JPH0749532B2 - Dye recovery method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for regenerating a dye recovered from a coating solution for solution coating used in the production of optical recording media such as optical cards and optical disks.

[0002]

2. Description of the Related Art A spray coating method, an electrostatic coating method, an electrodeposition coating method, a flow coating method, a dip coating method, a roll coating method, a brush coating method and the like are known as thin film forming methods by solution coating. It is also used in the manufacture of optical recording media. Among these, a spin coating method, which is a kind of flow coating method, is used for the recording layer of an optical disk, particularly a write-once compact disk (CD-WO). This is a method in which a recording material, that is, a coating solution in which a dye is dissolved is dropped on the inner circumference of a disk-shaped substrate and the substrate is rotated at high speed to form a uniform film by centrifugal force. In this process, the dye was attached around the spin coater, but the attached dye was not reused.

[0003]

DISCLOSURE OF THE INVENTION The present inventors consider that it is very advantageous from the viewpoint of cost reduction if the dye attached to the periphery of the spin coater can be recovered and reused, and the dye for an optical disk. As an example, an alkoxyphthalocyanine derivative described in JP-A-3-62878, which has good solubility and can be used in the spin coating method, was developed, and coating was performed by the spin coating method described above, and an attempt was made to recover and reuse the dye. However, the recovered dye does not have sufficient solubility in the coating solvent as it is, and it does not dissolve up to the optimum concentration of the coating liquid of 15 g / l to 90 g / l found by the present inventors, or once it dissolves. Even though it looked like a precipitate, a precipitate was formed in a short time, and a coating solution having a required concentration could not be prepared, and coating was impossible.

The present inventors have found that the cause of reducing the solubility is crystallization of alkoxyphthalocyanine. That is, the dye deposited by evaporation or drying of the solvent is in a certain crystalline state and its solubility is lowered. Even when this crystalline dye is dissolved in the coating solvent, dye association still exists in the solvent, and the association causes crystallization to proceed, decreasing the solubility in the solvent and causing precipitation from the dissolved state. ing. In particular, the presence of a small amount of aggregates serves as a nucleus for larger association, and thus it is necessary to completely remove the aggregates.

[0005]

The present inventors have found that the alkoxyphthalocyanine derivative having initial solubility can be obtained by cleaving the association state of the alkoxyphthalocyanine derivative, that is, by making it amorphous. The present invention has been reached.

That is, the present invention is a method for recovering a dye, which comprises heating a coating solution used in a thin film forming method by solution coating and a dye recovered from a coating apparatus in an organic solvent.

The organic solvent used in the present invention is for the purpose of bringing the crystalline state into an amorphous state, that is, breaking the association, 1) dissolving the alkoxyphthalocyanine derivative, and 2) having a boiling point of 50 ° C. or higher, preferably 100. It is necessary that the temperature is not lower than ℃, and specific examples thereof include benzene, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2- Trichloroethane, trichloroethylene, tetrahydrofuran, diisopropyl ether, dimethoxyethane, preferably toluene, ethylbenzene, isopropylbenzene, xylene, anisole, 1,1,2,2-tetrachloroethane, tetrachloroethylene, chlorobenzene, dichlorobenzene, 1,
3,5-trichlorobenzene, 1-chloronaphthalene,
2-chloronaphthalene, bromobenzene, difluorobenzene, 1-methylnaphthalene, 2-methylnaphthalene,
1,4-dioxane, di-n-butyl ether, diglyme and the like can be mentioned. Further, in breaking the association of phthalocyanine, 1) the effect is further enhanced by utilizing the π-π interaction and the coordination force of the solvent. 2) In the case of the association breakage, prompt removal of the solvent while preventing re-association. Considering the two points that it is necessary to do so, an aromatic hydrocarbon having a boiling point of 100 ° C. to 200 ° C. is preferable, and examples thereof include toluene, ethylbenzene, and xylene.

The temperature of the heat treatment is 50 ° C. to 250 ° C.
The temperature is preferably 80 ° C. to 200 ° C., and the heat treatment time is 30 minutes to 10 hours, preferably 1 hour to 5 hours. The concentration of the dye in the solvent is 5 g / l to 500 g
/ L, preferably 10 g / l to 300 g / l. After the heat treatment, the solvent is distilled off. Examples of the method of distilling off include methods such as an evaporator, distilling under reduced pressure, and freeze-drying under reduced pressure.

The alkoxyphthalocyanine derivative that can be used in the present invention is represented by the following general formula (1)

[0010]

[Chemical 1] [In the formula (1), R ^{1 to} R ⁴ each represent a branched alkyl group which may be different from each other, X represents a halogen atom, and n
Represents the number of X and is from 1 to 4. Met is 2
It represents a valent metal atom, a trivalent or tetravalent metal derivative, or an oxymetal. ] It is a compound represented by these, or its mixture.

In the formula (1), the branched alkyl group represented by R ^{1 to} R ⁴ is a hydrocarbon having 3 to 15 carbon atoms or a halogenated hydrocarbon. Preferred branched alkyl groups are groups having a total of 2 to 4 secondary, tertiary or quaternary carbon atoms. Specific examples include iso-propyl group, sec-butyl group, t-butyl group, neo-pentyl group,
1,2-dimethylpropyl group, cyclo-hexyl group, 1,3-dimethylbutyl group, 1-iso-propylpropyl group, 1,2-dimethylbutyl group, 1,4-dimethylpentyl group, 2-methyl-1 -iso
-Propylpropyl group, 1-ethyl-3-methylbutyl group, 3-
Hydrocarbon groups such as methyl-1-iso-propylbutyl group, 2-methyl-1-iso-propylbutyl group, 1-t-butyl-2-methylpropyl group, 1,1,1,3,3, Examples thereof include halogenated alkyl groups such as 3-hexafluoro-2-propyl group.

As an example of the divalent metal represented by Met,
Cu, Zn, Fe, Co, Ni, Ru, Rh, Pd, P
Examples of the trivalent or tetravalent metal derivative include AlCl, AlBr, AlI, and AlO.
H, InCl, InBr, InI, InOH, SiCl
₂ , SiBr ₂ , SiI ₂ , Si (OH) ₂ , GeCl ₂ ,
_{GeBr 2, GeI 2, SnCl 2} , SnBr 2, Sn
F ₂ and Sn (OH) ₂ are listed, and examples of the oxymetal include VO and TiO. Among these metals or their derivatives, Cu, Co, Ni, Rh, P
When d and Pt are central metals, the phthalocyanine represented by the above formula (1) easily associates with each other, and easily crystallizes, becomes insoluble in a solvent, and hardly dissolves, so that the method of the present invention is effective.

The synthesis of the phthalocyanine ring is carried out by mixing 1 to 4 kinds of the raw material phthalonitrile (2) or diiminoisoindoline (3) with a metal or metal compound capable of forming the above metal or metal derivative in a solvent, preferably in an alcohol. The reaction is carried out by heating in the temperature range of 10 to 300 ° C. When the raw material is phthalonitrile represented by (2), the reaction temperature is preferably in the temperature range of 80 to 160 ° C. When the starting material is diiminoisoindoline represented by (3), the reaction temperature is preferably in the temperature range of 140 to 200 ° C. Further, as a catalyst for ring formation, 1,8-diazabicyclo [5.4.0] -7-undecene (DBU), 1,5-diazabicyclo [4.3.
An auxiliary agent such as 0] -5-nonene (DBN) may be added.

[0014]

[Chemical 2] [In the formula (2), R ⁵ represents a branched alkyl group, X represents a halogen atom, and p represents 0, 1, 2 or 3. ]

[0015]

[Chemical 3] [In the formula (3), R ⁶ represents a branched alkyl group, X represents a halogen atom, and q represents 0, 1, 2 or 3. ] The halogenated alkoxy phthalocyanine synthesized under the above conditions is represented by the above formula (1).

Preferred halogenated alkoxy phthalocyanines are represented by the following formulas (4) to (7).

[0017]

[Chemical 4] [In the formulas (4) to (7), R ^{7 to} R ¹⁰ , X, n and Met are R ^{1 to} R ⁴ , X, n and M in the formula (1).
Each is synonymous with et. ] Particularly preferable halogenated alkoxy phthalocyanines are represented by formulas (4) to (7)
In the above, the branched alkyl group represented by R ^{7 to} R ¹⁰ is a group having a total of 2 to 4 secondary, tertiary or quaternary carbon atoms, and X is bromine.

The alkoxyphthalonitrile (2) or alkoxydiiminoisoindoline (3) used in the present invention is synthesized by the method shown in the following reaction formula (8).

[0019]

[Chemical 5] The starting material 3-nitrophthalonitrile or 4-nitrophthalonitrile was obtained from Tokyo Kasei. The first reaction from nitrophthalonitrile to alkoxyphthalonitrile is NOUVEAU JOURNAL DE CHIMIE, VOL.6, NO.12,
The method described in pp653-58, 1982 was used.
That is, sodium alkoxide obtained by reacting alcohol with sodium hydride and nitrophthalonitrile were reacted at 0 to 100 ° C. to obtain alkoxyphthalonitrile.

The synthesis of halogenated phthalonitrile is described in I.
Co-authored by T. HARRISON and S. HARRISON "COMPENDIUM OF ORGAN
IC SYNTHETIC METHOD "Volume 1 to 6 Alkoxyphthalonitrile was halogenated by the method described in WILEY-INTERSCIENCE. After that, it was separated and purified by column chromatography. Iodine, sulfuryl chloride, thionyl chloride, antimony chloride, ICl ₃ , FeCl ₃ , phosphorus pentachloride, phosphorus oxychloride, t-butyl hypochlorite, N-chlorosuccinic imide, cuprous bromide, quaternary ammonium bromide , N-bromosuccinic imide, iodine monochloride, 4
Preferred are ammonium iodide, potassium iodide and the like. The amount of the halogenating agent used is appropriately 1 to 2 molar ratio.

Alkoxyphthalocyanine derivatives recovered from a coating machine or coating solution before the treatment of the present invention are in a crystalline state in many cases, and therefore have low solvent solubility. That is, although the coating solution did not dissolve to a predetermined concentration, or even if once dissolved in a solvent, precipitation occurred in a short time, but the association state was broken by the heat treatment of the present invention, and And the solubility is significantly improved.

[0022]

EXAMPLES The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

In Examples 1 to 6, X-ray diffraction diagrams of the phthalocyanine derivative before and after the treatment are shown, and the X-ray diffraction conditions are as follows.

Tube: Cu, tube voltage: 50 kV, tube current:
200mA, Goniometer: Wide-angle goniometer, Sampling angle: 0.020 °, Scan speed: 8.0
° / min, scanning axis: 2θ / θ, filter: Ni, divergence slit: 1 ″, scattering slit: 1 ″, fluorescent slit: 0.
15 mm.

Example 1 Palladium tetra α- [3 recovered from a spin coater
60 g (X-ray diffraction pattern, FIG. 1) of a mixture of-(2,4-dimethyl) pentyloxy] phthalocyanine (the following formula (9)) was dissolved in 1.5 liters of ethylbenzene, and the mixture was dissolved at 120 ° C. for 2 hours.
After heating and stirring for a period of time and cooling to room temperature, the solvent was distilled off with an evaporator, and the residue was dried at 60 ° C. The treated phthalocyanine is dissolved in octane at a concentration of 30 g / l,
It was possible to apply even after 10 hours. The X-ray diffraction pattern after the treatment is shown in FIG.

[0026]

[Chemical 6]

Example 2 Palladium tetra α- [3 recovered from a spin coater
55 g (X-ray diffraction pattern, FIG. 3) of a brominated mixture of-(2,4-dimethyl) pentyloxy] phthalocyanine (the following formula (10)) was dissolved in 1.2 liters of toluene,
The mixture was heated and stirred at ℃ for 2 hours, cooled to room temperature, the solvent was distilled off by an evaporator, and the residue was dried at 60 ℃. The treated phthalocyanine was dissolved in ethylcyclohexane at a concentration of 30 g / l, and crystal precipitation was not observed even after 24 hours. The X-ray diffraction pattern after the treatment is shown in FIG.

[0028]

[Chemical 7]

Example 3 Palladium tetra α recovered from the coating solution in which crystals were precipitated
-[3- (2,2,4-trimethyl) pentyloxy]
50 g of phthalocyanine brominated mixture (the following formula (11))
(X-ray diffraction pattern, FIG. 5) was dissolved in 1.2 liters of isopropylbenzene, heated and stirred at 150 ° C. for 2 hours, cooled to room temperature, the solvent was distilled off with an evaporator, and the residue was dried at 60 ° C. Let Treated phthalocyanine is 30g /
It was dissolved in octane at a concentration of 1 and could be applied even after 12 hours. The X-ray diffraction pattern after the treatment is shown in FIG.

[0030]

[Chemical 8]

Example 4 Palladium tetra α- (1 recovered from a spin coater
70 g (X-ray diffraction pattern, FIG. 7) of -iso-propyl-2-methylbutyloxy) phthalocyanine brominated mixture (the following formula (12)) was dissolved in 1.5 liter of xylene, and
The mixture was heated and stirred at 5 ° C for 3 hours, cooled to room temperature, the solvent was distilled off with an evaporator, and the residue was dried at 60 ° C. The treated phthalocyanine was dissolved in ethylcyclohexane at a concentration of 30 g / l and no precipitation was observed even after 24 hours. The X-ray diffraction pattern after the treatment is shown in FIG.

[0032]

[Chemical 9]

Example 5 Copper tetra α- [3- (2, recovered from a spin coater
4-Dimethyl) pentyluloxy] phthalocyanine brominated mixture (the following formula (13)) 50 g (X-ray diffraction pattern, FIG. 9)
Was dissolved in 1 liter of toluene, heated and stirred at 100 ° C. for 4 hours, cooled to room temperature, the solvent was distilled off with an evaporator, and the residue was dried at 60 ° C. The treated phthalocyanine was dissolved in octane at a concentration of 30 g / l, and no crystal precipitation was observed even after 24 hours. The X-ray diffraction pattern after the treatment is shown in FIG.

[0034]

[Chemical 10]

Example 6 Copper tetra α- (1-iso recovered from a spin coater
-Propyl-2-methylbutyloxy) phthalocyanine brominated mixture (following formula (14)) 40 g (X-ray diffraction pattern, FIG. 11) was dissolved in 2 liters of xylene, heated and stirred at 135 ° C. for 2 hours, and brought to room temperature. After cooling, the solvent was distilled off with an evaporator, and the residue was dried at 60 ° C. The treated phthalocyanine was dissolved in ethylcyclohexane at a concentration of 30 g / l and no precipitation was observed even after 24 hours. The X-ray diffraction pattern after the treatment is shown in FIG.

[0036]

[Chemical 11]

Example 7 The coating liquid prepared in Example 2 was applied to a substrate to prepare a CD-WO.
A medium was prepared. The produced medium had a reflectance of 72%, a linear velocity of 1.3 m / s, a sensitivity of 7.7 mW, and a block error rate of 15, and satisfied the CD-WO standard.

Example 8 A CD-WO medium was prepared with the coating solution prepared in Example 2,
The dye adhering to the spin coater was recovered, and the second embodiment was carried out again.
Was processed. This coating-collecting operation was repeated 5 times, but the coating operation can be performed in the same manner as in the initial stage,
The CD-WO media produced each time satisfied the standards.

Example 9 A CD-WO medium was prepared from the coating solution prepared in Example 4,
The dye adhering to the spin coater was recovered, and Example 4 was repeated.
Was processed. This coating-collecting operation was repeated 5 times, but the coating operation can be performed in the same manner as in the initial stage,
The CD-WO media produced each time satisfied the standards.

[0040]

The solubility of the recovered dye treated according to the present invention is restored, and the coating solution can be prepared and applied. Further, according to the present invention, it is possible to recycle the coating-collecting-coating dye.

[Brief description of drawings]

1 is an X-ray diffraction diagram of phthalocyanine before treatment in Example 1. FIG.

2 is an X-ray diffraction pattern of phthalocyanine after the treatment of Example 1. FIG.

FIG. 3 is an X-ray diffraction diagram of phthalocyanine before treatment in Example 2.

4 is an X-ray diffraction pattern of phthalocyanine after the treatment of Example 2. FIG.

5 is an X-ray diffraction diagram of phthalocyanine before treatment in Example 3. FIG.

6 is an X-ray diffraction pattern of phthalocyanine after the treatment of Example 3. FIG.

FIG. 7 is an X-ray diffraction diagram of phthalocyanine before treatment in Example 4.

8 is an X-ray diffraction pattern of phthalocyanine after the treatment of Example 4. FIG.

FIG. 9 is an X-ray diffraction diagram of phthalocyanine before treatment in Example 5.

FIG. 10 is an X-ray diffraction pattern of phthalocyanine after the treatment of Example 5.

11 is an X-ray diffraction diagram of phthalocyanine before treatment in Example 6. FIG.

FIG. 12 is an X-ray diffraction pattern of phthalocyanine after the treatment of Example 6.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenichi Sugimoto 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Naoto Ito 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Kagaku (72) Inventor Tomoyuki Sasakawa 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Yuko Suzuki 1190, Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Hiroyuki Hyakutake Inventor Mitsui Toatsu Chemical Co., Ltd., 1190, Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa (56) Reference JP-A-2-265788 (JP, A)

Claims (4)

[Claims] 1. A method for recovering a dye, which comprises subjecting an alkoxyphthalocyanine derivative recovered from a thin film forming coating apparatus by spin coating to a heat treatment in an organic solvent at 50 to 250 ° C. and distilling off the solvent. 2. The recovery method according to claim 1, wherein the organic solvent is an aromatic organic solvent such as toluene, ethylbenzene, or xylene. 3. The recovery method according to claim 2, wherein the solvent is distilled off under reduced pressure. 4. The method according to claim 3, wherein the alkoxyphthalocyanine derivative is brominated alkoxyphthalocyanine.