U.S. patent application number 11/102756 was filed with the patent office on 2005-10-27 for styryl dyes.
This patent application is currently assigned to KABAYUSHI KAISHI HAYASHIBARA SEIBUTSU KAGAKU KENKYUJO. Invention is credited to Kasada, Chiaki, Kawata, Toshio, Yano, Kentaro, Yasui, Shigeo.
Application Number | 20050240019 11/102756 |
Document ID | / |
Family ID | 18359780 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050240019 |
Kind Code |
A1 |
Kasada, Chiaki ; et
al. |
October 27, 2005 |
Styryl dyes
Abstract
The present invention provides styryl dyes which have absorption
maxima at a wavelength of 400 nm or less and are sensitive to a
laser beam with a wavelength of 450 nm or less, light absorbents
and optical recording media which comprise the styryl dyes, and a
process for producing the styryl dyes which comprises reacting with
an aldehyde compound a quaternary ammonium salt of nitrogen atom
containing heterocyclic compound having an active methyl or active
methylene group.
Inventors: |
Kasada, Chiaki; (Okayama,
JP) ; Kawata, Toshio; (Okayama, JP) ; Yano,
Kentaro; (Okayama, JP) ; Yasui, Shigeo;
(Okayama, JP) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.
624 NINTH STREET, NW
SUITE 300
WASHINGTON
DC
20001-5303
US
|
Assignee: |
KABAYUSHI KAISHI HAYASHIBARA
SEIBUTSU KAGAKU KENKYUJO
Okayama-shi
JP
|
Family ID: |
18359780 |
Appl. No.: |
11/102756 |
Filed: |
April 11, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11102756 |
Apr 11, 2005 |
|
|
|
09890711 |
Aug 2, 2001 |
|
|
|
09890711 |
Aug 2, 2001 |
|
|
|
PCT/JP00/08298 |
Nov 24, 2000 |
|
|
|
Current U.S.
Class: |
546/2 ; 546/176;
548/101; 548/159; 548/217; 548/305.4; G9B/7.15; G9B/7.157 |
Current CPC
Class: |
G11B 7/259 20130101;
G11B 7/2478 20130101; G11B 7/2531 20130101; G11B 2007/24612
20130101; G11B 7/2495 20130101; G11B 7/2475 20130101; G11B 7/2463
20130101; G11B 7/2467 20130101; G11B 7/246 20130101; C09B 23/145
20130101; G11B 7/245 20130101; G11B 7/248 20130101; G11B 7/247
20130101; G11B 7/2472 20130101; Y10S 430/146 20130101 |
Class at
Publication: |
546/002 ;
548/101; 546/176; 548/159; 548/217; 548/305.4 |
International
Class: |
C07F 001/02; C07D
417/02; C07D 413/02; C07D 043/02 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 2, 1999 |
JP |
343211/1999 |
Claims
We claim:
1. A styryl dye represented by Formula 1: Formula 1: 16wherein in
Formula 1, .phi..sub.1 represents a heterocycle represented by any
one of Formulae 2 to 8; .phi..sub.2 represents an optionally
substituted aromatic ring or heterocycle; R.sub.1 represents a
hydrogen atom, an aliphatic hydrocarbon group, ether group, acyl
group, halogen, or cyano group, and the aliphatic hydrocarbon
group, ether group, and acyl group may have a substituent; X.sup.-
represents a counter ion; and "n" is a number of X.sup.- to balance
the electric charge in the styryl dye: 17throughout Formulae 2 to
7, A represents an optionally substituted monocyclic or polycyclic
aromatic ring or heterocycle; when A is not present in Formulae 2
to 7, a substituent similar to A is in position filled by A;
throughout Formulae 2 to 8, R.sub.2 represents an optionally
substituted aliphatic hydrocarbon group and R.sub.3 represents a
hydrogen or an optionally substituted aliphatic hydrocarbon group
which is identical to or different from R.sub.2.
2. The styryl dye of claim 1, wherein said .phi..sub.2 is a
nitrogen atom containing heterocycle which forms an ammonium
salt.
3. The styryl dye of claim 1 wherein said counter ion is an organic
metal complex anion with a light-resistant improving ability.
4. The styryl dye of claim 1 which has an absorption maximum at a
wavelength of 400 nm or less.
5. The styryl dye of claim 1 which substantially absorbs a visible
light with a wavelength of 450 nm or less when formed in a thin
layer.
6. A process for producing the styryl dye of claim 1 comprising
reacting a compound, represented by Formula 9 having .phi..sub.1
and R.sub.1 corresponding to Formula 1, with a compound represented
by Formula 10 having .phi..sub.2 corresponding to Formula 1. 18
7. The styryl dye of claim 2, wherein said counter ion is an
organic metal complex anion with a light-resistant improving
ability.
8. The styryl dye of claim 2 which has an absorption maximum at a
wavelength of 400 nm or less.
9. The styryl dye of claim 3 which has an absorption maximum at a
wavelength of 400 nm or less.
10. The styryl dye of claim 2 which substantially absorbs visible
light with a wavelength of 450 nm or less when formed in thin
layer.
11. The styryl dye of claim 3 which substantially absorbs visible
light with a wavelength of 450 nm or less when formed in thin
layer.
12. The styryl dye of claim 4 which substantially absorbs visible
light with a wavelength of 450 nm or less when formed in thin
layers.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional application of Ser.
No. 09/890,711, filed Aug. 9, 2001, the entire contents of which is
hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to organic dye compounds, and
more particularly, to styryl dyes which have absorption maxima at a
wavelength of 400 nm or less.
BACKGROUND OF THE INVENTION
[0003] In a multimedia age, optical recording media such as CD-R (a
write-once memory using compact disc) and DVD-R (a write-once
memory using digital video disc) are now of great importance. Most
of the conventional optical recording media can be roughly
classified into inorganic optical recording media which have
recording layers composed of inorganic substances such as
tellurium, selenium, rhodium, carbon, or carbon sulfide; and
organic optical recording media which have recording layers mainly
composed of light absorbents containing organic dye compounds.
[0004] Among these optical recording media, organic optical
recording media can be usually prepared by dissolving a polymethine
dye in an organic solvent such as 2,2,3,3-tetrafluoro-1-propanol
(abbreviated as "TFP" hereinafter), spin coating the solution onto
the surface of a polycarbonate substrate, drying the solution to
form a recording layer, and sequentially forming and coating onto
the surface of the recording layer a reflection layer comprising a
metal such as gold, silver or copper, and a protection layer
comprising an ultraviolet ray hardening resin. When compared with
inorganic optical recording media, organic ones may have the
drawback that their recording layers are susceptible to change
under environmental lights such as reading and natural light.
Organic optical recording media, however, have the advantage that
they can be made into optical recording media at a lesser cost
because their recording layers can be directly formed by coating
light absorbents in solution on the surface of substrates. Further,
organic optical recording media composed of organic materials are
now mainly used as low-cost optical recording media because they
are substantially free of corrosion even when contacted by moisture
or sea water and because information recorded therein in a
prescribed format can be read out by using commercially available
read-only readers after establishing thermal-deformation-type
optical recording media, a kind of organic optical recording
media.
[0005] What is urgently required in organic optical recording media
is to increase their storage capacity to suit to this multimedia
age. The research for such an increment, which is now being eagerly
continued in this field, is to increase the recording capacity per
one side from 4.7 GB (giga bite) to 15 GB or more by shortening the
wavelength for writing information to 450 nm or less from the
wavelengths of 635-650 nm which are commonly used. The high-density
optical recording media have the capacity to record movie and
animations for six hours in picture quality of standard television
or for two hours even in relatively-high picture quality of high
definition television. However, since most organic dye compounds
now used in the conventional optical recording media can not be
used with visible light with a wavelength of 450 nm or less, they
could not fulfill the need for high-storage density required in
many fields.
[0006] In view of the foregoing, the object of the present
invention is to provide organic dye compounds which have absorption
maxima at a wavelength of 400 nm or less and substantially absorb a
visible light with a wavelength of 450 nm or less when formed in a
thin layer, and to provide uses thereof.
SUMMARY OF THE INVENTION
[0007] The present inventors eagerly studied and screened
compounds. As a result, they found that specific styryl dyes (may
be called "styryl dyes" hereinafter), which are obtainable through
a step of reacting a quaternary ammonium salt of nitrogen
heterocyclic compound having an active methyl- or active
methylene-group with an aldehyde compound, have absorption maxima
at a wavelength of 400 nm or less and substantially absorb visible
light with a wavelength around 400 nm. The present inventors
confirmed that the styryl dyes, which substantially absorb visible
light with a wavelength of 450 nm or less when formed in a thin
layer, form remarkably minute pits at a relatively high density in
optical recording media by irradiating with a laser beam with a
wavelength of 450 nm or less. The present invention was made based
on the creation of novel styryl dyes and the discovery of their
industrially useful characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is the visible absorption spectra of one of the
styryl dyes of the present invention when in a solution form and in
a thin layer form, respectively.
[0009] FIG. 2 is the visible absorption spectra of another styryl
dye of the present invention when in a solution form and in a thin
layer form, respectively.
[0010] FIG. 3 is the visible absorption spectra of a conventional
related compound when in a solution form and in a thin layer form,
respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The present invention relates to the styryl dyes represented
by Formula 1.
[0012] Formula 1: 1
[0013] In Formula 1, R.sub.1 represents a hydrogen atom, an
aliphatic hydrocarbon group, ether group, acyl group, halogen, or
cyano group. The aliphatic hydrocarbon group in R.sub.1 represented
that having up to six carbon atoms, usually, from one to five
carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl,
isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, or
tert-pentyl group. Examples of the ether groups are methoxy,
ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, pentoxy, and
phenoxy groups. Examples of the acyl groups are formyl, acetyl,
propionyl, butyryl, tert-butyryl, benzoyl, o-tolyl, m-tolyl, and
p-tolyl groups. Examples of the halogens are fluorine, chlorine,
bromine, and iodine. One or more of the hydrogens in the aliphatic
hydrocarbon group, ethergroup, and acyl group may be replaced with
a short-chain aliphatic hydrocarbon group such as methyl, ethyl, or
propyl group; a short-chain ether group such as methoxy, ethoxy, or
propoxy group; or a halogen such as fluorine, chlorine, bromine, or
iodine.
[0014] In Formula 1, .phi..sub.1 represents a heterocycle which is
represented by any one of Formulae 2 to 8. 2
[0015] Throughout Formulae 2 to 7, A represents a monocyclic- or
polycyclic-aromatic-ring or heterocycle. Examples of the aromatic
ring are benzene and naphthalene rings. Examples of the heterocycle
are pyridine, quinoline, and quinoxaline rings. The aromatic ring
and heterocycle may have one or more substituents, for example, a
halogen atom such as fluorine, chlorine, bromine, or iodine atom; a
short-chain aliphatic hydrocarbon group such as methyl,
trifluoromethyl, ethyl, propyl, isopropyl, butyl, isobutyl,
sec-butyl, or tert-butyl group; a short-chain ether group such as
methoxy, trifluoromethoxy, ethoxy, propoxy, isopropoxy, butoxy, or
tert-butoxy group; an alkylaminosulfonyl group such as
methylaminosulfonyl, dimethylaminosulfonyl, ethylaminosulfonyl,
diethylaminosulfonyl, propylaminosulfonyl, dipropylaminosulfonyl,
butylaminosulfonyl, or dibutylaminosulfonyl group; an aromatic
hydrocarbon group such as phenyl, biphenylyl, o-tolyl, m-tolyl,
p-tolyl, xylyl, mesityl, o-cumenyl, m-cumenyl, p-cumenyl, or
naphthyl group; an ester group such as methoxycarbonyl,
trifluoromethoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, acetoxy,
trifluoroacetoxy, or benzoyloxy group; nitro group, cyano group,
carboxy group, or sulfo group. When A is not present in Formulae 2
to 7, one or more substituents similar to those that are similar to
A may be in the position where A is located.
[0016] Throughout Formulae 2 to 8, R.sub.2 represents an aliphatic
hydrocarbon group selected from those having up to eight carbon
atoms, usually, up to six carbon atoms such as methyl, ethyl,
propyl, isopropyl, isopropenyl, 1-propenyl, 2-propenyl, 2-propynyl,
butyl, isobutyl, sec-butyl, tert-butyl, 2-butenyl, 2-butynyl,
1,3-butadienyl, pentyl, isopentyl, neopentyl, 1-methylpentyl,
2-methylpentyl, 2-pentenyl, 2-pentynyl, 2-penten-4-ynyl, hexyl, or
isohexyl group. The aliphatic hydrocarbon group may have one or
more substituents, for example, a halogen such as fluorine,
chlorine, bromine, or iodine; an ether group such as methoxy,
trifluoromethoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy,
benzyloxy, or phenoxy group; an ester group such as
methoxycarbonyl, trifluoromethoxycarbonyl, ethoxycarbonyl,
propoxycarbonyl, acetoxy, trifluoroacetoxy, or benzoyloxy group; a
carboxy group; a sulfo group; a hydroxy group; an amido group such
as acetylamino or benzoylamino group; an aromatic hydrocarbon group
such as phenyl, biphenylyl, o-tolyl, m-tolyl, p-tolyl, xylyl,
mesityl, o-cumenyl, m-cumenyl, p-cumenyl, or naphthyl group; or
heterocyclic group such as 2-pyridyl, 2-quinolyl,
2-tetrahydropyranyl, 2,2-dimethyl-1,3-dioxolane-4-- yl,
1,3-dioxolane-2-yl, 3,5-dimethylisooxazole-4-yl, 3-piperidinyl,
piperidino, morpholino, 1-piperazinyl, pyrrolidine-1-yl,
1-methyl-2-pyrrolidinyl, 2-benzoimidazolyl, 5-uracil, or
benzotriazole-1-yl group.
[0017] In Formula 4, R.sub.3 represents a hydrogen atom or an
aliphatic hydrocarbon group which is identical to or different from
R.sub.2. Representative examples of the aliphatic hydrocarbon group
are short-chain groups such as methyl, ethyl, propyl, isopropyl,
butyl, isobutyl, sec-butyl, or tert-butyl group, which may have one
or more substituents, for example, an ether group such as methoxy,
trifluoromethoxy, ethoxy, propoxy, isopropoxy, butoxy, or
tert-butoxy group; an ester group such as methoxycarbonyl,
trifluoromethoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, acetoxy,
trifluoroacetoxy, or benzoyloxy group; or an aromatic hydrocarbon
group such as phenyl, o-tolyl, m-tolyl, p-tolyl, xylyl, mesityl,
o-cumenyl, m-cumenyl, p-cumenyl, or nitrophenyl group.
[0018] Furthermore, in Formula 1, .phi..sub.2 represents a
monocyclic/or polycyclic/aromatic ring or heterocycle which may
include one or more nitrogen atoms in the ring, for example, a
benzene, pyridine, pyrimidine, pyridazine, naphthalene, quinoline,
or quinoxaline ring. The aromatic ring and heterocycle may have one
or more substituents. The substituents are selected from those
having up to eight carbon atoms, usually, one to six carbon atoms,
for example, an aliphatic hydrocarbon group such as methyl, ethyl,
propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl,
isopentyl, neopentyl, tert-pentyl, 1-methylpentyl, 2-methylpentyl,
hexyl, or isohexyl group; a short-chain ether group such as
methoxy, trifluoromethoxy, ethoxy, propoxy, isopropoxy, butoxy, or
tert-butoxy group; an amido group such as acetylamino or
benzoylamino group; a halogen such as fluorine, chlorine, bromine,
or iodine; and cyano group, nitro group, hydroxy group, sulfo
group, or carboxy group. When .phi..sub.2 is a
nitrogen-atom-containing heterocycle, the nitrogen atom may combine
with a similar aliphatic hydrocarbon group as in R.sub.2 in
.phi..sub.1 to form an ammonium salt. When .phi..sub.2 has two
hydroxy groups as a substituent and the hydroxy groups combine with
adjacent carbon atoms in .phi..sub.2, the hydroxy groups may react
with an oxo compound such as formalin to form a cyclic structure
such as a dioxole ring.
[0019] X.sup.- in Formula 1 represents an arbitrary counter ion and
is usually selected from inorganic acid ions such as fluoride,
chloride, bromide, iodide, perchrolide acid, periodic acid,
phosphoric acid hexafluoride, antimony hexafluoride, tin acid
hexafluoride, phosphoric acid, fluoroboric acid, and
tetrafluoroboric acid ions; organic acid ions such as thiocyanic
acid, benzensulfonic acid, naphthalenesulfonic acid,
naphthalenedisulfonic acid, p-toluenesulfonic acid, alkylsulfonic
acid, benzenecarboxylic acid, alkylcarboxylic acid,
trihaloalkylcarboxylic acid, alkylsulfonic acid,
trihaloalkylsulfonic acid, nicotinic acid, and
tetracyanoquinonedimethane ions; and organic metal complex ions
such as azo, bisphenyldithiol, thiocatechol chelate,
thiobisphenolate chelate, and bisdiol-.alpha.-diketone. "n" is the
number of X.sup.- to balance the electric charge in the styryl
dyes, and is usually an integer selected from one and two.
[0020] The present invention relates to styryl dyes having the
structures as mentioned above, particularly, to those which have
absorption maxima at a wavelength of 400 nm or less, and desirably
those which substantially absorb a visible light with a wavelength
of 450 nm or less when formed in a thin layer. Concrete examples of
the styryl dyes are those represented by Chemical Formulae 1 to 60.
Since all of them have absorption maxima at a wavelength of 400 nm
or less and substantially absorb a visible light with a wavelength
around 400 nm, they have diversified uses in the fields which need
organic compounds that absorb the aforesaid visible light. Among
the styryl dyes, those, which substantially absorb a visible light
with a wavelength of 450 nm or less when formed in a thin layer,
particularly, absorb the visible light in the absorption end of
longer wavelength region of the absorption maximum, are remarkably
useful as a material for producing a recording layer of high
density optical recording media such as DVD-Rs for the coming
generation. 3456789101112
[0021] The styryl dyes of the present invention can be prepared by
various procedures. They can be preferably and economically
produced by a step of reacting a quaternary ammonium salt of
nitrogen atom containing heterocyclic compound having either an
active methyl- or active methylene-group with an aldehyde compound.
With this method, the styryl dyes of the present invention can be
produced in a desired yield by reacting a compound represented by
Formula 9 having .phi..sub.1 and R.sub.1 corresponding to those in
Formula 1 with a compound represented by Formula 10 having
.phi..sub.2 corresponding to those in Formula 1. 13
[0022] For example, appropriate amounts (usually about equal mols)
of compounds represented by Formulae 9 and 10 are placed in a
reaction vessel, and the resulting mixture is dissolved in an
adequate solvent, if necessary, and then reacted at ambient
temperature or under heating and stirring conditions, for example,
a reflux in the presence of an appropriate amount of a basic
compound such as sodium hydroxide, potassium hydroxide, sodium
carbonate, potassium carbonate, sodium hydrogencarbonate, potassium
hydrogencarbonate, ammonia, triethylamine, piperidine, pyridine,
pyrrolidine, aniline, N,N-dimethylaniline, N,N-diethylaniline, or
N-methyl-2-pyrrolidone; an acidic compound such as hydrochloric
acid, sulfuric acid, nitric acid, methanesulforic acid,
p-toluenesulfonic acid, acetic acid, acetic anhydride, propionic
anhydride, trifluoroacetic acid, or trifluorosulfonic acid; or a
Lewis acidic compound such as aluminium chloride, zinc chloride,
tin tetrachloride, or titanium tetrachloride.
[0023] As to solvents which can be used in the present invention,
for example, hydrocarbons such as pentane, hexane, cyclohexane,
octane, benzene, toluene, and xylene; halides such as carbon
tetrachloride, chloroform, 1,2-dichloroethane, 1,2-dibromoethane,
trichloroethylene, tetrachloroethylene, chlorobenzene,
bromobenzene, and .alpha.-dichlorobenzene; alcohols and phenols
such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol,
2-butanol, isobutyl alcohol, isopentyl alcohol, cyclohexanol,
ethylene glycol, propylene glycol, 2-methoxyethanol,
2-ethoxyethanol, phenol, benzyl alcohol, cresol, diethyleneglycol,
triethylene glycol, and glycerin; ethers such as diethyl ether,
diisopropyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane,
anisole, 1,2-dimethoxyethane, diethylene glycol dimethyl ether,
dicyclohexyl-18-crown-6, methylcarbitol, and ethylcarbitol; ketones
such as furfural, acetone, ethyl methyl ketone, and cyclohexanone;
acids and acidic derivatives such as acetic acid, acetic anhydride,
trichloroacetic acid, trifluoroacetic acid, propionic anhydride,
ethyl acetate, butyl carbonate, ethylene carbonate, propylene
carbonate, formamide, N-methylformamide, N,N-dimethylformamide,
N-methylacetamide, N,N-dimethylacetamide, hexamethylphosphoric
triamide, and phosphoric trimethyl; nitriles such as acetonitrile,
propionitrile, succinonitrile, and benzonitrile; nitro compounds
such as nitromethane and nitrobenzene; sulfur-containing compounds
such as dimethylsulfoxide and sulfolane; and water can be used and
arbitrarily used in a combination, if necessary.
[0024] In general, when solvents are used, the greater the volume
of solvents the lower the reaction efficiency. On the contrary, the
lower the volume of solvents the more difficult homogeneous heating
and stirring of the contents becomes and undesirable side reactions
may easily occur. Thus, the volume of solvents is desirably set to
a level up to 100-folds, usually, in the range of 5-50-folds to the
total volume of material compounds by weight. The reaction is
complete within 10 hours, usually, 0.5-10 hours, depending on the
kinds of reactants and the reaction conditions. The reaction
progress can be monitored by conventional methods, for example,
thin layer chromatography, gas chromatography, and high-performance
liquid chromatography. After completion of the reaction, the styryl
dyes of the present invention with desired counter ions are
obtainable by subjecting the reaction mixture to a conventional
counter ion-exchange reaction, if necessary. Thus, all of the
styryl dyes represented by Chemical Formulae 1 to 60 are obtainable
in a desired yield by the above method. Compounds represented by
Formulae 9 and 10 are obtainable in accordance with conventional
methods to form a cyclic nucleus in the styryl dyes.
[0025] The styryl dyes thus obtained can be used in the form of a
reaction mixture without any further treatment, but are usually
used after being purified by conventional techniques which are
generally used for purifying their related compounds, such as
dissolution, extraction, separation, decantation, filtration,
concentration, thin layer chromatography, column chromatography,
gas chromatography, high-performance liquid chromatography,
distillation, crystallization, and sublimation. If necessary, these
methods can be used in combination. When the styryl dyes of the
present invention are used in dye lasers and optical recording
media such as DVD-Rs, it is preferable that the styryl dyes of the
present invention be distilled, crystallized, and/or sublimated
prior to use.
[0026] The light absorbents of the present invention comprise one
or more of the styryl dyes and include those which utilize the
nature of the styryl dyes which substantially absorb visible light
with a wavelength around 400 nm. The compositions or the physical
forms of the light absorbents are not restricted. Therefore, the
light absorbents of the present invention may comprise one or more
other compounds in addition to the styryl dyes, depending on use.
One of the fields in which the light absorbents of the present
invention can be advantageously used is optical recording media. In
this field, the light absorbents of the present invention are
suitable as a material for producing recording layers of optical
recording media using a laser beam with a wavelength of 450 nm or
less as a writing light. In using the light absorbents of the
present invention in optical recording media, unless the use
deviates from the object of the present invention, the styryl dyes
can be mixed with other light absorbents comprising other organic
dye compounds which are sensitive to visible light and one or more
conventional materials used in optical recording media, such as a
light-resistant improver, binder, dispersing agent, flame
retardant, lubricant, antistatic agent, surfactant, thermal
interference inhibitor, plasticizer, color fixing agent, developer,
and dissolving assistant, if necessary.
[0027] Explaining the uses of the light absorbents of the present
invention by examplifying organic optical recording media (organic
heat-deformative-type optical recording media), the optical
recording media of the present invention can be prepared in
accordance with conventional organic recording media because the
styryl dyes of the present invention require no special treatment
beyond the treatments which are commonly used in this art. For
example, one or more of the styryl dyes of the present invention
can be mixed with one or more other organic dye compounds which are
sensitive to visible light, and one or more conventional
light-resistant improvers, binders, dispersing agents, flame
retardants, lubricants, antistatic agents, surfactants, thermal
interference inhibitors, and plasticizers to control the reflection
rate and the light absorption rate in a recording layer, if
necessary. The resulting mixture is dissolved in an organic
solvent, and the solution is uniformly coated over either surface
of the substrates by means of spraying, soaking, roller coating, or
rotatory coating methods; and dried to form a recording layer, a
thin layer comprising light absorbents, and if necessary, followed
by forming a reflection layer to be closely attached onto the
recording layer by the method of vacuum deposition, chemical vapor
deposition, sputtering, or ion plating using metals such as gold,
silver, copper, platinum, aluminium, cobalt, tin, nickel, iron, and
chromium or using conventional organic materials for reflection
layers to impart a reflection efficiency with which the written
information can be read, for example, 20% or more, and preferably
30% or more. Then ultraviolet-ray-hardening resins or thermosetting
resins, which contain flame retardants, stabilizers, and/or
antistatic agents are spin coated over the recording layer, and
then the coated are hardened resins by either irradiating light or
heating to form a protection layer to be closely attached onto the
reflection layer to protect the recording layer from scratches,
dusts, spills, etc. Thereafter, if necessary, a pair of the above
substrates with recording, reflection, and recording layers are
faced and attached together using, for example, adhesives or
viscous sheets; or protection plates, which are comprising the same
materials and shapes as the substrates, are attached to the
protection layers of the substrates.
[0028] As another organic dye compounds usable in combination with
the styryl dyes of the present invention, dye compounds are
particularly restricted as long as they are sensitive to visible
light and can modulate the light reflection- and the light
absorption-rates of recording layers of optical recording media. As
the organic dye compounds, the following compounds can be used in
an arbitrary combination, if necessary: Acridine dye, azaannulene
dye, azo dye, azo metal complex dye, anthraquinone dye, indigo dye,
indanthrene dye, oxazine dye, xanthene dye, dioxazine dye, thiazine
dye, thioindigo dye, tetrapyrapolphyradine dye, triphenylmethine
dye, triphenylthiazine dye, naphthoquinone dye, pyrromethene dye,
phthalocyanine dye, benzoquinone dye, benzopyrandye, benzofuranone
dye, polyphyrin dye, rhodamine dye, and polymethine dyes such as
cyanine dye, merocyanine dye, oxonol dye, azulenium dye, squalilium
dye, styryl dye, pyririum dye, thiopyririum dye, and phenanthrene
dye in which the same or different rings are bound to both ends of
polymethine chain such as monomethine, dimethine, trimethine,
tetramethine, pentamethine, hexamethine, or heptamethine. The chain
and rings can have one or more substituents. Examples of the ring
are imidazoline ring, imidazole ring, banzoimidazole ring,
.alpha.-naphthimidazole ring, .beta.-naphthimidazole ring, indole
ring, isoindole ring, indolenine ring, isoindolenine ring,
benzoindolenine ring, pyridinoindolenine ring, oxazoline ring,
oxazole ring, isooxazole ring, benzooxazole ring, pyridinooxazole
ring, .alpha.-naphthoxazole ring, .beta.-naphthoxazole ring,
selenazoline ring, selenazole ring, benzoselenazole ring,
.alpha.-naphthselenazole ring, .beta.-naphthselenazole ring,
thiazoline ring, thiazole ring, isothiazole ring, benzothiazole
ring, .alpha.-naphththiazole ring, .beta.-naphththiazole ring,
tellurazoline ring, tellurazole ring, benzotellurazole ring,
.alpha.-naphthtellurazole ring, .beta.-naphthtellurazole ring,
acridine ring, anthracene ring, isoquinoline ring, isopyrrole ring,
imidanoxaline ring, indandione ring, indazole ring, indaline ring,
oxadiazole ring, carbazole ring, xanthene ring, quinazoline ring,
quinoxaline ring, quinoline ring, chroman ring, cyclohexanedione
ring, cyclopentandione ring, cinnoline ring, thiodiazole ring,
thiooxazolidone ring, thiophene ring, thionaphthene ring,
thiobarbituric acid ring, thiohydantoin ring, tetrazole ring,
triazine ring, naphthalene ring, naphthyridine ring, piperazine
ring, pyrazine ring, pyrazole ring, pyrazoline ring, pyrazolidine
ring, pyrazolone ring, pyran ring, pyridine ring, pyridazine ring,
pyrimidine ring, pyrylium ring, pyrrolidine ring, pyrroline ring,
pyrrole ring, phenazine ring, phenanthridine ring, phenanthrene
ring, phenanthroline ring, phthalazine ring, pteridine ring,
furazane ring, furan ring, purine ring, benzene ring, benzoxazine
ring, benzopyran ring, morpholine ring, and rhodanine ring. As the
organic dye compounds used in combination with the styryl dyes of
the present invention, they desirably have an absorption maxima in
the visible region, particularly, at wavelengths of 400-850 nm,
when formed in a thin layer.
[0029] The light-resistant improvers are, for example, nitroso
compounds such as nitrosodiphenylamine, nitrosoaniline,
nitrosophenol, and nitrosonaphthol; and metal complexes such as
dithiolate metal complexes, for example, "NKX-1199"
(bis[2'-chloro-3-methoxy-4-(2-methoxyethoxy)dithi- obenzyl]nickel)
produced by Hayashibara Biochemical Laboratories, Inc., Okayama,
Japan, and formazane metal complexes, which all can be arbitrarily
used in combination, if necessary. Preferable light-resistance
improvers are those which contain metal complexes, and the most
preferable ones are metal complexes, more preferably, formazane
compounds which have a pyridine-ring at C-5 and a pyridine or furan
ring at C-3 of formazane skeleton as disclosed in Japanese Patent
Application No. 163,036/99, titled "Formazane metal complexes", and
complexes with metals such as nickel, zinc, cobalt, iron, copper,
and palladium, which have the tautomer of the aforesaid compounds
as a ligand. In the case of using such a light-resistance improver
in combination, the styryl dyes of the present invention can be
effectively prevented from undesirable deterioration, fading, color
changing, and quality changing, which are inducible by
environmental lights such reading- and natural-lights, without
lowering the solubility of the light absorbents of the present
invention in organic solvents and substantially deteriorating
preferable optical features. As to a composition ratio, 0.01-5
moles of a light-resistance improver(s), desirably, 0.1-1 moles,
can be incorporated into one mole of the styryl dye(s) while
increasing or decreasing the ratio. The light-resistant improver(s)
are not necessarily other compound(s) which exist separately from
the styryl dyes of the present invention, and if necessary, they
can be formulated into salts, complexes, or compounds by combining
the styryl dyes with organic metal complex anions, which are
capable of improving the light resistance as disclosed in Japanese
Patent Kokai Nos. 19,355/89, 139,043/93, 323,478/97, and 6,651/98.
These include conventional compounds such as azo, bisphenyldithiol,
phenyldithiol, thiocatecholchelate, thiobisphenolatechelate, or
bisdithiol-.alpha.-diketone by using appropriate spacers and
crosslinking agents such as alkoxides or cyanates of titanium,
zirconium, aluminium, etc., or complexes of these metal elements
having carbonyl compounds or hydroxy compounds as ligands.
[0030] The styryl dyes of the present invention have
satisfactorily-high solubility in organic solvents without
substantially causing undesirable problems in actual use, and do
not particularly restrict the types of organic solvents used for
coating the light absorbents of the present invention over
substrates. Thus, in the preparation of optical recording media
according to the present invention, arbitrary organic solvents can
be selected from the following conventional ones which are
arbitrarily used in combination, if necessary: TFP frequently used
to prepare optical recording media and the following organic
solvents other than TFP: For example, hydrocarbons such as benzene,
toluene, and xylene; halides such as carbon tetrachloride,
chloroform, 1,2-dichloroethane, 1,2-dibromoethane,
trichloroethylene, tetrachloroethylene, chlorobenzene,
bromobenzene, and .alpha.-dichlorobenzene; alcohols and phenols
such as methanol, ethanol, propanol, isopropanol,
2,2,2-trifluoroethanol, butanol, isobutanol, isopentanol,
cyclohexanol, ethylene glycol, propylene glycol, 2-methoxyethanol
(methyl cellosolve), 2-ethoxyethanol (ethyl cellosolve), phenol,
benzyl alcohol, cresol, diethylene glycol, triethyleneglycol,
glycerine, and diacetone alcohol; ethers such as diethyl ether,
diisopropyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane,
anisole, 1,2-dimethoxyethane, dicyclohexyl-18-crown-6,
methylcarbitol, and ethylcarbitol; ketones such as furfural,
acetone, 1,3-diacetylacetone, ethyl methyl ketone, and
cyclohexanone; esters such as ethyl acetate, butyl acetate,
ethylene carbonate, propylene carbonate, and trimethyl phosphate;
amides such as formamide, N-methylformamide, N,N-dimethylformamide,
and hexamethylphosphoric triamide; nitriles such as acetonitrile,
propionitrile, and succinonitrile; nitro compounds such as
nitromethane and nitrobenzene; amines such as ethylene diamine,
pyridine, piperidine, morpholine, and N-methylpyrrolidone; and
sulfur-containing compounds such as dimethylsulfoxide and
sulfolane.
[0031] Particularly, since the styryl dyes of the present invention
have relatively high solubilities in easily volatile organic
solvents such as TFP, methyl cellosolve, ethyl cellosolve, and
diacetone alcohol, they are substantially free from dye
crystallization when they are sequentially dissolved in the organic
solvents, coated on substrates, and dried and do not cause
inconsistent thickness and surface of the formed recording layers.
Most of the styryl dyes of the present invention exert desirable
solubilities in non-halogen solvents, for example, cellosolves such
as methyl cellosolve and ethyl cellosolve, alcohols such as
diacetone alcohol, and ketones such as ethyl methyl keton and
cyclohexanone. When the styryl dyes of the present invention
dissolve in the non-halogen solvents and the obtained solutions are
coated over the plastic substrates, the solvents neither damage the
substrates nor pollute the environment, which is an advantage.
[0032] Conventional substrates can be used in the present invention
and are usually processed with suitable materials, for example,
into discs, 12 cm in diameter and 0.1-1.2 mm in thickness, to be
conformed to final use by methods such as compression molding,
injection molding, compression-injection molding,
photopolymerization method (2P method), thermosetting integral
method, and light setting integral method. These discs can be used
singularly or plurally after they have been appropriately attached
together with adhesive sheets or adhesive agents, etc. In
principal, any materials for substrates can be used in the present
invention as long as they are substantially transparent and have
light transmissivity of at least 80%, and preferably 90% or more at
wavelengths ranging from 350 nm to 800 nm. Examples of such
materials are glasses, ceramics, and others such as plastics
including polyacrylate, polymethyl methacrylate, polycarbonate,
polystyrene (styrene copolymer), polymethylpentene, polyester,
polyolefin, polyimide, polyetherimide, polysulfone,
polyethersulfone, polyarylate, polycarbonate/polystyrene alloy,
polyestercarbonate, polyphthalatecarbonate, polycarbonateacrylate,
non-crystalline polyolefin, methacrylate copolymer,
diallylcarbonatediethylene-glycol, epoxy resin, and phenol resin,
where polycarbonate and acrylate are most frequently used. In
plastic substrates, concaves for expression of synchronizing
signals and addresses of tracks and sectors are usually transferred
to the internal circle of the tracks during their formation. The
present invention does not restrict the form of concaves and the
concaves are preferably formed to give 0.3-0.8 .mu.m in average
wide and 50-150 nm in depth.
[0033] The styryl dyes of the present invention can be prepared
into 0.5-5% (w/w) solutions of the organic solvents as mentioned
above while considering the viscosity of the solutions, and then
uniformly coated over a substrate to form a recording layer of
10-1,000 nm, preferably, 50-300 nm in thickness. Prior to the
coating, a preliminary layer can be formed over the substrate to
improve the protection and the adhesion ability of the substrate,
if necessary. Materials of the preliminary layer are, for example,
high-molecular substances such as ionomer resins, polyamide resins,
vinyl resins, natural resins, silicon, and liquid rubbers. In the
case of using binders, the following polymers can be used alone or
in combination in a weight ratio of 0.01-10 times of the light
absorbent(s): Cellulose esters such as nitrocellulose, cellulose
phosphate, cellulose sulfate, cellulose acetate, cellulose
propionate, cellulose lactate, cellulose palmitate, and cellulose
acetate/propionate; cellulose ethers such as methyl cellulose,
ethyl cellulose, propyl cellulose, and butyl cellulose; vinyl
resins such as polystyrene, poly(vinyl chloride), poly(vinyl
acetate), poly(vinyl acetal), poly(vinyl butyral), poly(vinyl
formal), poly(vinyl alcohol), and poly(vinyl pyrrolidone);
copolymer resins such as styrene-butadiene copolymers,
styrene-acrylonitrile copolymers, styrene-butadiene-acrylonitrile
copolymers, vinyl chloride-vinyl acetate copolymers, and maleic
anhydride copolymers; acrylic resins such as poly(methyl
methacrylate), poly(methyl acrylate), polyacrylate,
polymethacrylate, polyacrylamide, and polyacrylonitrile; polyesters
such as poly(ethylene terephthalate); and polyolefins such as
polyethylene, chlorinated polyethylene, and polypropylene.
[0034] Explaining the manner for using the optical recording media
according to the present invention, the high-density optical
recording media of the present invention such as DVD-Rs can write
information at a relatively high density by using a laser beam with
a wavelength of 450 nm or less, more particularly, a laser beam
with a wavelength around 350-450 nm irradiated by semiconductor
laser elements such as InN, GaN, InGaN, InAlGaN, InGaNAs, BInN,
InGaNP, InP, GaP, GaAsP, and SiC, which oscillate in the blue color
or violet color region; or a distributed feedback-type laser, which
oscillates in the red color region, and to which set a second
harmonics generating mechanism to a semiconductor element of
AlGaAs. To read recorded information, laser beams are used with
wavelengths identical to or slightly longer or shorter than those
used for writing information. As for the laser power for writing
and reading information, in the optical recording media of the
present invention. It is preferably set to a relatively high level,
which exceeds the threshold of the energy required for forming
pits, in writing information. It is preferably set to a relatively
low level, i.e., a level of below the threshold when used in
reading recorded information, although the power levels can be
varied depending on the types and ratios of the light-resistant
improvers used in combination with the light absorbents of the
present invention and further the writing speed. Generally, the
levels can be controlled to outputs of over 5 mW for writing,
usually in the range of 10-50 mW, and to outputs of 5 mW or lower
for reading, usually in the range of 0.1-5 mW. The recorded
information is read by detecting the changes of both the reflection
light level and the transmission light level in the pits and the
pit-less part on the surface of optical recording media by the
light pick-up manner.
[0035] Accordingly, in the optical recording media of the present
invention, remarkably minute pits with a pit width of below 0.4
.mu.m/pit and a track pitch of below 0.74 .mu.m used in the
conventional DVD-R, can be formed at a relatively high density by
using a laser beam with an oscillating wavelength of 450 nm. For
example, in using a substrate, 12 cm in diameter, it can realize an
extremely high density optical recording medium with an optical
recording capacity far exceeding 4.7 GB (giga bytes) per one side,
i.e., that of about two hours of information of sound and images in
relatively high image quality of high definition television which
could hardly be attained in the commonly used DVD-Rs.
[0036] Since the optical recording media of the present invention
can record information including characters, images, and sound at a
relatively high density, they are advantageously useful as
recording media for professional and family uses to record and care
for documents, data, and computer software. Particular examples of
the types of industries and the forms of information to which the
optical recording media can be applied are drawings of construction
and engineering works, maps, ledgers of roads and rivers, aperture
cards, architectural sketches, documents of disaster protection,
wiring diagrams, arrangement plans, information from newspapers and
magazines, local information, and construction specifications,
which all relate to construction and engineering works; blueprints,
ingredient tables, prescriptions, product specifications, product
price tables, parts lists, information for maintenance, case study
files of accidents and problems, manuals for claims, production
schemes, technical documents, sketches, details, company's
house-made product files, technical reports, and analysis reports,
which are all used in production; customers information,
information of business connections, information of companies,
contracts, information of newspapers and magazines, business
reports, company's credit research, and stock lists, which are all
used in sales; information of companies, records of stock prices,
statistical documents, information from newspapers and magazines,
contracts, customer lists, documents of application, notification,
licenses, authorization, and business reports, which are all used
in finance; information regarding real property and transportation,
sketches of construction, maps, local information, information from
newspapers and magazines, contracts for lease, information about
companies, stock lists, traffic information, and information
regarding business connections, which are all used in real property
and transportation; diagrams of writings and pipe arrangements for
electric and gas supplies, documents of disaster protection, tables
of operation manuals, documents of investigations, and technical
reports; medical charts, files of clinical histories and case
studies, and diagrams for medical care institution relationships;
texts, collections of questions, educational documents, and
statistical information; scientific papers, records in academic
societies, monthly reports of research, research data, documentary
records and indexes thereof, which are all used in universities,
colleges, and research institutes; inspection data, literatures,
patent publications, weather maps, analytical records of data, and
customer files, which are all used for information; case studies on
laws; membership lists, history notes, records of works, products,
competition data, data of meetings and congresses, which are all
used in several organizations/associations; sightseeing
information, traffic information, and local information, which are
all used for sightseeing; indexes of homemade publications,
information from newspapers and magazines, who's who files, sport
records, telop files, and scripts, which are all used in mass
communication and publishing; and maps, ledgers of roads and
rivers, fingerprint files, resident cards, documents of
application, notification, license, authorization, statistical
documents, and public documents, which are all used in government
offices. Particularly, the write-once type optical recording media
of the present invention can be advantageously useful for storing
records of charts and official documents which should never be
falsified and deleted, and used as electronic libraries for art
galleries, libraries, museums, broadcasting stations, etc.
[0037] As a rather specific use, the optical recording media of the
present invention can be used to edit and proofread compact discs,
digital video discs, laser discs, MD (a mini disc as an information
recording system using photomagnetic disc), CDV (a laser disc using
compact disc), DAT (an information recording system using magnetic
tape), CD-ROM (a read-only memory using compact disc), DVD-ROM (a
read-only memory using digital video disc), DVD-RAM (a writable and
readable memory using digital video disc), digital photos, movies,
computer graphics, publishing products, broadcasting programs,
commercial messages, computer programs, video software, audio
software, game software, etc.; and used as external program
recording means for large computers and car navigation systems.
[0038] Hereinbefore, the use of the light absorbents of the present
invention in the field of optical recording media has been mainly
limited to high-density optical recording media which use a laser
beam with a wavelength of 450 nm or less as a writing light.
However, in the field of optical recording media, the light
absorbents of the present invention can be also advantageously used
as materials for changing or regulating the optical absorption rate
or the optical reflection rate in the existing optical recording
media such as CD-Rs, DVD-Rs, and other high-density optical
recording media by using in combination, for example, with one or
more other organic dye compounds which are sensitive to a laser
beam with a wavelength around 635-650 nm or 775-795 nm. When
applied to organic-ablation type optical recording media using a
laser beam with a wavelength of 450 nm or less as a writing light,
the styryl dyes of the present invention can be used not to
directly form pits on substrates but to indirectly form pits in
such a manner that the excitation energy of a laser beam with a
wavelength of 450 nm or less is allowed to transfer to the
aforesaid organic dye compounds via the styryl dyes by using the
styryl dyes along with one or more other organic dye compounds
which are sensitive to a laser beam with a longer wavelength, e.g.,
a laser beam with a wavelength around 635-650 nm or 775-795 nm,
resulting in a decomposition of the organic dye compounds. The
optical recording media as referred to in the present invention
mean optical recording media in general which use the
characteristics of the specific styryl dyes of the present
invention that have an absorption maxima at a wavelength of 400 nm
or less and substantially absorb visible light with a wavelength
around 400 nm in addition to organic thermal-deformed optical
recording media, thermal coloration method using the chemical
reaction of coloring agents and developers using the heat generated
when organic dye compounds absorb light, and the technique called
"moth-eye type technique" which uses the phenomenon that the above
heat smooths the pattern of periodical unevenness provided on the
surface of the substrates.
[0039] Since the styryl dyes of the present invention have
absorption maxima at a wavelength of 400 nm or less and
substantially absorb visible light with a wavelength around 400 nm,
the light absorbents of the present invention containing the styryl
dyes can be advantageously useful in the aforesaid optical
recording media and also used as materials for polymerizing
polymerizable compounds by exposure to visible light, sensitizing
solar batteries, light absorptive materials for lithography,
materials for laser active substances in dye lasers which oscillate
in the blue or violet region, and for dying clothes in combination
with one or more other organic dye compounds which substantially
absorb visible light. If necessary, in combination with one or more
other light absorbents capable of absorbing light in the
ultraviolet, visible and/or infrared regions, the light absorbents
can be used in clothes in general and others including
building/bedding/decorating products such as drapes, lace,
casements, prints, casement cloth, roll screens, shutters, shop
curtains, blankets, thick bedquilts including comforters,
peripheral materials for the thick bedquilt, cover for the thick
bedquilt, cotton for the thick bedquilts, bed sheets, cushions,
pillows, pillow covers, cushions, mats, carpets, sleeping bags,
tents, interior finish for cars, and window glasses including car
window glass; sanitary and health goods such as paper diapers,
diaper-covers, eyeglasses, monocles, and lorgnettes; internal base
sheets, linings, and materials for shoes; wrappers; materials for
umbrellas; parasols; stuffed toys; lighting devices; filters,
panels and screens for information displaying devices such as
televisions and personal computers which use cathode-ray tubes,
liquid crystal displays, electroluminescent displays, and plasma
displays; sunglasses; sunroofs; sun visors; pet bottles;
refrigerators; vinyl houses; lawns; optical fibers; prepaid cards;
and windows of ovens including electric ovens. When used as
wrapping materials, injection materials, and vessels for the above
products, the light absorbents of the present invention prevent
living bodies and products from problems and discomforts induced by
environmental lights such as natural- and artificial-lights or even
minimize the above them. Furthermore, they can advantageously
regulate the color, tint, and appearance and control the light
reflected by or passed through the products to a desirable color
balance.
[0040] The following examples describe the preferred embodiments of
the present invention:
EXAMPLE 1
Styryl Dye
[0041] Twenty milliliters (ml) of acetic anhydride and 0.6 ml of
triethylamine were placed in a reaction vessel, and mixed with 4 g
of 2,3,4-trimethylthiazolium=iodide and 2 g of 4-cyanobenzaldehyde.
The resulting mixture was reacted at 80.degree. C. for one hour
under stirring conditions, and then was cooled down. The crystals
formed were collected, washed with ethanol, dissolved in a solution
of methanol and chloroform under heating, and then filtered. The
obtained filtrate was distilled to remove chloroform and cooled
down to obtain 1.1 g of a yellow crystal of the styryl dye
represented by Chemical Formula 9. When measured in a conventional
manner, the melting point of the crystal was 261-263.degree. C.
[0042] The styryl dye of this Example with remarkable optical
properties has various uses in many fields including those of
optical recording media as a light absorbent.
EXAMPLE 2
Styryl Dye
[0043] Forty milliliters of ethanol and 2 ml of triethylamine were
placed in a reaction vessel, and mixed with 6 g of
1,2,3,3-tetramethyl-3H-indole- nium=tosylate and 3 g of
3-nitrobenzaldehyde. The resulting mixture was reacted at
80.degree. C. for one hour under stirring conditions, and then was
cooled down. The crystals formed were collected, dissolved in a
solution of methanol and chloroform under heating conditions, and
then filtered. The obtained filtrate was distilled to remove
chloroform and cooled to obtain 3.4 g of an orangish yellow crystal
of the styryl dye represented by Chemical Formula 40. When measured
in a conventional manner, the melting point of the crystal was
233.degree. C.
[0044] The styryl dye of this Example with remarkable optical
properties has various uses in many fields including those of
optical recording media as a light absorbent.
EXAMPLE 3
Styryl Dye
[0045] Twenty milliliters of ethanol and a very small amount of
piperidine were placed in a reaction vessel, and mixed with 5 g of
1,2-dimethylquinolium=iodide and 2.2 g of 2-formylpyridine. The
resulting mixture was reacted at 80.degree. C. for 20 min under
stirring conditions, and then was cooled down. The crystals formed
were collected and recrystallized in ethanol to obtain 1.3 g of an
orangish yellow crystal of the styryl dye represented by Chemical
Formula 34. When measured in a conventional manner, the melting
point of the crystal was 199-200.degree. C.
[0046] The styryl dye of this Example with remarkable optical
properties has various uses in many fields including those of
optical recording media as a light absorbent.
EXAMPLE 4
Styryl Dye
[0047] Ten milliliters of dimethylformamide and 1 ml of iodomethyl
were placed in a reaction vessel, and mixed with 1 g of the styryl
dye obtained in Example 3. The resulting mixture was reacted at
100.degree. C. for one hour under stirring conditions, and then was
cooled. The crystals formed were collected and recrystallized in
ethanol to obtain 0.8 g of an orangish red crystal of the styryl
dye represented by Chemical Formula 36. When measured in a
conventional manner, the melting point of the crystal was
222-223.degree. C.
EXAMPLE 5
Styryl Dye
[0048] Twelve milliliters of ethanol and 0.24 ml of piperidine were
placed in a reaction vessel, and mixed with 3 g of
1,3-diethyl-2-methyl-5,6-dich- lorobenzimidazolium tosylate and 1.1
g of 4-nitrobenzaldehyde. The resulting mixture was reacted at 80
CC for one hour under stirring conditions, and then was cooled. The
crystals formed were collected, dissolved in a solution of methanol
and water under heating conditions, and then filtered. The obtained
filtrate was distilled to concentrate the solution to half volume
and cooled to obtain 1.7 g of a yellow crystal of the styryl dye
represented by Chemical Formula 23. When measured in a conventional
manner, the melting point of the crystal was 287-290.degree. C.
[0049] The styryl dye of this Example with remarkable optical
properties has various uses in many fields including those of
optical recording media as a light absorbent.
[0050] Although the production conditions and yields are varied in
some degrees depending on the structures of the styryl dyes of the
present invention, all the styryl dyes of the present invention
including the compounds represented by Chemical Formulae 1 to 60
can be produced in a satisfactory yield by the methods in Examples
1 to 5 or in accordance therewith.
EXAMPLE 6
Optical Property of Styryl Dye
EXAMPLE 6-1
Light Absorption Characteristics of Styryl Dye
[0051] The styryl dyes of the present invention represented by
Chemical Formulae 8, 9, 19, 23, 34, 36, 38, 40, and 44 were
measured for visible absorption spectra when dissolved in methanol
and formed into thin layers over glasses. In parallel, the
conventional related compound represented by Chemical Formula 61
was measured for visible absorption spectrum when formed in a
solution and in a thin layer similarly as above. The results were
tabulated in Table 1 and FIGS. 1 to 3 show visible absorption
spectra of the styryl dye of the present invention represented by
Chemical Formulae 8, 36, and 61 when formed in a solution and in a
thin layer, respectively.
1TABLE 1 Chemical Formula 61: 14 Maximum absorption(nm) Styryl dye
Solution Thin layer Remarks Chemical Formula 8 354 354 Present
invention Chemical Formula 9 350 368 Present invention Chemical
Formula 19 359 366 Present invention Chemical Formula 23 334 346
Present invention Chemical Formula 34 364 376 Present invention
Chemical Formula 36 346 357 Present invention Chemical Formula 38
375 430 Present invention Chemical Formula 40 371 383 Present
invention Chemical Formula 44 372 405 Present invention Chemical
Formula 61 550 542, 574 Control
[0052] As shown in the visible absorption spectra of FIG. 3, the
conventional related compound represented by Chemical Formula 61
has absorption maxima at a wavelength longer than 400 nm when
formed in a solution and in a thin layer. As shown in the results
of FIGS. 1 and 2 and Table 1, most of the styryl dyes of the
present invention have absorption maxima at a wavelength of 400 nm
or less when formed in a solution and in a thin layer, and the
absorption ends to the side of longer wavelength area extended to
around 450 nm when formed in a thin layer. These results showed
that the styryl dyes of the present invention were different from
conventional related compounds and that they were sensitive to a
laser beam with a wavelength of 450 nm or less, particularly, a
laser beam with a wavelength around 350-450 nm, and substantially
absorb such a laser beam.
EXAMPLE 6-2
Light-Resistance Improvement of Styryl Dye
[0053] Fifteen milligrams (mg) of either of the styryl dyes of the
present invention represented by Chemical Formulae 9, 19, 23, 34,
36, 38, 40, and 44 was added to three milliliters (ml) of TFP. To
the mixture was added 2 mg of nitrosodiphenylamine represented by
Chemical Formula 62 which is used in conventional optical recording
media as a light-resistant improver, followed by 5 min ultrasonic
energization at ambient temperature to dissolve the contents in the
solvent. Thereafter, in a conventional manner, a prescribed amount
of the resulting solution was dropped on either surface of a
polished glass substrate, 5 cm.times.5 cm, while the glass
substrate was rotated at a rotation rate of 1,200 rpm for one
minute to uniformly coat the solution thereupon, and sequentially
blown with hot air and cold air to form a thin layer on the glass
substrate.
[0054] Chemical Formula 62: 15
[0055] The resulting glass substrate coated with either of the
styryl dyes was measured for transmittance (T.sub.0) at a
wavelength of 400 nm, and then set to the position seven cm away
from a 500 W xenon lamp and exposed to the light of the lamp for 25
min while sending cold air to the substrate. Immediately after
that, the resulting substrate was remeasured for transmittance (T)
at a wavelength of 400 nm, and the transmittance of T and T.sub.0
for each styryl dye was substituted for the Equation 1 to calculate
the residual percentage (%) of the styryl dye. In parallel, control
systems with no light-resistant improver for each styryl dye were
provided. 1 Equation1: Residual percentage of styryl dye ( % ) =
100 - T 100 - T 0 .times. 100
2 TABLE 2 Residual percentage of styryl dye (%) With
light-resistant With no light-resistant Styryl dye improver
improver Chemical Formula 9 91.1 44.8 Chemical Formula 19 76.0 45.9
Chemical Formula 23 96.6 45.6 Chemical Formula 34 90.0 86.1
Chemical Formula 36 99.9 99.0 Chemical Formula 38 93.4 30.0
Chemical Formula 40 97.6 96.0 Chemical Formula 44 87.1 61.0
[0056] As shown in the results of Table 2, in the system with no
light-resistant improvers, maximum 70% of the styryl dyes had
changed with only 25 min exposure of light to be incapable of
exerting their inherent light absorbent properties. When used in
combination with the nitroso compound represented by Chemical
Formula 62, over 76% of the styryl dyes still remained intact
without being changed by the exposure. These results indicate that
light-resistant improvers are useful to suppress undesirable
changes of the styryl dyes of the present invention by exposure to
natural and artificial light.
EXAMPLE 7
Optical Recording Medium
[0057] Either of the styryl dyes of the present invention
represented by Chemical Formulae 8, 9, 19, 23, 34, 36, 38, 40, and
44 as a light absorbent was admixed with TFP to give a
concentration of 3.0% (w/w), and the mixture was further added the
nitroso compound represented by Chemical Formula 62 to give a
concentration of 0.35% (w/w), heated for a while, followed by
ultrasonically dissolving the contents. The resulting solution was
in a conventional manner filtered through a membrane, coated in a
rotatory manner over one side of an acrylic disc substrate, 12 cm
in diameter, to which had been transferred concaves for expressing
synchronizing signals and addresses of tracks and sectors by an
injection molding, to give a thickness of 200 nm. Thereafter, the
substrate was spattered with silver to form a reflection layer, 100
nm in thickness, to be closely attached on the surface of the
recording layer by vaporization, and the reflection layer was
homogeneously coated in a rotatory manner with "DAICURE CLEAR
SD1700", a known ultraviolet ray hardening resin commercialized by
Dainippon Ink and Chemicals, Inc., Tokyo, Japan, and irradiated to
form a protection layer to be closely attached on the surface of
the reflection layer, followed by obtaining nine types of optical
recording media.
[0058] All of the optical recording media of this Example can be
used for writing large amounts of information in the form of
documents, images, and sound at a relatively-high density by using
a laser element with an oscillation wavelength of 450 nm or
less.
[0059] As described above, the present invention was made based on
the creation of novel styryl dyes and the findings of their
industrially usable characteristics. Since the styryl dyes of the
present invention have absorption maxima at a wavelength of 400 nm
or less and substantially absorb visible light with a wavelength
around 400 nm, they have diversified uses in the fields of optical
recording media, photochemical polymerization, dye laser, solar
batteries, lithography, dyeing, etc., which need organic compounds
with such properties. Particularly, among the styryl dyes, they,
being sensitive to a laser beam with a wavelength of 450 nm or
less, are advantageously useful as a material for a recording layer
of high-density optical recording media such as DVD-Rs.
[0060] As compared with the conventional DVD-Rs which use
polymethine dyes as a light absorbent and write information by
using a laser beam with a wavelength of 635 nm or 650 nm, the
optical recording media of the present invention, which include the
styryl dyes of the present invention and use a laser beam with a
wavelength of 450 nm or less as a writing light, can form minute
pits at a relatively narrower track pitch and a relatively high
density. Accordingly, when used the optical recording media of the
present invention, they can record a vast amount of information of
characters, images, and sound at a relatively-high density,
resulting in greatly lowering the cost of recording information per
bit and recording animations for a long time, which need much
recording volume, of course standing picture as a merit.
[0061] The useful styryl dyes can be easily prepared in a desirable
amount by the process of the present invention which comprises a
step of reacting a quaternary ammonium salt of nitrogen
heterocyclic compound having an active methyl- or active
methylene-group with an aldehyde compound.
[0062] The present invention having such outstanding effects and
functions is a significant invention that will greatly contribute
to this art.
* * * * *