Optical data carrier comprising a cyanine dye as light-absorbent compound in the information layer
View Patent ↗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 at least one cyanine dye is used as light-absorbent compound.
1. 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, light, preferably laser light, where the information layer comprises a light-absorbent compound and, if desired, a binder, characterized in that at least one cyanine dye is used as light-absorbent compound; wherein the cyanine dye has the formula (I)
where
X 1 and X 3 represent nitrogen or
X 1 —R 1 and X 3 —R 2 represent, independently of one another, S,
X 2 represents O, S, N—R 6 , CR 8 or CR 8 R 9 ,
X 4 represents O, S, CR 10 or N—R 7 ,
Y represents C—CN,
R 1 , R 2 , R 6 and R 7 represent, independently of one another, C 1 –C 16 -alkyl, C 3 –C 6 -alkenyl, C 5 –C 7 -cycloalkyl or C 7 –C 16 -aralkyl,
R 3 and R 4 represent, independently of one another, hydrogen, C 1 –C 16 -alkyl or cyano or
R 1 and R 3 together represent a —(CH 2 ) 2 —, —(CH 2 ) 3 — or —(CH 2 ) 4 — bridge when m=0 and p>0 or
R 1 and R 5 together represent a —(CH 2 ) 2 —, —(CH 2 ) 3 — or —(CH 2 ) 4 — bridge when m=0 and p=0 or
R 2 and R 5 together represent a —(CH 2 ) 2 —, —(CH 2 ) 3 — or —(CH 2 ) 4 — bridge when n=0,
R 8 , R 9 and R 10 represent, independently of one another, hydrogen or C 1 –C 16 -alkyl or
CR 8 R 9 represents a bivalent radical of the formula
where the two bonds go out from the ring atom marked with an asterisk (*),
m and n represent, independently of one another, 0 or 1,
p represents 0 or 1,
the ring A including X 1 , X 2 and the radical connecting X 1 and X 2 and the ring B including X 3 , X 4 and the radical connecting X 3 and X 4 each represent, independently of one another, a five- or six-membered aromatic or pseudoaromatic or partially hydrogenated heterocyclic ring which may contain from 1 to 4 heteroatoms and/or be benzo- or naphtho-fused and/or be substituted by nonionic radicals, where the rings A and B are preferably not identical, and
An − represents an anion.
2. Optical data carrier according to claim 1 , characterized in that, in the formula (I), the ring A of the formula
represents benzothiazol-2-yl, thiazol-2-yl, thiazolin-2-yl, benzoxazol-2-yl, oxazol-2-yl, oxazolin-2-yl, benzimidazol-2-yl, imidazol-2-yl, imidazolin-2-yl, pyrrolin-2-yl, 3-H-indol-2-yl, benz[c,d]indol-2-yl, 2- or 4-pyridyl or 2- or 4-quinolyl,
where X 1 represents N,
where the abovementioned rings may each be substituted by C 1 –C 6 -alkyl, C 1 –C 6 -alkoxy, fluorine, chlorine, bromine, iodine, cyano, nitro, C 1 –C 6 -alkoxy-carbonyl, C 1 –C 6 -alkylthio, C 1 –C 6 -acylamino, C 6 –C 10 -aryl, C 6 –C 10 -aryloxy or C 6 –C 10 -arylcarbonylamino and the ring B of the formula
represents benzothiazol-2-ylidene, thiazol-2-ylidene, thiazolin-2-ylidene, isothiazol-3-ylidene, 1,3,4-thiadiazol-2-ylidene, 1,2,4-thiadiazol-5-ylidene, benzoxazol-2-ylidene, oxazol-2-ylidene, oxazolin-2-ylidene, 1,3,4-oxadiazol-2-ylidene, benzimidazol-2-ylidene, imidazol-2-ylidene, imidazolin-2-ylidene, pyrrolin-2-ylidene, 1,3,4-triazol-2-ylidene, 3H-indol-2-ylidene, benz[c,d]indol-2-ylidene, 2- or 4-pyridyl or 2- or 4-quinolyl, each of which bear the radical R 2 , which is as defined in claim 2 , in X 3 which represents N,
where the abovementioned rings may each be substituted by C 1 –C 6 -alkyl, C 1 –C 6 -alkoxy, fluorine, chlorine, bromine, iodine, cyano, nitro, C 1 –C 6 -alkoxy-carbonyl, C 1 –C 6 -alkylthio, C 1 –C 6 -acylamino, C 6 –C 10 -aryl, C 6 –C 10 -aryloxy, C 6 –C 10 -arylcarbonylamino, mono- or di-C 1 –C 6 -alkylamino, N—C 1 –C 6 -alkyl-N—C 6 –C 10 -arylamino, pyrrolidino, morpholino or piperazino.
3. Optical data carrier according to one or more of claim 1 , characterized in that the cyanine dye has the formula (I)
in which
the ring A and the ring B represent different heterocycles.
4. Optical data carrier according to claim 1 wherein the cyanine dyes have an absorption maximum λ max1 in the range from 340 to 410 nm.
5. Optical data carrier according to claim 1 wherein the cyanine dyes have an absorption maximum λ max2 in the range from 420 to 650 nm.
6. Process for producing the optical data carriers according to claim 1 , which is characterized in that a preferably transparent substrate which may, if desired, have previously been coated with a reflection layer is coated with the cyanine dyes, if desired in combination with suitable binders and additives and, if desired, suitable solvents, and provided, if desired, with a reflection layer, further intermediate layers and, if desired, a protective layer or a further substrate or a covering layer.
7. Optical data carrier according to claim 1 which can be written on by means of blue laser light.