Optical data carrier comprising a light-absorbent compound having a plurality of chromophoric centres in the information layer

[0001] The invention relates to a write-once optical data carrier comprising a light-absorbent compound having at least two identical or different chromophoric centres in the information layer, to a process for its production and also to the application of the abovementioned dyes to a polymer substrate, in particular polycarbonate, by spin coating or vapour deposition.

[0002] Write-once optical data carriers using specific light-absorbent substances or mixtures thereof are particularly suitable for use in high-density writeable optical data stores which operate with blue laser diodes, in particular GaN or SHG laser diodes (360-460 nm) and/or for use in DVD-R or CD-R disks which operate with red (635-660 nm) or infrared (780-830 nm) laser diodes.

[0003] The write-once compact disk (CD-R, 780 nm) has recently experienced enormous volume growth and represents the technically established system.

[0004] The next generation of optical data stores—DVDs—is currently being introduced onto the market. Through the use of shorter-wave laser radiation (635-660 nm) and higher numerical aperture NA, the storage density can be increased. The writeable format in this case is DVD-R.

[0005] Today, optical data storage formats which use blue laser diodes (based on GaN, JP 08 191 171 or Second Harmonic Generation SHG JP 09 050 629) (360 nm-460 nm) with high laser power are being developed. Writeable optical data stores will therefore also be used in this generation. The achievable storage density depends on the focusing of the laser spot on the information plane. Spot size scales with the laser wavelength λ/NA. NA is the numerical aperture of the objective lens used. In order to obtain the highest possible storage density, the use of the smallest possible wavelength λ is the aim. At present 390 nm is possible on the basis of semiconductor laser diodes.

[0006] The patent literature describes dye-based writeable optical data stores which are equally suitable for CD-R and DVD-R systems (JP-A 11 043 481 and JP-A 10 181 206). To achieve a high reflectivity and a high modulation height of the read-out signal and also to achieve sufficient sensitivity in writing, use is made of the fact that the IR wavelength of 780 nm of CD-Rs is located at the foot of the long wavelength flank of the absorption peak of the dye and the red wavelength of 635 nm or 650 nm of DVD-Rs is located at the foot of the short wavelength flank of the absorption peak of the dye. In JP-A 02 557 335, JP-A 10 058 828, JP-A 06 336 086, JP-A 02 865 955, WO-A 09 917 284 and U.S. Pat. No. 5,266,699, this concept is extended to the 450 nm working wavelength region on the short wavelength flank and the red and IR region on the long wavelength flank of the absorption peak.

[0007] Apart from the abovementioned optical properties, the writeable information layer comprising light-absorbent organic substances has to have a substantially amorphous morphology to keep the noise signal during writing or reading as small as possible. For this reason, it is particularly preferred that crystallization of the light-absorbent substances be prevented in the application of the substances by spin coating from a solution, by vapour deposition and/or sublimation during subsequent covering with metallic or dielectric layers under reduced pressure.

[0008] The amorphous layer comprising light-absorbent substances preferably has a high heat distortion resistance, since otherwise further layers of organic or inorganic material which are applied to the light-absorbent information layer by sputtering or vapour deposition would form blurred boundaries due to diffusion and thus adversely affect the reflectivity. Furthermore, a light-absorbent substance which has insufficient heat distortion resistance can, at the boundary to a polymeric support, diffuse into the latter and once again adversely affect the reflectivity.

[0009] A light-absorbent substance whose vapour pressure is too high can sublime during the abovementioned deposition of further layers by sputtering or vapour deposition in a high vacuum and thus reduce the layer thickness to below the desired value. This in turn has an adverse effect on the reflectivity.

[0010] It is therefore an object of the invention to provide suitable compounds which satisfy the high requirements (e.g. light stability, favourable signal/noise ratio, damage-free application to the substrate material, and the like) for use in the information layer in a write-once optical data carrier, in particular for high-density writeable optical data store formats in a laser wavelength range from 340 to 830 nm.

[0011] Surprisingly, it has been found that light-absorbent substances having a plurality of chromophoric centres can satisfy the abovementioned requirement profile particularly well.

[0012] The invention accordingly provides an optical data carrier comprising a preferably transparent substrate which may, if desired, have previously been coated with one or more reflection layers and to whose surface a light-writeable information layer, if desired one or more reflection layers and if desired a protective layer or a further substrate or a covering layer have been applied, which can be written on or read by means of blue, red or infrared light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that the light-absorbent compound has at least two identical or different chromophoric centres and has at least one absorption maximum in the range from 340 to 820 nm.

[0013] Light-Absorbent Compound (Physical Definition)

[0014] For the purposes of the present patent application, a “chromophoric centre” is a part of the molecule of a light-absorbing compound which has an absorption maximum in the range from 340 to 820 nm. This part of the molecule is preferably a monovalent group (radical).

[0015] Preference is given to light-absorbent compounds which have an absorption maximum λmax1 in the range from 340 to 410 nm or an absorption maximum λmax2 in the range from 400 to 650 nm or an absorption maximum λmax3 in the range from 630 to 820 nm, where the wavelength λ1/2 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax1, λmax2 or λmax3 or the absorbance in the short wavelength flank of the absorption maximum at the wavelength λmax2 or λmax3 is half the absorbance at λmax1, λmax2 or λmax3 and the wavelength λ1/10 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax1, λmax2 or λmax3 or the absorbance in the short wavelength flank of the absorption maximum at the wavelength λmax2 or λmax3 is one tenth of the absorbance at λmax1, λmax2 or λmax3 are preferably not more than 80 nm apart in each case.

[0016] The physical characterization of the light-absorbent compound applies in the same way to the chromophoric centres, i.e. shape and position of the absorption bands apply equally to the light-absorbent compound and the chromophoric centre in a preferred embodiment.

[0017] The light-absorbent compound should preferably be able to be changed thermally. The thermal change preferably occurs at a temperature of <600° C., particularly preferably at a temperature of <400° C., very particularly preferably at a temperature of <300° C., in particular <200° C. Such a change can be, for example, a decomposition or chemical change of the chromophoric centre of the light-absorbent compound.

[0018] In a preferred embodiment of the invention, the absorption maximum mal of the light-absorbent compound is in the range from 340 to 410 nm, preferably from 345 to 400 nm, in particular from 350 to 380 nm, particularly preferably from 360 to 370 nm, where the wavelength λ1/2 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax3 is half the absorbance at λmax1 and the wavelength λ1/10 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax3 is one tenth of the absorbance at λmax1 must in each case be no more than 50 nm apart. Such a light-absorbent compound preferably has no longer-wavelength maximum λmax2 up to a wavelength of 500 nm, particularly preferably 550 nm, very particularly preferably 600 nm.

[0019] In such light-absorbent compounds, λ1/2 and kilo, as defined above, are preferably not more than 40 nm apart, particularly preferably not more than 30 rum apart, very particularly preferably not more than 10 nm apart.

[0020] In a further embodiment of the invention, the absorption maximum λmax2 of the light-absorbent compound(s) is in the range from 420 to 550 nm, preferably from 410 to 510 nm, in particular from 420 to 510 nm, particularly preferably from 430 to 500 nm, where the wavelength λ1/2 at which the absorbance in the short wavelength flank of the absorption maximum at the wavelength λmax2 is half the absorbance at max and the wavelength λ1/10 at which the absorbance in the short wavelength flank of the absorption maximum at the wavelength λmax2 is one tenth of the absorbance at a must in each case be no more than 50 nm apart. Such a light-absorbent compound preferably has no shorter-wavelength maximum λmax1 down to a wavelength of 350 nm, particularly preferably 320 run, very particularly preferably 290 nm.

[0021] In these compounds, λ1/2 and λ1/10, as defined above, are preferably not more than 40 nm apart, particularly preferably not more than 30 nm apart, very particularly preferably not more than 20 nm apart.

[0022] In a further embodiment of the invention, the absorption maximum λmax2 of the light-absorbent compound(s) is in the range from 500 to 650 mm, preferably from 530 to 630 nm, in particular from 550 to 620 m, particularly preferably from 580 to 610 nm, where the wavelength λ1/2 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax2 is half the absorbance at λmax2 and the wavelength λ1/10 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax2 is one tenth of the absorbance at λmax2 must in each case be no more than 50 nm apart. Such a compound preferably has no longer-wavelength maximum λmax3 up to a wavelength of 750 nm, particularly preferably 800 nm, very particularly preferably 850 nm.

[0023] In these light-absorbent compound(s), λ1/2 and λ1/10, as defined above, are preferably not more than 40 nm apart, particularly preferably not more than 30 nm apart, very particularly preferably not more than 10 nm apart.

[0024] In a further embodiment of the invention, the absorption maximum λmax3 of the light-absorbent compound(s) is in the range from 630 to 800 nm, preferably from 650 to 770 nm, in particular from 670 to 750 nm, particularly preferably from 680 to 720 nm, where the wavelength λ1/2 at which the absorbance in the short wavelength flank of the absorption maximum at the wavelength λmax3 is half the absorbance at λmax3 and the wavelength λ1/10 at which the absorbance in the short wavelength flank of the absorption maximum at the wavelength λmax3 is one tenth of the absorbance at λmax3 must in each case be no more than 50 nm apart. Such a compound preferably has no shorter-wavelength maximum )max down to a wavelength of 600 nm, particularly preferably 550 nm, very particularly preferably 500 nm.

[0025] In these light-absorbent compound(s), λ1/a and λ1/10, as defined above, are preferably not more than 40 nm apart, particularly preferably not more than 30 nm apart, very particularly preferably not more than 20 nm apart.

[0026] In a further embodiment of the invention, the absorption maximum λmax3 of the light-absorbent compound(s) is in the range from 650 to 810 um, preferably from 660 to 790 nm, in particular from 670 to 760 nm, particularly preferably from 680 to 740 nm, where the wavelength λ1/2 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax3 is half the absorbance at λmax3 and the wavelength λ1/10 at which the absorbance in the long wavelength flank of the absorption maximum at the wavelength λmax3 is one tenth of the absorbance at λmax3 are preferably no more than 50 nm apart.

[0027] In these compounds, λ1/2 and λ1/10, as defined above, are preferably not more than 40 nm apart, particularly preferably not more than 30 nm apart, very particularly preferably not more than 10 nm apart.

[0028] The light-absorbent compounds preferably have a molar extinction coefficient F of >10 000 l/mol cm, preferably >15 000 l/mol cm, particularly preferably >20 000 l/mol cm, very particularly preferably >25 000 l/mol cm, in particular >30 000 l/mol cm, most preferably >40 000 l/mol cm, at the absorption maximum λmax1, λmax2 and/or λmax3.

[0029] Light-Absorbent Compound (Chemical Definitions)

[0030] The light-absorbent compounds can, for example, be in the form of polymers, e.g. as homopolymers, copolymers or graft polymers, dendrimers or in another form.

[0031] Preference is given to linear homopolymers whose repeating units bear the chromophoric centres. Particular preference is given to polymers of the formula (I). Preference is likewise given to light-absorbent compounds in dendritic form, where the chromophoric centres are preferably located at the ends of a molecule having a dendritic structure. Particular preference is given to dendrimers of the formula (II).

[0032] Preference is likewise given to light-absorbent compounds in the form of side-chain polymers in which the chromophoric centres are preferably bound in an appropriate manner to a polymer chain.

[0033] As light-absorbent compound in the information layer of an optical data carrier, preference is given to using a compound of the formula

F1—(BF2)nBF1 (I)

DFk (II),

[0034] or a polymer having a main chain acting as backbone and covalently bound side groups of the formula (III)

—S—F1 (III)

[0035] branching off therefrom, where the polymer has a degree of polymerization of from 2 to 1 000,

[0036] where

[0037] F1 represents a monovalent chromophoric centre,

[0038] F2 represents a bivalent chromophoric centre,

[0039] B represents a bivalent bridge —B1— or —(B2F1)— or —(B3F12)—,

[0040] where

[0041] B2 is a trivalent radical and B3 is a tetravalent radical,

[0042] D represents a dendritic structure of the generation 21,

[0043] S represents a bivalent spacer group,

[0044] n represents an integer from 0 to 1 000,

[0045] k represents the number 3·21 or 4·21,

[0046] l represents an integer from 0 to 6.

[0047] As preferred light-absorbent compounds, mention may be made of those of the formulae (I) and (II)

[0048] in which B1

[0049] D represents a radical of the formulae

[0050] Q1 to Q6 represent, independently of one another, a direct bond, —O—, —S—, —NR1—, —C(R2R3)—, —(C═O)—, —(CO—O)—, —(CO—NR1)—, —(SO2)—, —(SO2—O)—, —(SO2—NR1)—, —(C═NR4)—, —(CNR1—NR4)—, —(CH2)p—, —(CH2CH2O)p—CH2CH2—, o-, m- or p-phenylene, where the chain —(CH2)p— may be interrupted by —O—, —NR1— or —OSiR52O—,

[0051] T1 and T4 represent, independently of one another, a direct bond, —(CH2)p— or o-, m- or p-phenylene, where the chain —(CH2)p— may be interrupted by —O—, —NR— or —OSiR52O—,

[0052] T5 represents CR6, N or a trivalent radical of the formula

[0053] T6 represents C, Si(O—)4, >N—(CH2)u—N< or a tetravalent radical of the formula

[0054] p represents an integer from 1 to 12,

[0055] q, r, s and t represent, independently of one another, an integer from 0 to 12,

[0056] u represents an integer from 2 to 4,

[0057] R1 represents hydrogen, C1-C12-alkyl, C3-C10-cycloalkyl, C2-C12-alkenyl, C6-C10-aryl, C1-C12-alkyl-(C═O)—, C3-C10-cycloalkyl-(C═O)—, C2-C12-alkenyl-(C═O)—, C6-C10-aryl-(C═O)—, C1-C12-alkyl-(SO2)—, C3-C10-cycloalkyl-(SO2)—, C2-C12-alkenyl-(SO2)— or C6-C10-aryl-(SO2)—,

[0058] R2 to R4 and R6 represent, independently of one another, hydrogen, C1-C12-alkyl, C3-C10-cycloalkyl, C2-C12-alkenyl, C6-C10-aryl,

[0059] R5 represents methyl or ethyl and

[0060] the other radicals are as defined above.

[0061] n is preferably an integer from 0 to 10, particularly preferably from 0 to 2, very particularly preferably 0. 1 is preferably an integer from 0 to 3, particularly preferably 0 or 1.

[0062] Preferred polymers bearing radicals of the formula (III) as light-absorbent compounds are ones in which the polymer chain is built up on the basis of identical or different structural elements K and

[0063] K represents a structural element of a poly-acrylate, -methacrylate, -acrylamide, -methacrylamide, -siloxane, -α-oxirane, -ether, -amide, -urethane, -urea, -ester, -carbonate, -styrene or -maleic acid and

[0064] the other radicals are as defined above.

[0065] Preference is given to

[0066] S representing a spacer group of the formula —Q5—T4—Q6— which connects the main chain of the side-chain polymer to the chromophoric centre F1.

[0067] Preference is given to poly-acrylates, -methacrylates and -esters. Preference is likewise given to copolymers comprising acrylate or methacrylate and acrylamide units. Particular preference is given to poly-acrylates and -methacrylates. In these cases,

[0068] K represents

[0069] where

[0070] R represents hydrogen or methyl and

[0071] the asterisked (*) bond leads to the bivalent spacer group S.

[0072] Particular preference is likewise given to copolymers in which K represents K′ and K″ where

[0073] where

[0074] R represents hydrogen or methyl and the asterisked (*) bond leads to the bivalent spacer group S.

[0075] Preference is given to a degree of polymerization of from 2 to 100, particularly preferably from 2 to 20.

[0076] The chromophoric centres of the light-absorbent compounds can be, for example, radicals of the following structural types (cf., for example, G. Ebner and D. Schulz, Textilfarberei und Farbstoffe, Springer-Verlag, Berlin Heidelberg, 1989; H. Zollinger, Color Chemistry, VCH Verlagsgesellschaft mbH Weinheim, 1991):

[0077] azo dyes, anthraquinoid dyes, indigoid dyes, polymethine dyes, arylcarbonium dyes, phthalocyanine dyes, nitro dyes, perylenes, coumarins, formazanes, metal complexes, in particular

[0078] bridged or unbridged (hetero)cinnamic acid derivatives, (hetero)stilbenes, coumarins, methines, cyanines, hemicyanines, neutromethines (merocyanines), nullmethines, azomethines, hydrazones, azine dyes, triphendioxazines, pyronines, acridines, rhodamines, indamines, indophenols, di- or triphenylmethanes, aryl- and hetaryl azo dyes, quinoid dyes, phthalocyanines, naphthocyanines, subphthalocyanines, porphyrins, tetraazaporphyrins and metal complexes.

[0079] Preferred light-absorbent compounds having an absorption maximum λmax1 in the range from 340 to 410 nm are, for example, those of the following formulae. Corresponding optical data carriers comprising these compounds in the information layer can be read and written on by means of blue or red light, in particular laser light:

[0080] where

[0081] Ar101 and Ar102 represent, independently of one another, C6-C10-aryl or the radical of a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or substituted by nonionic radicals,

[0082] Y101 and Y102 represent, independently of one another, N or C—R101 or

[0083] Y101═Y102 may be a direct bond,

[0084] R101 and R104 represent, independently of one another, hydrogen, C1-C16-alkyl, cyano, carboxyl, C1-C16-alkoxycarbonyl, C1-C16-alkanoyl or Ar102, or R101 represents a bridge to Ar101,

[0085] R102 and R103 represent, independently of one another, cyano, nitro, carboxyl, C1-C16-alkoxycarbonyl, aminocarbonyl or C1-C16-alkanoyl, or R102 represents hydrogen, halogen, C1-C16-alkyl or a radical of the formula

[0086] or R103 represents Ar102, CH2—COOalkyl or P(O)(O—C1-C12-alkyl)2 or C1-C16-alkyl or R102; R103 together with the carbon atom connecting them represent a five- or six-membered carbocyclic or aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals, or R103 forms a bridge to Ar101 or ring A101 which may contain a heteroatom and/or be substituted by nonionic radicals,

[0087] R100 represents hydrogen, C1-C16-alkyl, C7-C16-aralkyl or R101 or NR100R100 represents pyrrolidino, piperidino or morpholino or

[0088] R100 and R104 together represent a —CH2—CH2— or —CH2—CH2—CH2— bridge, R105 represents cyano, carboxyl, C1-C16-alkoxycarbonyl, aminocarbonyl, C1-C16-alkanoyl or Ar101 or R104; R105 together with the carbon atom connecting them represent a five- or six-membered carbocyclic or aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals,

[0089] X101, X102, X103, X104, X106, X109 and X110 represent, independently of one another, O, S, or N—R100 or X102, X104 or X106 may also be CH or CR100R100,

[0090] A101, B101, C101, F101, G101 and H101 represent, independently of one another, a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals,

[0091] X105 and X108 represent, independently of one another, N,

[0092] E101 represents a direct double bond, ═CH—CH═, ═N—CH═ or ═N—N═,

[0093] E102 represents a direct bond, —CH═CH—, —N═CH— or —N═N—,

[0094] Ar103 and Ar104 represent, independently of one another, 2-hydroxyphenyl radicals which may be benzo-fused and/or be substituted by hydroxy, C1-C16-alkoxy or C6-C10-aryloxy,

[0095] R106 and R107 represent, independently of one another, hydrogen, C1-C16-alkyl or C6-C10-aryl or together represent a —CH═CH—CH═CH— or o-C6H4—CH═CH—CH═CH— bridge,

[0096] R108 represents C1-C16-alkyl, CHO, CN, CO—C1-C8-alkyl, CO—C6-C10-aryl or CH═C(CO—C1-C8-alkyl)—CH2—CO—C1-C8-alkyl,

[0097] R109 represents hydroxy or C1-C16-alkoxy,

[0098] R110 and R111 represent hydrogen or together represent a —CH═CH—CH═CH— bridge,

[0099] R112 represents hydrogen, C1-C16-alkyl or cyano,

[0100] R113 represents hydrogen, cyano, C1-C4-alkoxycarbonyl, C6-C10-aryl, thien-2-yl, pyrid-2- or S-4yl, pyrazol-1-yl or 1,2,4-triazol-1- or -4-yl, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals,

[0101] R114 represents hydrogen, C1-C16-alkoxy, 1,2,3-triazol-2-yl which may be substituted by nonionic radicals, C1-C16-alkanoylamino, C1-C8-alkanesulphonylamino or C6-C10-arylsulphonylamino,

[0102] Ar105 and Ar106 represent, independently of one another, C6-C10-aryl or the radical of a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals and/or by sulpho,

[0103] a, b and c represent, independently of one another, an integer from 0 to 2,

[0104] X107 represents N or N+—R100 An−,

[0105] An− represents an anion,

[0106] E103 represents N, CH, C—CH3 or C—CN,

[0107] R115 and R116 represent, independently of one another, hydrogen or C1-C16-alkyl,

[0108] R117 and R118 represent, independently of one another, hydrogen, C1-C16-alkyl, cyano or C1-C16-alkoxycarbonyl,

[0109] R119 represents hydrogen, C1-C16-alkyl, C1-C16-alkoxy or 2 radicals R119 of a thiophene ring represent a bivalent radical of the formula —O—CH2—CH2—O—,

[0110] Y103 and Y104 represent, independently of one another, O or N—CN,

[0111] R120 to R121 represent, independently of one another, hydrogen, C1-C16-alkyl, C1-C16-alkoxy, cyano, C1-C16-alkoxycarbonyl, halogen, Ar101, Ar102 or

[0112] R120 together with R121 and/or R122 together with R123 represent a —CH═CH—CH═CH— or o-C6H4—CH═CH—CH═CH— bridge which may be substituted by nonionic substituents,

[0113] R124 represents C1-C16-alkyl, C1-C16-alkoxy, cyano, C1-C16-alkoxycarbonyl, carboxyl, C1-C16-alkylaminocarbonyl or C1-C16-dialkylaminocarbonyl,

[0114] R125 and R126 represent, independently of one another, hydrogen, C1-C16-alkyl, C1-C16-alkoxy, cyano, C1-C16-alkoxycarbonyl, hydroxy, carboxyl or C6-C10-aryloxy,

[0115] e, f and g represent, independently of one another, an integer from 1 to 4, where, if e, f or g >1, the radicals may be different,

[0116] X111 represents N or C—Ar102,

[0117] R127 represents hydrogen, C1-C16-alkyl or C6-C10-aryl,

[0118] R128 and R129 represent, independently of one another, hydrogen, C1-C16-alkyl, C6-C10-aryl or C7-C15-aralkyl or

[0119] NR128R29 represents morpholino, piperidino or pyrrolidino,

[0120] R130 represents C1-C16-allyl, C7-C15-aralkyl or Ar1,

[0121] R131 and R132 represent, independently of one another, hydrogen, C1-C16-alkyl, C1-C16-alkoxy, cyano, C1-C16-alkoxycarbonyl, halogen or C6-C10-aryl or together represent a bridge of the formula —CO—N(R130)—CO—, and the radicals M300, R306 to R309 and w to z of the formula (CCCIX) are described in more detail below,

[0122] with bonding to the bridge B, the dendritic structure D or the spacer group S being via the radicals R100 to R132, M300, R306 to R309 or via the nonionic radicals by which Ar101 to Ar106 and the rings A101 to H101 may be substituted. In this case, these radicals represent a direct bond.

[0123] Nonionic radicals are C1-C4-alkyl, C1-C4-alkoxy, halogen, cyano, nitro, C1-C4-alkoxycarbonyl, C1-C4-alkylthio, C1-C4-alkanoylamino, benzoylamino, mono- or di-C1-C4-alkylamino.

[0124] Alkyl, alkoxy, aryl and heterocyclic radicals may, if desired, bear further radicals such as alkyl, halogen, nitro, cyano, CO—NH2, alkoxy, trialkylsilyl, trialkylsiloxy or phenyl, the alkyl and alkoxy radicals may be straight-chain or branched, the alkyl radicals may be partially halogenated or perhalogenated, the alkyl and alkoxy radicals may be ethoxylated or propoxylated or silylated, adjacent alkyl and/or aLkoxy radicals on aryl or heterocyclic radicals may together form a three- or four-membered bridge and the heterocyclic radicals may be benzo-fused and/or quaternized.

[0125] Particular preference is given to light-absorbent compounds of the formulae (CI) to (CXXI), (CIIIa) and (CCCIX),

[0126] where

[0127] Ar101 and Ar102 represent, independently of one another, phenyl, naphthyl, benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl, thiazol-2-yl, thiazolin-2-yl, pyrrolin-2-yl, isothiazol-3-yl, imidazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,3,4-triazol-2-yl, 2- or 4-pyridyl, 2- or 4-quinolyl, pyrrol-2- or -3-yl, thiophen-2- or -3-yl, furan-2- or -3-yl, indol-2- or -3-yl, benzothiophen-2-yl, benzofuran-2-yl or 3,3-dimethylindolen-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, dimethylamino, diethylamino, dipropylamino or dibutylamino,

[0128] Y101 and Y102 represent, independently of one another, N or C—R101 or

[0129] Y101═Y102 may represent a direct bond,

[0130] R101 and R104 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, acetyl, propionyl or Ar102, or Ar101 and R101 together represent a ring of the formula

[0131] which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, where the asterisk (*) indicates the ring atom from which the double bond extends,

[0132] R102, R103 and R105 represent, independently of one another, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, methoxyethoxycarbonyl, acetyl, propionyl or butanoyl or R102 represents hydrogen, or a radical of the formula

[0133] or R103 represents Ar102 or R105 represents Ar101 or R02; R103 or R104; R105 together with the carbon atom connecting them represent a ring of the formula

[0134] which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals, where the asterisk (*) indicates the ring atom from which the double bond extends, or R103 represents a —CH2—, —C(CH3)2—, —O—, —NH—, —N(CH3)—, —N(C2H5)—, —N(COCH3)—, N(COC4H9)— or —N(COC6H5)— bridge which is bound to the 2 position (relative to the site of substitution) of Ar101 or ring A101,

[0135] R100 represents hydrogen, methyl, ethyl, propyl, butyl or benzyl or

[0136] NR100R100 represents pyrrolidino, morpholino or piperidino or

[0137] R100 and R10 together represent a —CH2—CH2— bridge or

[0138] two radicals R100 in formula (CVII) or (CXIII) represent a —CH2—CH2— or —CH2—CH2—CH2— bridge,

[0139] A101, B101 and G101 represent, independently of one another, benzothiazol-2-ylidene, benzoxazol-2-ylidene, benzimidazol-2-ylidene, thiazol-2-ylidene, thiazolin-2-ylidene, pyrrolin-2-ylidene, isothiazol-3-ylidene, imidazol -2-ylidene, 1,3,4-thiadiazol-2-ylidene, 1,3,4-triazol-2-ylidene, pyridin -2- or 4-ylidene, quinolin-2- or 4-ylidene, pyrrol-2- or -3-ylidene, thiophen-2- or -3-ylidene, furan-2- or -3-ylidene, indol-2- or -3-ylidene, benzothiophen-2-ylidene, benzofuran-2-ylidene or 3,3-dimethylindolen-2-ylidene and A and B may also be 1,3-dithiol-2-ylidene or benzo-1,3-dithiol-2-ylidene, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino or benzoylamino,

[0140] C101 and F101 represent, independently of one another, benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl, thiazol-2-yl, thiazolin-2-yl, pyrrolin-2-yl, isothiazol-3-yl, imidazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,3,4-triazol-2-yl, 2- or 4-pyridyl, 2- or 4-quinolyl, pyrrol-2- or -3-yl, thiophen-2- or -3-yl, furan-2- or -3-yl, indol-2- or -3-yl, benzothiophen-2-yl, benzofuran-2-yl or 3,3-dimethylindolen-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino or benzoylamino, where

[0141] X101, X102, X103, X104, X106, X109 and X110 represent, independently of one another, O, S or N—R100 and X102, X104 or X106 may also be CH or X105 and X108 represent, independently of one another, N,

[0142] X107 represents N or N+—R100 An− and

[0143] An− represents an anion,

[0144] E101 represents a direct double bond or ═N—N═,

[0145] Ar103 and Ar104 represent, independently of one another, 2-hydroxyphenyl radicals which may be substituted by hydroxy, methoxy, ethoxy, propoxy, butoxy or phenoxy,

[0146] R106 and R107 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl or phenyl or together represent a —CH═CH—CH═CH— or o-C6H4—CH═CH—CH═CH— bridge,

[0147] R108 represents methyl, ethyl, propyl, butyl, CHO, CN, acetyl, propionyl or benzoyl,

[0148] R109 represents hydroxy, methoxy, ethoxy, propoxy or butoxy,

[0149] R110 and R111 represent hydrogen or together represent a —CH═CH—CH═CH— bridge,

[0150] R112 represents hydrogen or methyl,

[0151] R113 represents hydrogen, cyano, methoxycarbonyl, ethoxycarbonyl, phenyl, thien-2-yl, pyrid-2- or -4-yl, pyrazol-1-yl or 1,2,4-triazol-1- or 4-yl, which may be substituted by methyl, methoxy or chlorine,

[0152] R114 represents hydrogen, methoxy, ethoxy, propoxy, butoxy, 1,2,3-triazol -2-yl which may be substituted by methyl and/or phenyl, acetylamino, methanesulphonylamino or benzenesulphonylamino,

[0153] Ar105 and Ar106 represent, independently of one another, phenyl, benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl, thiazol-2-yl, thiazolin-2-yl, pyrrolin-2-yl, isothiazol-3-yl, imidazol-2-yl, 1,3,4-triazol-2-yl, 2- or 4-pyridyl, 2- or 4-quinolyl, thiophen-2- or -3-yl, furan-2- or -3-yl, benzothiophen-2-yl or benzofuran-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl or sulpho,

[0154] a, b and c represent, independently of one another, an integer from 0 to 1,

[0155] E102 represents a direct bond, —CH═CH— or —N═CH—,

[0156] E103 represents N or C—CN,

[0157] R115 and R116 represent, independently of one another, hydrogen, methyl or ethyl,

[0158] R117 and R118 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, cyano, methoxycarbonyl or ethoxycarbonyl,

[0159] R119 represents hydrogen, methyl, methoxy, ethoxy or 2 radicals R119 of a thiophene ring represent a bivalent radical of the formula —O—CH2CH2—O—,

[0160] Y103 and Y104 represent, independently of one another, O or N—CN,

[0161] R120to R123 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, cyano, methoxycarbonyl, ethoxycarbonyl, chlorine, bromine, or

[0162] R120 together with R121 and/or R122 together with R123 represent a —CH═CH—CH═CH— bridge,

[0163] R124 represents methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, cyano, methoxycarbonyl or ethoxycarbonyl,

[0164] R125 and R126 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, cyano, methoxycarbonyl, ethoxycarbonyl or hydroxy, where at least one of the radicals R126 is located in the ring position 1 or 3 and is methoxy, ethoxy, propoxy or butoxy,

[0165] e, f and g represent, independently of one another, 1 or 2, where, if e, f or g>1, the radicals may be different,

[0166] X111 represents N or C—Ar102,

[0167] R127 represents hydrogen, methyl, ethyl, propyl, butyl or phenyl,

[0168] R128 and R129 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, phenyl or benzyl or

[0169] NR128R129 represents morpholino, piperidino or pyrrolidino,

[0170] R130 represents methyl, ethyl, propyl, butyl, methoxyethyl, ethoxyethyl, methoxypropyl, benzyl, phenethyl or Ar1,

[0171] R131 and R132 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, methoxycarbonyl, ethoxycarbonyl, chlorine or bromine or together represent a bridge of the formula —CO—N(R130)—CO—,

[0172] M300 represents 2H atoms, Al, Si, Ge, Zn, Mg or TiIV, where in the case of M300 being Al, Si, Ge or TiIV it bears one or two further substituents or ligands R313 and/or R314 which are arranged axially relative to the phthalocyanine plane,

[0173] R306 to R309 represent, independently of one another, methyl, ethyl, propyl, butyl, methoxy or chlorine,

[0174] w to z represent, independently of one another, an integer from 0 to 4,

[0175] R313 and R314 represent, independently of one another, methyl, ethyl, phenyl, hydroxy, fluorine, chlorine, bromine, methoxy, ethoxy, phenoxy, tolyloxy, cyano or ═O,

[0176] and the radicals R306 to R309, M300 and w to z may also have the meanings defined below,

[0177] where bonding to the bridge B, the dendritic structure D or the spacer group S is via the radicals R100 to R132, via the radicals by which Ar101 to Ar106 and the rings A101 to G101 may be substituted, via R306 to R309, R313 or R314. In this case, these radicals represent a direct bond.

[0178] The following examples serve to illustrate:

[0179] Preferred light-absorbent compounds having an absorption maximum λmax2 in the range from 400 to 650 nm are, for example, those of the following formulae:

[0180] Corresponding optical data stores comprising these compounds in the information layer can be read and written on by means of blue or red light, in particular blue or red laser light.

[0181] where

[0182] Ar201, Ar202, Ar204, Ar205 and Ar206 represent, independently of one another, C6-C10-aryl or the radical of a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals or sulpho,

[0183] Ar203 represents the bifunctional radical of a C6-C10-aromatic or the bifunctional radical of a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals or sulpho, where two such bifunctional radicals may be joined via a bifunctional bridge,

[0184] Y201 represents N or C—R201,

[0185] R201 represents hydrogen, C1-C16-alkyl, cyano, carboxyl, C1-C16-alkoxycarbonyl, C1-C16-alkanoyl or Ar202 or a bridge to Ar201 or R200,

[0186] R202 and R203 represent, independently of one another, cyano, carboxyl, C1-C16-alkoxycarbonyl, aminocarbonyl or C1-C16-alkanoyl or R202 represents hydrogen, halogen or a radical of the formula

[0187] R203 represents Ar202, CH2—COOalkyl or P(O)(O—C1-C12-alkyl)2 or C1-C16-alkyl or R202; R203 together with the carbon atom connecting them represent a five- or six-membered carbocyclic or aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals,

[0188] E201 represents a direct bond, —CH═CH—, —CH═C(CN)— or —C(CN)═C(CN)—,

[0189] o represents 1 or 2,

[0190] R204 represents hydrogen, C1-C16-alkyl or C7-C16-aralkyl or a bridge to Ar201 or Ar202 or E201 or Ar205 or E207 or

[0191] NR204R204 represents pyrrolidino, piperidino or morpholino,

[0192] X201, X202, X204 and X26 represent, independently of one another, O, S or N—R200, and X202, X204 and X206 may also be CH or CR200R200,

[0193] A201, B201, C201 and J201 represent, independently of one another, a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals,

[0194] X203 and X205 represent, independently of one another, N,

[0195] R200 represents hydrogen, C1-C16-alkyl or C7-C16-aralkyl or forms a ring to E202, E203, E205 or E206,

[0196] E202 represents a direct double bond, ═CH—CH═, ═N—CH═ or ═N—N═,

[0197] E203, E204, E205, E206 and E207 represent, independently of one another, N or C—R201, —E203═E204— or —E206═E207 may represent a direct bond and two radicals R201 may together form a two-, three- or four-membered bridge which may contain heteroatoms and/or be substituted by nonionic radicals and/or be benzo-fused,

[0198] R205 and R205′ represent hydrogen or together represent a —CH═CH—CH═CH— bridge,

[0199] R206 represents hydrogen, cyano or C1-C4-alkyl-SO2—,

[0200] R207 represents hydrogen, cyano, C1-C4-alkoxycarbonyl or Ar201,

[0201] R208 represents NR222R221, piperidino, morpholino or pyrrolidino,

[0202] R213, R218, R219, R222 and R223 represent, independently of one another, hydrogen, C1-C16-alkyl, C7-C16-aralkyl or C6-C10-aryl,

[0203] X207 represents O, S, N—R222 or C(CH3)2,

[0204] Y202 and Y204 represent, independently of one another, OR222, SR222 or NR222R223,

[0205] Y203 and Y205 represent, independently of one another, O, S or N+R222R223 An−,

[0206] An− represents an anion,

[0207] R209 and R210 represent, independently of one another, hydrogen, C1-C4-alkyl, C1-C4-alkoxy, halogen, Y202 or Y204 or together with R216 and/or R217 form a bridge or two adjacent radicals R209 or R210 form a —CH═CH—CH═CH— bridge,

[0208] h and i represent, independently of one another, an integer from 0 to 3,

[0209] R211 represents hydrogen, C1-C4-alkyl or Ar201,

[0210] Y210 and Y211 represent, independently of one another, O, S or N—CN,

[0211] X208 and X209 represent, independently of one another, O, S or N—R213,

[0212] R212 represents hydrogen, halogen, C1-C16-allyl, C7-C16-aralkyl or C6-C10-aryl,

[0213] R214 and R215 represent, independently of one another, hydrogen, C1-C8-alkyl, C1-C8-alkoxy, halogen, cyano, nitro or NR222R223 or two adjacent radicals R214 or R215 form a —CH═CH—CH═CH— bridge which may in turn be substituted by R214 or R215, where at least one of the radicals R214 or R215 represents NR222R223,

[0214] j and m represent, independently of one another, an integer from 1 to 4,

[0215] D201, E201, G201 and H201 represent, independently of one another, a five- or six-membered aromatic or pseudoaromatic carbocyclic ring or an aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals or sulpho,

[0216] Y206 and Y207 represent, independently of one another, —O—, —NR224—, —CO—O—, —CO—NR224, —SO2—O— or SO2—NR224—,

[0217] Y208, Y209 and Y210 represent, independently of one another, N or CH,

[0218] Y211 represents O or —NR224,

[0219] R224 represents hydrogen, C1-C16-alkyl, cyano, C1-C16-alkoxycarbonyl, C1-C16-alkanoyl, C1-C16-alkylsulphonyl, C6-C10-aryl, C6-C10-arylcarbonyl or C6-C10-arylsulphonyl,

[0220] M200 and M201 represent, independently of one another, an at least divalent metal ion which may bear further substituents and/or ligands, and M201 may also represent two hydrogen atoms,

[0221] F201 represents a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring which may contain further heteroatoms and/or be benzo- or naphtho-fused and/or be substituted by nonionic radicals or sulpho,

[0222] R220 and R221 represent, independently of one another, hydrogen, C1-C16-alkyl, C1-C16-alkoxy, cyano, C1-C16-alkoxycarbonyl, halogen, C6-C10-aryl, NR211R223 or together represent a bivalent radical of the formula

[0223] X210 represents N, CH, C1-C6-alkyl, C—Ar201, C—Cl or C—N(C1-C6-alkyl)2,

[0224] Y212 represents N—R204, N—Ar201, N—N═CH—Ar201, CR202R203 or CH—C—R202R203 An−,

[0225] Y213 represents NH—R204, NH—Ar201, NH—N═CH—Ar201, C—R203 An− or CH═CR202R203,

[0226] where bonding to the bridge B, the dendritic structure D or the spacer group S is via the radicals R200 to R224 or via the nonionic radicals by which Ar201 to Ar205 and the rings A201 to J201 may be substituted. In this case, the radicals represent a direct bond.

[0227] Nonionic radicals are C1-C4-alkyl, C1-C4-alkoxy, halogen, cyano, nitro, C1-C4-alkoxycarbonyl, C1-C4-alkylthio, C1-C4-alkanoylamino, benzoylamino, mono- or di-C1-C4-alkylamino.

[0228] Alkyl, alkoxy, aryl and heterocyclic radicals may, if desired, bear further radicals such as alkyl, halogen, nitro, cyano, COOH, CO—NH2, alkoxy, trialkylsilyl, trialkylsiloxy, phenyl or SO3H, the alkyl and alkoxy radicals may be straight-chain or branched, the alkyl radicals may be partially halogenated or perhalogenated, the alkyl and alkoxy radicals may be ethoxylated or propoxylated or silylated, adjacent alkyl and/or alkoxy radicals on aryl or heterocyclic radicals may together form a three- or four-membered bridge and the heterocyclic radicals may be benzo-fused and/or quaternized.

[0229] Particular preference is given to light-absorbent compounds of the formulae (CCI) to (CCXXVI) and (CCIVa),

[0230] where

[0231] Ar201, Ar202, Ar204, Ar205 and Ar206 represent, independently of one another, phenyl, naphthyl, benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl, thiazol-2- or -5-yl, thiazolin-2-yl, pyrrolin-2-yl, isothiazol-3-yl, imidazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,3,4-triazol-2-yl, 2- or 4-pyridyl, 2- or 4-quinolyl, pyrrol-2- or -3-yl, thiophen-2- or -3-yl, furan-2- or -3-yl, indol-2- or -3-yl, benzothiophen-2-yl, benzofuran-2-yl or 3,3-dimethylindolen-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, hydroxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, amino, dimethylamino, diethylamino, dipropylamino, dibutylamino, pyrrolidino, piperidino, morpholino, COOH or SO3H,

[0232] Ar203 represents phenylene, naphthylene, 1,3,4-thiadiazol-2,5-diyl, 1,3,4-oxadiazol-2,5-diyl, 1,3,4-triazol-2,5-diyl or a bifunctional radical of the following formula

[0233] which may be substituted by chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, amino, dimethylamino, diethylamino, dipropylamino, dibutylamino, COOH or SO3H,

[0234] Y210 represents Cl, OH, NHR or NR2002,

[0235] Y201 represents N or C—R201,

[0236] R201 represents hydrogen, methyl, ethyl, propyl, butyl, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, acetyl, propionyl or Ar202,

[0237] R202 and R203 represent, independently of one another, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, methoxyethoxycarbonyl, acetyl, propionyl or butanoyl or R202 represents hydrogen or a radical of the formula

[0238] or R203 represents Ar202 or R202; R203 together with the carbon atom connecting them represent a ring of the formula

[0239] which may be benzo- or naphtho-fused and/or be substituted by nonionic or ionic radicals, where the asterisk (*) indicates the ring atom from which the double bond extends,

[0240] E201 represents a direct bond or —CH═CH—,

[0241] R204 represents hydrogen, methyl, ethyl, propyl, butyl, benzyl or

[0242] Ar201—N—R204 or Ar205—N—R204 represents an N-bonded pyrrole, indole or carbazole ring which may be substituted by methyl, ethyl, methoxy, ethoxy, propoxy, chlorine, bromine, iodine, cyano, nitro or methoxycarbonyl or

[0243] NR204R204 represents pyrrolidino, piperidino or morpholino,

[0244] A201 represents benzothiazol-2-ylidene, benzoxazol-2-ylidene, benzimidazol-2-ylidene, thiazol-2-ylidene, thiazolin-2-ylidene, pyrrolin-2-ylidene, isothiazol-3-ylidene, imidazol-2-ylidene, 1,3,4-thiadiazol-2-ylidene, 1,3,4-triazol-2-ylidene, pyridin-2- or 4-ylidene, quinolin-2- or 4-ylidene, pyrrol-2- or -3-ylidene, thiophen-2- or -3-ylidene, furan-2- or -3-ylidene, indol-2- or -3-ylidene, benzothiophen-2-ylidene, benzofuran-2-ylidene, 1,3-dithiol-2-ylidene, benzo-1,3-dithiol-2-ylidene or 3,3-dimethylindolen-2-ylidene, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, dimethylamino, diethylamino, dipropylamino, dibutylamino, methylbenzylamino, methylphenylamino, pyrrolidino or morpholino,

[0245] B201 represents benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl, thiazol-2-yl, thiazolin-2-yl, pyrrolin-2-yl, isothiazol-3-yl, imidazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,3,4-triazol-2-yl, 2- or 4-pyridyl, 2- or 4-quinolyl, indol-3-yl or 3,3-dimethylindolen-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, dimethylamino, diethylamino, dipropylamino, dibutylamino, methylbenzylamino, methylphenylamino, pyrrolidino or morpholino,

[0246] C201 represents benzothiazol-2-ylidene, benzoxazol-2-ylidene, benzimidazol -2-ylidene, thiazol-2-ylidene, thiazol-5-ylidene, thiazolin-2-ylidene, pyrrolin-2-ylidene, isothiazol-3-ylidene, imidazol-2-ylidene, 1,3,4-thiadiazol-2-ylidene, 1,3,4-triazol-2-ylidene, pyridin-2- or 4-ylidene, quinolin-2- or 4-ylidene, indol-3-yl or 3,3-dimethylindolen-2-ylidene, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, dimethylamino, diethylamino, dipropylamino, dibutylamino, methylbenzylamino, methylphenylamino, pyrrolidino, piperidino or morpholino, where

[0247] X201, X202, X204 and X206 represent, independently of one another, O, S or N—R200, and X202, X204 and X206 may also represent CR200R200,

[0248] X203 and X205 represent, independently of one another, N, and

[0249] An− represents an anion,

[0250] R200 represents hydrogen, methyl, ethyl, propyl, butyl or benzyl,

[0251] R200′ represents methyl, ethyl, propyl, butyl or benzyl,

[0252] E202 represents ═CH—CH═, ═N—CH═ or ═N—N═,

[0253] —E203═E204—E205═ represents —CR201′═CR201′—CR201′═, —N═N—N═, —N═CR201′—CR201′═, —CR201′═N—CR201′═, —CR201′═CR201′—N═, —N═N—CR201′═ or —CR201′═N—N═,

[0254] E206═E207 represents CR201′═CR201′, N═N, N═CR201′, CR201′═N or a direct bond,

[0255] R201′ represents hydrogen, methyl or cyano or two radicals R201′ represent a —CH2—CH2—, —CH2—CH2—CH2— or —CH═CH—CH═CH— bridge,

[0256] R205 and R205′ represent hydrogen or together represent a —CH═CH—CH═CH— bridge,

[0257] R206 represents cyano or methyl-SO2—,

[0258] R207 represents hydrogen, cyano, C1-C4-alkoxycarbonyl or Ar201,

[0259] R208 represents NR222R223, piperidino, morpholino or pyrrolidino,

[0260] R213, R218, R219, R222 and R223 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenethyl, phenylpropyl or phenyl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, COOH or SO3H,

[0261] X207 represents O, S or N—R222,

[0262] Y202 and Y204 represent, independently of one another, NR222R223,

[0263] Y203 and Y205 represent, independently of one another, O or N+R222R223 An−,

[0264] R209 and R210 represent, independently of one another, hydrogen, methyl, ethyl, methoxy, ethoxy, chlorine or bromine or R209; R222, R209; R223, R210; R222 and/or R210; R223 form a —CH2—CH2— or —CH2—CH2—CH2-bridge or two adjacent radicals R209 or R210 form a —CH═CH—CH═CH-bridge,

[0265] a and b represent, independently of one another, an integer from 0 to 3,

[0266] R211 represents hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl or phenyl, which may be substituted by from 1 to 3 radicals selected from the group consisting of hydroxy, methyl, methoxy, chlorine, bromine, COOH, methoxycarbonyl, ethoxycarbonyl or SO3H,

[0267] Y210 and Y211 represent, independently of one another, O or N—CN,

[0268] X208 and X209 represent, independently of one another, O or N—R213,

[0269] R212 represents hydrogen or chlorine,

[0270] R214 and R215 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, cyano, nitro or NR222R223 or two adjacent radicals R214 and R215 may form a —CH═CH—CH═CH— bridge, where at least one, preferably two, of the radicals R214 or R215 represent NR222R223,

[0271] d and e represent, independently of one another, an integer from 1 to 3,

[0272] D201 and E201 represent, independently of one another, phenyl, naphthyl, pyrrole, indole, pyridine, quinoline, pyrazole or pyrimidine, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, cyano, nitro, hydroxy, NR222R223, acetylamino, propionylamino or benzoylamino,

[0273] Y206 and Y207 represent, independently of one another, —O—, —NR224—, —CO—O— or —CO—NR224—,

[0274] Y208═Y209 represents N═N or CH═N,

[0275] Y210 represents N or CH,

[0276] R224 represents hydrogen, methyl, formyl, acetyl, propionyl, methylsulphonyl or ethylsulphonyl,

[0277] M200 represents Cu, Fe, Co, Ni, Mn or Zn,

[0278] M201 represents 2 H atoms, CuII, CoII, CoIII, NiII, Zn, Mg, Cr, Al, Ca, Ba, In, Be, Cd, Pb, Ru, Be, PdII, PtII, Al, FeII, FeII, MnII, VIV, Ge, Sn, Ti or Si, where in the case of M201 being CoIII, FeII, FeIII, Al, In, Ge, Ti, VIV and Si it bears one or two further substituents or ligands R225 and/or R226 which are arranged axially relative to the plane of the porphyrin ring,

[0279] R225 and R226 represent, independently of one another, methyl, ethyl, phenyl, hydroxy, fluorine, chlorine, bromine, methoxy, ethoxy, phenoxy, tolyloxy, cyano or ═O,

[0280] F201 represents pyrrol-2-yl, imidazol-2- or 4-yl, pyrrazol-3- or -5-yl, 1,3,4-triazol-2-yl, thiazol-2- or -4-yl, thiazolin-2-yl, pyrrolin-2-yl, oxazol-2- or -4-yl, isothiazol-3-yl, isoxazol-3-yl, indol-2-yl, benzimidazol-2-yl, benzothiazol-2-yl, benzoxazol-2-yl, benzoisothiazol-3-yl, 1,3,4-thiadiazol-2-yl, 1,2,4-thiadiazol-3- or -5-yl, 1,3,4-oxadiazol-2-yl, pyrid-2-yl, quinol-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, dimethylamino, diethylamino, dipropylamino, diethylamino, dicyclohexylamino, anilino, N-methylanilino, diethanolamino, N-methylethanolamino, pyrrolidino, morpholino or piperidino,

[0281] G201 represents a ring of the formula

[0282] which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals, where the asterisk (*) indicates the ring atom from which the single bond to Y210 extends and the squiggle (˜) indicates the oxygen atom (═Y206) from which the single bond to M extends, and

[0283] Y206 represents —O—,

[0284] H201 represents a ring of the formula

[0285] which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals, where the asterisk (*) indicates the ring atom from which the double bond to Y210 extends, and

[0286] Y211 represents ═O,

[0287] E201 represents a direct bond,

[0288] R204 represents hydrogen, methyl, ethyl, propyl, butyl, benzyl or

[0289] Ar201—N—R204 or Ar205—N—R204 represents an N-bonded pyrrole, indole or carbazole ring which may be substituted by methyl, ethyl, methoxy, ethoxy, propoxy, chlorine, bromine, iodine, cyano, nitro or methoxycarbonyl,

[0290] R220 and R21 represent, independently of one another, hydrogen, methoxy, ethoxy, propoxy, butoxy, cyano, methoxycarbonyl, chlorine, bromine, phenyl, dimethylamino, diethylamino, dipropylamino, dibutylamino, anilino or together represent a bivalent radical of the formula

[0291] X201 represents N or CH,

[0292] Y212 represents N—R204, N—Ar201 or CR202R203,

[0293] Y213 represents NH—R204, NH—Ar201 or CR202R203 An−,

[0294] where bonding to the bridge B, the dendritic structure D or the spacer group S is via the radicals R200 to R224 or via the nonionic radicals by which Ar201 to Ar205 and the rings A201 to H201 may be substituted. In this case, these radicals represent a direct bond.

[0295] The following examples serve to illustrate:

[0296] Preferred light-absorbent compounds having an absorption maximum λmax3 in the range from 630 to 820 nm are those of the following formulae:

[0297] Corresponding optical data stores comprising these compounds in the information layer can be read and written on by means of red or infrared light, in particular red or infrared laser light.

[0298] where

[0299] Ar301 and Ar302 represent, independently of one another, C6-C10-aryl or the radical of a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals or sulpho,

[0300] Ar303 represents the bifunctional radical of a C6-C10-aromatic or the bifunctional radical of a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring, which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals or sulpho, where two such bifunctional radicals may be connected via a bifunctional bridge,

[0301] E301 represents N, C—Ar302 or N+—Ar302 An−,

[0302] An− represents an anion,

[0303] R302 and R303 represent, independently of one another, cyano, carboxyl, C1-C16-alkoxycarbonyl, aminocarbonyl or C1-C16-alkanoyl or R303 represents Ar302 or R302; R303 together with the carbon atom connecting them represent a five- or six-membered carbocyclic or aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring which may be benzo- or naphtho-fused and/or be substituted by nonionic or ionic radicals,

[0304] E303 to E309 represent, independently of one another, C—R310 or N, where the radicals R310 of two elements E303 to E309 may together form a 2- to 4-membered bridge which may contain heteroatoms and/or be substituted by nonionic radicals and/or be benzo-fused, and E305—E306 and/or E307—E308 may represent a direct bond,

[0305] R310 represents hydrogen, C1-C16-alkyl, cyano, carboxyl, C1-C16-alkoxycarbonyl, C1-C16-alkanoyl, Ar302, —CH═CH—Ar302, —(CH═CH)2—Ar302 or a radical of the formula

[0306] X301, X302, X304 and X306 represent, independently of one another, O, S or N—R300, and X302, X304 and X306 may also represent CR300OOR300,

[0307] A301, B301 and C301 represent, independently of one another, a five- or six-membered aromatic, pseudoaromatic or partially hydrogenated heterocyclic ring which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals,

[0308] X303 and X305 represent, independently of one another, N, or (X303)+—R300 represents O+ or S+ and/or X305—R300 represents O or S,

[0309] R300 represents hydrogen, C1-C16-alkyl or C7-C16-aralkyl or forms a ring to E302, E303 or E307,

[0310] E302 represents ═CH═CH—, ═N—CH═, ═N—N═ or a bivalent radical of the formula

[0311] where the six-membered ring may be substituted by nonionic radicals and/or be benzo-fused,

[0312] Y301 represents N or C—R301,

[0313] R301 represents hydrogen, C1-C16-alkyl, cyano, carboxyl, C1-C16-alkoxycarbonyl, C1-C16-alkanoyl or Ar302 or a bridge to R302 or Ar303,

[0314] v represents 1 or 2,

[0315] X307 represents O, S or N—R311,

[0316] R311 and R312 represent, independently of one another, hydrogen, C1-C16-alkyl, C7-C16-aralkyl or C6-C10-aryl,

[0317] Y302 represents NR311R312,

[0318] Y303 represents CR302R303,

[0319] R304 and R305 represent, independently of one another, hydrogen, C1-C16-alkyl, C1-C16-alkoxy, C6-C10-aryloxy or two adjacent radicals R304 or R305 represent a —CH═CH—CH═CH— bridge,

[0320] h and i represent, independently of one another, an integer from 0 to 3,

[0321] M300 represents 2 H atoms or an at least divalent metal or nonmetal, where M may bear further, preferably 2, substituents or ligands R313 and/or R314,

[0322] R306 to R309 represent, independently of one another, C1-C16-alkyl, C1-C16-alkoxy, C1-C16-alkylthio, C6-C10-aryloxy, halogen, COOH, —CO—OR311, —CO—NR311R312, —SO3H, —SO2—NR311R312 or two adjacent radicals R306, R307, R308 or R309 represent a —CH═CH—CH═CH— bridge,

[0323] w to z represent, independently of one another, an integer from 0 to 4, where, if w, x, y or z>1, R306, R307, R308 or R309 may have different meanings,

[0324] R313 and R314 represent, independently of one another, C1-C16-alkoxy, C6-C10-aryloxy, hydroxy, halogen, cyano, thiocyanato, C1-C12-alkylisonitrilo, C6-C10-aryl, C1-C16-alkyl, C1-C12-alkyl-CO—O—, C1-C12-alkyl-SO2—O—, C6-C10-aryl-CO—O—, C6-C10-aryl-SO2—O, tri-C1-C12-alkylsiloxy or NR311R312,

[0325] where bonding to the bridge B, the dendritic structure D or the spacer group S is via the radicals R300 to R314 or via the nonionic radicals by which Ar301 to Ar303 and the rings A301 to C301 may be substituted. In this case, these radicals represent a direct bond.

[0326] The phthalocyanines of the formula (CCCIX) also encompass the corresponding monoaza to tetraaza derivatives and their quaternary salts.

[0327] Nonionic radicals are, for example, C1-C4-alkyl, C1-C4-alkoxy, halogen, cyano, nitro, C1-C4-alkoxycarbonyl, C1-C4-alkylthio, C1-C4-alkanoylamino, benzoylamino, mono- or di-C1-C4-alkylamino.

[0328] Alkyl, alkoxy, aryl and heterocyclic radicals may, if desired, bear further radicals such as alkyl, halogen, nitro, cyano, COOH, CO—NH2, alkoxy, trialkylsilyl, trialkylsiloxy, phenyl or SO3H, the alkyl and alkoxy radicals may be straight-chain or branched, the alkyl radicals may be partially halogenated or perhalogenated, the alkyl and alkoxy radicals may be ethoxylated or propoxylated or silylated, adjacent alkyl and/or alkoxy radicals on aryl or heterocyclic radicals may together form a three- or four-membered bridge and the heterocyclic radicals may be benzo-fused and/or quaternized.

[0329] Particular preference is given to light-absorbent compounds of the formulae (CCCI) to (CCCIX),

[0330] where

[0331] Ar301 and Ar302 represent, independently of one another, phenyl, naphthyl, benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl, thiazol-2-yl, isothiazol-3-yl, imidazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,3,4-triazol-2-yl, 2- or 4-pyridyl, 2- or 4-quinolyl, pyrrol-2- or -3-yl, thiophen-2- or -3-yl, furan-2- or -3-yl, indol-2- or -3-yl, benzothiophen-2-yl, benzofuran-2-yl, 1,2-dithiol-3-yl or 3,3-dimethylindolen-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, hydroxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino, benzoylamino, amino, dimethylamino, diethylamino, dipropylamino, dibutylamino, pyrrolidino, piperidino, morpholino, COOH or SO3H, and Ar301 may also represent a ring of the formula

[0332] which may be benzo- or naphtho-fused and/or be substituted by nonionic radicals, where the asterisk (*) indicates the ring atom from which the single bond extends,

[0333] Ar303 represents phenylene, naphthylene, thiazol-2,5-diyl, thiophen-2,5-diyl or furan-2,5-diyl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, hydroxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino or benzoylamino,

[0334] E301 represents N, C—Ar302 or N+—Ar302 An−,

[0335] An− represents an anion,

[0336] R302 and R303 represent, independently of one another, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, methoxyethoxycarbonyl, acetyl, propionyl or butanoyl, or R203 represents Ar302 or R302; R303 together with the carbon atom connecting them represent a ring of the formula

[0337] which may be benzo- or naphtho-fused and/or be substituted by nonionic or ionic radicals, where the asterisk (*) indicates the ring atom from which the double bond extends,

[0338] E303 to E309 represent, independently of one another, C—R310 or N, where two adjacent elements E33 to E319 may represent a bivalent group of the formula

[0339] or three adjacent elements E303 to E309 may represent a bivalent group of the formula

[0340] or five adjacent elements E303 to E309 may represent a bivalent group of the formula

[0341] where in each case the asterisked (*) bonds represent single or double bonds to the next element E, to Ar301, CR302R303 or to a ring B301 or C301 and the rings may be substituted by methyl, methoxy, chlorine, cyano or phenyl, and E305═E306 and/or E307═E308 may represent a direct bond,

[0342] R310 represents hydrogen, methyl, ethyl, cyano, chlorine, phenyl or a radical of the formula

[0343] A301 represents benzothiazol-2-ylidene, benzoxazol-2-ylidene, benzimidazol-2-ylidene, thiazol-2-ylidene, isothiazol-3-ylidene, imidazol-2-ylidene, 1,3,4-thiadiazol-2-ylidene, 1,3,4-triazol-2-ylidene, pyridin-2- or 4-ylidene, quinolin-2- or 4-ylidene, pyrrol-2- or -3-ylidene, thiophen-2- or -3-ylidene, furan-2- or -3-ylidene, indol-2- or -3-ylidene, benzothiophen-2-ylidene, benzofuran-2-ylidene, 1,3-dithiol-2-ylidene, benzo-1,3-dithiol-2-ylidene, 1,2-dithiol-3-ylidene or 3,3-dimethylindolen-2-ylidene, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino or benzoylamino,

[0344] B301 represents benzothiazol-2-yl, benzoxazol-2-yl, benzimidazol-2-yl, thiazol-2-yl, isothiazol-3-yl, imidazol-2-yl, 1,3,4-thiadiazol-2-yl, 1,3,4-triazol-2-yl, 2- or 4-pyridyl, 2- or 4-quinolyl, pyrrylium-2- or -4-yl, thiopyrrylium-2- or -4-yl, indol-3-yl, benz[c,d]indol-2-yl or 3,3-dimethylindolen-2-yl, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino or benzoylamino,

[0345] C301 represents benzothiazol-2-ylidene, benzoxazol-2-ylidene, benzimidazol-2-ylidene, thiazol-2-ylidene, isothiazol-3-ylidene, imidazol-2-ylidene, 1,3,4-thiadiazol-2-ylidene, 1,3,4-triazol-2-ylidene, pyridin-2- or 4-ylidene, quinolin-2- or 4-ylidene, dehydropyran-2- or -4-ylidene, thiopyran-2- or -4-ylidene, indol-3-yl, benz[c,d]indol-2-ylidene or 3,3-dimethylindolen-2-ylidene, which may be substituted by methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy, butoxy, chlorine, bromine, iodine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl, methylthio, acetylamino, propionylamino, butanoylamino or benzoylamino, where

[0346] X301, X302, X304 and X306 represent, independently of one another, O, S or N—R300 and X302, X34 and X306 may also be CR300R300,

[0347] X303 and X305 represent, independently of one another, N, or (X303)+—R300 represents O+ or S+ and/or X305—R300 represents O or S, and

[0348] An− represents an anion,

[0349] R300 represents hydrogen, methyl, ethyl, propyl, butyl or benzyl,

[0350] R300′ represents methyl, ethyl, propyl, butyl or benzyl,

[0351] E302 represents a bivalent radical of the formula

[0352] where the six-membered ring may be substituted by methyl, ethyl, methoxy, ethoxy, propoxy, butoxy, acetamino, propionylamino or methylsulphonylamino and/or be benzo-fused,

[0353] Y301 represents N or C—R301,

[0354] R301 represents hydrogen, methyl, ethyl, cyano, carboxyl, methoxycarbonyl, ethoxycarbonyl, acetyl or propionyl,

[0355] v represents 1 or 2,

[0356] X307 represents O, S or N—R311,

[0357] R311 and R312 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenyl, which may be substituted by one or more of the radicals methoxy, ethoxy, propoxy, chlorine, bromine, dimethylamino or diethylamino,

[0358] Y302 represents NR311R312,

[0359] Y303 represents CR302R303,

[0360] R304 and R305 represent, independently of one another, hydrogen, methyl, ethyl, propyl, butyl, methoxy, ethoxy or phenoxy or two adjacent radicals R304 or R305 represent a —CH═CH—CH═CH— bridge,

[0361] M300 represents 2 H atoms, CuII, CoII, CoIII, NiII, Zn, Mg, Cr, Ca, Ba, In, Be, Cd, Pb, Ru, Be, Al, PdII, PtII, Al, FeII, FeIII, MnII, VIV, Ge, Sn, Ti or Si, where in the case of M being CoIII, FeII, FeIII, Al, In, Ge, Ti, VIV and Si it bears one or two further substituents or ligands R313 and/or R314 which are arranged axially relative to the plane of the phthalocyanine ring,

[0362] R306 to R309 represent, independently of one another, methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, phenoxy, chlorine, bromine, —SO3H or SO2NR311R312 or two adjacent radicals R306, R307, R308 or R309 represent a —CH═CH—CH═CH— bridge,

[0363] w to z represent, independently of one another, an integer from 0 to 4, where, if w, x, y or Z>1, R306, R307, R308 or R319 may have different meanings, R313 and R314 represent, independently of one another, hydroxy, fluorine, chlorine, bromine, cyano, ═O, methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, phenoxy, pyrazolo, imidazolo or NR311R312, which may be substituted by one or more of the radicals methoxy, ethoxy, propoxy, chlorine, bromine, dimethylamino or diethylamino,

[0364] where bonding to the bridge B, the dendritic structure D or the spacer group S is via the radicals R300 to R314 or via the nonionic radicals by which Ar301 to Ar303 and the rings A301 to C301 may be substituted. In this case, these radicals represent a direct bond.

[0365] The following examples serve to illustrate:

[0366] Examples of light-absorbent compounds which have at least two chromophoric centres as described above and are suitable for the optical data carrier of the invention are:

[0367] The absorption spectra are preferably measured in solution. The light-absorbent compounds described guarantee a sufficiently high reflectivity (>10%) of the optical data carrier in the unwritten state and a sufficiently high absorption for thermal degradation of the information layer on point-wise illumination with focused light if the wavelength of the light is in the range from 360 to 460 nm, from 600 to 680 nm or from 750 to 820 nm. The contrast between written and unwritten points on the data carrier is achieved by the reflectivity change of the amplitude and also the phase of the incident light due to the changed optical properties of the information layer after the thermal degradation.

[0368] The invention further provides a write-once optical data carrier comprising a preferably transparent substrate to whose surface at least one light-writeable information layer, if desired a reflection layer and/or if desired a protective layer have been applied, which can be written on or read by means of blue, red or infrared light, preferably laser light, where the information layer comprises at least one of the abovementioned light-absorbent compounds and, if desired, a binder, wetting agents, stabilizers, diluents and sensitizers and also further constituents. Alternatively, the structure of the optical data carrier may:

[0369] comprise a preferably transparent substrate to whose surface at least one light-writeable information layer, if desired a reflection layer and, if desired, an adhesive layer and a further preferably transparent substrate have been applied, or

[0370] comprise a preferably transparent substrate to whose surface if desired a reflection layer, at least one light-writeable information layer, if desired an adhesive layer and a transparent covering layer have been applied.

[0371] Apart from the information layer, further layers such as metal layers, dielectric layers and protective layers may be present in the optical data carrier. Metals and dielectric layers serve, inter alia, to adjust the reflectivity and the heat absorption/retention. Metals can be, depending on the laser wavelength, gold, silver, aluminium, etc. Examples of dielectric layers are silicon dioxide and silicon nitride. Protective layers are, for example, photocurable surface coatings, pressure-sensitive) adhesive layers and protective films.

[0372] Pressure-sensitive adhesive layers consist mainly of acrylic adhesives. Nitto Denko DA-8320 or DA-8310, disclosed in the patent JP-A 11-2731471, can, for example, be used for this purpose.

[0373] The optical data carrier has, for example, the following layer structure (cf. FIG. 1): a transparent substrate (1), if desired a protective layer (2), an information layer (3), if desired a protective layer (4), if desired an adhesive layer (5), a covering layer (6).

[0374] The structure of the optical data carrier preferably:

[0375] comprises a preferably transparent substrate (1) to whose surface at least one light-writeable information layer (3) which can be written on by means of light, preferably laser light, if desired a protective layer (4), if desired an adhesive layer (5) and a transparent covering layer (6) have been applied.

[0376] comprises a preferably transparent substrate (1) to whose surface a protective layer (2), at least one information layer (3) which can be written on by means of light, preferably laser light, if desired an adhesive layer (5) and a transparent covering layer (6) have been applied.

[0377] comprises a preferably transparent substrate (1) to whose surface a protective layer (2) if desired, at least one information layer (3) which can be written on by means of light, preferably laser light, if desired a protective layer (4), if desired an adhesive layer (5) and a transparent covering layer (6) have been applied.

[0378] comprises a preferably transparent substrate (1) to whose surface at least one information layer (3) which can be written on by means of light, preferably laser light, if desired an adhesive layer (5) and a transparent covering layer (6) have been applied.

[0379] Alternatively, the optical data carrier has, for example, the following layer structure (cf. FIG. 2): a preferably transparent substrate (11), an information layer (12), if desired a reflection layer (13), if desired an adhesive layer (14), a further preferably transparent substrate (15).

[0380] Alternatively, the optical data carrier has, for example, the following layer structure (cf. FIG. 3): a preferably transparent substrate (21), an information layer (22), if desired a reflection layer (23), a protective layer (24).

[0381] The invention further provides optical data carriers according to the invention which have been written on by means of blue, red or infrared light, in particular laser light.

[0382] In addition, the invention relates to the novel optical data stores after they have been written on once by means of blue, red or infrared light, in particular laser light.

[0383] Furthermore, the invention relates to the use of light-absorbent compounds which have at least two identical or different chromophoric centres and have at least one absorption maximum in the range from 340 to 820 nm in the information layer of write-once optical data carriers. The preferred ranges for the light-absorbent compounds and for the optical data carriers also apply to this use according to the invention.

[0384] Apart from the light-absorbent compound, the information layer may further comprise binders, wetting agents, stabilizers, diluents and sensitizers and also further constituents.

[0385] The substrates can be produced from optically transparent plastics which, if necessary, have undergone surface treatment. Preferred plastics are polycarbonates and polyacrylates, and also polycycloolefins or polyolefins. The light-absorbent compound can also be used in a low concentration to protect the polymer substrate and its light stabilization.

[0386] The reflection layer can be produced from any metal or metal alloy which is customarily utilized for writeable optical data carriers. Suitable metals or metal alloys can be applied by vapour deposition or sputtering and comprise, for example, gold, silver, copper, aluminium and alloys of these with one another or with other metals.

[0387] The protective surface coating over the reflection layer can comprise UV-curing acrylates.

[0388] An intermediate layer which protects the reflection layer from oxidation can likewise be present.

[0389] Mixtures of the abovementioned light-absorbent compounds can likewise be used.

[0390] The invention further provides a process for producing the optical data carriers of the invention, which is characterized in that a preferably transparent substrate which has, if desired, previously been provided with a reflection layer is coated with the light-absorbent compound in combination with suitable binders and, if desired, suitable solvents and is provided, if desired, with a reflection layer, further intermediate layers and, if desired, a protective layer or a further substrate or a covering layer.

[0391] Coating of the substrate with the light-absorbent compound, if desired in combination with dyes, binders and/or solvents, is preferably carried out by spin coating.

[0392] To carry out the coating procedure, the light-absorbent compound is preferably dissolved, with or without additives, in a suitable solvent or solvent mixture in such an amount that 100 parts by weight or less, for example from 10 to 2 parts by weight, of the UV absorber are present per 100 parts by weight of solvent. The writeable information layer is then metallized (reflection layer) by sputtering or vapour deposition, preferably under reduced pressure, and possibly provided subsequently with a protective surface coating (protective layer) or a further substrate or a covering layer. Multilayer assemblies with a partially transparent reflection layer are also possible.

[0393] Solvents or solvent mixtures for coating with the light-absorbent compounds or their mixtures with additives and/or binders are selected, firstly, according to their solvent capacity for the light-absorbent compound and the other additives and, secondly, so that they have a minimal effect on the substrate. Suitable solvents which have little effect on the substrate are, for example, alcohols, ethers, hydrocarbons, halogenated hydrocarbons, cellosolves, ketones. Examples of such solvents are methanol, ethanol, propanol, 2,2,3,3-tetrafluoropropanol, butanol, diacetone alcohol, benzyl alcohol, tetrachloroethane, dichloromethane, diethyl ether, dipropyl ether, dibutyl ether, methyl tert-butyl ether, methyl cellosolve, ethyl cellosolve, 1-methyl-2-propanol, methyl ethyl ketone, 4-hydroxy-4-methyl-2-pentanone, hexane, cyclohexane, ethyl-cyclohexane, octane, benzene, toluene, xylene. Preferred solvents are hydrocarbons and alcohols, since they have the smallest effect on the substrate.

[0394] Suitable additives for the writeable information layer are stabilizers, wetting agents, binders, diluents and sensitizers.

[0395] The following examples illustrate the subject-matter of the invention:

EXAMPLES

Example A

[0396] 31.8 g of diethylene glycol, 102.1 g of cyanoacetic acid and 4 g of p-toluenesulphonic acid were refluxed in 150 ml of toluene for 12 hours using a water separator. After cooling, the mixture was stirred with 500 ml of saturated sodium hydrogen carbonate solution and extracted with 800 ml+2×100 ml of ethyl acetate. The organic phase was dried over sodium sulphate and evaporated under reduced pressure. This gave 59 g (82% of theory) of an oil of the formula

[0397] MS(CI): m/e=241 (M++H).

Example A-a

[0398] The procedure of Example A was repeated using 18.6 g of ethylene glycol and 102.1 g of cyanoacetic acid to give 44.6 g (76% of theory) of an oil of the formula

[0399] MS (CI): m/e=197 (M++H).

Example A-b

[0400] The procedure of Example A was repeated using 36.0 g of 2-(hydroxymethyl)-2-methyl-1,3-propanediol and 153.1 g of cyanoacetic acid to give 81.3 g (84% of theory) of a slowly crystallizing oil of the formula

[0401] MS(CI): m/e=322 (M++H).

Example B

[0402] 9.5 g of pyrrole-2-carbaldehyde were placed in a reaction vessel together with a mixture of 50 g of 25% strength by weight aqueous sodium hydroxide and 50 ml of toluene. At 75-80° C., a solution of 13.2 g of α,α′-dibromo-m-xylene in 100 ml of toluene was added dropwise. The mixture was stirred at 75-80° C. for 3.5 hours. After cooling, the organic phase was separated off, dried over sodium sulphate and evaporated under reduced pressure. This gave 14 g (96% of theory) of an oil of the formula

Example B-a

[0403] The procedure of Example B was repeated using 9.5 g of pyrrole-2-carbaldehyde and 10.1 g of 1,3-dibromopropane to give 10.8 g (47% of theory) of the product of the formula

[0404] MS: m/e=230.

Example C

[0405] 7.9 g of succinyl chloride and subsequently 10.0 g of triethylamine were added dropwise to a solution of 15.1 g of N-methyl-N-(2-hydroxyethyl)aniline in 100 ml of methylene chloride. After the mixture had been boiled for 4 hours, the solvent was taken off under reduced pressure. The oily crude product was dissolved in 100 ml of toluene, filtered and filtered through 30 g of aluminium oxide. Taking off the solvent under reduced pressure gave 12.3 g (64% of theory) of an oil of the formula

[0406] MS: m/e=384.

Example C-a

[0407] The procedure of Example C was repeated using 18.1 g of N-ethyl-N-(2-hydroxyethyl)-m-toluidine to give 15.0 g (68% of theory) of an oil of the formula

[0408] MS: m/e=440.

Example D

[0409] 21.6 g of 1,4-dibromobutane were added dropwise at 60° C. to a solution of 15.9 g of 2,3,3-trimethyl-3H-indole and 100 mg of tetrabutylammonium iodide in 50 ml of butyrolactone. After 6 hours at 90-120° C., the mixture was cooled and filtered with suction. This gave 8.2 g (30.6% of theory) of a colourless powder of the formula

[0410]

1
H-NMR (CDCl3): δ=8.58 (d), 7.63 (m), 7.55 (d), 4.84 (m), 3.27 (s), 2.56 (m), 1.64 ppm (s).

Example E

[0411] 8.2 g of dibromo-o-xylene and 5.6 g of γ-picoline were stirred in 60 ml of γ-butyrolactone at 80° C. for 30 minutes. After cooling, the mixture was filtered with suction, the solid was washed with 2×10 ml of γ-butyrolactone and dried. This gave 8.7 g (64% of theory) of a colourless powder of the formula

[0412]

1
H-NMR ([d6]-DMSO): δ=9.02 (d), 808 (d), 7.50 (m), 7.19 (m), 6.18 (s), 2.66 ppm (s).

Example F

[0413] Using a procedure analogous to that described in Tetrahedron 55, (1999), 6511, the furfural derivative of the formula

[0414] was prepared from 5-bromofuran-2-carbaldehyde and piperazine.

[0415] m.p. 235-240° C.

Example 1

[0416] 44.1 g of 3,3-dimethyl-5,6-dimethoxy-indan-1-one, 19.6 g of the product from Example A-a, 14.8 g of propionic acid, 3.6 g of ammonium acetate and 40 g of xylene were boiled for 13 hours using a water separator. After cooling, the mixture was filtered with suction and the solid was washed with 9 ml of xylene. The solid was stirred in 200 ml of water, filtered off with suction once again and washed with 200 ml of methanol. Drying under reduced pressure gave 21.7 g (36% of theory) of a pale yellow crystalline powder of the formula

[0417] m.p. 244-248° C.,

[0418] λmax (dioxane)=363 nm, 378 nm.

Example 2

[0419] 6.0 g of the product from Example A, 2.4 g of pyrrole-2-carbaldehyde and 2.8 g of 2-methylfurfural were dissolved in 100 ml of ethanol and admixed with 5 g of triethylamine. The mixture was stirred overnight at room temperature. The product which had precipitated was filtered off with suction, washed with 10 ml of ethanol and dried under reduced pressure. This gave 5.8 g (56.6% of theory) of a pale yellow powder of the formula

[0420] m.p. 131-135° C.

[0421] λmax (dioxane)=359 nm.

[0422] MS(CI): m/e=395, 410,425 (M++H).

Example 3

[0423] 6.4 g of the product from Example A-b and 6.6 g of 2-methylfurfural were stirred overnight in 70 ml of pyridine at room temperature. The solvent was taken off under reduced pressure, the residue was dissolved in 50 ml of acetone and once again evaporated under reduced pressure. This residue was stirred in 100 ml of water, filtered off with suction, washed with water and dried under reduced pressure. This gave 6.2 g (52% of theory) of a slightly yellowish powder of the formula

[0424] m.p. 135-140° C.

[0425] λmax (dioxane)=354 nm.

Example 4

[0426] 2.9 g of the product from Example B and 2.6 g of propyl cyanoacetate in 30 ml of ethanol were admixed with 2 g of triethylamine and stirred overnight at room temperature. The product was filtered off with suction and washed with ethanol. Drying under reduced pressure gave 3.9 g (76% of theory) of a slightly yellowish powder of the formula

[0427] m.p. 123-125° C.

[0428] λmax (dioxane)=370 nm.

[0429] MS: m/e=510 (M).

Example 5

[0430] 11.5 g of tetracyanoethene were added at room temperature to a solution of 18.8 g of N-methyl-N-(2-hydroxyethyl)-aniline in 30 ml of dimethylformamide at such a rate that the temperature did not exceed 50° C. This temperature was maintained for 10 minutes, the mixture was then cooled to 2° C. and filtered with suction. Drying of the solid gave 21.8 g (96% of theory) of red crystalline powder of the formula

[0431] 5.1 g of this dye in 50 ml of ethylene chloride were admixed with 2.1 g of succinyl chloride and subsequently with 2 g of triethylamine. The mixture was refluxed for 8 hours. After cooling, the mixture was filtered and the filtrate was evaporated under reduced pressure. The residue was stirred in 50 ml of ethanol at room temperature, filtered off with suction, stirred in 500 ml of water at room temperature, filtered off with suction once again and dried. This gave 2.4 g (41% of theory) of a red powder of the formula

[0432] m.p. 292-299° C.

[0433] λmax (dioxane)=493 nm.

[0434] ε=64340 l/mol cm.

[0435] solubility: 1% in TFP.

Example 6

[0436] The same product was obtained by reacting 7.7 g of the product from Example C with 5.6 g of tetracyanoethene in 15 ml of dimethylformamide at 50° C. for 10 minutes.

Example 7

[0437] 10.8 g of 4-aminophthalonitrile were introduced into a mixture of 105 ml of glacial acetic acid, 37 ml of propionic acid and 26 ml of concentrated hydrochloric acid. 24.8 ml of nitrosylsulphuric acid were added dropwise at 0-5° C. and the mixture was stirred at this temperature for another 30 minutes.

[0438] This diazotization product was added dropwise at 10° C. to a solution of 18.6 g of 2-(N-ethyl-3-methylanilino)ethyl methacrylate in a mixture of 60 ml of glacial acetic acid and 0.5 g of amidosulphonic acid over a period of 1 hour, with the pH being raised to 3 by dropwise addition of 20% strength by weight sodium carbonate solution. The mixture was stirred overnight at room temperature and pH=3. It was then filtered with suction. The crude product was stirred in 300 ml of water and the pH was adjusted to 7.5 by means of 20% strength by weight sodium carbonate solution. The mixture was filtered with suction once again, the solid was washed with water and dried under reduced pressure. This gave 26.0 g (86.5% of theory) of a red crystalline powder of the formula

[0439] m.p. 95-110° C.

[0440] λmax (dioxane)=479 nm.

[0441] ε=33040 l/mol cm.

Example 8

[0442] 2 g of this dye from Example 7 were stirred with 0.1 g of 2,2′-azobis-(2-methylpropionitrile) and 0.5 g of triethylamine in 20 ml of dimethylformamide at 70° C. under a nitrogen atmosphere for 25 hours. After cooling, 150 ml of water were added dropwise. The product which had precipitated was filtered off with suction, washed with water and dried. This gave 1.9 g (95% of theory) of the polymer of the formula

[0443] solubility: 0.3% in TFP.

Example 9

[0444] 5.8 g of the product from Example B-a and 5.9 g of benzyl cyamide were dissolved in 100 ml of ethanol. 4 ml of 50% strength by weight aqueous sodium hydroxide were added dropwise. After the mixture had been stirred at room temperature for 3 hours, 4 ml of glacial acetic acid were added and the precipitated solvent was filtered off with suction, washed with ethanol and dried. This gave 3.0 g (28% of theory) of the product of the formula

[0445] m.p. 123-127° C.

[0446] λmax (dioxane)=366 nm.

[0447] δ=49860 l/mol cm.

[0448] MS: m/e=428 (M+).

[0449] solubility: 2% in diacetone alcohol.

Example 10

[0450] 2.7 g of the furfural derivative from Example F and 2.8 g of dimedone were stirred in 50 ml of acetic anhydride at 80° C. for 30 minutes. After cooling, the mixture was poured into 200 ml of water. This gave, after drying, 3.0 g (58% of theory) of a red powder of the formula

[0451] m.p. 230-235° C.

[0452] λmax (dioxane)=495 nm.

[0453] δ=76250 μl/mol cm.

[0454] solubility: 2% in TFP.

Example 11

[0455] 2.0 g of dibromo-o-xylene were added dropwise at 70° C. to a solution of 5 g of the dye of the formula

[0456] prepared by a method analogous to Example 1 of DE-A 29 11 258) in 25 ml of y-butyrolactone. After 27 hours at 70° C., the mixture was cooled, poured into 200 ml of water, admixed with 1 g of activated carbon and thus clarified, and the product was salted out by addition of sodium chloride. Filtration with suction and drying gave 6.2 g (89% of theory) of the dye of the formula

[0457] 1.4 g of this dye were refluxed in 20 ml of methanol. 2 g of tetrabutylammonium tetrafluoroborate were added. After refluxing for 10 minutes, the mixture was cooled, filtered with suction, the solid was washed with methanol and dried. This gave 1.2 g (85% of theory) of the dye of the formula

[0458] λmax (methanol/glacial acetic acid 9:1)=567, 615 nm.

[0459] ε(567 nm)=90520.

Example 12

[0460] 13.5 g of the product from Example E were introduced into 30 ml of glacial acetic acid. 30 ml of piperidine were slowly added to this mixture, with the temperature rising to 80° C. 10.8 g of 4-(diethylamino)benzaldehyde were sprinkled in. After 2 hours at 80° C., the mixture was cooled and poured into 500 ml of water. Filtration with suction and drying gave 17.2 g (74% of theory) of a blackish red powder of the formula

[0461]

1
H-NMR ([d6]-DMSO): δ=8.76 (d), 8.08 (d), 7.58 (d), 7.52 (m), 7.28 (m), 7.16 (d, —CH═CH—), 6.74 (d), 5.98 (s), 3.45 (q), 1.13 ppm (t).

[0462] 7.7 g of this dye in 170 ml of methanol were admixed at the boiling point with 13.2 g of tetrabutylammonium tetrafluoroborate. After refluxing for 15 minutes, the mixture was cooled, filtered with suction, the solid was washed with 30 ml of methanol in which 1 g of tetrabutylammonium tetrafluoroborate had been dissolved and subsequently with 3×10 ml of methanol and dried. This gave 5.8 g (74% of theory) of a blackish blue powder of the formula

[0463] m.p. 264-266° C.

[0464] λmax (methanol/glacial acetic acid 9:1)=504 nm

[0465] ε=90535 l/mol cm

[0466] solubility: 2% in TFP

Example 13

[0467] The procedure of Example 12 was repeated using the product from Example D and N-methyl-N-cyanoethylbenzaldehyde to give the dye of the formula

[0468] in a yield of 49% of theory.

[0469] m.p.>300° C.

[0470] λmax (DMF)=532 run

[0471] ε=84550 l/mol cm

[0472] solubility: 2% in TFP

Example I (Comparative Example)

[0473] A 1/1 mixture (by mass) of substances of the following formulae was dissolved in tetrafluoropropanol (TFP) in a mass ratio of 2 parts of solid to 98 parts of TFP. This solution was applied by spin coating to a fused silica support and gave a transparent film. Evaluation of the transmission and reflection spectra indicated a film thickness of 165 nm.

[0474] This film was subjected to a vacuum (pressure ˜10−6 mbar) for 1 hour at room temperature to simulate the conditions when applying metallic or dielectric layers by sputtering during the production of optical data carriers. After this vacuum treatment, the total thickness d of the layer evaluated by the above-described method was 0 nm, i.e. all of the substance has sublimed.

Example II

[0475] The substance of the following formula, which represents the dimer of the substance B in Example I, was synthesized as described in Example 1. The substance was dissolved in tetrafluoropropanol (TFP) in a mass ratio of 1 part of solid to 99 parts of TFP. This solution was applied by spin coating to a fused silica support and gave a transparent film. Evaluation of the transmission and reflection spectra indicated a film thickness of 85 nm.

[0476] This film was subjected to a vacuum (pressure ˜10−6 mbar) for 1 hour at room temperature to simulate the conditions when applying metallic or dielectric layers by sputtering during the production of optical data carriers. After this vacuum treatment, the total thickness d of the layer evaluated by the above-described method was 85 nm, i.e. the substance has been fully retained.

Example III

[0477] The substance of the following formula, prepared as described in WO 9851721, was dissolved in tetrahydrofuran (THF) in a mass ratio of 2 parts of solid to 98 parts of THF. This solution was applied by spin coating to a fused silica support and gave a transparent film. Evaluation of the transmission and reflection spectra indicated a film thickness of 90 nm.

[0478] This film was subjected to a vacuum (pressure ˜10−6 mbar) for 1 hour at room temperature to simulate the conditions when applying metallic or dielectric layers by sputtering during the production of optical data carriers. After this vacuum treatment, the total thickness d of the layer evaluated by the above-described method was 91 nm, i.e. the substance has been fully retained.

[0479] A layer of SiN was subsequently applied by vapour deposition on top of the layer which had been pretreated in the above-described manner. Vapour deposition was carried out by electric heating of Si3N4 in a molybdenum boat under reduced pressure. The pressure during the vapour deposition process was ˜10−4 mbar, and the deposition rate was ˜4-5 Angström per second. To determine the complex index of refraction of the deposited SiN layer, control experiments were carried out on plain fused silica plates. The thickness of the SiN layer was determined by means of a profiler (Tencor Alpha Step 500 Surface Profiler). In turn, evaluation of the transmission and reflection spectra of the layer system taking into account the complex index of refraction and the thickness of the SiN layer enabled the apparent thickness of the organic film to be determined. It was 94 nm. This shows that the layer has not been changed by the vapour deposition process and that a sharp boundary between organic layer and SiN has been obtained.

Example IV

[0480] The substance of the following formula was dissolved in tetrafluoropropanol (TFP) in a mass ratio of 1 part of solid to 99 parts of TFP. This solution was applied by spin coating to a fused silica support and gave a crystalline film.

Example V

[0481] The substance of the following formula, which represents the branched trimer of the substance from Example IV, was synthesized as described in Example 3. The substance was dissolved in tetrafluoropropanol (TFP) in a mass ratio of 1 part of solid to 99 parts of TFP. This solution was applied by spin coating to a fused silica support and gave a transparent film. Evaluation of the transmission and reflection spectra indicated a film thickness of 153 nm.

[0482] This film was subjected to a vacuum (pressure ˜10−6 mbar) for 1 hour at room temperature to simulate the conditions when applying metallic or dielectric layers by sputtering during the production of optical data carriers. After this vacuum treatment, the total thickness d of the layer evaluated by the above-described method was 143 nm, i.e. the substance has been virtually fully retained.

[0483] A layer of SiN was subsequently applied by vapour deposition on top of the layer which had been pretreated in the above-described manner. Vapour deposition was carried out by electric heating of Si3N4 in a molybdenum boat under reduced pressure. The pressure during the vapour deposition process was ˜10−4 mbar, and the deposition rate was ˜4-5 Angström per second. To determine the complex index of refraction of the deposited SiN layer, control experiments were carried out on plain fused silica plates. The thickness of the SiN layer was determined by means of a profiler (Tencor Alpha Step 500 Surface Profiler). In turn, evaluation of the transmission and reflection spectra of the layer system taking into account the complex index of refraction and the thickness of the SiN layer enabled the apparent thickness of the organic film to be determined. It was 160 nm. This shows that, within measurement errors, the layer has not been changed by the vapour deposition process and that a sharp boundary between organic layer and SiN has been obtained.

[0484] Determination of the complex index of refraction and the thickness of the layer of the organic substances by means of transmission and reflection spectra:

[0485] The transmission and reflection spectra of the layer systems film/fused silica or SiN/film/fused silica or SiN/fused silica were determined with perpendicular incidence of a parallel beam of light in a wavelength range of from 200 nm to 1 700 nm. The fused silica substrates had a thickness of 1 mm. The reflected light was detected at an angle of 172° relative to the direction of incidence. Two different thicknesses of the organic film were in each case produced by spin coating. The thickness of the layer was adjusted by means of the solution concentration. The thicknesses were in the range from 50 nm to 500 nm. To evaluate the transmission and reflection spectra, the known Fresnel formulae were employed and the interferences caused by multiple reflection in the layer system were taken into account. A simultaneous least squares fit of the measured transmission and reflection spectra to the calculated spectra of the two layer systems of differing thickness enabled the layer thicknesses and the complex index of refraction of the organic substance to be determined at each wavelength. For this purpose, the index of refraction of the fused silica support has to be known. The index of refraction curve of the fused silica substrate in this spectral range was determined independently on an uncoated substrate.

Example VI

[0486] A 3% strength by weight solution of a dye mixture consisting of 91.4% by weight of the dye of the formula

[0487] and 8.6% by weight of the polymeric dye from Sample 13d having the formula

[0488] in 2,2,3,3-tetrafluoropropanol was prepared at room temperature. This solution was applied by means of spin coating to a pregrooved polycarbonate substrate. The pregrooved polycarbonate substrate had been produced as a disk by means of injection moulding. The dimensions of the disk and the groove structure corresponded to those customarily used for DVD-Rs. The disk with the dye layer as information carrier was coated with 100 nm of silver by vapour deposition. A UV-curable acrylic coating composition was subsequently applied by spin coating and cured by means of a UV lamp. The disk was tested by means of a dynamic writing test apparatus constructed on an optical tester bench comprising a diode laser (λ=656 nm) for generating linearly polarized light,. a polarization-sensitive beam splitter, a λ/4 plate and a movably suspended collecting lens having a numerical aperture NA=0.6 (actuator lens). The light reflected from the reflection layer of the disk was taken out from the beam path by means of the abovementioned polarization-sensitive beam splitter and focused by means of an astigmatic lens onto a four-quadrant detector. At a linear velocity V=3.5 m/s and a writing power Pw=10.5 mW, a signal/noise ratio C/N=50 dB was measured. The writing power was applied as an oscillating pulse sequence, with the disk being irradiated alternately for 1 is with the abovementioned writing power Pw and for 4 μs with the reading power Pr≈0.6 mW. The disk was irradiated with this oscillating pulse sequence until it had rotated once. The marking produced in this way was then read using the reading power Pr≈0.6 mW and the abovementioned signal/noise ratio C/N was measured.

Example VII

[0489] Using an analogous procedure, a disk was produced using a dye mixture consisting of 85% by weight of the dye of the formula

[0490] and 15% by weight of the polymeric dye from Sample 13d having the formula

[0491] and measured. At a writing power Pw=10.5 mW, a C/N=44 dB was obtained.

Optical data carrier comprising a light-absorbent compound having a plurality of chromophoric centres in the information layer

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