JPH0220565A - Fluoran compound and chromogenic recording medium prepared by using same - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (wherein E is a 9-12C alkyl). USE:A chromogenic dye useful for a chromogenic recording medium. PREPARATION:A benzoic acid derivative of formula II is reacted with a phenol derivative of formula III or its derivative formed by converting the phenolic OH group into a lower alkoxy group in sulfuric acid.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a green color-forming dye that has excellent color-forming performance due to the action of acidic substances, and pressure-sensitive copying paper, heat-sensitive recording paper, etc. using the same. It relates to a chromogenic recording medium.

[Prior art and problems] Color-forming dyes (hereinafter referred to as "color-forming dyes") are colorless or almost colorless in themselves, but develop color under the action of acidic substances.
Recording media based on a color-forming system consisting of an acidic substance (color developer) that develops the color are widely used today as pressure-sensitive copying paper, heat-sensitive recording paper, etc., and the use and purpose of the recording media A large number of color-forming dyes are desired. Furthermore, as communication recording machines such as facsimiles become faster, it is necessary to increase the coloring speed of the heat-sensitive recording paper used therein.

In these recording bodies, a dye that develops a black color is mainly used, but in order to adjust the color tone, a dye that develops a red or green color may be mixed and used. Also, recently, many proposals have been made regarding multicolor thermosensitive recording paper.

Under these circumstances, in addition to black dyes, red dyes,
There is a demand for color-forming dyes that exhibit excellent color-forming performance such as green colors.

Conventionally, 3-diethylamino-
5-Methyl-7-dipendylaminof! Rheolan (Japanese Patent Publication No. 49-34044), 3-pyrrolidino-7-phenylaminofluorane (Japanese Patent Publication No. 51-38245), etc. are in practical use.

In addition, as a compound similar to the present invention, formula (JP-A-60-1999
35053) has been reported.

These known fluoran compounds are not necessarily satisfactory in terms of coloring performance, and there is a demand for even more excellent and distinctive dyes.

An object of the present invention is to provide a novel color-forming dye that has high color density, excellent color-forming sensitivity, and excellent properties such as storage stability of a colored image and background.

Means for Solving Problem C] The present invention provides a compound represented by the general formula (in the formula, R represents an alkyl group having 9 to 12 carbon atoms) and one or more of the compounds as a color-forming dye. The invention relates to a chromogenic recording medium containing the present invention.

The compounds of the present invention can be produced by conventional methods. That is, a benzoic acid derivative represented by the formula (wherein R is the same as above) and a phenol derivative represented by the formula or a derivative in which the phenolic hydroxyl group of the compound is converted to a lower alkoxy group are reacted in sulfuric acid. It can be manufactured by

By using the fluoran compound of the present invention alone, it is possible to produce a recording material of the color developed by the fluoran compound. Of course, it is also possible to use a mixture of two or more of these, or to use a mixture with other color-forming dyes. For example, red,
It is possible to produce a recording medium that produces a black color by mixing the three primary color dyes of blue and green, and it is also possible to obtain a color close to true black by mixing it with a black color dye. .

Color-forming dyes that can be used in combination with the fluoran compound of the present invention include various color-forming dyes such as fluoran-based, triphenylmethane-phthalide-based, phenothiazine-based, spiropyran-based, and rhodamine lactam-based dyes.

Color-forming recording materials manufactured using the fluoran compound of the present invention include pressure-sensitive copying paper, thermal recording paper, thermal transfer recording paper, electrically conductive thermal recording paper, and toner containing an acidic substance as a developer. Electrophotography, ultrasound recording paper used,
Examples include, but are not limited to, photosensitive printing materials, electron beam recording paper, stamping materials, stamp inks, and typewriter ribbons.

The method for producing thermal recording paper using the fluoran compound of the present invention is the same as that for known color-forming dyes.
No. 45-14039 or Japanese Patent Publication No. 59-70
It can be manufactured according to the method described in Publication No. 87 and the like. That is, by coating paper with a suspension in which fine particles of the fluoran compound of the present invention or a mixture of it and other color-forming dyes and fine particles of a color developer are dispersed in an aqueous solution of a water-soluble binder and drying. A thermosensitive recording paper with excellent color development can be obtained. In addition, a sensitizer, a filler, a dispersion side, a color image stabilizing side, an antioxidant, a desensitizer, an anti-blocking agent, an antifoaming agent, a light stabilizer, a fluorescent whitening agent, etc. are added to the above suspension. It can be included if necessary.

At this time, examples of the color developer used include bisphenol A, 4,4°-5ec-butylidene bisphenol,
4.4″-cyclohexylidene bisphenol, 2,2
°-dihydroxydiphenyl, pentamethylene-bis(
Bisphenol compounds such as 4-hydroxybenzoate), 1,7-di(4-hydroxyphenylthio)-3,
Sulfur-containing bisphenol compounds such as 5-dioxahebutane, benzyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, isopropyl 4-hydroxybenzoate, butyl 4-hydroxybenzoate, 4-hydroxybenzoate 4-hydroxybenzoic acid esters such as isobutyl acid, chlorobenzyl 4-hydroxybenzoate, methylbenzyl 4-hydroxybenzoate, and diphenylmethyl 4-hydroxybenzoate; benzoic acids such as zinc benzoate and zinc 4-nitrobenzoate; metal salt, 4-hydroxy-4°-methyldiphenylsulfone,
Hydroxynes such as 4-hydroxy-4'-isopropoxydiphenylsulfone, 4-hydroxy-4'-butoxydiphenylsulfone, dimethyl 4-hydroxyphthalate, dicyclohexyl 4-hydroxyphthalate, 4-hydroxy 4-hydroxyphthalic acid diesters such as diphenyl phthalate, 2-hydroxy-6-
Esters of hydroxynaphthoic acid such as carboxynaphthalene, hydroxyacetophenone, p-phenylene) Lt
Phenol, benzyl 4-hydroxyphenylacetate,
Examples include p-benzylphenol, hydroquinone monobenzyl ether, and tribromomethylsulfones such as tribromomethylphenylsulfone.

Examples of the sensitizer include higher fatty acid amide, benzamide, stearanilide, acetoacetanilide, thioacetanilide, dimethyl phthalate, dibenzyl terephthalate, dibenzyl isophthalate, bis(tert
-butylphenol),! 1Ax4.4°-dibutoxydiphenylsulfone 4-iso-propoxy-4'
Diethers of bisphenol S such as -n-butoxydiphenylsulfone, 4.4°-dibutoxydiphenylsulfone, 4.4°-di-n-(or 1SO)pentyloxydiphenylsulfone, diphenylamine, carbazole, 2.3-di- m-1-lylbutane, 4-benzylbiphenyl, 4,4'-dimethylbiphenyl, di-
Examples include β-naphthylphenylenediamine.

Examples of fillers include clay talc, kaolin, satin white, titanium oxide, calcium carbonate, magnesium carbonate, barium sulfate, magnesium silicate, and aluminum silicate. Examples of dispersants include sulfosuccinate esters such as dioctyl sodium sulfosuccinate. etc., sodium dodecylbenzenesulfonate, sodium salt of lauryl alcohol sulfate, fatty acid salts, etc., and as color image stabilizers, salicylic acid derivatives, metal salts (especially zinc salts) of oxynaphthoic acid derivatives, and pond water-insoluble zinc. 2. Compounds etc. as antioxidants.
2'-methylenebis(4-methyl-6-tert-butylphenol), 22'-methylenebis(4-ethyl-
6-tert-butylphenol), 4.4'-propylmethylenebis(3-methyl-6-tert-butylphenol), 4°4°-thiobis(2-tert-butyl-5-methylphenol), etc. Examples of sensitizing agents include aliphatic higher alcohols, polyethylene glycols, guanidine derivatives, etc., and examples of anti-blocking agents include stearic acid, zinc stearate, calcium stearate, carnauba wax, paraffin wax, and ester wax.

Pressure-sensitive copying paper using the fluoran compound of the present invention as a color-forming dye can be produced in the same manner as in the case of general color-forming dyes. i.e., U.S. Patent Box 2,548.365;
．． No. 366, No. 2,800,457, No. 2.800
．． It can be produced according to the method described in JP-A No. 458, JP-A-58-112041, or JP-A-58-139738. Pressure-sensitive copying paper consists of two types of paper: upper paper, which has microcapsules containing a color-forming dye in an organic solvent applied to the lower surface, and lower paper, which has the color-developing side (acidic substance) coated and carried on the upper surface. (in addition, a medium paper carrying a color developer on the upper surface may also be included in the unit), or a so-called self-content paper in which microcapsules and a color developer are coated on the same paper surface. It's okay.

Conventionally known color developers are used in this case, such as acid clay, activated clay, acpulgite, bentonite, colloidal silica, aluminum silicate, magnesium silicate, zinc silicate, tin silicate, calcined kaolin, talc, etc. inorganic acidic substances, aliphatic carboxylic acids such as oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, stearic acid, benzoic acid, p-tert-butylbenzoic acid, phthalic acid, gallic acid, salicylic acid, 3-isopropylsalicylic acid , 3-phenylsalicylic acid, 3-cyclohexylsalicylic acid, 3,5-di-tert-butylsalicylic acid, 3-
Methyl-5-benzylsalicylic acid, 3-phenyl-5-
Aromatic carboxylic acids such as (2,2-dimethylbenzyl)salicylic acid, 3,5-di(2-methylbenzyl)salicylic acid, 2-hydroxy-1-benzyl-3-naphthoic acid, zinc of these aromatic carboxylic acids, Metal salts such as magnesium, aluminum, titanium, etc., phenolic resin color developers such as p-phenylphenol-formalin resin, p-butylphenol-acetylene resin, these phenolic resin color developers and metal salts of the above aromatic carboxylic acids. Examples include mixtures of the following.

The thermal transfer paper using the fluoran compound of the present invention is disclosed in JP-A-58-212985, JP-A-59-33185,
JP-A-59-42995, JP-A-59-225986
The current-carrying recording paper was prepared according to the known method described in Japanese Patent Application Laid-open No. 48-96137 and Japanese Patent Application Laid-open No. 48-10193.
No. 5, according to the method described in JP-A-49-11344, etc. For electrophotography, JP-A-52-24530,
It can be produced according to the method described in JP-A-52-56932.

Furthermore, in order to use the fluoran compound of the present invention in a photosensitive recording medium, Japanese Patent Publication No. 38-24188, Japanese Patent Publication No. 45-105
50, Japanese Patent Publication No. 49-45987, Japanese Patent Publication No. 50-8012
0, JP-A-50-126228, JP-A-52-141
633, Japanese Patent Publication No. 147829/1982, etc., for use in electrostatic recording.
No. 3932, for use in photosensitive printing agents, JP-A-48-1
It can be carried out according to the method described in Japanese Patent No. 2104.

can be manufactured.

The fluoran compound of the present invention is used in these color-forming recording materials, as well as in JP-A-50-75991 and JP-A-60-75991.
It can also be used as a coloring component of a reversible temperature-indicating material disclosed in Japanese Patent No. 219289 and the like.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Example 1 (Synthesis Example) Synthesis of 2-anilino-6-N-cyclohexyl-n-nonylaminofluorane m-cyclohexylaminophenol 143°3 g, n
-170.7g of nonyl bromide, 47g of sodium carbonate
．． 7 g and 300 m of pseudocumene were mixed and reacted under reflux for 6.5 hours. To the reaction solution, 100 m of toluene was added, washed three times with 100 d of water, and then evaporated to dryness. Add 100 g of phthalic anhydride and 430 d of toluene to this
After refluxing for 0 hours, 1701 d of water and 5.6 g of sodium hydroxide were added, and after refluxing, the mixture was separated into layers. Next, water 1
After washing with water at 00af, 12% sodium hydroxide solution 1200
g was added to precipitate Na salt, which was filtered and washed with isopropyl alcohol. This Na salt was placed in 750 d of water, refluxed to completely expel the isopropyl alcohol, and then cooled. Neutralize with 50% sulfuric acid (pH 2), add 300 ml of toluene, reflux, and separate the layers. The toluene layer was washed with water (200 tt) and evaporated to dryness. Furthermore, it is vacuum dried to give a candy-like 2-(4-
N-cyclohexylnonylamino-2-hydroxybenzoyl)benzoic acid was obtained.

27.9 g of the above 2-(4-N-cyclohexylnonylamino-2-hydroxybenzoyl)benzoic acid and 12.5 g of 4-methoxydiphenylamine in 132 g of concentrated sulfuric acid.
After adding and reacting for 25 hours with stirring at a temperature of 15 to 25°C, the reaction solution was poured into 320 g of ice water, and the precipitated reaction product was collected by filtration. After washing the precipitate collected by filtration with water, add 6
8ml, 23g of sodium hydroxide and 350ml of toluene
2-anilino-6-N-cyclohexyl-n-nonylaminofluorane (compound number 1 ) crystals 11.9g
(mp, 1426-144.6°C).

Example 2 (Synthesis Example) Synthesis of 2-anilino-6-N-cyclohexyl-n-decylaminofluorane The above 2-(4-N-cyclohexyldecylamino-2-hydroxy) was added to 65 g of concentrated sulfuric acid. benzoyl)benzoic acid 1
3 g and 5.4 g of 4-methoxydiphenylamine were added and reacted for 28 hours with stirring at a temperature of 25 to 30°C. The reaction solution was dispersed in a solution of 75 g of sodium hydroxide and 380 m of water, 220 d of toluene was added, and after refluxing for 2 hours, the toluene layer was washed twice with 60 d of water, concentrated, and 00 d of methanol was added to precipitate crystals. Ta. Recrystallization was performed with a mixed solvent of toluene 1 and isobrobyl alcohol 5 to obtain 8.3 g of crystals of 2-anilino-6N-cyclohexyl-n-decylaminofluorane (compound 2) (mp, 1
10.5-114.8°C).

Representative examples of the compounds of the present invention produced in the same manner are shown in Table 1.

Table 1 I n-CvH+w 142.6-144.6
Dark green 2 n-C+oHz+ 110.5-
114.8 Green 3 n-C+Jzs 133
．． 0-134.4 Green Example 3. (Thermal recording paper) Dye suspension/dye compound 3.5g/clay 15.0g/15%
Polyvinyl alcohol aqueous solution 41.5g/water
40. Og developer suspension/bisphenol A I, 0.5g/
Clay 8.0g15
% polyvinyl alcohol water 1fi41.5g/water
40.0g of each of the above compositions was placed in a polyethylene bottle together with 150g of glass beads (diameter 1-1.5mm), the bottle was tightly stoppered, and the mixture was ground for several hours in a paint conditioner manufactured by Red Devi1 to form a dye suspension and a microscope. A colorant suspension/a solution was prepared. A coating liquid was prepared by mixing them at a ratio of 1:1.

This coating liquid was applied to white base paper and dried to produce heat-sensitive recording paper.

This thermosensitive recording paper was colored using a thermal gradient tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.), and the density of the colored surface was measured using a Macbeth reflection densitometer RD-514 model (Ratten #106).

The results are shown in Table 2.

The compounds of the present invention in Table 2 had higher color density than the comparative compounds (and the temperature at which the practical density reached 1.0 was lower), and showed excellent color development sensitivity.

Example 4. (Thermal recording paper) A part of the thermal recording paper produced in the same manner as in Example 3 was saturated and colored, and after being left in an atmosphere of 50° C. and 80% relative humidity for 24 hours, the density of the background and coloring surface was determined as in Example 3. Measured in the same manner. The results are shown in Table 3.

Table 3 Example 5. (Thermal recording paper) A thermosensitive recording paper was produced in the same manner as in Example 3 except that benzyl P-hydroxybenzoate was used instead of bisphenol A as a color developer, and after cajindering, Toshiba Spot- 2 was used for normal printing, and the color density was measured in the same manner as in Example 3. The results are shown in Table 4.

Table 4 Comparative compounds used in Examples 3 to 5 above are shown in Example 5 (
Pressure-sensitive copying paper) 2.0 g of the compound of the present invention was mixed with alkyldiphenylmethane (Hisol SAS 296, Nisseki Chemical Co., Ltd.) 25.
0 g and 18.0 g of diisopropylnaphthalene (Kureha Chemical Co., Ltd. rKMC-113J) were mixed and heated to dissolve (Liquid A).

On the other hand, 10 of sulfonic acid-modified polyvinyl alcohol (Nippon Gosei Kagaku Kogyo Co., Ltd. "Gohsenol C3K-50")
% aqueous solution, 7.5 g of a 10% aqueous solution of ethylene-maleic anhydride copolymer (Monsanto Co., Ltd. rEMA-31J) and 0.25 g of resorcin were added and dissolved, and then the pH was adjusted to 3 using a 20% aqueous sodium hydroxide solution. 4 (liquid B).

Solution A was added to solution B to form an emulsion using a homomixer, then 7.0 g of a 35% formalin aqueous solution was added, and stirring was continued at a temperature of 60 to 65° C. for 1 hour. After cooling to 40° C., 28% ammonia water was added to adjust the pH to 7.5 to obtain a microcapsule dispersion.

A coating solution was prepared by mixing 27.0 g of this dispersion, 3.5 g of wheat starch, 8.5 g of an 8% wheat starch aqueous solution, and 34.0 ml of water.

This coating solution was applied to white paper using a wire bar Na12 and dried to prepare a top sheet of pressure-sensitive copying paper.

The coated side of the upper paper was layered on the coated side of pressure-sensitive copying paper and clay lower paper (manufactured by Fuji Photo Film Co., Ltd.) prepared by coating and drying phenol-formalin resin, and printed using a typewriter. Colored. As a result, the letters printed on the paper appeared green.

(Effect of the invention〕

Claims (2)

[Claims] (1) A compound represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, R represents an alkyl group having 9 to 12 carbon atoms). (2) A color-forming recording medium containing one or more of the compounds described in claim 1 as a color-forming dye.