JP6264763B2 - Pyrazolone dye - Google Patents

Description

The present invention relates to a novel pyrazolone dye.

Many pyrazolone dyes have been synthesized so far and their usefulness has been confirmed and widely used. In recent years, it has been widely applied to various uses such as photographic photosensitive materials, thermal transfer recording materials, color toners, optical recording media, and ink jets.

In addition, the performance required for the above applications includes, for example, favorable spectral characteristics for color reproduction, solubility in a desired organic solvent, large molecular extinction coefficient, and robustness to light and heat. In addition, it is robust to various chemicals, easy to synthesize, and safe.

On the other hand, many pyrazolone dyes have been proposed for the purpose of improving these, for example, although improvement of light and heat fastness has been proposed (Patent Documents 1 to 4), the solubility was insufficient. Further improvements were desired.

Moreover, although the improvement of solvent solubility is proposed (patent document 5), since it is inferior to heat resistance, the further improvement is strongly desired about heat fastness.
JP 2006-15668 A JP 2006-63171 A JP-A-9-226259 Japanese Patent Laid-Open No. 10-62978 JP 2006-16564 A

An object of the present invention is to provide a novel pyrazolone dye having high heat fastness and high solubility.

As a result of intensive studies, the present inventors have found that the above problems can be achieved by the following configuration.

（一般式（１）中、Ｒ_１は分岐アルキル基を表す。Ｒ_２は複素環基を表す。Ｒ_３は炭素数が２以上のアルキル基又はアリール基を表す。Ｘは―Ｏ―を表す。） 1. A pyrazolone dye represented by the following general formula (1):

(In General Formula (1), R ₁ represents a branched alkyl group, R ₂ represents a heterocyclic group, R ₃ represents an alkyl group or aryl group having 2 or more carbon atoms, and X represents —O—. .)

（一般式（２）中、Ｒ_１２は複素環基を表す。Ｒ_１３は炭素数が２以上のアルキル基又はアリール基を表す。） 2. Formula pyrazolone dye represented by formula (1) is, pyrazolone dyes described in paragraph 1, characterized in that the pyrazolone dye represented by the following general formula (2).

(In the general formula (2), R ₁₂ is table to a heterocyclic group. _{R 13} represents 2 or more alkyl groups or aryl group carbon atoms.)

3. In formula (1) and (2), R ₂ or _{R 12} is the first term or pyrazolone dyes described in paragraph 2, characterized in that a pyridine ring group.

According to the present invention, a novel pyrazolone dye having high heat fastness and light fastness, excellent color tone and high solubility can be provided.

The present invention will be described in detail below.

The present invention is a dye represented by the general formula (1).

In general formula (1), R1 represents a branched alkyl group.

Examples of the branched alkyl group include an iso-propyl group, a tert-butyl group, an iso-butyl group, a sec-butyl group, a neo-pentyl group, and a tert-amyl group, preferably an iso-propyl group, A tert-butyl group, most preferably a tert-butyl group.

When R1 becomes bulky, the heat resistance and solubility of the dye are improved.

In the general formulas (1) and (2), R2 or R12 represents a heterocyclic group.

Examples of the heterocyclic ring include a pyridine ring, a pyrazole ring, an imidazole ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a thiazole ring, an oxazole ring, a quinoline ring, a benzothiazole ring, and a benzoxazole ring. More preferred are a pyridine ring, pyrazole ring, imidazole ring, pyrazine ring and pyrimidine ring, and most preferred is a pyridine ring.

When R2 or R12 is a heterocyclic ring, it contributes to heat resistance.

In the general formulas (1) and (2), R3 or R13 represents an alkyl group or aryl group having 2 or more carbon atoms.

Examples of the alkyl group include an ethyl group, a propyl group, an iso-propyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a dodecyl group, a tridecyl group, a tetradecyl group, and a pentadecyl group, and an aryl group. Examples thereof include a phenyl group and a naphthyl group.

Preferably, it is an alkyl group. Among the alkyl groups, more preferred are a propyl group, an iso-propyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a dodecyl group, a tridecyl group, a tetradecyl group, and a pentadecyl group, and most preferred is the number of carbon atoms. Is from 3 to 6.

In general formula (1), X represents —O— .

As an alkyl group, the group similar to the alkyl group in said R3 or R13 can be mentioned.

Specific examples of the pyrazolone dyes of the present invention represented by the general formulas (1) and (2) are shown below, but the present invention is not limited thereto. However, among exemplary dyes, 37, 38, 39, 41, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 56 and 60 are reference examples.

Typical examples of the synthesis of the present dye are shown below, but these are described in JP-A-10-60296, 2006-16564, 2006-63171, etc., “The Cyanine Dyes and Related Compounds”, F.C. It can be synthesized with reference to conventionally known methods described in Hamer, Interscience Publishers, 1964.

Example 1 Synthesis of Illustrative Dye 2

10.0 g of Compound 1 and 5.1 g of Compound 2 were added to 30 ml of acetonitrile, and a mixed solution of 2.2 g of acetic anhydride and 4.4 g of triethylamine was added dropwise with stirring at an internal temperature of 45 ° C. After completion of the dropwise addition, acetonitrile was removed under reduced pressure, and the resulting residue was dissolved in ethyl acetate, washed with water, concentrated, and the obtained residue was washed with a mixed solution of methanol and water and dried to give an orange solid. 6.7 g was obtained.

1H-NMR of the obtained solid was as follows and was confirmed to be Exemplified Dye 2. The yield was 75%. The absorption maximum of the obtained dye in the ethyl acetate solution was 456 nm.

1H-NMR (400 MHz, deuterium dichloromethane, δ (ppm)): 0.98 (t, 3H), 1.45 (m, 2H), 1.51 (s, 9H), 1.87 (m, 2H) ), 4.01 (t, 2H), 7.02 (t, 1H), 7.13 (d, 1H), 7.24-7.35 (m, 3H), 7.43 (d, 1H) 7.71 (t, 1 H), 8.12 (d, 1 H), 8.20 (d, 1 H), 8.55 (d, 1 H)

５０ｇの２−メチルベンゾイミダゾールと１２４．４ｇのｔｅｒｔ−ブチルブロミドを内温８０℃で二時間攪拌した。攪拌終了後、減圧下でｔｅｒｔ−ブチルブロミドを取り除き、得られた油状物を５６ｍｌのアセトニトリルに溶解し、５３ｍｌの無水酢酸、８９．１ｇのジフェニルホルムアミドを加え、内温７０℃で３時間攪拌した。攪拌終了後、エタノールを投入し、結析、濾過、乾燥し黄色固体（化合物３）を１４２ｇ得た。 Example 2 Synthesis of Intermediate (Compound 3) of Illustrative Dye 44

50 g of 2-methylbenzimidazole and 124.4 g of tert-butyl bromide were stirred at an internal temperature of 80 ° C. for 2 hours. After completion of the stirring, tert-butyl bromide was removed under reduced pressure, and the resulting oil was dissolved in 56 ml of acetonitrile, 53 ml of acetic anhydride and 89.1 g of diphenylformamide were added, and the mixture was stirred at an internal temperature of 70 ° C. for 3 hours. . After completion of the stirring, ethanol was added thereto, followed by precipitation, filtration and drying to obtain 142 g of a yellow solid (compound 3).

アセトニトリル３０ｍｌに、１０．０ｇの化合物３、４．６ｇの化合物２を加え、内温４５℃で攪拌しながら、無水酢酸２．２ｇとトリエチルアミン４．４ｇの混合溶液を滴下した。滴下終了後減圧下でアセトニトリルを取り除いた後、得られた残渣を酢酸エチルに溶かし、水洗、濃縮後、得られた残渣をメタノールと水の混合溶液で洗浄し、乾燥させて、橙色の固体を５．０ｇ得た。得られた固体の１Ｈ−ＮＭＲスペクトルによる分析結果より例示色素４４であることが確認された。結果を表１に示す。 Example 3 Synthesis of Illustrative Dye 44

10.0 g of Compound 3 and 4.6 g of Compound 2 were added to 30 ml of acetonitrile, and a mixed solution of 2.2 g of acetic anhydride and 4.4 g of triethylamine was added dropwise with stirring at an internal temperature of 45 ° C. After completion of the dropwise addition, acetonitrile was removed under reduced pressure, and the resulting residue was dissolved in ethyl acetate, washed with water, concentrated, and the obtained residue was washed with a mixed solution of methanol and water and dried to give an orange solid. 5.0 g was obtained. From the analysis result of the obtained solid by 1H-NMR spectrum, it was confirmed to be Exemplified Dye 44. The results are shown in Table 1.

Exemplified dye 4, Exemplified dye 20, and Exemplified dye 27 were obtained by the same operation as Exemplified dye 2. Each result is shown in Table 1 below.

Example 4
The pyrazolone dye of the present invention is dissolved in a 1: 1 mixed solution of toluene and M EK, and the resulting colored solution is a synthetic paper having a thickness of 150 μm (Yupo FPG-150: manufactured by Oji Oil Chemical Co., Ltd.). )
A coated sample was prepared by applying and drying each with a wet film thickness of 60 μm. By adjusting the dye concentration of each solution, the concentration is 1
The following coating samples were prepared, and the following performance was evaluated for these coating samples.

<< Solubility >>
The dye was dissolved in a 1: 1 mixed solution of toluene and M EK so as to have a concentration of 3% by mass, and the solubility was evaluated by visual evaluation based on the following evaluation criteria.

◎: Completely dissolved immediately ○: Completely dissolved by shaking overnight at room temperature △: Completely dissolved by heating ×: Undissolved residue present ○ More than or equal to desirable.

《Light resistance》
About the sample after 120 hours exposure with a xenon fade meter, the rate of decrease from the reflection spectrum concentration at the maximum absorption wavelength in the visible region of the unexposed sample was evaluated.

Light resistance (%) = (Maximum absorption wavelength concentration of exposed sample / Maximum absorption wavelength concentration of unexposed sample) × 10 0, 4 based on the following evaluation criteria
Graded.

◎: Light resistance is 95% or more ○: Light resistance is 90% or more and less than 95% △: Light resistance is 80% or more and less than 90% ×: Light resistance is less than 80% ○ or more There is no practical problem.

"Heat-resistant"
It was stored for 7 days under conditions of 77 ° C. and 10% RH or less, and the rate of decrease from the concentration ratio before and after the start of storage was evaluated.

Heat resistance (%) = (concentration after storage / concentration before storage start) × 100, and evaluated based on the following standard criteria.

◎: Heat resistance is 95% or more ○: Heat resistance is 80% or more and less than 95% △: Heat resistance is 60% or more and less than 80% ×: Heat resistance is less than 60% ○ or more There is no practical problem.

《Color tone》
The color tone of each coated sample was visually evaluated as yellow, and evaluated in four stages as follows.

◎: Remarkably vivid color ○: Vivid color △: Dull color ×: Dirty color ○ It is desirable that it is more than the above.

Comparative dye

As shown in Table 2, it was found that the dye of the present invention was superior in solubility, light resistance and color tone as compared with the comparative example. In particular, if there is a branched alkyl group such as tert-butyl at the 5-position of the pyrazolone site, or if the N-position substituent of the benzoxazole or imidazole site has 2 or more carbon atoms, solubility, light resistance, and heat resistance In addition, when the N-substituted site of pyrazolone was made a heterocyclic ring, a dye having excellent color tone was obtained. And when these were combined, it turned out that it is excellent in especially solubility, light resistance, heat resistance, and a color tone.

Claims (3)

A pyrazolone dye represented by the following general formula (1):

(In General Formula (1), R ₁ represents a branched alkyl group, R ₂ represents a heterocyclic group, R ₃ represents an alkyl group or aryl group having 2 or more carbon atoms, and X represents —O—. .) The pyrazolone dye according to claim 1, wherein the pyrazolone dye represented by the general formula (1) is a pyrazolone dye represented by the following general formula (2).

(In general formula (2), R ₁₂ represents a heterocyclic group. R ₁₃ represents an alkyl group or aryl group having 2 or more carbon atoms.) The pyrazolone dye according to claim 1 or 2, wherein in the general formulas (1) and (2), R ₂ or R ₁₂ is a pyridine ring group.