JPH0253866A - Imidazole-based dye - Google Patents

Abstract

NEW MATERIAL:A compound shown by formula I [R1 and R2 are H, (substituted) alkyl, R1 and R2 are mutually bonded to form 5-6-membered ring; R3-R6 are halogen, amido, (substituted) alkyl or (substituted) alkoxy; R7 is monofunctional organic group; n is 0-4; B is organic group bonded through C, N, O or S to imidazole ring or directly to imidazole ring]. USE:Dye for recording material of heat transfer capable of recording full color with excellent color reproduction, readily subliming and providing high heat transfer recording with high color concentration at high speed without loading a heatsensitive head heavily because of high molecular extinction coefficient. PREPARATION:A coupler shown by formula II and a developing agent of p- phenylenediamine base shown by formula III are oxidized and coupled in the presence of an oxidizing agent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel imidazole dye useful for color image formation, filter use, etc.

[Background of the invention]

British patents 1 and 5 show that diphenylimidazoles form pigments through oxidative coupling with aminophenols.
No. 45,507. These diphenylimidazoles are useful as photographic couplers, and it has been shown that oxidatively coupled dyes with aminephenols can be mordanted with quaternary ammonium mortants to produce images with good light resistance.

However, the color tone of the oxidatively coupled dye with aminophenol is highly dependent on pH, and the absorption wavelength λmax becomes significantly shorter at neutral pH, so when used as an image, the presence of quaternary mordan 1. is required.

Therefore, in systems where these mordants do not exist, the light absorption λmax of these dyes is at the edge of the visible light range, and various color reproduction methods using subtractive color methods such as photography, thermal transfer, inkjet, and printing are difficult to reproduce. It cannot be used as a cyan dye in image forming means.

As a result of various studies, the present inventors replaced the above-mentioned aminophenols with specific para-phenylene diamine compounds, and found that the aminophenols were replaced with organic compounds bonded to the imidazole ring at the 2-position via a carbon atom, nitrogen atom, oxygen atom, or sulfur atom. By introducing a hydroxyl group into the 0-position of the group and the 4-position phenyl group,
It has little pH dependence, and there is no need for Mordan 1.
The present inventors have discovered that a compound suitable as a cyan dye in the above-mentioned image forming means can be obtained, which has more preferable spectral absorption characteristics as a cyan dye and has excellent heat resistance.

[Purpose of the invention]

The purpose of the present invention is to provide photographic, thermal transfer, and inkjet dyes that have less pH dependence, do not require a mordant, have more preferable absorption characteristics as a dye, and have excellent light resistance.
The purpose of the present invention is to provide a cyan dye suitable for image media such as printing.

[Structure of the invention]

The above object of the present invention is achieved by an imidasol dye represented by the following general formula [E].

General formula (1) In the formula, R1 and R2 each represent a hydrogen atom, an alkyl group, or a substituted argyl group, and R1 and R2 are bonded to each other to form 5
or a six-membered ring. R3, R4, R5 and R6 each represent a haloken atom, an alkyl group, a substituted alkyl group, an alkokene group or a substituted alkoxy group, and R7
represents a monovalent organic group, and n represents an integer of O to 4. When n is 2 or more, a plurality of R7s may be the same or different. B represents an organic group bonded directly to the imidazole ring via a carbon atom, nitrogen atom, oxygen atom or sulfur atom.

The present invention will be explained in more detail below.

In general formula [I], R1 and R2 are preferably hydrogen atoms, alkyl groups, and substituted alkyl groups such as hydroxyalkyl groups, alkoxyalkyl groups, alkoxyalkoxyalkyl groups, and alkylsulfonamidoalkyl groups. Examples of these groups include methyl, ethyl, propyl, isopropyl, 5ee-butyl, butyl,
Alkyl groups having 1 to 18 carbon atoms such as isobutyl, t-butyl, octyl, dodecyl, octadecyl, nclohexyl, hydroxyethyl, methoxyethyl, methoxybutyl, quinethyl, methoxyethoxyethyl, β- Examples include substituted alkyl groups such as methanesulfonamidoethyl.

Examples of the 5-membered ring or 6-membered ring formed by combining R1 and R2 include (:I pyrrolidino, piperidino, piperazino,
Examples include various groups such as morpholino.

R3, R4, R5 and R6 may be the same or different from each other, preferably a hydrogen atom, a halogen atom, an argylamido group, an arylamide group, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkylsulfonamidoalkyl group, or an alkoxy These are the basics. Examples of these include atoms or groups such as chlorine, bromine, acetamide, propionamide, benzamide, tolylamide, methyl, ethyl, hydroxymethyl, hydroxyethyl, methoxyethyl, methanesulfonamidoethyl, metquine, ethquine, etc. .

Among the substituents represented by B, organic groups via carbon atoms include alkyl groups, aryl groups, heterocyclic groups, cyano groups,
Examples thereof include a carboxyl group, an acyl group, a carbamoyl group, an alkoxycarbonyl group, an aryloquine group, and the like.

Examples of the organic group via a nitrogen atom include an acylamino group, an alkoxycarbonylamino group, an aryloquinylamino group, a sulfonamide group, anilino group, a ureido group, a sulfamoylamino group, an amine group, and a heterocyclic group.

Examples of the organic group via an oxygen atom include an alkoxy group, an aryloxy group, a nlyloxy group, a heterocyclic oxy group, and the like.

The organic group via a sulfur atom and 17 include an argylthio group, an aryldio group, a heterocyclic thio group, and the like.

Any of these substituents may further have a substituent.

The substituent represented by R7 is not particularly limited, and includes, for example, a herokene atom, cyano, dichloride, carboquine, alkyl, alkokyne, carbamoyl, sulfamoyl,
Acyl, acyloxy, alkoxycarbonyl, -NH
CORs, -NH3O2R8, Ru.

The argyl group represented by R7 has 1 to 2 carbon atoms.
2 is preferably a straight chain or branched alkyl group, which also includes a cycloalkyl group such as a cyclohexyl group, and may be substituted.

The alkoxy group is preferably a linear or branched alkoxy group having 1 to 22 carbon atoms.

The carbamoyl group includes a thermal alkylcarbamoyl group, a substituted alkylcarbamoyl group, a phenylcarbamoyl group,
Examples include substituted phenylcarbamoyl groups.

Examples of the sulfamoyl group include an alkylsulfamoyl group, a substituted alkylsulfamoyl group, a phenylsulfamoyl group, and a substituted phenylsulfamoyl group.

Further, examples of the acyl group include acetyl, benzoyl, and benzenesulfonyl groups, examples of the acyloxy group include acetoxy and butanesulfonyloxy groups, and examples of the alkoxycarbonyl group include 2-ethylhexyloxycarbonyl group.

The NHCOR group is an algylamide group having 1 to 22 carbon atoms (including substituted, unsubstituted alkylamides, and alicyclic alkylamides, and may have an unsaturated bond) or an arylamide group (having a substituent). ).

NH3O2R8 represents a substituted or unsubstituted alkoxycarbonylamino group or aryloxycarbonyl group having 1 to 22 carbon atoms.

It represents a mino group, and the NH30□R8 group represents an alkylsulfonamide group or an arylsulfonamide group.

Examples include dialkylsulfamoylamino groups.

Among the substituents represented by R7, alkyl groups, alkoxy groups, alkylamido groups, arylamido groups, etc. are preferred.

Next, typical examples of the cyan coupler represented by the general formula [I] used in the present invention will be shown, but the present invention is not limited thereto.

1 1/1 J6 The dye of the present invention can be synthesized by the known method of oxidatively coupling a p-phinidine diamine color developing agent to a cyan coupler described in Japanese Patent Application No. 51324/1983. . Since the method for producing the coupler is described in the synthesis examples of the patent application, only representative synthesis examples of the dye will be shown.

Synthesis Example 1 (Synthesis of Compound Example 4) Exemplary coupler No. described in Japanese Patent Application No. 63-51324,
71.0g was dissolved in 100ml of ethyl acetate. Dissolve 400 mα of 5% aqueous sodium carbonate solution, and add 1.5 g of 4-amino-3-methyl-N-ethyl-N-β-methanesulfonamidoethylaniline sulfate dissolved in 50 m of water (2. A small amount of silver powder was added, and 5% hydrogen peroxide solution was added little by little over about 6 hours to cause a coupling reaction.

The ethyl acetate layer was separated, washed with water, dehydrated with anhydrous magnesium sulfate, concentrated, and purified by column chromatography to obtain 0.65 g of an amorphous solid.

This product showed M+=892 by mass spectrometry, and was confirmed to be the target compound.

In addition, the imidazole dye represented by the general formula [I] can be used as a coupler represented by the following general formula (Il'l) and a paraphenylenediamine developing agent represented by the following general formula (III), as shown in the above synthesis example. can be similarly synthesized by oxidative coupling in the presence of an oxidizing agent.

General formula [■] (Here, R7, B and n are the above-mentioned general formula [I]
It has the same meaning as defined in . ) General formula (
III) (where R1, R2, R3, R4, R5 and R
6 represents the same meaning as defined in general formula CI). ) This coupling reaction is preferably carried out under basic conditions, and the reaction medium may be a residual solvent, an aqueous organic solvent, or an aqueous solution.

The oxidizing agent may be any organic or inorganic one having a potential capable of oxidizing p-phenylenediamine.
As the oxidizing agent, inorganic oxidizing agents such as silver halide, hydrogen peroxide, mankane dioxide, potassium persulfate, and oxygen, and various organic oxidizing agents such as NBS and chloramine T can be used.

As described above, the cyan dye of the present invention is obtained by oxidative camping of an imidazole coupler and p-phenylenediamine.

The imidasol dye of the present invention uses, for example, a coupler represented by the general formula [■] as a cyan coupler used in a silver halide color photographic light-sensitive material;
(2) Developing with a color developer containing a p-phenylenecyamine color developing agent represented by [2], and coupling the p-phenylenediamine developer oxidized by exposed silver halide with the coupler. It is particularly useful as a cyan dye for photography to obtain cyan images. In this case, the coupler is usually contained in the photographic light-sensitive material, or it can be used in an external color development method in which the coupler or the coupler is dissolved together with a color developing agent in a developer.

The imidasol dye of the present invention can also be used for photography as a filter dye,
No. 8-18169, No. 58-205798, No. 58-
It is also useful as a cyan dye for images in thermal transfer processes, inkjet systems, color electrophotography, printing, etc. as shown in No. 219086.

In order to improve the stability of the dye of the present invention against light or heat, known stabilizers can be used in combination. Such stabilizers include, for example, U.S. Pat. No. 3,935,016
hydroquinone derivatives described in U.S. Pat. No. 4,254,216 and JP-A-55-21004; phenol derivatives, spiroindane derivatives and methylenedioxybenzene derivatives described in British Patent Publications No. 2,077.455 and British Patent Publication No. 2,062,888, U.S. Patent Nos. 3,764,337 and 3,432,300 No. 3.574627, No. 3,573,050, JP-A-51-152225, No. 5320327 and No. 53
Chroman derivatives, spirochroman derivatives and coumaran derivatives described in No.-17729, JP-A-55-632
No. 1, British Patent 1. ．． Hydroquinone heptanoether derivatives and p-
Examples include amine phenol derivatives, bisphenol derivatives described in Japanese Patent Publication No. 48-31625 and US Pat. No. 3,700,455, and metal complexes such as those described in US Pat. No. 4,245.018.

〔Effect of the invention〕

The dye of the present invention is useful as a cyan dye for color image formation using a subtractive color method, and can also be used as a filter dye for solid-state image pickup tubes, color LCD televisions, etc. by mixing with yellow or magenta dye to form a green or blue filter. can also be used.

At least in the above applications, the dye of the present invention has an extremely good hue as a cyan dye, and has a molar extinction coefficient (
ε) is also high.

Compared to known phenolic and naphthol-based indoaniline cyan dyes, the dye of the present invention has a sharply cut tail on the short wavelength side of the spectral transmittance curve in hue, and therefore the sub-absorption in the linear region is greatly reduced. , there is little irregular absorption, and the molar absorption coefficient in the red region is about twice as large. It also has good light fastness and heat resistance, and has extremely favorable properties in terms of color reproduction for color photography based on the subtractive color method.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example 1 Exemplary compounds (4), (9), (16) of the dye of the present invention,
For (36) and (47), the results of measuring the absorption spectra in the visible light region in ethyl acetate solvent are shown in the table below. , is defined as the difference between the wavelength λs (0,2) on the short wave side at which the absorbance is 20% of the absorbance at λmax and λmax, that is, Δλ(0,2)−λmax−λs(0,2).

As mentioned above, the novel imidazole dye of the present invention is 640
It has an absorption maximum at ~700 nm, and is found to be useful as a dye for cyan image formation and as a near-infrared dye.

Example 2 A coloring agent layer coating solution using a dispersion A having the following composition was coated on a polyethylene terephthalate film base having a thickness of 6 μM using a wire bar and dried to prepare a thermal transfer recording medium sample 1. Next, in place of the comparative dye (A), compounds (4), (5), (7), (9) and (20) of the present invention were used.
Samples 2, 3, 4, 5, and 6 were prepared in the same manner as sample 1 using .

(Dispersion A) Comparative dye (A) Ig and tricresyl phosphate 0.
After dissolving 5 g in 3 ml of ethyl acetate, 12 ml of a 10% gelatin aqueous solution (plus 4.5 mQ of a 3,75% Alkanol , heat to about 80°C to remove ethyl acetate, add water and bring the total volume to 30ml.
It was set as 2.

Each sample obtained was thermally transferred onto plain paper using a thermal head. The heating time is constant, and the heating section is set at 100°C.
It was varied in the range of ~200°C. FIG. 1 shows the relationship between transfer temperature and transfer density.

As is clear from FIG. 1, according to the present invention, a significant increase in sensitivity can be achieved even in thermal transfer.

Comparative dye (A)

[Brief explanation of the drawing]

FIG. 1 is a temperature-density curve when thermal transfer was performed using the thermosensitive recording medium in Example 2.

Claims (1)

[Claims] An imidazole dye characterized by being represented by the following general formula [I]. General formula [I] ▲ Numerical formulas, chemical formulas, tables, etc. may form a ring. R_3, R_4, R_5 and R_6 each represent a halogen atom, an amide group, an alkyl group, a substituted alkyl group, an alkoxy group, or a substituted alkoxy group, R_7 represents a monovalent organic group, and n is an integer of 0 to 4. represent. When n is 2 or more, the plurality of R_7s may be the same or different. B
represents an organic group bonded to the imidazole ring via a carbon, nitrogen, oxygen or sulfur atom or directly. ]