic, carboxymethyl cellulose, polyvinyl alcohol, styrene / butadiene copolymer latex, vinyl acetate latex and the like. In addition, in the coating liquid, if necessary, various inorganic pigments such as zinc oxide, magnesium sulfate, titanium oxide, aluminum hydroxide, calcium carbonate, magnesium sulfate, and calcium sulfate, and various auxiliary agents known in the field of pressure-sensitive copying paper production may be used. Agents can also be added as appropriate.

The method of applying the coating liquid is not particularly limited, and for example, an on-machine or off-machine coater equipped with an appropriate coating device such as an air knife coater, a roll coater, a blade coater, a rod plate coater, a curtain coater, and a lip coater. And the dry weight is 2-10
It is applied to a support such as paper, synthetic paper, film or the like so as to have a degree of g / m ² .

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an example show a weight part and weight%, respectively.

Example 1 [Preparation of Coloring Agent Coating Liquid] 20 parts of zinc salt of 3,5-di (α-methylbenzyl) salicylic acid, 80 parts of kaolin, 1 part of magnesium oxide, carboxy-modified styrene-butadiene copolymer 20 parts (solid content) of latex and 1 part of sodium carboxymethyl cellulose were added to prepare a coloring agent coating liquid. [Manufacture of lower paper] The above color developing agent coating liquid is applied to a base paper of 40 g / m ^{2 by} an air knife coater so that the dry weight is 5 g / m ² , dried, and calendered to prepare a lower paper for pressure-sensitive recording. It was created.

[Preparation of Microcapsule Dispersion] In a stirring and mixing container equipped with a heating device, 150 parts of a 3% aqueous solution of polyvinyl alcohol (trade name: PVA-117, manufactured by Kuraray Co., Ltd.) was added to prepare an aqueous medium for capsule production. And Separately, alkylnaphthalene (trade name: KMC oil, manufactured by Kureha Chemical Co., Ltd.) 100 parts 9 as a basic dye 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4-
5 parts of azaphthalide and 3- [2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3
5 parts of-(4-diethylaminophenyl) phthalide and 2 parts of 2- (2'-hydroxy-5'-methylphenyl) benzotriazole as an ultraviolet absorber were dissolved, and polymethylene polyphenyl isocyanate (trade name: Millionate MR400, A solution obtained by dissolving 5 parts of Japan Polyurethane Industry Co., Ltd.) and 2 parts of a hexamethylene diisocyanate trimer having a burette bond (trade name: N-3200, manufactured by Sumitomo Bayer Co., Ltd.) as a capsule core substance,
In the above aqueous medium for capsule preparation, TK homomixer was used to disperse at 10000 rpm for 1 minute.

Diethylenetriamine 1 was added to this emulsion dispersion.
Parts and after stirring for 30 minutes at room temperature, the system temperature was adjusted to 7
The temperature was raised to 0 ° C. and the reaction was continued for 3 hours while continuing stirring, and then the temperature was lowered to room temperature to prepare microcapsules composed of a polyurea resin / polyurethane resin wall film having an average particle diameter of 5.7 μm.

[Preparation of Microcapsule Coating Liquid] 70 parts of wheat starch powder and 2 parts of oxidized starch aqueous solution per 100 parts by weight (solid content) of the microcapsule dispersion thus obtained.
0 part (solid content) was added to prepare a microcapsule coating solution. [Manufacture of medium-sized paper] For pressure-sensitive recording, the microcapsule coating liquid is applied to the opposite side of the lower paper from the surface coated with the coloring agent by an air knife coater so as to have a dry weight of 4 g / m ² . I got the inside paper.

Examples 2 to 4 In the preparation of the microcapsule dispersion of Example 1, 3
Example 1 except that the following compound was used instead of-[2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3- (4-diethylaminophenyl) phthalide. In the same manner as above, three types of pressure-sensitive recording medium paper were obtained. -Example 2: 3- [2,2-bis (1-n-butyl-2)
-Methylindol-3-yl) ethenyl] -3- (4
-Diethylamino-2-ethoxyphenyl) phthalide Example 3: 3- [2,2-bis (1-n-butyl-2)
-Methylindol-3-yl) ethenyl] -3- (4
-Diethylamino-2-methylphenyl) phthalide Example 4: 3- [2,2-bis (1-n-butyl-2)
-Methylindol-3-yl) ethenyl] -3- (4
-Di-n-butylaminophenyl) phthalide

Examples 5 to 7 Three kinds of pressure-sensitive recording medium paper were obtained in the same manner as in Example 1 except that the following compounds were used as the basic dye in the preparation of the microcapsule dispersion of Example 1. It was -Example 5: 3,3-bis (4-diethylamino-2-
7 parts ethoxyphenyl) -4-azaphthalide and 3-
[2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3- (4-diethylaminophenyl) phthalide 3 parts Example 6: 3,3-bis (p-dimethyl) Aminophenyl) -6-dimethylaminophthalide 3 parts, 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4-
Azaphthalide 3 parts, 3- [2,2-bis (1-n-butyl-2-methylindol-3-yl) ethenyl] -3
-(4-Diethylaminophenyl) phthalide 3 parts and 3,3-bis (1-n-butyl-2-methylindol-3-yl) phthalide 1 part-Example 7: 3- (1-n-octyl-2) -Methylindol-3-yl) -3- (4-diethylamino-2-
Ethoxyphenyl) -4-azaphthalide 4 parts, 3,3-
Bis (4-diethylamino-2-ethoxyphenyl)-
4-azaphthalide 3 parts, 3- [2,2-bis (1-n-
Butyl-2-methylindol-3-yl) ethenyl]
-3- (4-diethylaminophenyl) phthalide 3 parts and 3,3-bis (1-n-butyl-2-methylindol-3-yl) phthalide 2 parts Examples 8 to 9 Coloring agent coating of Example 1 In the preparation of the liquid, 3,5-di (α-
Two kinds of pressure-sensitive recording intermediate papers were obtained in the same manner as in Example 1 except that the following compound was used in place of the methylbenzyl) salicylic acid zinc salt. Example 8: Zinc salt of carboxylated terpene phenolic resin Example 9: Zinc salt of benzylated styrenated salicylic acid

Example 10 A pressure-sensitive recording medium paper was obtained in the same manner as in Example 1 except that the microcapsule dispersion was prepared as follows. [Preparation of Microcapsule Dispersion] In a stirring and mixing vessel equipped with a heating device, 200 parts of a 3% aqueous solution of an ethylene-maleic anhydride copolymer (trade name: EMA31, manufactured by Monsanto) was charged, and then 20% caustic soda was added. The aqueous solution was added dropwise to adjust the pH to 6.0 to obtain an aqueous medium for capsule production. Separately, 100 parts of alkylnaphthalene (trade name: KMC Oil, manufactured by Kureha Chemical Co., Ltd.) and 5 parts of 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4-azaphthalide as a basic dye and 3- [2 , 2-bis (1-n-butyl-2-methylindol-3-yl)
5 parts of ethenyl] -3- (4-diethylaminophenyl) phthalide and 2 parts of 2- (2'-hydroxy-5'-methylphenyl) benzotriazole as an ultraviolet absorber were dissolved to obtain an internal phase oil. Then, this internal phase oil was charged into the above-mentioned aqueous medium for capsule production, and the mixture was emulsified and dispersed for 1 minute at 10,000 rpm using a TK homomixer, and then 5
The temperature was raised to 5 ° C. Separately 37% formaldehyde aqueous solution 4
15 parts of melamine was added to 5 parts and reacted at 60 ° C. for 15 minutes to prepare a prepolymer aqueous solution. This prepolymer aqueous solution was added dropwise to the emulsion, and the mixture was further stirred and then mixed with water.
After adjusting the pH to 5.3 with 1N-hydrochloric acid, the temperature was raised to 80 ° C. and kept at that temperature for 1 hour, and then the pH was adjusted to 3.0 with 0.2N-hydrochloric acid.
The mixture was cooled to 5 and kept for 3 hours, and then allowed to cool to prepare microcapsules consisting of an aminoaldehyde resin film having an average particle diameter of 5.3 μm.

Comparative Examples 1 to 5 Five kinds of pressure-sensitive recording medium paper were obtained in the same manner as in Example 1 except that the following dyes were used as the basic dye in the preparation of the microcapsule dispersion liquid of Example 1. It was Comparative Example 1: 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide 10 parts Comparative Example 2: 3,3-bis (4-diethylamino-2-)
Ethoxyphenyl) -4-azaphthalide 10 parts-Comparative Example 3: 3- [2,2-bis (1-n-butyl-2)
-Methylindol-3-yl) ethenyl] -3- (4
-Diethylaminophenyl) phthalide 10 parts-Comparative Example 4: 3,3-bis (4-diethylamino-2-)
Ethoxyphenyl) -4-azaphthalide 5 parts and 3-
[2,2-bis (1-ethyl-2-methylindole-
3-yl) ethenyl] -3- (4-diethylaminophenyl) phthalide 5 parts Comparative Example 5: 3-diethylamino-6-methyl-7-anilinofluorane 5 parts and 3- [2,2-bis (1 -N-
Butyl-2-methylindol-3-yl) ethenyl]
5 parts of -3- (4-diethylaminophenyl) phthalide

Comparative Example 6 In the preparation of the coloring agent coating liquid of Example 1, 3,5-di (α
A pressure-sensitive recording medium paper was obtained in the same manner as in Example 1 except that 100 parts of activated clay was used instead of 20 parts of the zinc salt of methylbenzyl) salicylic acid and 80 parts of kaolin. Comparative Example 7 In the preparation of the coloring agent coating liquid of Example 1, 3,5-di (α
-Methylbenzyl) p-instead of the zinc salt of salicylic acid
A pressure-sensitive recording medium paper was obtained in the same manner as in Example 1 except that a phenylphenol novolac resin was used.

Using the 17 kinds of pressure-sensitive recording medium paper thus obtained, various performance comparison tests were conducted, and the results are shown in Table 1. [PCS Value] The PCS value is an index indicating the degree of OCR readability. The PCS value represents the relative density difference between the color print and the paper and is calculated by the following equation. PCS = (Rw-Rp) / Rw Here, Rw represents the reflectance of the blank portion and Rp represents the reflectance of the printed portion. Therefore, the higher the PCS value, the clearer the identification of characters and the higher the readability. Generally, a PCS value of 0.7 or more is required. [Measurement of PCS value at 670 nm] The prepared pressure-sensitive recording medium paper was overlaid so that the capsule-coated surface and the coloring agent-coated surface faced each other, and printed with a dot printer. Total (Hitachi U-33
00) to measure the reflectance at 670 nm, and from that value P
The CS value was calculated and shown in Table 1. [Lightfastness test] Colored surface of printing obtained above (coloring agent coated surface)
After exposed to direct sunlight for 8 hours, the PCS value was similarly calculated and shown in Table 1. [Plasticizer resistance test] A vinyl chloride film was overlaid on the print color-developing surface (coloring agent-coated surface) obtained above and left at room temperature for 24 hours, and then the PCS value was similarly calculated and shown in Table 1. [Desensitization aptitude test] Offset desensitizing ink (No. 804, manufactured by Teikoku Ink Co., Ltd.) on the surface of the medium for pressure-sensitive recording on which the coloring agent is applied.
The desensitizing ink coated surface obtained by printing so that the coating amount becomes 2.5 g / m ² and the desensitizing ink are printed on a dot printer by overlapping the capsule coated surface of the unprinted medium paper. The desensitization suitability was visually judged according to the following evaluation criteria and shown in Table 1. (Evaluation criteria) ○: Good desensitization suitability ×: Poor desensitization suitability

[0030]

[Table 1]

[0031]

As is clear from the results shown in Table 1, the pressure-sensitive recording material of the present invention exhibits excellent characteristics with respect to an optical character reading (OCR) device having a reading wavelength of 670 nm, and has a reduced characteristic. The pressure-sensitive recording material was also excellent in sensitivity.

Claims (3)

[Claims] 1. A pressure-sensitive recording material utilizing a color-forming reaction between a colorless or light-colored basic dye and a coloring agent, which comprises 3,3-bis (4-diethylamino-2-ethoxyphenyl) -4.
A pressure-sensitive recording material comprising a combination of azaphthalide and at least one monovinylphthalide compound represented by the following general formula (1), and a zinc salt of a salicylic acid derivative as a colorant. [Chemical 1] (R ₁ is a methyl group, an ethyl group, an n-propyl group or n
-Butyl group, R ₂ is a hydrogen atom, a methyl group, an ethyl group,
A methoxy group or an ethoxy group is shown. ) 2. The coloring agent is at least one of zinc salt of 3,5-di (α-methylbenzyl) salicylic acid, zinc salt of carboxylated terpene phenol resin and zinc salt of benzylated styrenated salicylate. 1. The pressure-sensitive recording material according to 1. 3. A monovinylphthalide compound is 3- [2,
2-bis (1-n-butyl-2-methylindole-3
The pressure-sensitive recording material according to claim 1, which is -yl) ethenyl] -3- (4-diethylaminophenyl) phthalide.