JPS61268761A - Naphthoquinone-based green dyestuff and its preparation - Google Patents

Abstract

NEW MATERIAL:A compound of formula I [R and R' are each lower alkyl, cycloalkyl, lower alkoxyalkyl, hydroxyalkyl, cyanoalkyl, alkoxycarbonylalkyl or (substituted)aryl; n is 1-2]. EXAMPLE:A compound of formula II. USE:Laser-ray recording materials, heat-sensitive transfer recording materials, color filters, and dyestuffs for liquid crystal display materials. PREPARATION:A compound of formula III (e.g., 4,8-ditoluidino-1,4-naphtho quinone) is made to react, in the presence of ammonium bicarbonate, with sodium cyanide or potassium cyanide in a non-protonic polar solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application The present invention provides compounds of formula (I) [in formula [11], R and R' are each independently a lower alkyl group, a cycloalkyl group, a lower alkoxyalkyl group, a hydroxyalkyl group, Represents a cyanoalkyl group, an alkoxycarbonylalkyl group, or a substituted or unsubstituted aryl group. n is an integer of 1 to 2. ] The present invention relates to a naphthoquinone-based green pigment represented by the following formula and a method for producing the same.

The dye according to the present invention can be used as a dye for color filters used in color solid-state imaging devices, color imaging devices such as color image pickup tubes, laser devices, dyes for laser light recording materials, and furthermore, for televisions. It is a useful new dye that can be expected to be effective when used as a dye for thermal transfer recording to obtain flat color hard copies such as color facsimiles, or as a liquid crystal dye for liquid crystal color display using a guest-host system.

The present invention also provides a method for producing a dye having these useful uses.

Conventional technology and problems Color filters used in color image pickup devices such as color image pickup tubes and color solid-state image pickup devices or laser devices have traditionally been made of water-soluble polymeric substances such as gelatin. Durability was insufficient. Therefore,
Recently, durable base materials such as glass having a porous layer of oil-soluble polymers or inorganic substances such as alumina and silica have been used. However, there has been no green dye that colors these substrates and has excellent spectral properties as a filter dye.

In addition, dyes for optical recording materials that use laser beams must not only have high absorption in the near-infrared region and be chemically stable, but also be easy to form a film because they are usually used in the form of a film. However, there was no dye that could satisfy these requirements. For example, known cyanine dyes become chemically unstable when their molecular chains are lengthened to increase near-infrared absorption, and metal phthalocyanine dyes become amorphous when they form a film, resulting in long-term stability. , had crystallization problems.

In addition, dyes for transfer printing of polyester fibers have conventionally been used as dyes for thermal recording, but their coloring power is poor due to their low sublimation properties, and sufficient color density cannot be obtained with the thermal energy of a normal thermal recording head. Furthermore, among dichroic dyes used as liquid crystal dyes, a green dye with a large dichroic ratio and absorption in the vicinity of 650 to 750 nm has not yet been found.

Method for Solving the Problems Based on the above circumstances, the present inventors have discovered that the dye represented by the following general formula (I) has excellent thermal stability, sublimation property, and compatibility with resins, etc. When used as a dye for color filters, it has excellent spectral properties; when used for laser light recording, it has excellent film-forming properties; and when used as a dye for thermal transfer recording, it has appropriate sublimation properties. It is oil-soluble and produces clear images. In addition, when used as a dye for liquid crystals, it has a high dichroic ratio, so it has been found that it can also be used for color liquid crystal display panels with good contrast. It represents a cycloalkyl group, a lower alkoxyalkyl group, a hydroxyalkyl group, a cyanoalkyl group, an alkoxycarbonylalkyl group, or a substituted or unsubstituted aryl group. n
is an integer between 1 and 2. ].

The alkyl group in the above formula fl according to the present invention represents a linear or branched alkyl group having 1 to 10 carbon atoms, the cycloalkyl group represents a cyclohexyl group, a cyclopentyl group, a cyclohebutyl group, and an alkoxyalkyl group Examples include ethoxymethyl group, methoxyethyl group, ethoxyethyl group, 1so-propoxyethyl group, n-butoxyethyl group, hexyloxyethyl group, r-methoxypropyl group, 3-methoxybutyl group, etc. 2-hydroxyethyl group, benzyl group, phenylethyl group, and substituted or unsubstituted 7-aryl group such as phenyl group, 4-methylphenyl group, 3-methylphenyl group, 2-methylphenyl group, 3.4-dimethylphenyl group. a phenyl group substituted with an alkyl group having 1 to 6 carbon atoms such as a group, 4
-methoxyphenyl group, 4-ethoxyphenyl group, 2-
Examples include methoxyphenyl group, alkoxy group-substituted phenyl group having 1 to G carbon atoms, trifluoromethylphenyl group, halogenated phenyl group, nitrophenyl group, etc.C-!
6 t'L 6. Layer These dyes of the present invention are prepared by treating the corresponding 4,8-disubstituted-1,5 naphthoquinones, which are extruded raw materials, with an aprotic polar solvent such as 1 to 20 times by weight dimethyl sulfoxide or N,N-dimethylformamide. 1 to 1 of ammonium bicarbonate after dissolving or suspending in
of sodium cyanide or potassium cyanide in the presence of 0 molar ratio
It can be obtained by adding 10 molar ratios and heating and reacting at 40 to 100°C. Subsequently, the reaction solution was discharged to a volume 5 to 100 times that of water or alcohol, subjected to oxidation treatment, and then filtered, washed with water, and dried to obtain formula CI).
The compound is purified and separated into monocyano compound and dicyano compound by column chromatography or thin layer chromatography.

The color filter may be produced using the dye of the present invention using known methods, such as coating alumina gel on glass and baking it, a transparent substrate coated with resin, or using polyester, polyvinyl chloride, polystyrene, etc. , a method of sublimating the dye of the invention under reduced pressure using a transparent film substrate such as polyacrylonitrile to color the substrate, a method of applying a solution or dispersion of the dye of the invention to the substrate and coloring it by heating, or There is a method of immersing a substrate in a solution or dispersion of the dye of the present invention to color it.

When the dye of the present invention is used in a laser beam recording material, the dye of the present invention may be deposited on a substrate by a known method, for example, as described in JP-A-50-15458, or the dye of the present invention may be deposited in an organic solvent. There is a method of forming a pigment film by dissolving and applying the pigment.

When applying the dye of the present invention to thermal transfer recording, the dye of the present invention is mixed with a suitable resin, solvent, water, etc. to prepare an ink, and the ink is applied onto a suitable substrate. When the coated transfer sheet is placed on a recording medium and heated and pressed from the back side of the sheet using a heat-sensitive recording head, the dye on the transfer sheet is transferred onto the recording medium and a recording is obtained.

Furthermore, when the dye of the present invention is used in a liquid crystal color display material, it can be used in commonly used display devices. For example, trans-4-n-propyl-(4-cyanophenyl)-cyclohexane, trans-4-n-pentyl-(
4-cyanophenyl)-cyclohexane, trans-4
Cyclohexane-based liquid crystal mixtures such as -n-hebutyl-(4-cyanophenyl)-cyclohexane and trans-4-n-pentyl-(4'-cyanobiphenyl)-cyclohexane (for example, Merck & Co. product code ZLI-1132,
Liquid crystal 1 such as ZLI-1840): Add and dissolve the dye of the present invention at a concentration of 0.01 to 10% by weight, and pre-process to align parallel or perpendicular to the transparent electrode surface of the liquid crystal display device. [Example-1] 12 g of 4.8-di-toluidino-1 #4-naphthoquinone
4.9 g of ammonium monocarbonate, 7.4 I of sodium cyanide, and 100 g of dimethyl sulfoxide were mixed and reacted at 90 to 95° C. for 3 hours.

Drain the reaction solution into water 3oo, 9, separate the discharged crystals,
Dry. Yield sin The crystals were separated by column to isolate 31 purified products of the following formulas and (2).

The infrared absorption spectra (KBr tablet method) of the above-isolated compounds and the 011 compound are shown in Figures 1 and 2, respectively. In addition, the molecular weights of compounds (5) and CB) were determined by mass NMR.
The spectrum is shown below.

Solid compound λmaxw 720 nm (in chloroform) NMR spectrum 6 (in CDC13) 2.4 (s, 6H), 3.
3 (s, IH), 5.3 (s, IH), 6.95 (d
, IH), 7.2 (m, 8H), 7.5 (d, IH),
7.85 (s, iH), ppm 03) Compound λmax - 740 nm (in chloroform) NMR spectrum ip (in CDCA! 3) 2.36 (s, 3
H), 2.44 (s, 3H), 6.9 (a, IH),
7.0-7.4 (m, 8H), 7.5 (d, IH),
ppm To prepare a laser beam permanent recording medium, the pigments of each of the above compounds were placed in a resistance heating container made of molybdenum and deposited on an acrylic plate under vacuum and heating. The resulting film had good physical properties such as reflectance, transmittance, and absorption, and no aggregation was observed in the film when it came into contact with air or moisture, indicating that it could be used indefinitely.

[Example-2] Synthesis was performed using 4,8-di-anindino-1,5-naphthoquinone in place of 4,8-di-toluidino-1,5-naphthoquinone in Example-1, and a dye of the following formula was synthesized. was separated on a column to obtain 4I.

A transfer sheet coated with an ink prepared by mixing the above dye with ethyl cellulose and isopropanol according to a conventional method is applied to the coated surface of image receiving paper using a conventional thermal transfer recording method. When the coated surfaces of the sheets were overlapped and thermal transfer recording was performed using a heating head, clear recording was obtained.

[Example 3] A green color filter was obtained by sublimating and coloring a base material made by firing glass coated with alumina gel under reduced pressure with the dye of [Example 3].

This filter has good spectral characteristics of transmitted light and durability as a filter.

The compound of the above formula was synthesized in the same manner as in Example 1, and the above dye purified by column chromatography was used. The λmaxc of this dye (in chloroform) is 710
nm,; (The transmittance in chloroform is 400 nm.
Unfortunately, 18% at 440 nm, 64 at 545Hm, 62
It was 20 units at 0 nm and 2 units at 700 nm.

[Example-4] The dye of the 031 compound of Example-1 was placed in a small beaker using Merck's liquid crystal ZLI-18.
40,100 parts of the above dyes O and S were added and heated to about 80°C to form a completely clear solution.

After the contents were left to cool, the colored liquid crystal solution was sealed inside a liquid crystal display element.

This display device showed a blue-green color when no voltage was applied, and only the electrode portions became colorless when a voltage was applied, showing good contrast. Further, the dichroic ratio was 10.0 at a maximum absorption wavelength of 725 nm.

[Examples 5 to 15] Synthesis was performed in the same manner as in Example-1, and the compounds shown in the table below were isolated. Each λm1LX is shown.

(Left below) 5 -(n)-C4H9-(n)-C4H971
07-C3H60CH3-C3H60CH37158-
C2H4CN -C2H4CN
7G09 -CHz -
CHz 7101o-C
) Ia -(n)-C4H9712 [Examples 16 to 26] Synthesized in the same manner as in Example-1, and the compounds shown in the table below were isolated. Indicates each entry (nax).

(Left below) 18 -C3H60CH3-Cs Hs OCH
374519-C2H4CN-C2H4C
N7252G-CN5
-CN5 73021
-CN5-(n)-04Hg
730

[Brief explanation of the drawing]

Figures 1 and 2 are infrared absorption spectra (KBr tablet method) of the dye according to the present invention. Figure 1 shows the absorption spectrum of the Al compound in Example 1. Figure 2 shows the absorption spectrum of the compound in Example 1.

Claims (1)

[Claims] 1 General formula (I) ▲ Includes mathematical formulas, chemical formulas, tables, etc. ▼ (I) [In formula (I), R and R' each independently represent a lower alkyl group, a cycloalkyl group, or a lower alkoxy It represents an alkyl group, a hydroxyalkyl group, a cyanoalkyl group, an alkoxycarbonylalkyl group, or a substituted or unsubstituted aryl group. n is an integer of 1 to 2. ] Naphthoquinone green dye 2 represented by General formula (II) ▲Mathematical formulas, chemical formulas, tables, etc.▼(II) [In formula (II), R and R' each independently represent a lower alkyl group, a cycloalkyl group, It represents a lower alkoxyalkyl group, a hydroxyalkyl group, a cyanoalkyl group, an alkoxycarbonylalkyl group, or a substituted or unsubstituted aryl group. ] The general formula (I) is characterized by reacting the compound represented by with sodium cyanide or potassium cyanide in an aprotic polar solvent in the presence of ammonium bicarbonate. ) [In formula (I), R and R' each represent the same meaning as R and R' in formula (II). n is an integer of 1 to 2. ] A method for producing a naphthoquinone-based green pigment. 3. The dye according to claim (1), wherein the dye represented by formula (I) is used in a laser beam recording material. 4. The dye according to claim (1), wherein the dye represented by formula (I) is used in a heat-sensitive transfer recording material. 5. The dye according to claim (1), wherein the dye represented by formula (I) is used in a color filter material. 6. The dye according to claim (1), wherein the dye represented by formula (I) is used in a liquid crystal display material.