JPH01113482A - Infrared-absorbing compound and optical recording medium utilizing the same - Google Patents

Abstract

PURPOSE:To obtain an infrared-absorbing compound having durability to repeated reproduction and light resistance, represented by a specified formula. CONSTITUTION:An infrared-absorbing compound represented by formula I or II (wherein A is a group of formula III or IV, B is a group of formula V or VI, X is an anion, R1-R8 are each a 1-8C substituted or unsubstituted alkenyl, a substituted or unsubstituted aralkyl or alkinyl, each of pairs of R1 and R2, R3 and R4, R5 and R6, and R7 and R8 are combined together with the N atom to form a substituted or unsubstituted five-membered, six-membered, or seven- membered ring. The substituents in R1-R8 may be the same or different. An optical recording medium having durability to repeated reproduction can be obtained by using this infrared-absorbing compound. This compound can be used for heat-insulating films, sunglasses, etc., as well as for a material of an optical recording medium. The recording layer may contain a surfactant, an antistatic agent, a stabilizer, a dispersible flame retardant, a lubricant, a plasticizer, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an infrared absorbing compound and an optical recording medium using the same.

In particular, the present invention relates to an infrared absorbing compound and an optical recording medium that improve durability and light resistance during repeated reproduction in optical discs or optical cards.

[Conventional technology]

Generally, optical disks and optical cards are optically detectable small (
For example, about 1 μm) pits can be in the form of spirals or circular and linear tracks to store high density information. To write information on such a disc, a focused laser is scanned over the surface of the laser-sensitive layer, and only the surface that is irradiated with this laser beam forms pits, which are then shaped into spiral or circular and linear tracks. Formed in the form of.

The laser sensitive layer can absorb laser energy to form optically detectable pits. For example, in the heat mode recording method, the laser sensitive layer absorbs thermal energy and forms small pits at that location due to evaporation or melting.
can be formed. In addition, in another heat mode recording method,
By absorbing the irradiated laser energy, pits with optically detectable density differences can be formed at the locations. - Here, by using an organic dye thin film as a recording layer with high reflectance, the optical contrast of the recording pits can be set high. For example, if polymethine dyes, azulene dyes, cyanine dyes, pyrylium dyes, etc., which have large light absorption against laser light, are used as the organic dye thin film, a light absorption/reflection film exhibiting metallic luster (reflectance of 10 to 50%) can be used. is obtained, resulting in an optical recording medium that is capable of laser recording and reflective reading. In particular, use of a semiconductor laser with an oscillation wavelength of 700 to 900 nm as a laser light source has the advantage that the device can be made smaller and lower in cost. However, organic dye thin films generally have a problem in that their recording and reproducing characteristics and storage stability, that is, their repeated reproduction durability and light resistance, are deteriorated due to the fact that they are easily subject to material changes due to heat and light.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a new infrared absorbing compound having repeated playback durability and light resistance, and an optical recording medium using the same that has repeated playback durability and light resistance. There is a particular thing.

[Means for solving problems]

That is, the object of the present invention is to satisfy the following general formulas (1), (2
) The above general formula (1) and/or (2
) is achieved by an optical recording medium characterized by containing the compound.

shows. R1 to R8 are substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, or substituted or unsubstituted aralkyl groups or alkynyl groups having 1 to 8 carbon atoms, and R1 and R2'+ R3 and R4 ，
A combination of R, and R6+ and R7 and RII may form a substituted or unsubstituted 5-membered ring, a substituted or unsubstituted 6-membered ring, or a substituted or unsubstituted 7-membered ring together with N. The substituents R1 to R8 may be the same or different. ) The central aromatic ring may be substituted with a lower alkyl group or a halogen group.

Xe is chloride ion, bromide ion, iodide ion, perchlorate ion, nitrate ion, benzenesulfonate ion, P-toluenesulfonate ion, methyl sulfate ion, ethyl sulfate ion, propyl sulfate salt ion, tetrafluoroborate ion, tetraphenylborate ion, hexafluorophosphate ion, benzenesulfinate ion, acetate ion, trifluoroacetate ion, propionate ion, benzoate ion, Oxalate ion, succinate ion, malonate ion, oleate ion, stearate ion, citrate ion, -hydrogen diphosphate ion, dihydrogen-phosphate ion, pentachlorostannic acid salt ion, chlorosulfonate ion, fluorosulfonate ion, trifluoromethanesulfonate ion, hexafluoroarsenate ion, hexafluoroantimonate ion, molybutate ion, tungstate ion,
Represents anions such as titanate ions and zirconate ions.

The method for producing the present compounds (1) and (2) is described in US Pat. No. 3,251,881. U.S. Patent No. 3,575,871° - U.S. Patent No. 3,484,467 and JP-A-61
The method described in No.-69991 etc. can be used. For example, it can be manufactured by the following process.

H2N-A-NH2+4I-@)-NO2□, that is, the amino compound obtained by the above-mentioned Ullmann reaction and reduction reaction is selectively alkylated and alkenylated.

After aralkylation and alkynylation, the final product can be obtained by oxidation reaction.

RI +R2+R3+R4+R5rR8+R7+R8 is an alkyl group such as a methyl group, ethyl group, n-
Propyl group, 1so-propyl group, n-butyl group,
sec-butyl group, 1so-butyl group, t-butyl group, n-amyl group, t-amyl group, n-hexyl group, n-octyl group, t-orthyl group, etc., and further includes other alkyl groups, such as Substituted alkyl groups include 2-hydroxyethyl group, 3-hydroxypropyl group, 4-hydroxybutyl group, 2-acetoxyethyl group, carboxymethyl group, 2-carboxyethyl group, 3-carboxypropyl group, methoxyethyl group, Examples of alkenyl groups such as ethoxyethyl group and methoxypropyl group include vinyl group and propenyl group.

butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, etc. Aralkyl groups include benzyl group, p-chlorobenzyl group, p-methylbenzyl group, 2-phenylmethyl group, 2-phenylpropyl group,
3-phenylpropyl group, α-naphthylmethyl group, β-
Alkynyl groups such as naphthylethyl groups include propargyl, butynyl, pentynyl, hexynyl groups, etc., substituted or unsubstituted 5-membered hetero rings include pyrrolidine rings, and substituted or unsubstituted 6-membered rings include, for example. Examples of substituted or unsubstituted 7-membered rings such as piperidine ring, morpholine ring, and tetrahydropyridine ring include a cyclohexylamine ring. Furthermore, when R, to R8 are made asymmetrical, this alkylation must be performed in multiple stages, and from the viewpoint of cost, it is preferable that R1 to R8 are the same.

Next, specific examples of compounds used in general formulas (1) and (2) will be given. For simplification, the compound represented by formula (1) is represented by A, X, (RI R2)CRs R4) (R5Re
) (R7R8), the compound represented by formula (2) is B
,X,(RI R2)(R3R4)(RIS R6)(
127Ra) Xe is C104e, R1 color R8 color C
When the 3H border Xe is C104e, R2 and R2 form a piperidine ring, and R3 to R8 are n-butyl groups,
CH2CH2CH2CH2).

Compound no.

Compound no.

Such aminium salt compounds or diimonium salt compounds have a maximum absorption wavelength of 900 nm or more, and have large absorption peaks with extinction coefficients ranging from tens of thousands to hundreds of thousands.

In addition to being used as materials for optical recording media, such compounds are also used for heat insulating films, sunglasses, and the like.

As the near-infrared absorbing dye used in combination with these compounds as an optical recording medium, commonly known dyes are used, such as cyanine dyes, merocyanine dyes, croconium dyes, squalium dyes, and azulenium dyes. dyes, polymethine dyes.

These include naphthoquinone pigments, pyrylium pigments, and phthalocyanine pigments.

The amount of the aminium salt compound of the general formula (1) or the diimmonium salt compound of the general formula (2) added to these dyes is 1 to 60% of the recording layer based on the total solid content.
% by weight, preferably 5-40% by weight, more preferably 1
0 to 30% by weight is suitable.

In addition to these compounds, a binder may be included in the recording layer. Examples of the binder include nitrocellulose, cellulose phosphate, cellulose sulfate, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose myristate, cellulose parimitate, and cellulose acetate.
Cellulose esters such as cellulose propionate, cellulose acetate and butyrate, cellulose ethers such as methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, polystyrene, polyvinyl chloride, polyvinyl acetate, polyvinyl butyral, polyvinyl acecool, polyvinyl alcohol, polyvinyl Vinyl resins such as pyrrolidone, copolymer resins such as styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, polymethyl methacrylate, polymethyl acrylate, polybutyl acrylate, Acrylic resins such as polyacrylic acid, polymethacrylic acid, polyacrylamide, polyacrylonitrile, polyesters such as polyethylene terephthalate, poly(4,4'-isopropylidene diphenylene-co-1,4-cyclohexylene dimethylene carbonate) ), poly(ethylenedioxy-3,3'-
) unilentiocarbonate), poly(4,4'-isopropylidene diphenylene carbonate coated terephthalate), poly(4,4'-isopropylidene diphenylene carbonate), poly(4,4'-5ec- butylidene diphenylene carbonate), poly(4,4'-
Polyarylate resins such as isopropylidene diphenylene carbonate block-oxyethylene), or polyolefins such as polyamides, polyimides, epoxy resins, phenolic resins, polyethylene ethylene, polypropylene, and chlorinated polyethylene ethylene. etc. can be used.

Further, the recording layer may contain surfactants, antistatic agents, stabilizers, dispersible flame retardants, lubricants, plasticizers, and the like.

Further, an undercoat layer may be provided between the recording layer and the substrate, and a protective layer may be provided on the recording layer.

As an undercoat layer, the protective layer should be protected against scratches and
It is used for protection from dust, dirt, etc. and for environmental stability of the recording layer. The materials used for these are mainly inorganic compounds, metals, or organic polymer compounds. Examples of inorganic compounds include SiO2+ M g
F 2 + SiO+ TiO2+ ZnO
+TiN, SiN, etc.; examples of metals include Zn,
Cu.

Ni, Af, Cr, Ge, Se, Cd, etc., and organic polymer compounds include ionomer resins, polyamide resins, vinyl resins, natural polymers, and epoxy resins.

A silane coupling agent or the like can be used.

As the substrate, plastics such as polyester, polycarbonate, acrylic resin, polyolefin resin, phenol resin, epoxy resin, polyamide, polyimide, glass, or metals can be used.

Organic solvents that can be used during coating should be in a dispersed state or
Or, depending on the dissolved state, alcohols such as methanol, ethanol, isopropanol, and diacetone alcohol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, N, N-
Amides such as dimethylformamide, N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, butyl acetate, chloroform, chloride Aliphatic halogenated hydrocarbons such as methylene, dichloroethylene, carbon tetrachloride, trichlorethylene, benzene, toluene, xylene, monochlorobenzene, dichlorobenzene aromatics, or aliphatic carbonization such as n-hexane, cyclohexanoligroin, etc. Hydrogens etc. can be used.

Coating methods include dip coating, spray coating, spinner coating, bead coating,
This can be carried out using a coating method such as a wire bar coating method, a blade coating method, a roller coating method, or a curtain coating method.

The thickness of the recording layer formed using such a solvent is 50
Appropriate range is from 200 people to 1 μm, preferably from 200 people to 1 μm.

〔Example〕

Next, the present invention will be described in detail by giving examples.

<Synthesis Example 1> 1.5-diaminonaphthalene 0.1 mol, P-nitrochlorobenzene 0.43 mol, anhydrous potassium carbonate 0.
21 mol of copper powder (2 parts by weight) was stirred and refluxed for 4 days in 120 parts of dimethylformamide. After the reaction, the reaction mixture was filtered, and the filter residue was thoroughly washed with dimethylformamide, water, and acetone, and then dried to obtain 30 parts of reddish-brown tetrakis(P-nitrophenyl)-1°5-diaminonaphthalene.

23 parts of the compound obtained above were added into an autoclave together with 90 parts of dimethylformamide palladium-carbon hydrogenation catalyst and 2 parts, and hydrogen gas was applied at 5.0 kg/am'' at 90°C to 100°C until hydrogen absorption stopped. Stirred.

After the reaction, the reaction solution was filtered, and the filter residue was washed with dimethylformamide, and then the filtrate was poured into 350 parts of ice water. After stirring for a while, the precipitate was collected by filtration.

Recrystallization was performed using an ethanol dimethylformamide mixed solvent to obtain 10 parts of tetrakis(P-aminophenyl)-1,5-diaminonaphthalene. The purity was found to be 98.9% by high performance liquid chromatography analysis.

The results of infrared absorption analysis are shown in Figure 1.

<Synthesis of 1-16> 3 parts of the above amino compound were heated and stirred at 1000C-130C with 18 parts of dimethylformamide, 0.7 parts of anhydrous sodium bicarbonate, and 3.9 parts of n-butyl bromide. ′! After reacting for 16 hours, the reaction solution was poured into 100 parts of ice water and extracted with ethyl acetate. After drying, it was purified using a silica gel column. Obtained amount: 3.4 parts Disappearance of absorption due to NH stretching vibration of the amino group was confirmed by infrared absorption analysis. (Figure 2
0.5 part of this compound was dispersed in 20 parts of acetone, and the same mole of silver perchlorate was added while stirring. After reacting at room temperature for 1 hour, the precipitated silver was filtered off, the filtrate was diluted with isopropyl ether and allowed to stand, and the precipitated crystals were collected by filtration. The amount obtained was 0.7 parts.

1-16 synthesized in this way has a maximum absorption wavelength of 11
The compound had a large absorption region in the infrared region at 20 nm and an extinction coefficient of 40,000.

<Synthesis of 2-16> Disperse 0.5 parts of tetrakis(p-dibutylaminophenyl)-1,5-diaminonaphthalene used in the synthesis of 1-16 in 10 parts of acetone, and add 2 times the mole of filtrate with stirring. Silver chlorate was added. After reacting at room temperature for 1 hour, the precipitated silver was filtered off, and the filtrate was diluted with isopropyl ether. 0.55 parts of precipitated crystals were collected by filtration.

The example explained above is when the anion is perchloric acid,
When using other anions, the desired compound can be easily obtained by using the corresponding silver salt. For example, AgSbF6°AgBF4. AgSO4
,AgNO3,Ag503C6H4CH,.

Silver salts such as Ag5O3CF3 can be used.

In addition to this, it can also be obtained by electrolytic oxidation.

Synthesis Example 2> Synthesis Example 1 except that 1,5-diaminonaphthalene used in Synthesis Example 1 was changed to 1,4-diaminonaphthalene.
The reaction was carried out in the same manner as above to obtain 12 parts of tetrakis(p-aminophenyl)-1,4-diaminonaphthalene.

<Synthesis of 1-13> Add 2 parts of the amino compound obtained in Synthesis Example 2 to 1 part of dimethylformamide.
2 parts, 0.5 parts of anhydrous sodium bicarbonate, and 2.7 parts of 2-ethoxyethyl bromide at 100°C to 130°C.
The mixture was heated and stirred at ℃. After 36 hours of reaction, the reaction solution was diluted with ice water.
00 parts and extracted with ethyl acetate.

After drying, it was purified using a silica gel column. Disappearance of absorption due to NH stretching vibration of the amino group was confirmed by infrared absorption analysis using 2.4 parts of the obtained amount.

One part of this compound was dispersed in 20 parts of acetone, and the same mole of silver hexafluoroantimonate was added while stirring. At room temperature 1
After reacting for a period of time, the precipitated silver was filtered off, the filtrate was diluted with isopropyl ether and allowed to stand, and the precipitated crystals were collected by filtration. The amount obtained was 0.8 parts, and the maximum absorption wavelength was 118 nm.

<Synthesis of 2-13> 1.0 part of tetrakis(p-dipropylaminophenyl)-1,4-diaminonaphthalene obtained during the synthesis of 1-3 was dispersed in 20 parts of acetone while stirring at room temperature. Two times the molar amount of silver perchlorate was added and stirred for 1 hour.

After the reaction, the precipitated silver was filtered off and thoroughly washed with acetone.

After acetone was distilled off from the filtrate, it was washed with water and then dried under reduced pressure. The yield was 0.65 parts, and it was an infrared absorbing compound with a maximum peak at 1130 nm.

Next, actual examples in which infrared absorbing compounds represented by general formulas (1) and (2) are used as optical recording materials will be described.

<Example 1> PMM with a diameter of 130 mmφ and a thickness of 1 and 2 mm
A 50 μm pregroove was provided on the A substrate, and an organic dye such as a polymethine dye (IR-820 manufactured by Nippon Kayaku Co., Ltd.) and the above infrared absorbing compound &1-16 were added on the pregroove at a weight ratio of 90:10.
800 recording layers were formed by spin coating a solution dissolved in 2-dichloroethane. Spacers of 0.3 mm were sandwiched between the inner and outer circumferential sides of the medium thus obtained, and the medium was bonded to another PMMA substrate using an ultraviolet adhesive to obtain an optical recording medium having an air sandwich structure.

This was rotated at 180 rpm, and writing was performed from the substrate side using an 830 nm semiconductor laser at a recording power of -6 mW and a recording frequency of 2 MHz with a spot diameter of 1.5 μm.

Next, reproduction was performed with a read power of 0.9 mW, and the C/N ratio was measured by spectrum analysis. Subsequently, the C/N ratio was measured after 100,000 readings and reproductions.

Furthermore, a light resistance stability test was conducted by irradiating the recording medium prepared under the above conditions with xenon lamp light of IKW/rrr for 100 hours, and the reflectance and C/N ratio were measured.

Initial stage After repeated playbacks Reflectance after both light tests (%) C/N (dB) C/N (dB)
Reflectance (%) C/N (dB) 24.9 58
56 22.8 54 <Example 2> On the same substrate as in Example 1, by the same method as in Example 1,
A recording layer was formed using a solution of l-guaiazulenyl-5-(6'-t-butylazulenyl)-2,4-pentadienol verchlorate and an infrared absorbing compound Na 1-16 in a weight ratio of 90:10.

The same test as in Example 1 was conducted using the optical recording medium thus obtained. The results are shown in Table-2.

Table-2 Initial After repeated playback Reflectance after both light tests (%”) C/N (dB) C/N (d
B) Reflectance (%) C/N (dB) 27.7
55 54 23.4 5
2 <Examples 3 to 7> Optical recording media having the compositions shown in Table 3 were prepared in the same manner as in Example 1, and the same tests as in Example 1 were conducted.

The results are shown in Table 4.

Table 3 Example No. Organic dye BiM yield. 0 weight ratio chloraterateanine/perchlorate 7 NK-14142-2070: 30 manufactured by Nippon Kanko Shiki Co., Ltd. Comparative Examples 1 to 3> Performed except for excluding the infrared absorbing compound used in Examples 1.2 and 5. Optical recording media were prepared and evaluated in the same manner as in Examples 2 and 5. The results are shown in Table 4.

Table-4 No. Initial playback (after repeating) Reflectance after both light tests (%) C/N (dB) C/N (dB
) Reflectance (%) C/N (dB) Example 3 27.3 54 51 22.0 504
25.2 53 52 19.9 495
25.4 55 53 20.5 506-35
．． 2 54 53 29.5 497 32.4
53 51 19.8 47 Comparative Example 1 19.8 50 46 13.1 322
28.2 54 51 15.1 333 2
5.8 54 48 13.8 30〈Example 8
~11> A pregroove was formed on a card-sized polycarbonate (hereinafter abbreviated as rPcJ) substrate with a thickness of 0 and 4 mm by a heat press method, and an organic dye and an infrared absorbing compound shown in Table 5 below were applied thereon. After applying the solution mixed in diacetone alcohol using the barcode method, it is dried and
Obtained a record number of 50 people. Furthermore, a card-sized thickness of 0.3 mm is coated with an ethylene-acetate dry film on top.
An optical recording medium with an adhesive structure was produced using a PC board and a hot roll method.

The optical recording medium of the example produced in this way was mounted on a stage driven in the X-Y direction, and the oscillation wavelength was 830 nm.
Information was written in the Y-axis direction with a recording pulse of 80 μsec at a spot size of 3.0 μmφ, a recording power of 4.0 mW, and a read power of 0. 4 mW
The signal strength of the recording section (B→signal strength of the recording section) was measured.

Further, the same recording medium produced under the above conditions was subjected to a tip stability test under the same conditions as in Example 1, and the reflectance and contrast ratio were measured thereafter.

The results are shown in Table-6.

Table-5 8IR-820 (Nippon Kayaku) 2-1
6 80:20 Itrolate Comparative Examples 5 and 6> Optical recording media were prepared and evaluated in the same manner as in Examples 8 and 10, except that the infrared absorbing compound was removed from 1O. The results are shown in Table-6.

Table-6 No. Initial Reflectance after light fastness test (%) Contrast ratio Reflectance (%) Contrast ratio Example 8 14.9 0.75 12.9
0.70〃 9 15.1 0.72
13.5 0.62〃 10 15,2
0.71 13.1 0.67”11 1
5.1 0.73 12,9 0.6
9 Comparative Example 5 14.9 0.69 11.5
0.64# 6 15.1 0.70
9.9 0.60 [Effect of the invention] As explained above, the compounds represented by general formulas (1) and (2) have a large absorption region in the infrared region, and when used as an optical recording medium, , it is possible to provide a medium with significantly increased durability and tip stability during repeated playback.

[Brief explanation of the drawing]

FIGS. 1 and 2 are infrared absorption spectra of the compound obtained in Synthesis Example 1 and the compound obtained in the synthesis of 1-16, respectively.

Claims (1)

[Claims] (1) Infrared absorbing compounds represented by the following general formulas (1) and (2). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(2) (A in the formula is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ indicates, B indicates ▲ mathematical formula,
Chemical formulas, tables, etc. are available ▼ or ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼, and X■ indicates an anion. R_1 to R_8 are substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, or substituted or unsubstituted aralkyl groups or alkynyl groups having 1 to 8 carbon atoms, and R_1 and R_2, R_3 and R_4, A combination of R_5 and R_6, and R_7 and R_8 may form a substituted or unsubstituted 5-membered ring, a substituted or unsubstituted 6-membered ring, or a substituted or unsubstituted 7-membered ring together with N. The substituents R_1 to R_8 may be the same or different. ) (2) An optical recording medium characterized in that the organic dye thin film contains a compound selected from the following general formulas (1) and (2). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(2) (A in the formula is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ or ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ indicates, B indicates ▲ mathematical formula,
Chemical formulas, tables, etc. are available ▼ or ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼, and X■ indicates an anion. R_1 to R_8 are substituted or unsubstituted alkyl groups, substituted or unsubstituted alkenyl groups, or substituted or unsubstituted aralkyl groups or alkynyl groups having 1 to 8 carbon atoms, and R_1 and R_2, R_3 and R_4, A combination of R_5 and R_6, and R_7 and R_8 may form a substituted or unsubstituted 5-membered ring, a substituted or unsubstituted 6-membered ring, or a substituted or unsubstituted 7-membered ring together with N. The substituents R_1 to R_8 may be the same or different. )