Optical recording medium

Abstract

An optical recording medium is disclosed, comprising a support having provided thereon a recording layer containing a naphtholactam dye represented by formula: ##STR1## wherein K represents a substituted or unsubstituted aromatic amine residue; R represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group; Z.sup.- represents an anion; ring A represents a substituted or unsubstituted naphthalene ring; and m represents 1 or 2. The recording layer can be formed by coating easily, has a high reflectance to provide a satisfactory contrast of recording, and exhibits excellent resistance to light.

Description

FIELD OF THE INVENTION

This invention relates to an optical recording medium. More particularly, it relates to an optical recording medium whose recording layer has a high reflectance and can be formed easily.

BACKGROUND OF THE INVENTION

Optical recording media using a laser beam, etc. including laser discs are capable of recording and preserving informations at high densities and reproducing the recorded informations easily.

Laser discs generally comprise a disc base having provided thereon a thin recording layer, on which a laser beam condensed to a diameter of about 1 .mu.m is irradiated to carry out high-density recording. Upon absorption of energy of the irradiated laser beams, the recording layer undergoes thermal changes, such as decomposition, evaporation, dissolution, and the like to thereby make a difference in reflectance between the irradiated areas and the non-irradiated areas. Reproduction of the recorded informations can be carried out by reading the difference of reflectance.

Therefore, in order to effect high-density recording and precise reproduction, optical recording media are required to show efficient absorption of a laser beam having a specific wavelength used for recording and to highly reflect a laser beam having a specific wavelength used for reproduction.

Various structures are known for this type of optical recording media. For example, Japanese Patent Application (OPI) No. 97033/80 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") discloses a support having provided thereon a single layer of phthalocyanine dyes. However, phthalocyanine dyes have disadvantages, such as low sensitivity, high decomposition points which lead to difficulty in vacuum deposition, and very low solubility in organic solvents which lead to difficulty in coating for formation of the recording layer.

Japanese Patent Application (OPI) Nos. 83344/83 and 22479/83 disclose phenalene dyes and naphthoquinone dyes, respectively, to be coated as a recording layer. These dyes, though easy to evaporate in vacuo, show low reflectances. Low reflectances result in poor contrast in reflectance between the recorded areas and non-recorded areas, thus making it difficult to reproduce the recorded informations.

In addition, Japanese Patent Application (OPI) Nos. 24692/84, 67092/84, and 71895/84 disclose recording layers comprising cyanine dyes. The cyanine dyes have an advantage of easy coating but are inferior in light resistance and undergo deterioration due to light for reproduction.

SUMMARY OF THE INVENTION

One object of this invention is to provide an optical recording medium whose recording layer can be formed by coating easily.

Another object of this invention is to provide an optical recording medium whose recording layer has a high reflectance to provide a satisfactory contrast of recording.

A further object of this invention is to provide an optical recording medium having excellent resistance to light, particularly light for reproduction.

As a result of extensive investigations, it has now been found that the above objects can be accomplished easily by providing a recording layer containing a naphtholactam light-absorbing dye having a specific chemical structure.

The present invention relates to an optical recording medium comprising a support having provided thereon a recording layer containing a naphthostyril light-absorbing dye represented by formula (I): ##STR2## wherein K represents a substituted or unsubstituted aromatic amine residue; R represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group; Z.sup.- represents an anion; ring A represents a substituted or unsubstituted naphthalene ring; and m represents 1 or 2.

DETAILED DESCRIPTION OF THE INVENTION

In formula (I), substituents for the alkyl, cycloalkyl, aryl or allyl group as represented by R include an alkoxy group, an alkoxyalkoxy group, an alkoxyalkoxyalkoxy group, an allyloxy group, an aryl group, an aryloxy group, a cyano group, a hydroxyl group, a tetrahydrofuryl group, a halogen atom, etc.

Substituents for the naphthalene ring as represented by ring A include a halogen atom, a cyano group, a thiocyanate group, an alkyl group having up to 10 carbon atoms, an alkoxy group having up to 10 carbon atoms, an alkylamino group, an acylamino group, an amino group, a hydroxyl group, and a like nonionic substituent.

The substituted or unsubstituted aromatic amine residue as represented by K include residual groups of heterocyclic amines containing a nitrogen atom, an oxygen atom or a sulfur atom, residual groups of tetrahydroquinolines, and groups represented by formula: ##STR3##

wherein X and Y each represents a hydrogen atom, an alkyl group, an acylamino group, an alkoxy group, or a halogen atom; and R.sup.2 and R.sup.3 each represents a hydrogen atom, a substituted or unsubstituted alkyl group having up to 20 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted allyl group, or a substituted or unsubstituted cycloalkyl group.

Substituted for the alkyl, aryl, allyl or cycloalkyl group as represented by R.sup.2 or R.sup.3 include an alkoxy group, an alkoxyalkoxy group, an alkoxyalkoxyalkoxy group, an allyloxy group, an aryl group, an aryloxy group, a cyano group, a hydroxyl group, a tetrahydrofuryl group, etc.

Anions represented by Z.sup.- include I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, SCN.sup.-, ##STR4##

The naphtholactam dyes represented by formula (I) absorbs light in the wavelength region of from 600 to 900 nm and have a molecular absorption coefficient of from 10.sup.4 to 10.sup.5 cm.sup.-1.

Among the naphtholactam dyes of formula (I), the preferred are those represented by formula (II): ##STR5## wherein X and Y each represents a hydrogen atom, a halogen atom, an alkyl group, an acylamino group, or an alkoxy group; R.sup.1 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group; R.sup.2 and R.sup.3 each represents a hydrogen atom, a substituted or unsubstituted alkyl group having up to 20 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted allyl group, or a substituted or unsubstituted cycloalkyl group; R.sup.4 and R.sup.5 each represents a hydrogen atom, a halogen atom, a cyano group, a thiocyanato group, an alkyl group having up to 10 carbon atoms, an alkoxy group having up to 10 carbon atoms, an alkylamino group, an acylamino group, an amino group, or a hydroxyl group; Z.sup.- represents an anion; and m represents 1 or 2.

In formula (II), substituents for the alkyl, aryl, allyl, or cycloalkyl group as represented by R.sup.2 or R.sup.3 include an alkoxy group, an alkoxyalkoxy group, an allyloxy group, an aryl group, an aryloxy group, a cyano group, a hydroxyl group, a tetrahydrofurfuryl group, a halogen atom, etc.

The more preferred of the naphthostyril dyes of formula (II) are those represented by formula (III): ##STR6## wherein X represents a hydrogen atom or a methyl group; R.sup.1 represents an alkyl group having up to 8 carbon atoms, and preferably up to 5 carbon atoms, an alkyl group having up to 8 carbon atoms, and preferably up to 5 carbon atoms, which is substituted with an alkoxy group, preferably the one having up to 4 carbon atoms, an allyloxy group or a hydroxyl group, or an allyl group; R.sup.2 and R.sup.3 each represents an alkyl group having up to 8 carbon atoms, an alkyl group having up to 8 carbon atoms which is substituted with an alkoxy group, preferably the one having up to 4 carbon atoms, an alkoxyalkoxy group, preferably the one having up to 4 carbon atoms, an allyloxy group, a hydroxyl group or a halogen atom, or an allyl group; R.sup.4 represents a hydrogen atom, a halogen atom, preferably a chlorine atom or a bromine atom, or a thiocyanate group; Z.sup.- represents an anion; and m represents 1 or 2.

The naphthostyril dyes represented by formula (II) can easily be prepared by condensing a compound represented by formula: ##STR7## wherein R.sup.1, R.sup.4, R.sup.5, and Z.sup.- are as defined for formula (II), with an aromatic aldehyde represented by formula: ##STR8## wherein X, Y, R.sup.2, R.sup.3, and m are as defined in formula (II).

The naphthostyril dyes of formula (II) can also be prepared by reacting a compound represented by formula: ##STR9## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, X, Y, and m are as defined above; and Z.sup.- represents I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, SCN.sup.-, PF.sub.6.sup.-, SiF.sub.6.sup.-, TiF.sub.6.sup.-, ##STR10## with a compound represented by formula:

Q.sup.-.X.sup.+ wherein Q represents ##STR11## and X.sup.+ represents a tetraalkylammonium cation, etc., in a polar solvent under heating with stirring.

The optical recording medium according to the present invention essentially comprises a support and a recording layer and, if desired, may further comprise a subbing layer on the support and a protective layer on the recording layer.

The support to be used may be either transparent or opaque to a laser beam used. Any of supports usually employed for this type of recording media, such as glass, plastics, paper, metal plates or foils, etc., may be used, with plastics being preferred from various respects. The plastics to be used include acrylic resins, methacrylic resins, vinyl acetate resins, vinyl chloride resins, nitrocellulose, polyethylene resins, polypropylene resins, polycarbonate resins, polyimide resins, polysulfone resins, and the like.

The recording layer of the optical recording medium of the invention has a thickness of from 100 .ANG. to 5 .mu.m, and preferably from 500 .ANG. to 3 .mu.m.

The recording layer can be formed by a commonly employed thin film formation techniques, such as a vacuum deposition process, a sputtering process, a doctor blade coating process, a casting process, a spinner coating process, a dip coating process, and the like.

In the formation of the recording layer, a binder may be simultaneously used in a naphthostyril type light absorbing dyes. Usable binders include polymers, such as polyvinyl alcohol, polyvinylpyrrolidone, nitrocellulose, cellulose acetate, polyvinyl butyral, polycarbonate, etc. The recording layer preferably contains at least 1% by weight of the naphthostyril dye based on the polymer binder.

In the case of coating the recording layer by the above-described doctor blade coating process, casting process, spinner coating process, dip coating process, and the like, and particularly spinner coating process, a solvent for coating is employed. Suitable solvents to be used include those having a boiling point of from 120.degree. to 160.degree. C., e.g., bromoform, dibromoethane, tetrachloroethane, ethyl cellosolve, xylene, chlorobenzene, cyclohexanone, etc. In the case of film formation by the spinner coating process, a rotational speed preferably ranges from 500 to 5,000 rpm, and the spin-coated layer may be heated or treated with a solvent vapor, if necessary.

For the purpose of ensuring stability or light resistance of the recording layer, the recording layer may contain, as a singlet state oxygen quencher, a transition metal chelate compound, e.g., acetylacetonato chelates, bisphenyldithiol, salicylaldehyde oxime chelates, bisdithiol-.alpha.-diketone, etc.

The recording layer according to the present invention may further contain other dyes in addition to the naphthostyril dyes of formula (I), such as naphthostyril dyes other than those of the present invention, indophenol dyes, triarylmethane dyes, azo dyes, cyanine dyes, squalilium dyes, etc.

The recording layer of the optical recording medium according to the present invention may be provided on either a single side or both sides of a support.

Recording on the optical recording medium of the invention can be performed by irradiating the recording layer provided on one or both sides of the support with a laser beam, and preferably a semiconductor laser beam, condensed to a diameter of about 1 .mu.m. The laser irradiation induces thermal deformation of the recording layer due to energy absorption, such as decomposition, evaporation, melting, and the like, to thereby effect recording.

Reproduction of the thus recorded information can be carried out by irradiating a laser beam to read a difference in reflectance between the area where such a thermal deformation has taken place and the area where no thermal deformation has taken place.

The laser beams which can be used for recording and reproduction include laser beams of N.sub.2, He--Cd, Ar, He--Ne, ruby, semiconductors, dyes, and the like. Of these, semiconductor laser beams are preferred in view of their lightweight, small size, and ease on handling.

This invention will now be illustrated in greater detail with reference to the following examples, but it should be understood that they are not intended to limit the present invention.

EXAMPLE 1

Synthesis of Naphthostyril Dye

To a mixture of 250 g of glacial acetic acid and 50 g of acetic anhydride were added 39.0 g of a compound of formula: ##STR12## and 19.1 g of a compound of formula: ##STR13## and the mixture was heated at 100.degree. to 105.degree. C. for 4 hours with stirring. After completion of the reaction, the reaction mixture was cooled to room temperature, and poured into 1.5 liters of water containing 16.0 g of sodium perchlorate, followed by stirring at room temperature for 8 hours. The formed crystals were collected by filtration and dried to obtain 45 g of a naphthostyril dye having the following formula as a dark green crystals. A chloroform solution of this dye showed a .lambda..sub.max of 740 nm. ##STR14##

Production of Optical Recording Medium

One gram of the naphthostyril dye as above prepared was dissolved in ethyl cellosolve, followed by filtration through a filter of 0.22 .mu.m, 2 ml of thus obtained solution was dropped on a substrate of polycarbonate resin disc having a diameter of 130 mm which had been grooved to a depth of 700 .ANG. and a width of 0.7 .mu.m, and coated by a spinner at 800 rpm, followed by drying at 60.degree. C. for 20 minutes. For film thickness measurement, a glass plate was separately coated with the coating solution under the same conditions as above, and the film thickness was measured by means of Talystep (Rank Taylor Hobson KK) and was found to be 650 .ANG.. The coated film exhibited its absorption maximum at a wavelength of 790 nm and a broad peak width.

When a semiconductor laser beam having a center wavelength of 830 nm and a beam diameter of 1 .mu.m was irradiated on the coated film at an output of 6 mW, clear-outlined pits having a width of about 1 .mu.m and a pit length of about 2 .mu.m were formed. The carrier level/noise level ratio (C/N ratio) of the pits was 52 dB. The coating film exhibited satisfactory light resistance and resistance to reproducing light.

EXAMPLE 2

A naphthostyril dye of the formula shown below was synthesized in the same manner as described in Example 1. A chloroform solution of the dye had a .lambda..sub.max of 740 nm. ##STR15##

One gram of the naphthostyril dye thus obtained was dissolved in 50 g of dibromoethane, followed by filtration through a filter of 0.22 .mu.m. 2 ml of the resulting solution was dropped on a substrate of methyl methacrylate resin (hereinafter referred to as PMMA) disc having a diameter of 120 mm which had been grooved to a depth of 700 .ANG. and a width of 0.7 .mu.m and coated by a spinner at 1200 rpm, followed by drying at 60.degree. C. for 10 minutes. The film thickness was measured in the same manner as in Example 1 and was found to be 700 .ANG.. The coating film showed its absorption maximum at 790 nm with a broad peak width.

When a semiconductor laser beam having a center wavelength of 830 nm and a beam diameter of about 1 .mu.m was irradiated on the coated film at an output of 6 mW, clear-outlined pits having a width of about 1 .mu.m and a pit length of about 2 .mu.m were formed. The C/N ratio of the pits was 48 dB. The coating film showed satisfactory light resistance and resistance to reproducing light.

EXAMPLE 3

Synthesis of Naphthostyril Dye

To 50 ml of N,N-dimethylformamide were added 6.48 g of a dye having formula: ##STR16## and 6.20 g of a compound of formula: ##STR17## and the mixture was heated at 90.degree. to 100.degree. C. for 3 hours. After cooling, the reaction mixture was poured into 300 ml of water, and the mixture was stirred at room temperature for 1 hour. The thus precipitated crystals were collected by filtration and dried to obtain 10.20 g of dark green crystals represented by the formula shown below. A chloroform solution of the product had a .lambda..sub.max of 745 nm. ##STR18##

Production of Optical Recording Medium

One gram of the naphthostyril dye as above prepared was dissolved in 50 g of tetrachloroethane, and the solution was filtered through a filter of 0.2 .mu.m. 2 ml of the resulting solution was dropped on a substrate of PMMA disc having a diameter of 130 mm which had been grooved to a depth of 700 .ANG. and a width of 0.7 .mu.m and coated thereon by a spinner at 800 rpm, followed by drying at 60.degree. C. for 20 minutes. The film thickness was measured in the same manner as in Example 1 and was found to be 700 .ANG.. The coated film exhibited its absorption maximum at 790 nm with a broad peak width.

When a semiconductor laser beam having a center wavelength of 830 nm and a beam diameter of 1 .mu.m was irradiated on the coated film at an output of 6 mW, clear-outlined pits having a width of about 1 .mu.m and a pit length of about 2 .mu.m were formed. The C/N ratio of the pits was 52 dB. The coated film exhibited satisfactory light resistance and resistance to reproducing light.

EXAMPLES 4 TO 95

In the same manner as described in Example 1, naphthostyril dyes shown in Table 1 were synthesized. The wavelength of the absorption maximum of each of the resulting dye in its chloroform solution was as shown in Table 1.

Each of the resulting dyes was coated on a substrate of grooved polycarbonate resin disc in the same manner as in Example 1. The wavelength of the absorption maximum of the coating film was as shown in Table 1.

When a semiconductor laser beam having a center wavelength of 830 nm was irradiated on the coated film, clearly outlined pits were formed. The thus formed recording layer had a high reflectance, high sensitivity, and an excellent C/N ratio, and exhibited satisfactory light resistance and resistance to reproducing light.

TABLE 1 Naphthostyril Dye ##STR19## .lambda. max .lambda. max Example (in CHCl.sub.3) (coating film) No. R A.sup.1 A.sup.2 A.sup.3 B.sup.1 B.sup.2 B.sup.3 K Z.sup.- (nm) (nm) 4 C.sub.2 H.sub.5 H H H H H H ##STR20## I.sup.- 740 790 5 " " " Br " " " ##STR21## ClO.sub.4.sup.- 735 780 6 " " " " " " " ##STR22## " 745 790 7 " " " " " " " ##STR23## " 745 785 8 " " " " " " " ##STR24## " 745 790 9 " " " " " " " ##STR25## " 740 780 10 " " " " " " " ##STR26## " 735 775 11 " " " " " " " ##STR27## " 730 770 12 " " " " " " " ##STR28## " 735 780 13 " " " " " " " ##STR29## " 735 780 14 " " " " " " " ##STR30## " 720 760 15 " " " " " " " ##STR31## " 740 780 16 " " " " " " " ##STR32## " 735 775 17 " " " " " " " ##STR33## " 735 775 18 " " " " " " " ##STR34## " 725 765 19 " " " " " " " ##STR35## " 740 780 20 " " " " " " " ##STR36## " 735 775 21 " " " " " " " ##STR37## " 740 780 22 " " " " " " " ##STR38## " 735 775 23 " " " " " " " ##STR39## " 765 800 24 " " " " " " " ##STR40## " 780 820 25 " " " " " " " ##STR41## " 760 800 26 " " " " " " " ##STR42## I.sup.- 800 845 27 " " " " " " " ##STR43## " 770 815 28 " " " " " " " ##STR44## " 715 755 29 " " " " " " " ##STR45## " 725 760 30 " " " " " " " ##STR46## " 735 770 31 " " " " " " " ##STR47## " 735 755 32 " " " " " " " ##STR48## " 735 775 33 " " " " " " " ##STR49## Br.sup. - 735 770 34 " " " " " " " ##STR50## " 735 770 35 " " " " " " " ##STR51## " 750 790 36 " " " " " " " ##STR52## " 740 780 37 " " " " " " " ##STR53## " 745 785 38 " " " " " " " ##STR54## " 745 785 39 " " " " " " " ##STR55## " 760 800 40 " " " " " " " ##STR56## BF.sub.4.sup.- 755 795 41 C.sub.3 H.sub.7 (n) " " " " " " ##STR57## " 740 780 42 C.sub.5 H.sub.11 (n) " " " " " " " " 740 780 43 ##STR58## " " " " " " " " 745 780 44 ##STR59## " " " " " " " " 745 785 45 C.sub.2 H.sub.4 OCH.sub.3 " " " " " " " " 740 780 45 CH.sub.2 CH.sub.2 CH.sub.2 OCH.sub.3 " " " " " " " " 740 780 46 ##STR60## " " " " " " " ##STR61## 740 780 48 ##STR62## " " " " " " " " 740 790 49 C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.3 " " " " " " " " 740 790 50 C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.3 " " " " " " " " 740 790 51 C.sub.2 H.sub.4 OCH.sub.2 C CHH.sub.2 " " " " " " " " 740 785 52 CH.sub.2 CHCH.sub.2 " " " " " " " " 745 785 53 ##STR63## " " " " " " " " 740 790 54 C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2 " " " " " " " ClO.sub.4.sup.- 740 780 55 C.sub.2 H.sub.4 OH " " " " " " " " 740 780 56 C.sub.2 H.sub.4 Cl " " " " " " " SCN.sup.- 745 785 57 ##STR64## " " " " " " " " 740 770 58 C.sub.2 H.sub.4 CN " " " " " " " " 745 780 59 " " " H " " " " " 740 775 60 " " " ##STR65## " " " " " 780 820 61 " " " H " " " ##STR66## ClO.sub.4.sup.- 745 760 62 " " " " " " " ##STR67## " 745 785 63 C.sub.2 H.sub.5 " " ##STR68## " " " ##STR69## ##STR70## 740 780 64 " " " Cl " " " ##STR71## ##STR72## 740 770 65 " Br " Br " " " " ##STR73## 745 775 66 " H " OCH.sub.3 " " " " " 750 790 67 " " " NHCH.sub.3 " " " " " 760 795 68 " " " Br " " " ##STR74## ClO.sub.4.sup.- 760 790 69 " " " " " " " ##STR75## " 780 810 70 " " " " " " " ##STR76## " 760 800 71 " " " " " " " ##STR77## " 785 815 72 " " " " " " " ##STR78## " 785 810 73 " " " " " " " ##STR79## " 770 800 74 " " " " " " " ##STR80## " 740 790 75 " " " " " " " ##STR81## " 755 790 76 " " " " " " " ##STR82## " 775 805 77 " " " OH " " " ##STR83## " 755 795 78 " " " NH.sub.2 " " " ##STR84## " 775 810 79 " " " NHC.sub.2 H.sub.5 " " " ##STR85## " 775 805 80 " " " NHCOCH.sub.3 " " " ##STR86## " 755 800 81 " " " ##STR87## " " " ##STR88## " 740 770 82 " " " Br " " " ##STR89## " 750 780 83 " Br " " " " " ##STR90## " 780 820 84 " " " " " " " ##STR91## " 750 770 85 " " " " " " Br ##STR92## " 775 800 86 " " " CH.sub.3 " " " ##STR93## " 775 805 87 " " " C.sub.2 H.sub.5 " " C.sub.2 H.sub.5 ##STR94## " 755 790 88 " H " H H " H ##STR95## " 740 780 89 " " " SCN " " " ##STR96## SCN.sup.- 748 780 90 " " " " " " " ##STR97## " 745 770 91 " " " " " " " ##STR98## " 740 765 92 " " " Br " " " ##STR99## " 747 780 93 " " " " " " " " PF.sub.6.sup.- 748 780 94 " " " " " " " " SiF.sub.6.sup.- 750 780 95 " " " " " " " " TiF.sub.6.sup.- 750 780

EXAMPLES 96 TO 184

In the same manner as described in Example 3, naphthostyril dyes shown in Table 2 were synthesized. Each of the resulting naphtolactam dyes was coated on a substrate of grooved PMMA disc in the same manner as in Example 1 to form a coated film. The wavelength of the maximum absorption of the coated film was shown in Table 2.

When a laser beam having a center wavelength of 830 nm was irradiated on the coated film, clear-outlined pits were formed. The coated film had a high reflectance, high sensitivity, and an excellent C/N ratio and exhibited satisfactory light resistance and resistance to reproducing light.

TABLE 2 Naphthostyril Dye ##STR100## .lambda. max (coating Example film) No. R A .sup.1 A.sup.2 A.sup.3 B.sup.1 B.sup.2 B.sup.3 K Z.sup.- (nm) 96 C.sub.2 H.sub.5 H H Br H H H ##STR101## ##STR102## 740 97 C.sub.2 H.sub.4 CN H H H H H H ##STR103## ##STR104## 740 98 C.sub.2 H.sub.5 H H Br H H H ##STR105## ##STR106## 780 99 C.sub.2 H.sub.5 H H Br H H H ##STR107## ##STR108## 790 100 C.sub.2 H.sub.5 H H Br H H H ##STR109## ##STR110## 785 101 C.sub.2 H.sub.5 H H Br H H H ##STR111## ##STR112## 790 102 C.sub.2 H.sub.5 H H Br H H H ##STR113## ##STR114## 780 103 C.sub.2 H.sub.5 H H Br H H H ##STR115## ##STR116## 775 104 C.sub.2 H.sub.5 H H Br H H H ##STR117## ##STR118## 770 105 C.sub.2 H.sub.5 H H Br H H H ##STR119## ##STR120## 780 106 C.sub.2 H.sub.5 H H Br H H H ##STR121## ##STR122## 780 107 C.sub.2 H.sub.5 H H Br H H H ##STR123## ##STR124## 760 108 C.sub.2 H.sub.5 H H Br H H H ##STR125## ##STR126## 780 109 C.sub.2 H.sub.5 H H Br H H H ##STR127## ##STR128## 775 110 C.sub.2 H.sub.5 H H Br H H H ##STR129## ##STR130## 775 111 C.sub.2 H.sub.5 H H Br H H H ##STR131## ##STR132## 765 112 C.sub.2 H.sub.5 H H Br H H H ##STR133## ##STR134## 780 113 C.sub.2 H.sub.5 H H Br H H H ##STR135## ##STR136## 775 114 C.sub.2 H.sub.5 H H Br H H H ##STR137## ##STR138## 780 115 C.sub.2 H.sub.5 H H Br H H H ##STR139## ##STR140## 775 116 C.sub.2 H.sub.5 H H Br H H H ##STR141## ##STR142## 800 117 C.sub.2 H.sub.5 H H Br H H H ##STR143## ##STR144## 820 118 C.sub.2 H.sub.5 H H Br H H H ##STR145## ##STR146## 800 119 C.sub.2 H.sub.5 H H Br H H H ##STR147## ##STR148## 845 120 C.sub.2 H.sub.5 H H Br H H H ##STR149## ##STR150## 815 121 C.sub.2 H.sub.5 H H Br H H H ##STR151## ##STR152## 755 122 C.sub.2 H.sub.5 H H Br H H H ##STR153## ##STR154## 760 123 C.sub.2 H.sub.5 H H Br H H H ##STR155## ##STR156## 770 124 C.sub.2 H.sub.5 H H Br H H H ##STR157## ##STR158## 755 125 C.sub.2 H.sub.5 H H Br H H H ##STR159## ##STR160## 775 126 C.sub.2 H.sub.5 H H Br H H H ##STR161## ##STR162## 770 127 C.sub.2 H.sub.5 H H Br H H H ##STR163## ##STR164## 770 128 C.sub.2 H.sub.5 H H Br H H H ##STR165## ##STR166## 790 129 C.sub.2 H.sub.5 H H Br H H H ##STR167## ##STR168## 780 130 C.sub.2 H.sub.5 H H Br H H H ##STR169## ##STR170## 785 131 C.sub.2 H.sub.5 H H Br H H H ##STR171## ##STR172## 785 132 C.sub.2 H.sub. 5 H H Br H H H ##STR173## ##STR174## 800 133 C.sub.2 H.sub.5 H H Br H H H ##STR175## ##STR176## 795 134 C.sub.3 H.sub.7 (n) H H Br H H H ##STR177## ##STR178## 780 135 C.sub.5 H.sub.11 (n) H H Br H H H ##STR179## ##STR180## 780 136 ##STR181## H H Br H H H ##STR182## ##STR183## 780 137 ##STR184## H H Br H H H ##STR185## ##STR186## 785 138 C.sub.2 H.sub.4 OCH.sub.3 H H Br H H H ##STR187## ##STR188## 780 139 CH.sub.2 CH.sub.2 CH.sub.2 OCH.sub.3 H H Br H H H ##STR189## ##STR190## 775 140 ##STR191## H H Br H H H ##STR192## ##STR193## 780 141 ##STR194## H H Br H H H ##STR195## ##STR196## 790 142 C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.3 H H Br H H H ##STR197## ##STR198## 790 143 C.sub.2 H.sub.4 (OC.sub.2 H.sub.4).sub.2 OCH.sub.3 H H Br H H H ##STR199## ##STR200## 790 144 C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2 H H Br H H H ##STR201## ##STR202## 785 145 CH.sub.2 CHCH.sub.2 H H Br H H H ##STR203## ##STR204## 785 146 ##STR205## H H Br H H H ##STR206## ##STR207## 790 147 C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2 H H Br H H H ##STR208## ##STR209## 780 148 C.sub.2 H.sub.4 OH H H Br H H H ##STR210## ##STR211## 780 149 C.sub.2 H.sub.4 Cl H H Br H H H ##STR212## ##STR213## 785 150 ##STR214## H H Br H H H ##STR215## ##STR216## 770 151 C.sub.2 H.sub.4 CN H H Br H H H ##STR217## ##STR218## 775 152 C.sub.2 H.sub.4 CN H H H H H H ##STR219## ##STR220## 780 153 C.sub.2 H.sub.4 CN H H ##STR221## H H H ##STR222## ##STR223## 820 154 C.sub.2 H.sub.4 CN H H H H H H ##STR224## ##STR225## 760 155 C.sub.2 H.sub.4 CN H H H H H H ##STR226## ##STR227## 785 156 C.sub.2 H.sub.5 H H ##STR228## H H H ##STR229## ##STR230## 780 157 C.sub.2 H.sub.5 H H Cl H H H ##STR231## ##STR232## 770 158 C.sub.2 H.sub.5 Br H Br H H H ##STR233## ##STR234## 775 159 C.sub.2 H.sub.5 H H OCH.sub.3 H H H ##STR235## ##STR236## 790 160 C.sub.2 H.sub.5 H H NHCH.sub.3 H H H ##STR237## ##STR238## 795 161 C.sub.2 H.sub.5 H H Br H H H ##STR239## ##STR240## 790 162 C.sub.2 H.sub.5 H H Br H H H ##STR241## ##STR242## 810 163 C.sub.2 H.sub.5 H H Br H H H ##STR243## ##STR244## 800 164 C.sub.2 H.sub.5 H H Br H H H ##STR245## ##STR246## 815 165 C.sub.2 H.sub. 5 H H Br H H H ##STR247## ##STR248## 810 166 C.sub.2 H.sub.5 H H Br H H H ##STR249## ##STR250## 800 167 C.sub.2 H.sub.5 H H Br H H H ##STR251## ##STR252## 790 168 C.sub.2 H.sub.5 H H Br H H H ##STR253## ##STR254## 790 169 C.sub.2 H.sub.5 H H Br H H H ##STR255## ##STR256## 805 170 C.sub.2 H.sub.5 H H OH H H H ##STR257## ##STR258## 795 171 C.sub.2 H.sub.5 H H NH.sub.2 H H H ##STR259## ##STR260## 810 172 C.sub.2 H.sub.5 H H NHC.sub.2 H.sub.5 H H H ##STR261## ##STR262## 805 173 C.sub.2 H.sub.5 H H NHCOCH.sub.3 H H H ##STR263## ##STR264## 800 174 C.sub.2 H.sub.5 H H ##STR265## H H H ##STR266## ##STR267## 770 175 C.sub.2 H.sub.5 H H Br H H H ##STR268## ##STR269## 780 176 C.sub.2 H.sub.5 Br H Br H H H ##STR270## ##STR271## 820 177 C.sub.2 H.sub.5 Br H Br Br H H ##STR272## ##STR273## 770 178 C.sub.2 H.sub.5 Br H Br Br H Br ##STR274## ##STR275## 800 179 C.sub.2 H.sub.5 Br H CH.sub.3 Br H Br ##STR276## ##STR277## 805 180 C.sub.2 H.sub.5 Br H C.sub.2 H.sub.5 Br H C.sub.2 H.sub.5 ##STR278## ##STR279## 790 181 C.sub.2 H.sub.5 H H H H H H ##STR280## ##STR281## 780 182 C.sub.2 H.sub.5 Br H SCN H H H ##STR282## ##STR283## 790 183 C.sub.3 H.sub.7 (n) Br H SCN H H H ##STR284## ##STR285## 790 184 C.sub.4 H.sub.9 (n) Br H SCN H H H ##STR286## ##STR287## 790

EXAMPLE 185

To a mixture of 250 g of glacial acetic acid and 50 g of acetic anhydride were added 40.2 g of a compound of formula: ##STR288## and 17.5 g of a compound of formula: ##STR289## and the mixture was heated at 100.degree. to 105.degree. C. for 4 hours while stirring. After completion of the reaction, the reaction mixture was cooled to room temperature. The reaction mixture was then poured into 1.5 liters of water containing 16.0 g of sodium perchlorate, and the mixture was stirred at room temperature for 8 hours. The thus precipitated crystals were collected by filtration and dried to obtain 53.0 g of a naphthostyril dye of the formula shown below as dark green crystals. A chloroform solution of the dye had a .lambda..sub.max of 800 nm. ##STR290##

One gram of the naphthostyril dye as above obtained was dissolved in 50 g of dibromoethane, followed by filtration through a filter of 0.22 .mu.m. The resulting solution (2 ml) was coated on a substrate of grooved PMMA disc in the same manner as in Example 2 to form a coating film having a thickness of 700 .ANG.. The coated film had a .lambda..sub.max of 820 nm with a broad peak width.

When a semiconductor laser beam having a center wavelength of 830 nm and a beam diameter of 1 .mu.m was irradiated on the coated film at an output of 6 mW, clearly outlined pits having a width of about 1 .mu.m and a pit length of about 2 .mu.m were formed. The C/N ratio of the pits was 52 dB. The coated film exhibited satisfactory light resistance and resistance to reproducing light.

EXAMPLE 186

In the same manner as described in Example 185, a naphthostyril dye of the formula shown below was synthesized. A chloroform solution of the dye had a .lambda..sub.max of 795 nm. ##STR291##

One gram of the naphthostyril dye as above prepared and 1.5 g of nitrocellulose ("RS-20" produced by Daicel Chemical Industries, Ltd.) were dissolved in 50 g of ethyl cellosolve, and the solution was filtered through a filter of 0.22 .mu.m. 3 ml of the resulting solution was dropped on a substrate of polycarbonate resin disc having a diameter of 120 mm which had been grooved to a depth of 650 .ANG. and a width of 0.7 .mu.m and coated by a spinner at 1,500 rpm, followed by drying at 60.degree. C. for 10 minutes. The coated film has a thickness of 700 .ANG. as measured in the same manner as in Example 1. The coated film exhibited maximum absorption at 810 nm of wavelength with a broad peak width.

When a semiconductor laser beam having a center wavelength of 830 nm and a beam diameter of 1 .mu.m was irradiated on the coated film at an output of 6 mW, clearly outlined pits having a width of about 1 .mu.m and a pit length of about 2 .mu.m were formed. The thus formed recording layer had a C/N ratio of 51 dB and exhibited satisfactory light resistance and resistance to reproducing light.

EXAMPLE 187

A naphthostyril dye of the formula shown below was synthesized in the same manner as in Example 3. A chloroform solution of the dye had a .lambda..sub.max of 800 nm. ##STR292##

One gram of the naphtholactam dye as above prepared was dissolved in 50 g of dibromoethane, followed by filtration through a filter of 0.22 .mu.m. 2 ml of the resulting solution was dropped on a substrate of PMMA disc having a diameter of 120 mm which had been grooved to a depth of 700 .ANG. and a width of 0.7 .mu.m and coated by a spinner at 650 rpm, followed by drying at 60.degree. C. for 10 minutes. The film thickness was 800 .ANG. as measured in the same manner as in Example 1. The coated film had a .lambda..sub.max of 820 nm with a broad peak width.

When a semiconductor laser beam having a center wavelength of 830 nm and a beam diameter of 1 .mu.m was irradiated on the coated film at an output of 6 mW, clearly outlined pits having a width of about 1 .mu.m and a pit length of about 2 .mu.m were formed. The recording layer thus formed had a C/N ratio of 51 dB and exhibited satisfactory light resistance and resistance to reproducing light.

EXAMPLES 188 TO 278

In the same manner as in Example 185, naphthostyril dyes shown in Table 3 were synthesized. The wavelength of the absorption maximum of each of the resulting dyes in its chloroform solution was as shown in Table 3.

Each of the dyes was coated on a substrate of grooved PMMA disc in the same manner as in Example 185 to form a recording layer. When a semiconductor laser beam having a center wavelength of 830 nm was irradiated on the recording layer, clearly outlined pits were formed. The recording layer had a high reflectance, high sensitivity, and an excellent C/N ratio and exhibited satisfactory light resistance and resistance to reproduced light.

TABLE 3 Naphtholactam Dye ##STR293## .lambda. max Example (in CHCl.sub.3) No. R A.sup.1 A.sup.2 A.sup.3 B.sup.1 B.sup.2 B.sup.3 K Z.sup.- (nm) 188 C.sub.2 H.sub.5 H H Br H H H ##STR294## ClO.sub.4.sup. - 805 189 " " " " " " " ##STR295## " 810 190 " " " " " " " ##STR296## " 807 191 " " " " " " " ##STR297## " 807 192 " " " " " " " ##STR298## " 800 193 " " " " " " " ##STR299## " 800 194 " " " " " " " ##STR300## " 790 195 " " " " " " " ##STR301## " 800 196 " " " " " " " ##STR302## " 800 197 " " " " " " " ##STR303## " 785 198 " " " " " " " ##STR304## " 800 199 " " " " " " " ##STR305## " 800 200 " " " " " " " ##STR306## " 810 201 " " " " " " " ##STR307## " 790 202 " " " " " " " ##STR308## " 800 203 " " " " " " " ##STR309## " 800 204 " " " " " " " ##STR310## " 800 205 " " " " " " " ##STR311## " 800 206 " " " " " " " ##STR312## " 820 207 " " " " " " " ##STR313## " 820 208 " " " " " " " ##STR314## " 825 209 " " " " " " " ##STR315## " 870 210 " " " " " " " ##STR316## " 840 211 " " " " " " " ##STR317## " 780 212 " " " " " " " ##STR318## " 810 213 " " " " " " " ##STR319## " 800 214 " " " " " " " ##STR320## I.sup.- 800 215 " " " " " " " ##STR321## " 795 216 " " " " " " " ##STR322## Br.sup.- 810 217 " " " " " " " ##STR323## " 810 218 " " " " " " " ##STR324## " 830 219 " " " " " " " ##STR325## " 820 220 " " " " " " " ##STR326## " 815 221 " " " " " " " ##STR327## " 806 222 " " " " " " " ##STR328## " 840 223 " " " " " " " ##STR329## BF.sub.4.sup.- 835 224 C.sub.3 H.sub.7 (n) " " " " " " ##STR330## " 805 225 C.sub.5 H.sub.11 (n) " " " " " " " " 805 226 ##STR331## " " " " " " " " 805 227 ##STR332## " " " " " " " " 805 228 C.sub.2 H.sub.4 OCH.sub.3 " " " " " " " " 805 229 CH.sub.2 CH.sub.2 CH.sub.2 OCH.sub.3 " " " " " " " " 805 230 ##STR333## " " " " " " " ##STR334## 805 231 ##STR335## " " " " " " " " 805 232 C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.3 " " " " " " " " 805 233 C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.3 " " " " " " " " 805 234 C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2 " " " " " " " " 805 235 CH.sub.2 CHCH.sub.2 " " " " " " " " 805 236 ##STR336## " " " " " " " " 805 237 C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2 " " " " " " " ClO.sub.4.sup.- 805 238 C.sub.2 H.sub.4 OH " " " " " " " " 805 239 C.sub.2 H.sub.4 Cl " " " " " " " SCN.sup.- 810 240 ##STR337## " " " " " " " " 805 241 C.sub.2 H.sub.4 CN " " " " " " " " 810 242 " " " H " " " " " 800 243 C.sub.2 H.sub.4 CN " " ##STR338## " " " " " 820 244 " " " H " " " ##STR339## ClO.sub.4.sup.- 810 245 " " " " " " " ##STR340## " 810 246 H " " " " " " ##STR341## ##STR342## 800 247 C.sub.2 H.sub.5 " " ##STR343## " " " ##STR344## " 820 248 " " " Cl " " " " ##STR345## 805 249 " Br " Br " " " " ##STR346## 810 250 " H " OCH.sub.3 " " " " " 815 251 " " " NHCH.sub.3 " " " " " 820 252 " " " Br " " " ##STR347## ClO.sub.4.sup.- 840 253 " " " " " " " ##STR348## " 860 254 " " " " " " " ##STR349## " 840 255 " " " " " " " ##STR350## " 860 256 " " " " " " " ##STR351## " 860 257 " " " " " " " ##STR352## " 850 258 " " " " " " " ##STR353## " 800 259 " " " " " " " ##STR354## " 835 260 " " " " " " " ##STR355## " 855 261 " " " OH " " " ##STR356## " 835 262 " " " NH.sub.2 " " " ##STR357## " 860 263 " " " NHC.sub.2 H.sub.5 " " " ##STR358## " 865 264 " " " NHCOCH.sub.3 " " " ##STR359## " 835 265 " " " ##STR360## " " " ##STR361## " 820 266 " " " Br " " " ##STR362## " 830 267 " Br " " " " " ##STR363## " 860 268 " " " " Br " " ##STR364## " 830 269 " " " " " " Br ##STR365## " 855 270 " " " CH.sub.3 " " " ##STR366## " 855 271 " " " C.sub.2 H.sub.5 " " C.sub.2 H.sub.5 ##STR367## " 835 272 " H " H H " H ##STR368## " 820 273 " " " SCN " " " ##STR369## SCN.sup.- 828 274 C.sub.3 H.sub.7 (n) " " " " " " " " 828 275 " " " Br " " " " " 825 276 C.sub.2 H.sub.5 " " " " " " " PF.sub.6.sup.- 825 277 " " " " " " " " SiF.sub.6.sup.- 825 278 " " " " " " " " TiF.sub.6.sup.- 820

EXAMPLES 279 TO 365

In the same manner as described in Example 187, naphthostyril dyes shown in Table 4 were synthesized. Each of the resulting naphthostyril dyes was coated on a substrate of grooved PMMA disc in the same manner as in Example 187 to form a coated film. The wavelength of the maximum absorption of the coated film was shown in Table 4.

When a laser beam having a center wavelength of 830 nm was irradiated on the coated film, clear-outlined pits were formed. The coated film had a high reflectance, high sensitivity, and an excellent C/N ratio and exhibited satisfactory light resistance and resistance to reproducing light.

TABLE 4 Naphtholactam Dye ##STR370## .lambda..sub.max Ex- (coat- am- ing) ple film No. R A.sup.1 A.sup.2 A.sup.3 B.sup.1 B.sup.2 B.sup.3 K Z.sup.- (nm) 279 C.sub.2 H.sub.5 H H Br H H H ##STR371## ##STR372## 825 280 C.sub.2 H.sub.5 H H Br H H H ##STR373## ##STR374## 830 281 C.sub.2 H.sub.5 H H Br H H H ##STR375## ##STR376## 827 282 C.sub.2 H.sub.5 H H Br H H H ##STR377## ##STR378## 827 283 C.sub.2 H.sub.5 H H Br H H H ##STR379## ##STR380## 815 284 C.sub.2 H.sub.5 H H Br H H H ##STR381## ##STR382## 815 285 C.sub.2 H.sub.5 H H Br H H H ##STR383## ##STR384## 810 286 C.sub.2 H.sub.5 H H Br H H H ##STR385## ##STR386## 815 287 C.sub.2 H.sub.5 H H Br H H H ##STR387## ##STR388## 815 288 C.sub.2 H.sub.5 H H Br H H H ##STR389## ##STR390## 800 289 C.sub.2 H.sub.5 H H Br H H H ##STR391## ##STR392## 815 290 C.sub.2 H.sub.5 H H Br H H H ##STR393## ##STR394## 815 291 C.sub.2 H.sub.5 H H Br H H H ##STR395## ##STR396## 825 292 C.sub.2 H.sub.5 H H Br H H H ##STR397## ##STR398## 805 293 C.sub.2 H.sub.5 H H Br H H H ##STR399## ##STR400## 815 294 C.sub.2 H.sub.5 H H Br H H H ##STR401## ##STR402## 815 295 C.sub.2 H.sub.5 H H Br H H H ##STR403## ##STR404## 815 296 C.sub.2 H.sub.5 H H Br H H H ##STR405## ##STR406## 820 297 C.sub.2 H.sub.5 H H Br H H H ##STR407## ##STR408## 835 298 C.sub.2 H.sub.5 H H Br H HH ##STR409## ##STR410## 835 299 C.sub.2 H.sub.5 H H Br HH H ##STR411## ##STR412## 840 300 C.sub.2 H.sub.5 H H Br H H H ##STR413## ##STR414## 870 301 C.sub.2 H.sub.5 H H Br H H H ##STR415## ##STR416## 850 302 C.sub.2 H.sub.5 H H Br H H H ##STR417## ##STR418## 800 303 C.sub.2 H.sub.5 H H Br H H H ##STR419## ##STR420## 830 304 C.sub.2 H.sub.5 H H Br H H H ##STR421## ##STR422## 820 305 C.sub.2 H.sub.5 H H Br H H H ##STR423## ##STR424## 820 306 C.sub.2 H.sub.5 H H Br H H H ##STR425## ##STR426## 815 307 C.sub.2 H.sub.5 H H Br H H H ##STR427## ##STR428## 830 308 C.sub.2 H.sub.5 H H Br H H H ##STR429## ##STR430## 830 309 C.sub.2 H.sub.5 H H Br H H H ##STR431## ##STR432## 845 310 C.sub.2 H.sub.5 H H Br H H H ##STR433## ##STR434## 835 311 C.sub.2 H.sub.5 H H Br H H H ##STR435## ##STR436## 835 312 C.sub.2 H.sub.5 H H Br H H H ##STR437## ##STR438## 826 313 C.sub.2 H.sub.5 H H Br H H H ##STR439## ##STR440## 855 314 C.sub.2 H.sub.5 H H Br H H H ##STR441## ##STR442## 845 315 C.sub.3 H.sub.7 (n) H H Br H H H ##STR443## ##STR444## 825 316 C.sub.5 H.sub.11 (n) H H Br H H H ##STR445## ##STR446## 825 317 ##STR447## H H Br H H H ##STR448## ##STR449## 825 318 ##STR450## H H Br H H H ##STR451## ##STR452## 825 318 C.sub.2 H.sub.4 OCH.sub.3 H H Br H H H ##STR453## ##STR454## 825 320 CH.sub.2 CH.sub.2 CH.sub.2 OCH.sub.3 H H Br H H H ##STR455## ##STR456## 825 321 ##STR457## HH Br H H H ##STR458## ##STR459## 820 322 ##STR460## H H Br H H H ##STR461## ##STR462## 820 323 C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.3 H H Br H H H ##STR463## ##STR464## 820 324C.sub.2 H.sub.4 OC.sub.2 H.sub.4 OC.sub.2 H.sub.4 OCH.sub.3 H H B r H H H ##STR465## ##STR466## 825 325 C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2 H H Br H H H ##STR467## ##STR468## 825 326 CH.sub.2 CHCH.sub.2 H H Br H H H ##STR469## ##STR470## 820 327 ##STR471## H H Br H H H ##STR472## ##STR473## 825 328 C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2 H H Br H H H ##STR474## ##STR475## 825 329 C.sub.2 H.sub.4 OH H H Br H H H ##STR476## ##STR477## 825 330 C.sub.2 H.sub.4 Cl H H Br H H H ##STR478## ##STR479## 830 331 ##STR480## H H Br H H H ##STR481## ##STR482## 825 332 C.sub.2 H.sub.4 CN H H Br H H H ##STR483## ##STR484## 830 333 C.sub.2 H.sub.4 CN H H H H H H ##STR485## ##STR486## 820 334 C.sub.2 H.sub.4 CN H H ##STR487## H H H ##STR488## ##STR489## 835 335 C.sub.2 H.sub.4 CN H H H H H H ##STR490## ##STR491## 830 336 C.sub.2 H.sub.4 CN H H H H H H ##STR492## ##STR493## 830 337 C.sub.2 H.sub.5 H H ##STR494## H H H ##STR495## ##STR496## 835 338 C.sub.2 H.sub.5 H H Cl H H H ##STR497## ##STR498## 815 339 C.sub.2 H.sub.5 Br H Br H H H ##STR499## ##STR500## 825 340 C.sub.2 H.sub.5 H H OCH.sub.3 H H H ##STR501## ##STR502## 835 341 C.sub.2 H.sub.5 H H NHCH.sub.3 H H H ##STR503## ##STR504## 835 342 C.sub.2 H.sub.5 H H Br H H H ##STR505## ##STR506## 860 343 C.sub.2 H.sub.5 H H Br H H H ##STR507## ##STR508## 875 344 C.sub.2 H.sub.5 H H Br H H H ##STR509## ##STR510## 855 345 C.sub.2 H.sub. 5 H H Br H H H ##STR511## ##STR512## 875 346 C.sub.2 H.sub.5 H H Br H HH ##STR513## ##STR514## 875 347 C.sub.2 H.sub.5 H H Br H H H ##STR515## ##STR516## 865 348 C.sub.2 H.sub.5 H H Br H H H ##STR517## ##STR518## 820 349 C.sub.2 H.sub.5 H H Br H H H ##STR519## ##STR520## 855 350 C.sub.2 H.sub.5 H H Br H H H ##STR521## ##STR522## 870 351 C.sub.2 H.sub.5 H H OH H HH ##STR523## ##STR524## 850 352 C.sub.2 H.sub.5 H H NH.sub.2 H HH ##STR525## ##STR526## 875 353 C.sub.2 H.sub.5 H H NHC.sub.2 H.sub.5 H H H ##STR527## ##STR528## 875 354 C.sub.2 H.sub.5 H H NHCOCH.sub.3 H H H ##STR529## ##STR530## 855 355 C.sub.2 H.sub.5 H H ##STR531## H H H ##STR532## ##STR533## 825 356 C.sub.2 H.sub.5 H H Br H H H ##STR534## ##STR535## 838 357 C.sub.2 H.sub.5 Br H Br H H H ##STR536## ##STR537## 875 358 C.sub.2 H.sub.5 Br H Br Br H H ##STR538## ##STR539## 845 359 C.sub.2 H.sub.5 Br H Br Br H Br ##STR540## ##STR541## 860 360 C.sub.2 H.sub.5 Br H CH.sub.3 Br H Br ##STR542## ##STR543## 860 361 C.sub.2 H.sub.5 Br HC.sub.2 H.sub.5 Br H C.sub.2 H.sub.5 ##STR544## ##STR545## 840 362 C.sub.2 H.sub.5 H H H H H H ##STR546## ##STR547## 830 363 C.sub.2 H.sub.5 H H SCN H H H ##STR548## ##STR549## 835 364 C.sub.3 H.sub.7 (n) H H SCN H H H ##STR550## ##STR551## 835 365 C.sub.4 H.sub.9 (n) H H SCN H H H ##STR552## ##STR553## 835

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

Claims

1. An optical recording medium adapted to record information by irradiating said recording medium comprising a support having provided thereon a recording layer containing a dye, with a focused laser beam, said dye undergoing thermal changes to thereby make a partial difference in reflectance on the recording medium, and for reproducing the recorded information by reading the difference in reflectance, which comprises a naphthostyril dye represented by formula (I): ##STR554## wherein K represents a substituted or unsubstituted aromatic amine residue; R represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group; Z.sup.- represents an anion; ring A represents a substituted or unsubstituted naphthalene ring; and m represents 1 or 2.

2. An optical recording medium as in claim 1, wherein said naphthostyril dye is a compound represented by formula (II): ##STR555## wherein X and Y each represents a hydrogen atom, a halogen atom, an alkyl group, an acylamino group, or an alkoxy group; R.sup.1 represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted allyl group; R.sup.2 and R.sup.3 each represents a hydrogen atom, a substituted or unsubstituted alkyl group having up to 20 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted allyl group, or a substituted or unsubstituted cycloalkyl group; R.sup.4 and R.sup.5 each represents a hydrogen atom, a halogen atom, a cyano group, a thiocyanate group, an alkyl group having up to 10 carbon atoms, an alkoxy group having up to 10 carbon atoms, an alkylamino group, an acylamino group, an amino group, or a hydroxyl group; Z.sup.- represents an anion; and m represents 1 or 2.

3. An optical recording medium as in claim 1, wherein said naphthostyril dye is a compound represented by formula (III): ##STR556## wherein X represents a hydrogen atom or a methyl group; R.sup.1 represents an alkyl group having up to 8 carbon atoms, an alkoxyalkyl group, an allyloxyalkyl group, an allyl group, or a hydroxyalkyl group; R.sup.2 and R.sup.3 each represents an alkyl group having up to 8 carbon atoms, an alkoxyalkyl group, an alkoxyalkoxyalkyl group, an allyloxyalkyl group, an allyl group, a hydroxyalkyl group, or a halogenoalkyl group; R.sup.4 represents a hydrogen atom, a halogen atom, or a thiocyanate group; Z.sup.- represents an anion; and m represents 1 or 2.

4. An optical recording medium as in claim 1, wherein the anion as represented by Z.sup.- is I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, SCN.sup.-, PF.sub.6.sup.-, SiF.sub.6.sup.-, TiF.sub.6.sup.-, ##STR557## wherein R.sup.6, which may be the same or different when multiple R.sup.6 s are substituted, represents a hydrogen atom, an alkyl group having up to 6 carbon atoms, a halogen atoms, or a dialkyl amino group; and n represents 0 or an integer of from 1 to 3.

5. An optical recording medium as in claim 2, wherein the anion as represented by Z.sup.- is I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, SCN.sup.-, PF.sub.6.sup.-, SiF.sub.6.sup.-, TiF.sub.6.sup.-, ##STR558## wherein R.sup.6, which may be the same or different when multiple R.sup.6 s are substituted, represents a hydrogen atom, an alkyl group having up to 6 carbon atoms, a halogen atom, or a dialkylamino group; and n represents 0 ro an integer of from 1 to 3.

6. An optical recording medium as in claim 3, wherein the anion as represented by Z.sup.- is I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, SCN.sup.-, PF.sub.6.sup.-, SiF.sub.6.sup.-, TiF.sub.6.sup.-, ##STR559## when R.sup.6, which may be the same or different when multiple R.sup.6 s are substituted, represents a hydrogen atom, an alkyl group having up to 6 carbon atoms, a halogen atom, or a dialkylamino group; and n represents 0 or an integer of from 1 to 3.

7. An optical recording medium as in claim 3, wherein R.sup.1 is an alkyl group having up to 5 carbon atoms, an alkyl group having up to 5 carbon atoms which is substituted with an alkoxy group having up to 4 carbon atoms, an allyloxy group, or a hydroxyl group, or an allyl group.

8. An optical recording medium as in claim 3, wherein R.sup.2 and R.sup.3 each is an alkyl group having up to 8 carbon atoms, an alkyl group having up to 8 carbon atoms which is substituted with an alkoxy group having up to 4 carbon atoms, an alkoxyalkoxy group having up to 4 carbon atoms, an allyloxy group, a hydroxyl group, or a halogen atom, or an allyl group.

9. An optical recording medium as in claim 3, wherein R.sup.4 is a hydrogen atom, a chlorine atom, a bromine atom, or a thiocyanato group.

10. An optical recording medium as in claim 1, wherein Z.sup.- is I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, SCN.sup.-, PF.sub.6.sup.-, SiF.sub.6.sup.- or TiF.sub.6.sup.-.

11. An optical recording medium as in claim 2, wherein Z.sup.- is I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, SCN.sup.-, PF.sub.6.sup.-, SiF.sub.6.sup.- or TiF.sub.6.sup.-.

12. An optical recording medium as in claim 3, wherein Z.sup.- is I.sup.-, Br.sup.-, Cl.sup.-, ClO.sub.4.sup.-, SCN.sup.-, PF.sub.6.sup.-, SiF.sub.6.sup.- or TiF.sub.6.sup.-.

13. An optical recording medium as in claim 1, wherein Z.sup.- is ##STR560## wherein R.sup.6 is a hydrogen atom, or an alkyl group having up to 4 carbon atoms.

14. An optical recording medium as in claim 2, wherein Z.sup.- is ##STR561## wherein R.sup.6 is a hydrogen atom, or an alkyl group having up to 4 carbon atoms.

15. An optical recording medium as in claim 3, wherein Z.sup.- is ##STR562## wherein R.sup.6 is a hydrogen atom, or an alkyl group having up to 4 carbon atoms.

16. An optical recording medium as in claim 1, wherein Z.sup.- is ##STR563## wherein R.sup.6, which may be the same or different when multiple R.sup.6 s are substituted, represents a hydrogen atom, an alkyl group having up to 4 carbon atoms, a chlorine atom, or a dialkyl group having up to 4 carbon atoms; and n represents 0 or an integer of from 1 to 3.

17. An optical recording medium as in claim 2, wherein Z.sup.- is ##STR564## wherein R.sup.6, which may be the same or different when multiple R.sup.6 s are substituted, represents a hydrogen atom, an alkyl group having up to 4 carbon atoms, a chlorine atom, or a dialkyl group having up to 4 carbon atoms; and n represents 0 or an integer of from 1 to 3.

18. An optical recording media as in claim 3, wherein Z.sup.- is ##STR565## wherein R.sup.6, which may be the same or different when multiple R.sup.6 s are substituted, represents a hydrogen atom, an alkyl group having up to 4 carbon atoms, a chlorine atom, or a dialkyl group having up to 4 carbon atoms; and n represents 0 or an integer of from 1 to 3.

19. An optical recording medium as in claim 16, wherein Z.sup.- is ##STR566##

20. An optical recording medium as in claim 17, wherein Z.sup.- is ##STR567##

21. An optical recording medium as in claim 18, wherein Z.sup.- is ##STR568##