JP2684766B2 - Dithiolene nickel complex - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a novel dithiolene nickel complex.

More specifically, it relates to a novel dithiolene nickel complex having absorption in the near infrared region, which can be used as various recording / memory materials and infrared filter materials, and an optical recording medium using the compound.

[Conventional technology]

The dithiolene nickel complex has absorption in the near infrared region, and various recording materials using the dithiolene nickel complex have been proposed.

For example, JP-A-62-173652 proposes an optical recording medium using a dithiolene nickel complex represented by the following formula.

Further, Japanese Patent Laid-Open No. 63-9576 proposes an optical recording medium using a dithiolene nickel complex represented by the following formula.

Further, JP-A-63-78794 proposes an optical recording medium using a dithiolene nickel complex represented by the following formula.

[Problems to be Solved by the Invention] Among the above-mentioned conventional optical recording media, those using a dithiolene nickel complex disclosed in JP-A-62-173652 and JP-A-63-9576 are suitable for organic solvents. It has a problem that its solubility is extremely low, coating by coating is difficult, and its compatibility with the resin is poor.

Further, the one using the dithiolene nickel complex disclosed in JP-A-63-78794 has a problem that the thin film stability is poor.

[Means for solving the problem]

The inventors of the present invention have arrived at the present invention as a result of diligent studies on a compound that has high solubility in an organic solvent, can be coated by coating, and has good compatibility with a resin.

That is, the present invention relates to the general formula [I] (In the formula, R represents a straight-chain alkyl group having 1 to 28 carbon atoms.) In the dithiolene nickel complex.

 Hereinafter, the present invention will be described in detail.

The dithiolene nickel complex of the present invention can be produced, for example, as follows. In the following general formula, R has the same definition as above.

That is, for example, o-dichlorobenzene and alkylmagnesium bromide are reacted in the presence of dichloro [1,2-bis (diphenylphosphino) ethane] nickel [II] and tetrahydrofuran to obtain o-dialkylbenzene, and then The obtained compound is reacted with aluminum chloride and acetyl chloride in the presence of dichloromethane to give the following general formula [II]. To obtain a compound represented by the following reaction with the obtained compound and sodium oxybromide in the presence of dioxane, the following general formula [III] A compound represented by the following general formula [IV] is obtained by reacting the obtained compound with ethanol and sulfuric acid. A compound represented by the following general formula [V] is obtained by reacting the obtained compound with sodium in the presence of xylene. A compound represented by the following general formula [I] is obtained by reacting the obtained compound with phosphorus tetrasulfide in the presence of dioxane and then reacting with nickel chloride hexahydrate. The dithiolene nickel complex represented by the present invention can be obtained.

When the dithiolene nickel complex of the present invention is used in an optical recording medium, it is basically composed of a substrate and a recording layer containing the dithiolene nickel complex represented by the above general formula [I], but it is further necessary. Depending on the subbing layer on the substrate,
A protective layer may be provided on the recording layer.

The substrate in the present invention may be either transparent or opaque to the laser beam used. As the material of the substrate, a general support for this kind of recording medium such as glass, plastic, paper, plate-shaped or foil-shaped metal can be used, but from various points, plastic is preferable. Examples of the plastic include acrylic resin,
Methacrylic resin, vinyl acetate resin, vinyl chloride resin, nitrocellulose, polyethylene resin, polypropylene resin, polycarbonate resin, polyimide resin, polysulfone resin, epoxy resin and the like can be mentioned.

When the dithiolene nickel complex of the present invention is used as the recording layer in the optical recording medium, the thickness of the recording layer is 100Å
-5 μm, preferably 1000 Å-3 μm.

As a film forming method for forming the recording layer, a thin film forming method which is generally used such as a vacuum vapor deposition method, a sputtering method, a doctor blade method, a casting method, a spinner method and a dipping method is used.

When forming the recording layer, a binder may be used in combination if necessary, and as the binder, resins such as polyvinyl alcohol, polyvinylpyrrolidone, nitrocellulose, cellulose acetate, polyvinyl butyral, polyvinyl carbonate and polyketone are used. It The amount of these resins used is preferably 0.1% by weight or more based on the weight of the dithiolene nickel complex of the present invention.

In the case of forming the recording layer by the doctor blade method, the cast method, the spinner method, the dipping method, especially the spinner method, a coating solvent is used, and examples of the solvent include tetrachloroethane, bromoform, dibromoform, ethylcellocelbu and xylene. Solvents having a boiling point of 120 to 160 ° C. such as chlorobenzene and cyclohexanone are preferably used. In addition, film formation by the spinner method is performed at a rotation speed of 500 to 5000 rpm.
After spin coating, a treatment such as heating or exposure to a solvent vapor may be performed in some cases.

Further, other dyes can be used in the recording layer if necessary. Other dyes include naphtholactam dyes, triarylmethane dyes, azo dyes, cyanine dyes, squarylium dyes, indoaniline dyes, naphthalocyanine dyes, phthalocyanine dyes,
And metal-containing azo dyes.

The recording layer in the optical recording medium of the present invention may be provided on both sides of the substrate, or may be provided only on one side.

The recording on the optical recording medium of the present invention is performed by irradiating a laser beam, preferably a semiconductor laser beam, focused on about 1 μm to a recording layer provided on both sides or one side of the substrate. In the portion irradiated with the laser light, thermal deformation of the recording layer such as decomposition, evaporation, and melting occurs due to absorption of laser light energy, and information is recorded.

Reproduction of the recorded information is performed by reading a difference in reflectance between a portion where thermal deformation has not occurred and a portion where thermal deformation has occurred using a laser beam.

As a laser used for recording and reproducing an optical recording _{medium, N 2, He-Cd,} Ar, He-Ne, ruby, although a laser of a semiconductor or dye may be mentioned, in particular light weight, ease of handling, A semiconductor laser is preferable from the viewpoint of compactness.

When the dithiolene nickel complex of the present invention is used for an infrared absorption filter, examples of the support include glass, plastic, paper, plate-shaped or foil-shaped metal, and the like.
Usually, a transparent plastic film or plate is used as a support, and a dye is applied to the surface or the inside thereof to be used. As plastics, those that transmit infrared rays well and have excellent strength are preferable, and polyesters represented by polyethylene terephthalate; cellulose diacetate,
Cellulose esters such as cellulose triacetate and cellulose acetate butyrate; polyolefins such as polyethylene and polypropylene; polyvinyl compounds such as polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, polystyrene; acrylics such as polymethylmethacrylate. Examples include a system addition polymer; a polycarbonate composed of a polycarbonate ester; a phenol resin; a polyvinyl butyral resin; a polyvinyl alcohol resin; a urethane resin; and gelatin.

Examples of the method for imparting a dye to the surface or inside of these plastic films or plates include the following 5
There are two methods.

(I) A method of blending with a plastic at the time of forming a film. That is, a method in which a pigment is mixed with various additives into a polymer powder or pellets, melted and extruded by a T-die method or an inflation method, or a film is formed by a calender method.

(Ii) A method of forming a thin film containing a dye on the film or plate by applying a solution of the dye alone or with a binder dissolved on a transparent plastic film or plate and then evaporating the solvent. As the binder used, known ones such as polymethylmethacrylate, cellulose acetate butyrate, polyvinyl butyral and polycarbonate are used. An undercoat may be applied to improve the adhesiveness.

(Iii) A method in which dispersed particles obtained by micronizing a dye together with a dispersant or the like are dispersed in water, and a plastic film or plate is immersed in this at high temperature to transfer the dye to the inside of the plastic film or plate by dyeing. .

(Iv) A method in which a dye and a polymerizable monomer are mixed, an appropriate polymerization initiator is added, and heat or light is applied to perform polymerization to form a polymer.

(V) A method of depositing a dye on a suitable support.

In this method, a protective layer can be further provided if necessary.

The amount of the dye used for preparing the infrared absorbing plastic film or absorbing plate in this manner is appropriately 0.01 to 20% by weight ratio with respect to the absorbing film or absorbing plate, and preferably 0.05 to 2%. . The thickness of the absorbing film or absorbing plate is usually 0.1 μm to 10 mm,
It is preferably 1 μm to 2 mm.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples unless it exceeds the gist.

Example 1 (1) Synthetic Example (a) Synthesis of o-dioctylbenzene 20 mg of tetrahydrofuran was added to magnesium (8.38 g; 0.345 mol), a few drops of n-octyl bromide was added dropwise and heated, and further 150 m of tetrahydrofuran was added when the reaction started.
l, then slowly n-octyl bromide (60.
84g: 0.315mol) was added. Reflux for 2 hours after the fever ends,
Then, it was cooled in ice, and dichloro [1,2-bis (diphenylphosphino) ethane] nickel (II) (0.91g; 1.7m
(mol) was suspended in 30 ml of tetrahydrofuran and added. Next, 20 ml of a tetrahydrofuran solution of o-dichlorobenzene (22.05 g; 0.15 mol) was slowly added dropwise. After stirring for 1 hour, the mixture was returned to room temperature and refluxed for 5 hours. After reaction, cool
1 mol / hydrochloric acid was added, extracted with 500 ml of ether, dried, and the solvent was distilled off to obtain a crude yield of 43.4 g. Then, vacuum distillation (1
Purification at 91.5 ° C./0.15 mmHg) gave 19 g of o-dioctylbenzene represented by the following structural formula.

(B) Synthesis of 3,4-di-n-octylacetophenone After cooling dichloromethane to −76 ° C., aluminum chloride (16.66 g; 0.125 mol) was thoroughly ground and added,
Then, a dichloromethane solution of acetyl chloride (9.77 g: 0.125 mol) was slowly added dropwise. Subsequently, o-dioctylbenzene (21.00 g; 0.069 mol) obtained in the above (a) was slowly added dropwise, and after the addition, the mixture was stirred for 6 to 8 hours. Then ice 50
The reaction solution was poured into 0 g / 100 ml of concentrated hydrochloric acid, stirred, extracted with dichloromethane, dried and the solvent was distilled off to obtain 23.3 g of 3,4-di-n-octylacetophenone represented by the following structural formula.

(C) 3,4-Di-n-octylbenzoic acid 180 ml of ion-exchanged water was added with sodium hydroxide (21.05 g; 0.52).
6mol) was added and dissolved, then cooled to 0 to 5 ° C, bromine (Br ₂ ) (31.58g; 0.1974mol) was added dropwise so as not to rise above 10 ° C, and a sodium oxybromide (NaOBr) solution was added. Obtained. 200 ml of a dioxane solution of 3,4-di-n-octylacetophenone (22.0 g; 0.0658 mol) obtained in (b) above was slowly added dropwise thereto, and the mixture was stirred at 10 ° C or lower for 24 hours.
The mixture was returned to room temperature, treated with an excess of sodium oxybromide with an aqueous solution of sodium hydrogensulfate, adjusted to pH 3 to 4 with concentrated hydrochloric acid, extracted with ether, dried, and the solvent was distilled off to obtain a crude yield of 25.6
g was obtained. After purification by silica gel chromatography (solvent chloroform), 14.2 g of 3,4-di-n-octylbenzoic acid represented by the following structural formula was obtained.

(D) Synthesis of ethyl-3,4-di-n-dioctylbenzoate 300 ml of ethanol and 3,4-di-n obtained in (c) above
-Octylbenzoic acid (13.0 g; 0.0386 mol) was added and refluxed, and then concentrated sulfuric acid (25.3 ml; 0.464 mol) was slowly added dropwise.
Refluxed for 0 hours. After the reaction, the product was discharged into ice water, extracted with ether, dried and the solvent was distilled off to obtain a crude yield of 15.0 g. Purification by vacuum distillation (0.06 mmHg / 153 ° C.) yielded 7.5 g of ethyl-3,4-di-n-benzoate represented by the following structural formula.

(E) Synthesis of 3,4,3 ', 4'-tetraoctylbenzoin 50 ml of xylene and sodium (1.58 g; 0.0686 mol) and 1 drop of oleic acid were added and heated to prepare a sodium dispersion. At a temperature of 100 ° C above (d)
Ethyl-3,4-di-n-octylbenzoate (10.0 g; 0.0274 mol) obtained in 1. was slowly added dropwise, and the solution gradually changed to reddish brown. After 20 hours of refluxing after the completion of dropping, the color of the solution became pale yellow. After cooling to room temperature, the remaining sodium was treated with ethanol, followed by treatment with dilute hydrochloric acid, extraction with 300 ml of ether, drying and evaporation of the solvent to obtain a crude yield of 9.0 g. 2.75 g after purification by silica gel column chromatography (solvent chloroform)
3,4,3 ′, 4′-tetraoctylbenzoin represented by the following structural formula was obtained.

[Spectral data] IR spectrum 3500 (-OH) 2950,2880 (alkyl group) 1680 (-C = 0), 1605,1500 (benzene ring) (F) Bis [1,2-di (3,4-n-octylphenyl)]
Synthesis of ethane-1,2-dithione] nickel 30 ml dioxane and 3,4,3 ′, 4 ′ obtained in (e) above
-Tetraoctylbenzoin (2.0 g; 3.78 x 10 ^-3 mol) and tetraphosphorus tetrasulfide (P ₄ S ₁₀ ) (3.36 g; 7.56 x 10 ^-3 mol) were added, and the mixture was refluxed for 4 hours. Then filtered, the filtrate nickel chloride hexahydrate _{(NiCl 2 · 6H 2 O)} (0.45g: 1.89 × 10 -3 mol)
Of ethanol solution was added dropwise, and the mixture was stirred for 1 hour, extracted with benzene, dried, and the solvent was distilled off, followed by purification by silica gel column chromatography (solvent n-hexane) to give 0.39.
A dithiolene nickel complex represented by g of the following structural formula was obtained.

[Physical property values] λ _max 940 nm (in chloroform) log ε 4.5 (2) Example of recording medium 0.1 g of dithiolene nickel complex obtained in Synthesis Example (1) above
Was dissolved in 10 g of tetrachloroethane and filtered through a 0.22 μm filter to obtain a solution. Lml of this solution was dropped onto a polymethylmethacrylate resin substrate (diameter 52mm),
It was applied at a rotation speed of 800 rpm by the spinner method. After application,
It was dried at 60 ° C for 10 minutes. Maximum absorption wavelength of coating film is 890 nm
And the shape of the spectrum was wide.

(3) Optical recording method When the coating film of the obtained optical recording medium was irradiated with a semiconductor laser beam having a central wavelength of 830 nm at an output of 4 mW, pits with extremely clear contours were formed.

Examples 2-5 By the method according to Example 1, the compounds shown in Table 1 were synthesized. Absorption spectra (λ
_max ) was measured and is shown in Table 1. Further, when a recording medium was prepared by a coating method by the method according to Example 1 and optical recording was performed, pits having extremely clear contours were formed.

[Effect of the Invention] The dithiolene nickel complex of the present invention has excellent solubility in an organic solvent, and also has good compatibility with a resin,
It is industrially useful because various recording / memory materials having excellent durability and infrared filters can be manufactured inexpensively and easily.

Claims (1)

(57) [Claims] 1. A compound of the formula [I] (In the formula, R represents a linear alkyl group having 1 to 28 carbon atoms.) A dithiolene nickel complex represented by: