JPH10182998A - Monovinyl phthalide compound and coloring recording material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound, providing a colored image manifesting storing absorption in a near infrared region of 590-750nm, having shelf life equal to or better than that of a conventional leuco coloring matter and useful as an electron donative leuco coloring matter. SOLUTION: This 3-[4-(N-ethyl-N-p-tolylamino)-2-ethoxyphenyl]-3-[1,1-bis(p- diethylaminophenyl)ethylen-2yl]phthalide is represented by the formula. The compound represented by the formula can be obtained as a white crystal by discharging a reactional product of ortho(4-(N-ethyl-N-p-tolylamino)-2- ethoxybenzoyl)benzoic acid with 1,1-bis(p-diethylaminophenyl)ethylene and acetic anhydride into water/toluene, neutralizing the reactional product with NaOH, then separating and collecting a toluene layer, distilling off the toluene, thermally dissolving the residual tar in acetonitrile, subsequently allowing the solution to cool and filtering the cooled solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel monovinylphthalide compound useful as an electron-donating leuco dye (hereinafter referred to as leuco dye), and a monovinylphthalide compound and an electron-accepting developer (hereinafter referred to as a developer). And a chromogenic recording material utilizing a chromogenic reaction. More specifically, the present invention provides a color image of 590 nm to 750 nm.
And a chromogenic recording material using the same.

[0002]

2. Description of the Related Art Heretofore, there have been some proposals relating to leuco dyes having absorption in the near infrared region. For example, JP
Phthalide compounds containing two vinyl groups as disclosed in JP-A-1-121035, JP-A-58-157779, JP-A-60-27589 and JP-A-62-243365; No.-121037, JP-A-57-
Phthalide compounds containing one vinyl group as disclosed in JP-A-167979 and JP-A-63-165379, and fluorene compounds as disclosed in JP-A-59-199757 and JP-A-60-226871. It is. Japanese Patent Laid-Open No. 4-17, which is partially used as a leuco dye having an absorption in the range of 650 nm to 800 nm.
There are also fluoran compounds as disclosed in JP-A-3288 and azaphthalide compounds as disclosed in JP-A-5-139026.

[0003] Such a conventional color image formed by a leuco dye has absorption in the near-infrared region, but the wavelength region and the intensity are considerably different depending on the leuco dye. For example, a color image formed by a fluoran compound represented by the following formula (2) disclosed in Japanese Unexamined Patent Publication No. 4-173288 is 675 nm and 477 nm.
There is strong maximum absorption in nm, and the color image formed by 3,3'-bis [4- (N, N-diethylamino) -2-ethoxyphenyl] -4-azaphthalide disclosed in JP-A-5-13926 is 640 nm. Strong maximum absorption, 410
There is a weak maximum absorption at nm.

[0004]

Embedded image

675 n in the former fluoran compound
m is 64 max in the latter azaphthalide compound.
Slightly weaker than the maximum absorption at 0 nm, the former absorption is broader than the latter absorption. When the former is 640 to 710 nm and the latter is 600 to 672 nm when comparing the absorption wavelength range exceeding a certain intensity appropriately set in the near infrared region.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a wavelength of 650 nm, which is currently receiving the most attention as a wavelength of a semiconductor laser.
A leuco dye capable of almost covering the region of about 800 nm alone, and capable of exhibiting the same or better performance as the fluoran compound or the azaphthalide compound of the formula (2) which is practically used. It is something you want to do.

[0007]

That is, the present invention provides a monovinyl phthalide compound represented by the formula (1) and a color development method in which the monovinyl phthalide compound is used as a leuco dye to form a color by reaction with a developer. The present invention is to provide a recording material for recording.

[0008]

Embedded image

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The color tone of the monovinylphthalide compound of the present invention varies from dark blue to green depending on the color developer. When a color recording material is formed using this monovinylphthalide compound, other leuco dyes can be used in combination for the purpose of color tone correction or correction of absorption characteristics.

The leuco dye to be used in combination is a leuco dye generally known in this type of leuco recording material, for example, a triphenylmethane-based, fluoran-based, phenothiazine-based or auramine-based leuco dye.

In producing a pressure-sensitive recording material using a leuco dye, for example, US Pat. No. 2,800,458,
The known method described in No. 2800457 can be employed. As the color developer, clay, bentonite, activated clay, acid clay, and other viscers, salicylic acid, metal salts of salicylic acid derivatives, p-phenylphenol formalin resin, p-octylphenol formalin resin and their metal salts are used. Is done. Among these, a metal salt of a salicylic acid derivative is preferable in terms of color density and image stability. Examples of the salicylic acid derivative include the following.

Salicylic acid, 3-methyl-5-tert-
Butylsalicylic acid, 3,5-tert-butylsalicylic acid, 3-cyclohexylsalicylic acid, 5-cyclohexylsalicylic acid, cresotic acid, 5-nonylsalicylic acid,
5-cumylsalicylic acid, 3-phenylsalicylic acid, 2,
5-dihydroxysalicylic acid, naphthoic acid, hydroxynaphthoic acid, 3-tert-butyl-5-α-methylbenzylsalicylic acid, 3,5-di (α-methylbenzyl)
And salicylic acid. Examples of polyvalent metals which form salts with these include zinc, magnesium, calcium, aluminum, nickel, copper and the like. Of these, zinc, magnesium, calcium and the like are preferable, and zinc is particularly preferable.

As a binder for producing a pressure-sensitive recording material, polyvinyl alcohol, methyl cellulose,
Hydroxyethyl cellulose, carboxymethyl cellulose, gum arabic, gelatin, casein, starch, polyvinylpyrrolidone, styrene-maleic anhydride copolymer and the like are used. Organic solvents for dissolving the color former include alkylbenzenes, alkylnaphthalenes,
Various types of alkyl diphenyl, diaryl ethane, hydrogenated terphenyl, and chlorinated paraffin can be used alone or as a mixture. For microencapsulation, coacervation, interfacial polymerization, in-situ
A law or the like can be adopted. In addition, if necessary, various antioxidants, ultraviolet absorbers, surfactants and the like can be used in combination.

In order to manufacture the heat-sensitive recording paper, for example, a known method described in Japanese Patent Publication No. 45-14039 may be employed. As a binder in the case of producing a thermal recording paper, polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, which are general for thermal recording paper,
Carboxymethyl cellulose, gum arabic, gelatin, casein, starch, polyvinylpyrrolidone, styrene-maleic anhydride copolymer and the like can be used.

In this case, the color developing agents include known p-hydroxybenzoic acid methyl ester, p-hydroxybenzoic acid benzyl ester, 2,2-bis (p-hydroxyphenyl) propane (bisphenol A), 3,4 '-
Isopropylidene diphenol, 2,2-bis (p-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxy-3-allylphenyl) propane,
Bis (4-hydroxyphenyl) acetic acid, butyl 1,1-bis (4-hydroxyphenyl) acetate, 4,4′-cyclohexylidenediphenol, 4,4′-thiodiphenol, bis- (4-hydroxy-3 -Methylphenyl) sulfide, bis (4-hydroxy-3-ter)
t-butyl-6-methylphenyl) sulfide, 4,
4′-dihydroxydiphenylsulfone, 4-hydroxy-4′-methyldiphenylsulfone, 3,4-dihydroxy-4′-methyldiphenylsulfone, 4-hydroxy-4′-isopropoxydiphenylsulfone, 4,
4'-dihydroxy-3,3'-dimethyldiphenylsulfone, 4,4'-dihydroxy-3,3'-diallyldiphenylsulfone, dimethyl 4-hydroxyphthalate, bis [2- (4-hydroxyphenylthio) ethyl] Ether, 4,4′-methylenebis (oxyethylenethio) diphenol, 1-benzyl-2-naphthol, 1,1′-methylenedi-2-naphthol, p-hydroxyphenylsalicylamide, 1,3-diphenylthiourea, 1,3-ditolylthiourea, 1,3-dichlorophenylthiourea and the like can be used alone or in combination.

Further, as a sensitivity enhancer (sensitizer), paraffin wax, carnauba wax, higher fatty acid ester,
Higher fatty acid amides, dibenzyl oxalate, di-p-methylbenzyl oxalate, di-p-chlorobenzyl oxalate, phthalate, terephthalate, benzyl 4-benzyloxybenzoate, naphthol benzyl ether, 1,4
-Dialkoxynaphthalene, 1,5-dialkoxynaphthalene, m-terphenyl, p-benzylbiphenyl,
Dibenzylbenzene, 1-hydroxy-2-naphthoic acid ester, 1-phenoxy-2-naphthoxy (1) ethane, 1,2-diphenoxyethane, 1,2-di (3-methylphenoxy) ethane, 1- ( 2-isopropylphenoxy) -2-naphthoxy (2) ethane, bis (p-methoxyphenoxyethyl) ether, 2-hydroxy-
3-naphthoic acid ester, 4,4′-dialkoxydiphenylsulfone, benzamide, diphenylamine, benzenesulfonamide, benzenesulfonanilide,
1,4-dibenzyloxybenzene, 1,4-di (vinyloxyethoxy) benzene, 1,3-di (vinyloxyethoxy) benzene, diphenyl carbonate, etc., can be used alone or in combination. can do. In addition to the sensitivity enhancer, various antioxidants, anti-deterioration agents, ultraviolet absorbers, etc. are added to improve the light fastness and preservability of the image, and the thermal recording paper is overcoated with a polymer substance or the like. You can also.

[0017]

Embodiment 1 13. ortho (4- (N-ethyl-Np-tolylamino) -2-ethoxybenzoyl) benzoic acid
4 g and 9.7 g of 1,1-bis (p-diethylaminophenyl) ethylene were added to 50 ml of acetic anhydride and reacted at 50 ° C. for 1 hour. 300 ml of water, 200 ml of toluene
And neutralized with 80 g of 48% NaOH. The toluene layer was separated, treated with carbon, and toluene was distilled off. After heating and dissolving in 60 ml of acetonitrile in the remaining tar, the mixture is allowed to cool and filtered, and as a white crystal, the monovinylphthalide compound of the formula (1), ie, 3- [4- (N-ethyl-N-p-
Tolylamino) -2-ethoxyphenyl] -3- [1,
1-bis (p-diethylaminophenyl) ethylene-2
-Yl] phthalide was obtained. Yield 14.0 g m. p. 129-131 ° C

Embodiment 2 FIG. 3.5 g of the phthalide compound synthesized in Example 1 was dissolved in 50 g of alkylnaphthalene while heating. 5 g of a system modifier was added to 100 g of water, and the pH was adjusted to 4 with an aqueous sodium hydroxide solution. The above solution and 10 g of melamine formaldehyde prepolymer were added thereto, and the mixture was emulsified with a homogenizer until oil droplets became 4 μm. Then, the mixture was heated to 50 ° C. with stirring and stirred for 1 hour. After cooling to room temperature, the pH was adjusted to 7.5 with 25% aqueous ammonia,
A capsule dispersion of the leuco dye was prepared. 10 g of the capsule dispersion thus prepared and 2 g of flour starch
And 1 g of latex were mixed well, and weighed 50 g /
m2 high-quality paper was applied so that the applied amount of the solid content was 5 g / m2, to produce white upper paper.

Test Example 1 The upper paper sheet prepared in Example 2 was overlapped with the lower paper sheet coated with the zinc salicylate derivative so that the coated surface was in contact with the lower paper sheet, and the color was developed by pressing with a roller to obtain a blue image. This color image was subjected to a light stability test (exposure to an ultraviolet lamp for 5 hours), and the image density and hue after the test were simultaneously measured to determine the image fastness. The results were as follows. Image density before exposure to ultraviolet lamp: 0.48 Image density after exposure to ultraviolet lamp: 0.45 Robustness (%): 94 The color density (initial density) of the image is calculated using a spectrophotometer (Shimadzu double monochromator (Spectrophotometer UV-365)
Was measured at 675 nm. The fastness was calculated by the following equation. Fastness (%) = [(image density after test) / (image density before test)] × 100

Embodiment 3 FIG. 0.4 g of the monovinylphthalide compound of the present invention synthesized in Example 1 was triturated with 4.5 g of a 10% aqueous solution of polyvinyl alcohol and 7.0 g of water to obtain a dispersion (component A). On the other hand, 4-hydroxy-4'-isopropoxydiphenyl sulfone 2.5
g of 10% aqueous solution of polyvinyl chloride 7.5 g, water 4.5 g
And a dispersion was obtained. 9.7 g of this dispersion and pigment
2.6 g and 0.9 g of zinc stearate were mixed well (referred to as component B). Separately, 2.0 g of di-p-methylbenzyl oxalate, 9.0 g of a 10% aqueous polyvinyl solution, and 1.0 g of water were ground to obtain a dispersion (component C). 4.0 g of component A, 3.0 g of component B, 2.0 g of component C
Were mixed, coated on a support and dried to obtain a thermosensitive recording paper.

Comparative Example 1 A thermosensitive recording paper was obtained in the same manner as in Example 3, except that the fluoran compound of the formula (2) was used instead of the monovinylphthalide of the present invention synthesized in Example 1.

Comparative Example 2 Instead of the monovinylphthalide of the present invention synthesized in Example 1, 3,3′-bis [4- (N,
N-diethylamino) -2-ethoxyphenyl] -4-
A thermal recording paper was obtained in the same manner as in Example 3 except that azaphthalide was used.

Test Example 2. The thermal recording paper obtained in Example 3 was printed using a thermal printing apparatus (TH-M1: manufactured by Okura Electric Co., Ltd.), and the color density and the background density (initial density) of the green image obtained thereby were calculated as follows: 6 with a spectrophotometer (Shimadzu double monochromator self-recording spectrophotometer UV-365)
It was measured at 75 nm. Next, the color-developed heat-sensitive recording paper was placed in a carbon arc fade meter, and the density of the image area and the background after exposure to an ultraviolet lamp for 5 hours was measured in the same manner as above to evaluate the light-resistant storage stability. The heat-resistant recording papers obtained in Comparative Examples 1 and 2 were also evaluated for light-resistant storage stability in the same manner as described above. The results were as shown in Table 1. In the table below, the PCS value is a value calculated by the following equation. PCS value = (background reflectance-image reflectance) / background reflectance ×
100

[0024]

[Table 1]

Separately from the above test, the absorption spectra of the color images formed on the heat-sensitive recording paper obtained in Example 3, Comparative Example 1 and Comparative Example 3 were taken and compared. As a result, the image according to Example 3 has a strong maximum absorption at 640 nm,
The image of Comparative Example 1 has strong maximum absorption at 675 nm and 477 nm, and the image of Comparative Example 2 has strong maximum absorption at 640 nm and weak maximum absorption at 410 nm. was there. In comparison of the maximum absorption in the near-infrared region, the intensity of the absorption was found in Example 3>
Comparative Example 2> Comparative Example 1 Further, when comparing the wavelength range of absorption exceeding a certain intensity appropriately set in the near-infrared region, Example 3 is 590 nm to 750 n.
In the case of m, Comparative Example 1 was 640 to 710 nm and Comparative Example 2 was 600 to 672 nm.

Test Example 3 The heat-sensitive recording papers obtained in Example 3, Comparative Example 1 and Comparative Example 2 were each colored and stored under drying conditions of 60 ° C. for 48 hours, then the density of the image area and the background were measured, and the heat-resistant storage stability was evaluated. did. The density of the image portion and the background portion was measured at 675 nm. The results were as shown in Table 2.

[0027]

[Table 2]

Test Example 4 The heat-sensitive recording materials obtained in Example 3, Comparative Example 1 and Comparative Example 2 were each colored and stored for 5 days under conditions of 40 ° C. and 95% humidity. The sex was evaluated. The density of the image portion and the background portion was measured at 675 nm. The results were as shown in Table 3.

[0029]

[Table 3]

Embodiment 4 FIG. 0.4 g of the monovinylphthalide compound of the present invention synthesized in Example 1 was triturated with 4.5 g of a 10% aqueous solution of polyvinyl alcohol and 7.0 g of water to obtain a dispersion (component A). Similarly, 6- (N-
Ethyl-N-isoamylamino) -3-methyl-2-anilinofluoran was triturated with a polyvinyl alcohol aqueous solution and water at the same weight ratio as in the case of the monovinylphthalide compound to obtain a dispersion (component B). ). On the other hand, 4-hydroxy-4'-isopropoxydiphenyl sulfone
5 g of a 10% aqueous polyvinyl chloride solution 7.5 g, water 4.5
g to obtain a dispersion. 9.7 g of this dispersion, 2.6 g of pigment, and 0.9 g of zinc stearate were mixed well (referred to as Component C). In addition, 2.0 g of di-p-methylbenzyl oxalate, 9.0 g of a 10% aqueous polyvinyl solution,
1.0 g of water was triturated to obtain a dispersion (component D).
0.4 g of component A, 3.6 g of component B and 3.0 g of component C
g and 2.0 g of Component C were mixed, applied to a support, and dried to obtain a thermosensitive recording paper having black coloring.

Comparative Example 3 A thermosensitive recording paper was obtained in the same manner as in Example 4 except that the fluoran compound of the formula (2) was used instead of the monovinylphthalide of the present invention synthesized in Example 1.

Comparative Example 4 Instead of the monovinylphthalide of the present invention synthesized in Example 1, 3,3′-bis [4- (N,
N-diethylamino) -2-ethoxyphenyl] -4-
A thermosensitive recording paper was obtained in the same manner as in Example 4 except that azaphthalide was used.

Test Example 5 The heat-resistant recording papers obtained in Example 4, Comparative Example 3 and Comparative Example 4 were evaluated for light-resistant storage stability in the same manner as in Test Example 2. The results were as shown in Table 4.

[0034]

[Table 4]

Test Example 6 The heat-resistant recording papers obtained in Example 4, Comparative Example 3, and Comparative Example 4 were evaluated for heat-resistant storage stability in the same manner as in Test Example 3. The results were as shown in Table 5.

[0036]

[Table 5]

Test Example 7 The heat-resistant recording papers obtained in Example 4, Comparative Examples 3 and 4 were evaluated for moisture-resistant storage stability in the same manner as in Test Example 4. The results were as shown in Table 6.

[0038]

[Table 6]

[0039]

When the monovinylphthalide compound of the present invention is used as a leuco dye, it is used alone in the form of 590 to 750.
It shows strong absorption in the near infrared region of nm. In addition, it exhibits the same or better performance than conventional typical leuco dyes in terms of preservability of color images.

Claims (2)

[Claims] 1. A monovinylphthalide compound represented by the formula (1). Embedded image 2. A color-forming recording material utilizing a color-forming reaction between an electron-donating leuco dye and an electron-accepting developer, wherein monovinyl represented by the formula (1) according to claim 1 is used as the electron-donating leuco dye. A color-forming recording material characterized by using a phthalide compound.