JP2007084686A - Organic pigment using 4- benzylidene hydantoin derivative - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic pigment which has an absorption band corresponding to the so-called blue laser, has high solubility in organic solvents such as cellosolve-based solvents, hardly crystallizes even in a solvent-evaporating time in a thin film-forming process such as casting, and is suitable for being used for optically recording media for blue lasers. <P>SOLUTION: This organic pigment uses a 4-benzylidene hydrantoin derivative of the general formula (A) as a new compound. Especially the compound having 2-ethylhexyl group as a substituent has large solubility in the cellosolve-based solvents. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a compound of an organic dye using a 4-benzylidenehydantoin derivative that absorbs a blue to violet region, and also relates to a novel 4-benzylidenehydantoin derivative compound. More specifically, the present invention relates to an organic dye suitable for a so-called blue laser wavelength region and a novel compound.

  Currently, so-called red lasers are widely used for writing and reading media on CD-R / RW, DVD-R / RW, MO, and the like. The medium used for this is coated on the surface with a dye that absorbs a wavelength corresponding to the wavelength of the red laser. There are inorganic dyes and organic dyes, but organic dyes are generally used because of their advantages such as high response speed.

  On the other hand, recently, development of equipment using a so-called blue laser has been advanced in order to enable higher density recording. The dye used for the blue laser medium must be a dye that efficiently absorbs wavelengths near 405 nm to accommodate the wavelength of the laser. As such pigments, several inorganic pigments are currently being developed for practical use.

However, in order to be able to cope with high-speed recording by a laser, an organic dye having a quick response is preferable as a dye used for the medium, not an inorganic dye. Examples of compounds having absorption in such a wavelength region include pyran compound derivatives, polyacene diimide dye derivatives, and cyanine organic dyes as the basic skeleton of organic dyes described in Patent Documents 1 to 5, for example. A mixture, a method using a benzene derivative having a specific amino group introduced at the para-position of the methine group, and the like have been proposed.
JP 2004-322564 A JP 2004-090372 A JP 2003-266554 A JP 2003-246142 A JP 2003-103935 A

  As a method of using such an organic dye for an optical recording medium or the like, a method in which an organic dye is dissolved in a solvent and a thin film containing the organic dye is formed by a casting method or the like is general. As the solvent, a cellosolve solvent such as methyl cellosolve is generally used.

  However, the organic dyes as described above are easily crystallized when the solvent is volatilized after casting, which causes defects. Further, the organic dye has insufficient solubility in the cellosolve solvent, and the organic dye tends to disperse unevenly.

Ｒ_１〜Ｒ_３は、水素原子、ハロゲン、シアノ基、ニトロ基、ヒドロキシル基、アミノ基、カルボキシル基、カルボキシアルキル基、炭素数１〜２０のアルコキシ基（いずれかで枝分かれしているものを含む）、炭素数１〜２０のアルキルオキシカルボニル基のうち、いずれかの官能基または原子であり、
Ｒ_４は、水素原子、炭素数１〜２０のアルキル基（いずれかで枝分かれしているものを含む）、炭素数１〜３のカルボキシアルキル基のうち、いずれかの官能基または原子である。 In the present invention, among the 4-benzylidenehydantoin derivatives represented by the general formula (A) shown in the following (Chemical Formula 1), R _{1 to} R ₄ in the formula (A) are any of the following functional groups or atoms, respectively. The use of a compound containing a 4-benzylidenehydantoin derivative as an organic dye is a main means for solving the above problems.

R _{1 to} R ₃ are each a hydrogen atom, a halogen, a cyano group, a nitro group, a hydroxyl group, an amino group, a carboxyl group, a carboxyalkyl group, or an alkoxy group having 1 to 20 carbon atoms (including those branched by any one). ), Any one of the alkyloxycarbonyl groups having 1 to 20 carbon atoms, or an atom,
R ₄ is any functional group or atom among a hydrogen atom, an alkyl group having 1 to 20 carbon atoms (including any branched one), and a carboxyalkyl group having 1 to 3 carbon atoms.

  The organic dye of the present invention has an absorber suitable for a so-called blue laser, is hardly crystallized even when the organic solvent volatilizes after forming a thin film by a casting method or the like, and has excellent solubility in a cellosolve solvent. Is.

化合物（ｂ）

Among them, compounds having 2-ethylhexyl ester as a substituent, such as compounds (a) and (b) of the following (Chemical Formula 3 and Chemical Formula 4), are further improved in solubility in various solvents such as cellosolve solvents. Therefore, with the organic dyes using the following compounds (a) and (b), a coating state can be easily formed even by a single casting.
Compound (a)

Compound (b)

化合物（ｄ）

In addition to the above compounds (a) to (b), among the compounds of the present invention, the following compounds (c) to (d) are difficult to crystallize even when the organic solvent volatilizes, and to the cellosolve solvent. It has also been experimentally clarified that the organic dye compound is excellent in solubility.
Compound (c)

Compound (d)

  Furthermore, the organic pigment | dye of this invention can be formed into a film on a board | substrate not only by wet application like the said casting method but by a vapor deposition method and sputtering method.

  The present invention will be described in detail below. In the present invention, an organic compound represented by the following general formula (A) is used as the organic dye. The compound represented by the general formula (A) will be described below.

(A) In formula, R < ₁ > -R < ₄ > represents a hydrogen atom or arbitrary substituents each independently, and arbitrary substituents may be further substituted. Examples of the optional substituent include R _{1 to} R ₃ as halogens such as fluorine, chlorine and bromine; methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert- A linear or branched alkyl group having 1 to 20 carbon atoms which may be substituted such as butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group; hydroxy group, methoxy group, ethoxy group, propoxy group, 1 to 1 carbon atoms which may be substituted such as isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, n-hexyloxy group, n-octyloxy group and 2-ethylhexyloxy group 20 linear or branched alkyloxy groups; amino group, monomethylamino group, dimethylamino group, monoethylamino group, diethylamino group, mono-n-propylamino group Group, di-n-propylamino group, monoisopropylamino group, diisopropylamino group and the like, an optionally substituted linear or branched amino group having 1 to 4 carbon atoms; carboxyl group, methoxycarbonyl group, ethoxycarbonyl group, iso Substitution of propoxycarbonyl group, n-butoxycarbonyl group, isobutoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, n-hexyloxycarbonyl group, n-octyloxycarbonyl group, 2-ethylhexyloxycarbonyl group, etc. A linear or branched carboxylic acid ester group having 1 to 20 carbon atoms; a cyano group; a nitro group, and the like.

Examples of the optional substituent include R _{4 as} a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-hexyl group, and an n-octyl group. A linear or branched alkyl group having 1 to 20 carbon atoms which may be substituted, such as 2-ethylhexyl group; an alkyl carboxyl group represented by —R ₅ COOH in the following (Chemical Formula 7 to Chemical Formula 9); alkyl carboxylic acid ester groups of the following represented by _-R 5 COOR ₆ in 10 of 19) and the like.

Alkyl carboxyl group (—R ₅ COOH)

Alkylcarboxylic acid ester (—R ₅ COOR ₆ )

  Among them, a compound having a 2-ethylhexyl ester group as a substituent is excellent in solubility in various solvents and has an excellent characteristic that it is difficult to crystallize after being coated on a substrate and dried. I understood. This seems to be the effect of introducing a bulky 2-ethylhexyl group or the like as a substituent. Specific examples of such a compound having particularly good characteristics include the above-mentioned compounds (a) and (b).

The compound of the present invention represented by the general formula (A) can be synthesized, for example, through the reaction formula shown in the following (Chemical Formula 20).

  An equimolar amount of hydantoin or a compound derived therefrom, benzaldehyde or a compound derived from benzaldehyde, and water are mixed and reacted at 90-100 ° C. for 5-6 hours in the presence of glycine and caustic soda. The precipitated crystals are filtered off, washed thoroughly with water, and washed with alcohol to obtain a compound having a high purity 4-benzylidenehydantoin derivative. Examples of the recrystallization solvent include, in addition to methyl isobutyl ketone, ketone solvents such as methyl ethyl ketone and cyclohexanone, cellosolves such as methyl cellosolve and ethyl cellosolve, and lower esters such as ethyl acetate and isopropyl acetate.

  As a method of forming and using the organic dye of the present invention, a vacuum deposition method, a sputtering method, a doctor blade method, a casting method, a spin coating method, an immersion method, etc. are common, but the spin coating method is desirable in terms of cost. .

  A coating solvent for coating by a doctor blade method, a cast method, a spin coating method, a dipping method, or the like is not particularly limited as long as it is a solvent that does not attack the substrate. Specifically, lower alcohols such as methanol, ethanol and isopropyl alcohol; ketone alcohol solvents such as diacetone alcohol and 3-hydroxy-3-methyl-2-butanone; cellosolv solvents such as methyl cellosolve and ethyl cellosolve; n -Chain hydrocarbon solvents such as hexane and n-heptane; Cyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane and ethylcyclohexane; Fluoroalkyl alcohol solvents such as tetrafluoropropanol and octafluoropentanol; Methyl lactate and lactic acid Examples thereof include hydroxycarboxylic acid ester solvents such as ethyl and methyl 2-hydroxyisobutyrate.

  The synthesis method of the compound used for the organic pigment | dye of this invention implemented by this invention and the characteristic of a compound are shown below. However, the synthesis method is not limited to this.

Example 1
(Synthesis of compounds)
Compound (c): Synthesis of 4-hydroxybenzylidenehydantoin

  Attach a condenser with a ball, a thermometer, and a stirrer to a 1 L four-neck flask, and p-hydroxybenzaldehyde 16.7 g (0.137 mol), hydantoin 13.7 g (0.137 mol), 32% NaOHaq 20.0 g (0.16 mol) Glycine (6.0 g, 0.08 mol) and water (70 mL) were mixed and stirred at 90 to 100 ° C. for 5 to 6 hours. After cooling, 500 ml of water was added and the mixture was adjusted to pH 6-7 with sulfuric acid. The solid was filtered off, washed well with water and washed with 2-propanol. Thereafter, 200 mL of 2-propanol was added and refluxed for 30 minutes to 1 hour. After cooling, the solid was collected by filtration, washed with 2-propanol, and 19.9 g of a pale yellow solid was obtained in a yield of 71% with a dryer at 60 ° C. The melting point was 300 ° C. or more, the 2-propanol solubility was less than 0.1 wt%, and the ethyl cellosolve solubility was 0.4 wt%.

Further, when the ultraviolet to visible absorption spectrum of compound (c) was measured, the maximum absorption wavelength λmax was 336 nm, and the absorbance ε at this time was 27500. The spectrum is shown in FIG. The spectrum measurement conditions are as follows.
<Measurement conditions>
Equipment: UV-2450 (manufactured by Shimadzu Corporation)
Measurement wavelength: 250-500nm
Note that the measurement conditions are the same under the same conditions in Example 2 and later.

Moreover, purity was measured by HPLC analysis.
Apparatus: LC-6A (manufactured by Shimadzu Corporation)
Column used: SUMPAX ODS A-212 5 μm 6 mmφ × 15 cm
Column temperature: 40 ° C
Mobile phase: acetonitrile: water: 0.1 M aqueous phosphoric acid solution = 4: 5: 1
Flow rate: 1.0 mL / min
<Measurement results>
HPLC area purity 99.9%

[Evaluation when coating film]
The compound (c) obtained above was adjusted to 0.4 wt% with respect to ethyl cellosolve. Next, a glass plate (7.5 cm × 2.5 cm, thickness about 1 mm) was attached to a polycarbonate disk (diameter 12 cm, thickness about 1.2 mm) and rotated at a rotational speed of 500 to 600 rpm. The ethyl cellosolve solution of the compound (c) prepared on the glass plate was dropped onto the rotating glass plate and applied by a spinner method. The glass plate which the compound (c) formed into a film and adhered by air-drying after application | coating was obtained. The crystallinity of the compound (c) formed into a film on the obtained glass plate was examined visually. Moreover, when the ultraviolet to visible light absorption spectrum when the film was formed was measured and the maximum absorption wavelength was determined, λmax was 343 nm.

(Example 2)
Compound (d); Synthesis of 3-methoxy-4-hydroxybenzylidenehydantoin

(Synthesis of compounds)
In the same manner as in Example 1, 15.2 g (0.10 mol) of vanillin, 10.0 g (0.10 mol) of hydantoin, 15.0 g (0.16 mol) of 32% NaOHaq, 6.0 g (0.08 mol) of glycine, and 50 mL of water were mixed and reacted. 16.6 g of a pale yellow solid was obtained with a yield of 71%. The melting point was 264.2 to 265.7 ° C., the solubility of 2-propanol was less than 0.1 wt%, and the solubility of ethyl cellosolve was 0.6 wt%.

  Further, when the ultraviolet to visible absorption spectrum of the compound (d) was measured, it was found that λmax was 345 nm and ε at this time was 24600. The spectrum is shown in FIG.

Moreover, purity was measured by HPLC analysis. The measurement conditions are the same as in Example 1.
<Measurement results>
HPLC area purity 99.9%

[Evaluation when coating film]
The compound (d) obtained above was adjusted to 0.6 wt% with respect to ethyl cellosolve. Next, a glass plate (7.5 cm × 2.5 cm, thickness about 1 mm) was attached to a polycarbonate disk (diameter 12 cm, thickness about 1.2 mm) and rotated at a rotational speed of 500 to 600 rpm. The ethyl cellosolve solution of the compound (d) prepared on the glass plate was dropped onto the rotating glass plate and applied by a spinner method. The glass plate which the compound (d) formed into a film and adhered by air-drying after application | coating was obtained. The crystallinity of the compound (d) formed into a film on the obtained glass plate was examined visually. Further, when the film was formed into an ultraviolet to visible light absorption spectrum and the maximum absorption wavelength was determined, λmax was 356 nm.

(Example 3)
Synthesis of compound (a); synthesis of 5- {3-methoxy-4- (2-ethylhexyloxy) benzylidene} -3- (2-ethylhexyl) hydantoin

  Attach a condenser with a ball, a thermometer, and a stirrer to a 100 mL four-necked flask. 11.8 g (0.0854 mol) of anhydrous potassium carbonate and 60 mL of dimethylformamide were mixed and stirred at 100 to 110 ° C. for 5 to 6 hours. A 1-L four-necked flask was equipped with a condenser with a ball, a thermometer, and a stirrer, and 500 mL of water was added and cooled, and the cooled reaction oil was injected, extracted with diethyl ether, and thoroughly washed with water. After separation, the solvent was distilled off under reduced pressure, and the remainder was dissolved in methanol for crystallization. 4.3 g of white solid was obtained with a yield of 22.0%. Melting point was 90.5-91.5 ° C., 2-propanol solubility was 1.8 wt%, and ethyl cellosolve solubility was 5 wt% or more.

  Further, when the ultraviolet to visible absorption spectrum of the compound (a) was measured, it was found that λmax was 346 nm and ε at this time was 27600. The spectrum is shown in FIG.

Moreover, purity was measured by HPLC analysis.
<Measurement conditions>
Apparatus: LC-6A (manufactured by Shimadzu Corporation)
Column used: Develosil ph-7 4mmφ × 25cm
Column temperature: 40 ° C
Mobile phase: methanol: water = 95: 5
Flow rate: 1.0 mL / min.
<Measurement results>
HPLC area purity 91.4%

[Evaluation when coating film]
The compound (a) obtained above was adjusted to 0.2 wt% with respect to ethyl cellosolve. Next, a glass plate (7.5 cm × 2.5 cm, thickness about 1 mm) was attached to a polycarbonate disk (diameter 12 cm, thickness about 1.2 mm) and rotated at a rotational speed of 500 to 600 rpm. The ethyl cellosolve solution of the compound (a) prepared on the glass plate was dropped onto the rotating glass plate and applied by a spinner method. The glass plate which the compound (a) formed into a film and adhered by air-drying after application | coating was obtained. The crystallinity of the compound (a) formed into a film on the obtained glass plate was examined visually. Further, the ultraviolet to visible light absorption spectrum when the film was formed was measured, and the maximum absorption wavelength was determined. As a result, λmax was 346 nm.

Example 4
Compound (b): Synthesis of 3-methoxy-4- (2-ethylhexyloxy) benzylidenehydantoin

  A 300 mL four-necked flask is equipped with a moisture meter, a condenser with a ball, a thermometer, and a stirrer at the top, vanillin 30.4 g (0.20 mol), 2-ethylhexyl bromide 57.9 g (0.30 mol), sodium carbonate 21.2 g (0.20 mol), 18-crown 1.0 g, potassium iodide 5.0 g, polyethylene glycol 400 10.0 g, 4-methyl-2-pentanone 50 mL were mixed, and the mixture was stirred at 120-140 ° C. for 5-6 hours while separating the water. did. After filtration, the oil layer was washed with water, the solvent was distilled off under reduced pressure, and 4- (2-ethylhexyl) oxy-3-methoxybenzaldehyde was distilled at 20 mmHg150 ° C. to obtain a pale yellow transparent oil in a yield of 66%. 34.8 g was obtained. The purity of the HPLC surface was 96%. The measurement conditions are as follows.

Attach a condenser with a ball, a thermometer, and a stirrer to a 100 mL four-necked flask, hydantoin 10.0 g (0.10 mol), 4- (2-ethylhexyl) oxy-3-methoxybenzaldehyde
24.6 g (0.1 mol), sodium acetate 8.2 g (0.10 mol), acetic anhydride 20.4 g (0.2 mol) and acetic acid 30 mL were mixed and stirred at 130-140 ° C. for 8-9 hours. 2-propanol after cooling
Crystals were precipitated at 100 mL. 25.3 g of a light brown solid was obtained with a yield of 76.1%. Recrystallization from toluene gave a pale yellow solid. The decomposition point was 205.3 ° C., 2-propanol solubility was 0.5 wt%, and ethyl cellosolve solubility was 3.4 wt%.

  Further, when the ultraviolet to visible absorption spectrum of the compound (b) was measured, it was found that λmax was 344 nm and ε at this time was 24600. The spectrum is shown in FIG.

Moreover, purity was measured by HPLC analysis.
<Measurement conditions>
Apparatus: LC-6A (manufactured by Shimadzu Corporation)
Column used: Develosil ph-7 4mmφ × 25cm
Column temperature: 40 ° C
Mobile phase: methanol: water = 95: 5
Flow rate: 1.0 mL / min.
<Measurement results>
HPLC area percentage purity 98.3%

[Evaluation when coating film]
The compound (a) obtained above was adjusted to 0.2 wt% with respect to ethyl cellosolve. Next, a glass plate (7.5 cm × 2.5 cm, thickness about 1 mm) was attached to a polycarbonate disk (diameter 12 cm, thickness about 1.2 mm) and rotated at a rotational speed of 500 to 600 rpm. The ethyl cellosolve solution of the compound (a) prepared on the glass plate was dropped onto the rotating glass plate and applied by a spinner method. The glass plate which the compound (a) formed into a film and adhered by air-drying after application | coating was obtained. The crystallinity of the compound (a) formed into a film on the obtained glass plate was examined visually. Further, the ultraviolet to visible light absorption spectrum when the film was formed was measured, and the maximum absorption wavelength was determined. As a result, λmax was 346 nm.

(Infrared absorption spectrum)
For the compounds (a) to (d), an infrared absorption spectrum was also measured. The measurement conditions are as follows.
Apparatus: FTIR-8400S (manufactured by Shimadzu Corporation)
Sample: 1/200 (KBr)
Infrared absorption spectra of the compounds (a) to (h) measured under the above conditions are shown in FIGS.

(Evaluation)
The results of these evaluations are summarized in Table 1. In Table 1, IPA means 2-propanol (isopropyl alcohol), and EC means ethyl cellosolve.

いずれの化合物もエチルセロソルブに対する溶解度に優れるが、特に化合物（ａ）及び化合物（ｂ）の溶解度が大きいことが分かる。なお、化合物（ｂ）の塗布膜の結晶性があまりよくないが、不純物を除去し切れていないためではないかと考えられる。

Any compound is excellent in the solubility with respect to ethyl cellosolve, but it turns out that especially the solubility of a compound (a) and a compound (b) is large. Although the crystallinity of the coating film of compound (b) is not so good, it is considered that the impurities are not completely removed.

  The organic dye of the present invention can be used as a general coloring material, but can be suitably used as a dye for an optical recording medium using a so-called blue laser. Moreover, the compound used for these organic pigment | dyes of this invention can also be used as the ligand of a metal complex, and the organometallic complex which used the compound of this invention as the ligand can also be utilized suitably as an organic pigment | dye.

It is an ultraviolet-visible absorption spectrum of a compound (c) (Example 1). It is an ultraviolet-visible absorption spectrum of a compound (d) (Example 2). It is an ultraviolet-visible absorption spectrum of a compound (a) (Example 3). It is an ultraviolet-visible absorption spectrum of a compound (b) (Example 4). It is an infrared absorption spectrum of a compound (c) (Example 1). It is an infrared absorption spectrum of a compound (d) (Example 2). It is an infrared absorption spectrum of a compound (a) (Example 3). It is an infrared absorption spectrum of a compound (b) (Example 4).

Claims (3)

Among the 4-benzylidenehydantoin derivatives represented by the following general formula (A),
(1) An organic dye containing a 4-benzylidenehydantoin derivative in which R _{1 to} R ₄ in the formula are each _one of the following functional groups or atoms.

R _{1 to} R ₃ = hydrogen atom, halogen, cyano group, nitro group, hydroxyl group, amino group, carboxyl group, carboxyalkyl group, alkoxy group having 1 to 20 carbon atoms (what is branched at any position) C 1-20 alkyloxycarbonyl group R ₄ = hydrogen atom, C 1-20 alkyl group (including any branched one), C 1-3 carboxyalkyl group A 4-benzylidenehydantoin derivative compound in which R _{1 to} R ₄ in the general formula (A) are any combination among the combinations described in the following (a) to (b).
(a) R ₁ = H, R ₂ = OCH ₃ ,

(b) R ₁ , R ₄ = H, R ₂ = OCH ₃ ,

A 4-benzylidenehydantoin derivative compound in which R _{1 to} R ₄ in the general formula (A) are any combination among the combinations described in the following (c) to (d).
(c) R ₁ , R ₂ , R ₄ = H, R ₃ = OH
(d) R ₁ , R ₄ = H, R ₂ = OCH ₃ , R ₃ = OH

Images