JPS60123557A - Fluoran derivative, and recording material using it - Google Patents

Abstract

NEW MATERIAL:A compound shown by the formula I [at least one of R1-R4 is alkyl, or cyclohexyl, and the rest is H, 1-4C alkyl, (halogen, etc.-substituted) aralkyl, (halogen, etc.-substituted) aryl, or R1, R2, and neighboring N are linked to form pyrrolidino, piperidino, or hexamethyleneimino]. EXAMPLE:3-i-Propyl-8-N-ethyl-N-n-hexylamino-benzo[a]fluoran. USE:Having improved light resistance of blue black - black coloring substance of pressure-sensitive, heat-sensitive, or electricity-sensitive recording paper. Having low fog on the surface of paper. PREPARATION:An m-substituted aminophenol derivative shown by the formula III is reacted with phthalic anhydride shown by the formula IV to give a 2-(2-hydroxy-4-substituted amino)benzoylbenzoic acid derivative shown by the formula V. This compound is condensed with a 2-amino-6-naphthol derivative shown by the formula VI.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluoran derivative useful as a color-forming substance for use in recording materials such as pressure-sensitive recording sheets, heat-sensitive recording sheets, and electrically conductive heat-sensitive recording sheets, and to recording materials using the derivatives.

Conventionally, various methods have been used to record information transmitted through the medium of energy such as pressure, heat, and electricity by utilizing the color reaction between colorless or light-colored basic dyes and organic or inorganic electron-accepting substances. For example, Chikakatsu, Iwasaki, Shipagi M/, Vol. 30, pp. 411-421, 46
Pressure-sensitive copying sheet 1-1 heat-sensitive recording sheet, electric heat-sensitive recording sheet, ultrasonic recording sheet, electron beam recording sheet, electrostatic recording sheet, photosensitive recording sheet as described on pages 3-470 (1976) Furthermore, a large number of methods have been proposed for application to photosensitive printing materials, type ribbons, ballpoint pen inks, crayons, stamp inks, etc.

For these recording materials that utilize a color reaction between an electron-donating color-forming substance (hereinafter simply referred to as a color-forming agent) and an electron-accepting color-forming substance (hereinafter simply referred to as a color-forming agent), it is necessary to select the type of color-forming agent. As a result, colored images exhibiting various hues are formed, but in recent years, there has been a strong demand for recording media that can produce black colored images for the purpose of making further copies of the obtained colored images. . In this case, in principle, it is possible to IM a black colored image by mixing coloring agents that produce different hues such as red, blue, yellow, and green.
Since the speed of color development and fastness to light, temperature and humidity vary depending on the type of color former, there is a drawback that the initially colored image cannot maintain its color tone. Therefore, research has been carried out to obtain black colored images using a single coloring agent, but it has not been possible to satisfy all of the requirements such as the stability of the coloring agent before coloring, coloring speed, coloring density, fastness, hue, and cost. A black color forming agent that can be obtained has not yet been found, and as a result, the black color recording material has not always been satisfactory.

However, the fluoran derivatives of the present invention represented by the following general formula [I] [wherein at least one of R1, R2, R3, and R2 is C9 to C, ? is an alkyl group or a cyclohexyl group, and the remaining substituents are hydrogen atoms i C1-C< alkyl group; halogen atom, C)-C2 alkyl group,
cl-, an aralkyl group optionally substituted with an alkoxyl group of -C4; a halogen atom, an aryl group optionally substituted with an alkyl group of cl-G(.
1 and R2 may be bonded to adjacent nitrogen atoms to form a pyrrolidino group, piperidino group or hexamethyleneimino group. ] is a colorless or light-colored stable compound that develops a highly concentrated hue when it comes into contact with a color developer, and recorded images obtained using this substance maintain their initial color tone stably even when exposed to sunlight. It has characteristics. Among them, fluoran derivatives represented by the following general formula CI+) [wherein at least one of R1, R2, and R is C,5-
~C8 alkyl group or cyclohexyl group, and the remaining substituents are each a hydrogen atom; a C1~C alkyl group; a halogen atom, a C1~C alkyl group, Cx-
An aralkyl group which may be substituted with a C,4 alkoxyl group; an aryl group which may be substituted with a halogen atom or a Cz -Cz alkyl group. Also R1 and R
2 may be bonded to adjacent nitrogen atoms to form a pyrrolidino group, piperidino group or hexamethyleneimino group. ] In particular, it has the property of being able to stably maintain a high density blue-black, purple-black, or black color tone over a long period of time. For example, when applied to pressure-sensitive recording paper, it has particularly excellent initial color development. When the recorded η image is iMed and applied to thermal recording paper, a recorded image with less background fog and excellent color development can be obtained.

As a compound having a structure similar to the fluoran derivative represented by the general formula (1), there are pressure-sensitive fluoran compounds described in British Patent No. 1374047 and West German Patent No. 2240991 previously filed by the present inventors. Although it is known as a chromogen in copying paper and thermal recording paper, the fluoran derivative represented by the general formula (1) has a color density that is not humanly possible due to close contact with an electron-accepting substance compared to these compounds. It is excellent in certain respects, and heat-sensitive recording paper manufactured using bisphenol octane or p-hydroxybenzoic acid hensyl ester as a color developer has high color development sensitivity, and is also excellent in preventing background stains on the coated surface. It is something.

The fluoran derivative represented by the general formula (1) of the present invention having excellent properties as described above can be produced mainly by the following representative method. That is, as shown below, first m-substituted aminophenol derivative (
2-
(2-hydroxy-4-substituted amino)benzoylbenzoic acid derivative [■] was synthesized, and this and 2-amino-6
A fluoran derivative represented by the general formula (1) can be produced by condensing -naphthol derivative a*[vn.

[V] [A] rT] [In the formula, Rs represents a hydrogen atom or a C1-C4 alkyl group, and R1, Rλ, Ra, and Rda have the above-mentioned meanings.

] In addition, in the above reaction, 2-amino-6-naph 1--
When R5 of the fluoran derivative is an alkyl group of 01 to Cj, the following general formula [■
] A triarylmethane derivative represented by the following may be synthesized.

[In the formula, R, R1, R2,, R3, R4, R, and 5- have the above-mentioned meanings. ] In this case, the obtained triarylmethane derivative is filtered if necessary, and the pH of the system is adjusted to 9 or higher with an alkaline substance such as sulfur/lium hydroxide or potassium hydroxide.
The desired fluoran derivative can be obtained by heating to 100°C. Note that the yield can be effectively increased by using an organic solvent such as acetone, Hensen, toluene, or xylene in combination with the above aqueous medium.

As another method of production, 3゜8-diaminohenzo(a)-fluorane [■] is synthesized according to the above-mentioned method, and if necessary, a solvent and a deoxidizing agent are used to synthesize the compound of general formula (IX). The desired fluoran derivative (1) can be obtained by reacting the compound at 30 to 150°C for several hours.

[In the formula, (1), R2, R3, and R4 have the above-mentioned meanings, and X represents a halogen atom. ] The thus obtained fluoran derivative represented by the general formula (1) of the present invention is a colorless to light-colored basic dye having excellent properties as described above, and is particularly suitable for various dyes that utilize a color reaction with a color developer. It exhibits extremely excellent effects when used in recording media.

The color developer used here is appropriately selected depending on the type of recording medium, but for example, for recording bodies such as pressure-sensitive recording bodies, heat-sensitive recording bodies, and electrically conductive heat-sensitive recording bodies, Brønsted or Lewis acids are used. Substances that act are preferably used. Specifically, for example, acid clay, activated clay, acpal guide, bentonite, colloidal silica, aluminum silicate, magnesium silicate, zinc silicate, tin silicate, calcined kaolin, inorganic color developer such as talc, oxalic acid, maleic acid, tartaric acid. , aliphatic carboxylic acids such as citric acid, succinic acid, and stearic acid, benzoic acid, balatajalibdelbenzoic acid, fucuric acid, gallic acid, salicylic acid, 3-isopropylsalicylic acid, 3-phenylsalicylic acid, 3-cyclohexylsalicylic acid, 3, 5-di-tajarybdelsalicylic acid, 3-methyl-5-hendylsalicylic acid,
Aromatic carboxylic acids such as 3-phenyl-5-(α,α-dimethylbenzyl)salicylic acid, 3.5-c(α-methylhensyl)salicylic acid, 2-hydroxy-1-hensyl-3-naphthoic acid, 4-tert -octylphenol, 4+ 4'-5ea-butylidene diphenol, 4-phenylphenol, 4.4'-isopropylidene diphenol, 4.42-cyclohexylidene diphenol, 4,4'-dihydroxydiphenyl sulfide, 4,4 '-thiobis(6-tert-butyl-3
-methylphenol), 4,4'-dihydroxydiphenylsulfone, hydroquinone monobenzyl ether,
4-Hydroxyenzof-non, 2,4-dihy-1-nyloxyhenzophenone, 2,4,4. '-1-lihydroxyhenzophenone, 2.2',4.4'-tetrahydroxybenzophenone, cimedyl 4-hytrogysiphthalate,
Methyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, propyl 4-hydroxybenzoate, 5ec-butyl 4-hydroxybenzoate, ethyl 4-hydroxybenzoate, phenyl 4-hydroxybenzoate, 4-hydroxybenzoic acid Hensyl, 4-hydroxybenzoic acid 1
-Ryl, chlorophenyl 4-hydroxybenzoate, 4-
Phenols such as phenylpropyl hydroxybenzoate, phenethyl 4-hydroxybenzoate, p-chlorobenzyl 4-hydroxybenzoate, p-methoxybenzyl 4-hydroxybenzoate ('! compounds, rose-phenylphenol-formalin resin, para - Organic color developers such as phenolic resins such as butylphenol-acetylene resins, and salts of these organic color developers with polyvalent metals such as zinc, magnesium, aluminum, calcium, titanium, manganese, tin, and nickel, and chlorides. Hydrogen, hydrohalic acids such as hydrogen bromide, hydrogen iodide, boric acid, silicic acid, phosphoric acid, sulfuric acid, nitric acid, perchloric acid, halocarbons such as aluminum, zinc, nickel, tin, titanium, boron, etc. Examples include inorganic acids.

Regarding various typical recording materials using such a color developer and the fluoran derivative represented by the general formula [I] of the present invention,
This will be explained in more detail below.

Pressure-sensitive recording bodies are disclosed in, for example, U.S. Pat.
No. 505471, No. 2505489, No. 254836
No. 6, No. 2712507, No. 2730456, No. 2
No. 730457, No. 3418250, No. 392402
As described in No. 7 and No. 4010038, there are various types of fluorane derivatives, and the fluoran derivative of the present invention can be applied to these various types of pressure-sensitive recording media.

Generally, the fluoran derivatives of the present invention are used alone or in combination, and if necessary, triphenylmethane lactone,
Spiropyrans, fluorans, diphenylmethanes,
Consists of basic dyes such as leucomethylene blue, synthetic oils such as alkylated naphthalene, alkylated diphenyl, alkylated diphenylmethane, and alkylated terphenyl, vegetable oils such as cotton oil and castor oil, animal oils, mineral oils, or mixtures thereof. A dispersion liquid obtained by dissolving it in a solvent and dispersing it in a binder, or a solution described in "II" is contained in microcapsules by various capsule manufacturing methods such as a coacerhesion method, an interfacial polymerization method, and a 1n-sttt+ method, The pressure-sensitive recording medium of the present invention is produced by coating a dispersion in a binder on a support such as paper, plastic sheet, resin-coated paper, or the like.

Of course, there are the so-called upper sheets in which one side of the support is coated with the above-mentioned dispersion, and the so-called top sheet in which one side of the support is coated with a color developer coating liquid mainly consisting of a color developer, and the other side is coated with the above-mentioned dispersion. A coating liquid containing a mixture of the above capsules and a color developer may be applied to the same side of the sheet or support, or the capsule portion IF1. As mentioned above, various forms are included, such as R"fl-1 body copy sheets, in which the capsules and the color developer are coexisted on the same surface by applying a color developer coating liquid on top of the liquid. The amount of fluoran derivative used depends on the desired coating amount,
Since it varies depending on various conditions such as the form of the pressure-sensitive recording medium, the capsule manufacturing method, the composition of the coating liquid including various auxiliaries, and the coating method, C may be appropriately selected according to the conditions. In any case, by using the fluoran derivative represented by the general formula (1) of the present invention as a basic dye in various conventional pressure-sensitive recording materials, it is possible to form recorded images with excellent color development. It's what the body gets.

For example, heat-sensitive recording materials are disclosed in Japanese Patent Publication Nos. 44-3680 and 44-3680.
No. 27880, 45-. No. 14039, 48-43
No. 830, No. 4.9-69, No. 49-70, No. 52
-2014.2, etc., and the fluoran derivative of the present invention can be applied to these various types of heat-sensitive recording materials, and moreover, the fluoran derivative of the present invention can be simply used as a dye. As described above, a heat-sensitive recording material exhibiting a recorded image having excellent properties can be obtained by using only this method. Generally, a coating liquid obtained by dispersing the fluoran derivative of the present invention and fine particles of a color developer in a medium in which a binder is melted or dispersed is applied to paper, plastic film, synthetic paper, woven fabric sheets, molded articles, etc. The heat-sensitive recording material of the present invention is produced by coating it on a suitable support. The ratio of the basic dye mainly consisting of a fluoran derivative and the color developer used in the recording layer is not particularly limited, but is generally 1 to 50 parts by weight, preferably 2 to 10 parts by weight, per 1 part by weight of the dye. A color developer is used.

In addition, inorganic metal compounds such as oxides, hydroxides, and carbonates of polyvalent metals and inorganic pigments are generally used as color developers for the purpose of improving color development, matting the surface of the recording layer, and improving writing properties.
0.1 to 5 parts by weight, preferably 0.2 to 2 parts by weight
Parts by weight can be used in combination, and various auxiliary agents such as dispersants, ultraviolet absorbers, thermofusible substances, antifoaming agents, fluorescent dyes, and coloring dyes can be used in combination as necessary.

As mentioned above, the heat-sensitive recording material of the present invention is generally manufactured by applying a coating liquid in which fine particles of a fluoran derivative and a color developer are dispersed to a support, but the fluoran derivative and the color developer are each dispersed separately. The two types of coating liquids may be coated on the support in layers, and it is of course also possible to produce the coating by impregnation or rolling. A method for preparing the base coating liquid,
There are no particular limitations on the application method, etc.
The coating amount is generally about 2 to 12 g/rl in terms of dry weight. In addition, examples of binders include starch cheeks,
Celluloses, proteins, gum arabic, polyvinyl alcohol, styrene-maleic anhydride copolymer salt, styrene-butadiene copolymer emulsion, bee-acetate maleic anhydride copolymer salt, polyacrylate, etc. are appropriately selected. used.

The electrically conductive heat-sensitive recording material is manufactured, for example, by the method described in JP-A-49-11344 and JP-A-50-48930. Generally, a coating liquid in which a conductive substance, a basic dye mainly composed of the fluoran derivative of the present invention, and a color developer are dispersed together with a binder is applied to a support such as paper, or a conductive substance is coated on the support to form a conductive layer. The current-carrying heat-sensitive recording material of the present invention is produced by forming a coating material and applying thereon a coating liquid in which a dye, a color developer, and a binder are dispersed. Note that if both the dye and the color developer do not melt in the preferred temperature range of 70 to 120°C, sensitivity to Joule heat can be adjusted by using an appropriate thermofusible substance in combination.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited thereto unless it goes beyond the gist of the present invention. Further, parts and % in the examples represent parts by weight and % by weight, respectively, unless otherwise specified.

[Example 1] 3.7 g of 2-(2-hydroxy-1-N-ethyl-N-n-hexylamino)henshiylbenzoic acid and 2-1-
10ml of 2.2g of propylamino-6-naphthol
The mixture was reacted in concentrated sulfuric acid at room temperature for 17 hours. The obtained reaction product was poured into 100 ml of ice water, and the pH was adjusted to 9 by adding a 20% aqueous solution of thorium hydroxide at room temperature, and the resulting precipitate was filtered, washed with water, and dried. Next, recrystallization was performed using Henzen-edanol to obtain 4.2 g of 3-4-propyl-3-N-ethyl-N-n-hexylamino-henzene (a) fluoran as colorless crystals. Yield 78%, m.
p, 169-171°C, blue-black color developed on silica gel.

[Example 2] 2-(2-hydroxy-4-N-conityl-N--i
3.6g and 2 pentylaminobenzoic acid
-2.7 g of anilino-6-me-1-xinaphthalene and 1
The reaction was carried out in 0 mN concentrated sulfuric acid at room temperature for 24 hours.

The obtained reaction product was poured into 100 mN ice water, and a 20% aqueous sodium hydroxide solution was added at room temperature to induce PHII.
After that, 5 Qm# of toluene was added and heated at 85°C for 3 hours. Next, the 1-toluene layer was separated, 1-toluene was distilled off under reduced pressure, and then recrystallized from benzene-ethanol to give 3-anilino-8-N-ethyl-N-4-pentylamino- ) 466 g of fluorane was obtained as colorless crystals. Yield 83%, m, p, 241-243°C
, developed a black color on silica gel.

[Example 3] 3.7 g of 2-(2-hydroxy-4,-N-ethyl-N-n-hexylamino)benzoylbenzoic acid and 2.7 g of 2-anilino-6-medoxynafucrene were added in 1Omβ. The reaction was carried out in concentrated sulfuric acid at room temperature for 24 hours. The iq reactant was poured into 10 Qm4 of ice water and 20% hydroxylated at room temperature.) An aqueous solution of IJ was added to adjust the pH to 11, and 30 mβ of acetone was added (refluxed for 3 hours. The crystalline eyewash obtained was filtered, washed with water, and further recrystallized with Hensen-ethanol to obtain 3-anilino-8-N-ethyl-N-n-hexylaminofluorane as colorless crystals. 4.4 g fl.Yield 77
%, m, p, 155-158°C, developed black color on silica gel.

[Example 4] 2-(2-hydroxy-4,-N-ethyl-
2-(2-hydroxy-4-N,N-diethylamino) instead of N-n-hexylamino)benzoylbenzoic acid
Same as Example 1 except that benzoylbenzoic acid was used and 2-amino-6-naphthol was used instead of 2-i-propylamino-6-naphthol. W was beaten,
4.4 g of 3-amino-8-diethylamino-henzo(a) fluorane and 1.3 g of 5ec-pentyl chloride were dissolved in 10 g of N,N-dimethylbormamide. After incubating at 70-80'C for 3 hours,
Add sodium bicarbonate and keep at the same temperature for 2 hours, then add 2
After adding 0 g, steam distillation was carried out under weak alkalinity to remove and decompose unreacted 5ec-pentyl chloride'. After cooling, the solid obtained under alkalinity was filtered, washed with water, dried, and then recrystallized from benzene-ethanol to give 3-sec-pendelamino-8-N,N-diethylaminobenzene.
(a) 4.4 g of colorless crystals of fluoran were obtained. Yield 86
%, m, p, 1.85-190°C, blue-black color developed on silica gel.

[Examples 5 to 18] 2-(2-hydroxy-4-N-edyl-N of Example 1)
The following 2-(2-hydroxy-4-amino-hendiyl)benzoic acid derivatives were used instead of -n-hexylamino)benzoylbenzoic acid, and the following 2-(2-hydroxy-4-amino-hendiyl)benzoic acid derivatives were used instead of 2-1-propylamino-6-naphthol. Using 2-amino-6-naphthol derivatives, similar fluorane derivatives as shown in Table 1 were obtained. Each color was developed with silica gel to the hue shown below.

[Examples 19 to 22, Comparative Examples 1 to 2] Using the fluoran derivative of Example 1, thermosensitive recording paper was produced in the following manner.

Fluoran derivative of A-wave preparation Example 1 5 parts Stearic acid amide 1 part 2% aqueous solution of hydroxyethyl cellulose 25 parts This composition was ground with a sand grinder to an average particle size of 2 microns.

4.4'-Isopropylidene diphenol 50 parts Stearamide 10 parts 250 parts 2% aqueous solution of hydroxyethyl cellulose This composition was ground to an average particle size of 2 microns using a sand grinder.

C wave preparation solution A 62 parts Solution B 31 parts Ultrafine anhydrous silica (trade name Thyroid 244, manufactured by Fuji Davison Chemical Co., Ltd.) 25 parts 20% aqueous solution of styrene-maleic anhydride copolymer salt 175 parts Zinc stearate 5 parts 100 parts of water were mixed at the above ratio to prepare a coating liquid.

The obtained coating liquid was coated onto a base paper of 50 g/r+ (dry coating amount of 6 g/m) to obtain a heat-sensitive recording paper.

Hereinafter, this thermal recording paper will be abbreviated as (NoA). In the same manner, thermal recording paper (NoB) (NoC) (No, D) was prepared using the fluoran derivative of Example 2.3.4. 3-diethylamino-8-
1-propylaminohenzo(a) fluorane (BF-
Thermal recording paper (NoE) (N.

F] was created. The following tests were conducted using these thermosensitive recording papers.

- Color development test of thermal recording paper Thermal recording paper (NoA) ~ (NoD) and (NoE)
(NoF) at 80°C and 90°C at a pressure of 4 kg/ct.
When pressed against a hot plate at 100°C and 1120°C for 5 seconds, the color hue, color density, and background stain were measured using a Macbeth densitometer.

The results are shown in Table 2.

From the test results shown in Table 2 and above, the thermal recording paper using the fluoran derivative represented by the general formula (1) of the present invention has better coloring property and background t'r5 than the thermal recording paper using the known fluoran compound. It was recognized that he was good at this.

[Example 23] 5 parts of the fluorane derivative obtained in Example 1 were dissolved in 100 parts of isopropylated naphthalene, and 25 parts of pigskin gelatin with an isoelectric point of 8 and 25 parts of gum arabic were dissolved in 35
It was added to 0 parts of warm water (50°C) and emulsified and dispersed. To this emulsion, 1000 parts of warm water was added, the pH was adjusted to 4 with acetic acid, the emulsion was cooled to 10°C, and 10 parts of a 25% aqueous solution of geltaraldehyde was added to harden the capsules. This capsule-containing coating solution was coated on one side of a 45 g/rrr base paper so that the dry weight was 5 g/rrr, and 2 ml of water was applied to the back side.
A color developer coating solution prepared by dispersing 20 parts of zinc salt of 3.5-di(α-methylhensyl)salicylic acid, 80 parts of kaolin, and 30 parts of styrene-butadiene copolymer emulsion (50% solids content) in 0.00 parts was prepared by dry weight. 5 g/r+ (pressure-sensitive recording thin paper) was obtained.

When several sheets were stacked and pressed so that the capsule-coated surface and the developer-coated surface faced each other, a black colored image was obtained on the developer-coated surface. The colored image of the lint had a faster coloring speed than the initial stage of coloring, a higher density than the initial stage of printing, and no discoloration or fading was observed even when exposed to sunlight.

[Example 24] 200 parts of 1% polyvinyl alcohol cupric iodide and 5 parts of 10% sodium sulfite aqueous solution were added and ground with a sand grinder until the average particle size was 2 microns. After adding 8 parts of polyacrylic acid ester emulsion and 20 parts of titanium oxide to this and thoroughly dispersing it, the dry coating amount was 7 g/rd on 50 g/% base paper.
It was coated so that

The heat-sensitive coating liquid prepared in Example 19 was coated on this coating layer so that the dry coating amount was 5 g/% to obtain an electrically conductive heat-sensitive recording paper.

This recording paper was scanned at a stylus force of 10 g and a scanning speed of 630 ts/sec.
When recorded with a cylindrical scanning recording tester, a deep black recorded image was obtained. This recorded image had excellent light resistance and did not change color or become discolored even when exposed to sunlight.

Patent applicant Kanzaki Paper Co., Ltd.

Claims (1)

[Claims] (1) Fluorane derivative represented by the following general formula (1) [in the formula, at least one of R1, RZ, R3, and R4 is an alkyl group or a cyclohexyl group of C5-(l, and the remaining substituents are each hydrogen Atom; C1-C-% alkyl group; halogen atom, 01-C, ? alkyl group,
An aralkyl group optionally substituted with an alkoxyl group of 01 to Cf; a halokene atom and an aryl group optionally substituted with an alkyl group of 01 to C4 are not shown. Furthermore, R1 and R2 may be bonded to adjacent nitrogen atoms to form a pyrrolidino group, a piperidino group, or a hexamethyleneimino group. (2) A recording medium containing at least one of the fluoran derivatives described in claim (1) as an electron-donating color-forming substance.