Stock material or miscellaneous articles – Circular sheet or circular blank – Recording medium or carrier
Reexamination Certificate
1999-12-20
2001-04-10
Barts, Samuel (Department: 1621)
Stock material or miscellaneous articles
Circular sheet or circular blank
Recording medium or carrier
C430S270190, C558S046000, C558S058000, C558S053000, C562S083000, C562S084000, C562S059000, C562S046000, C562S047000
Reexamination Certificate
active
06214435
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to aminium compounds and optical information recording media containing the same. More specifically, it relates to aminium compounds having divalent organic anions as counterions as well as optical information recording media containing the aminium compounds and, for example, cyanine dyes, having improved light fastness and useful for recording and reproduction of information or the formation of images by irradiating laser light.
PRIOR ARTS
Various dyes including phthalocyanine derivatives and cyanine dyes of indolenine type have been proposed as organic dyes useful for recording media, especially write-once CD-R and DVD-R. Phthalocyanine dyes are excellent in light fastness and storage stability, but almost insoluble in the solvents which do not etch conventionally used materials such as polycarbonate. Thus, a solution to be applied onto a substrate having the desired concentration of the dye cannot be obtained. On the other hand, cyanine dyes are soluble in solvents to some extent, but few solvents are suitable for practical use. Further, cyanine dyes have poor light fastness and storage stability and thus, in order to prevent the deterioration of cyanine dyes by light, a singlet oxygen quencher is usually added. The addition of organometallic complexes such as nickel complexes and salts of aminium or diimonium as described in JP-94026028B and JP-1099885A as the singlet oxygen quencher is known to improve light fastness of cyanine dyes and polymethine dyes which are easily deteriorated by oxygen due to their autosensitization. However, the nickel complexes have generally poor solubilities into organic solvents. And, the presence of a metal causes problems in terms of handling or environment. Although the salts of aminium and diimonium with various counterions such as perchlorate and antimony hexafluoride are known, perchlorate salts cause problem in terms of handling since they are hazardous chemicals. Antimony hexafluoride salts have a poor solubility for solvents, especially when combined with methine dyes and thus their coating solutions can be hardly recycled. The presence of metal causes environmental pollution.
An object of the present invention is to provide a novel aminium compound excellent in solubility for solvents and safe in terms of handling and environment as well as an optical information recording medium comprising the same.
SUMMARY OF THE INVENTION
The present inventors have made earnest researches into solution of the above-mentioned problem. As a result, they have found that an aminium compound of the following formula
(1) has a good solubility for solvents, especially when combined with a methine dye, that an optical information recording material having excellent stability and light fastness can be obtained by including at least one of the aminium compounds into an optical information recording medium, and that the solution of the aminium compound can be recycled.
That is, the present invention relates to:
(1) an aminium compound of the following formula (1):
wherein R
1
represents substituted or unsubstituted alkyl and A
2−
represents a divalent organic anion;
(2) an aminium compound as defined in (1) wherein R
1
is C
2
-C
4
alkyl;
(3) an aminium compound as defined in (1) wherein R
1
is n-butyl;
(4) an aminium compound as defined in any one of (1) to (3) wherein A
2−
is an ion of an aromatic disulfonic acid having two sulfonic acid groups within its molecule;
(5) an aminium compound as defined in (4) wherein the organic anion is a naphthalenedisulfonic acid ion;
(6) an aminium compound as defined in (5) wherein the naphthalenedisulfonic acid ion is an ion of a compound represented by the following formula (2)
wherein R
2
represents independently hydrogen, halogen, lower alkyl, hydroxyl, alkylamino, amino, acetyl, —NHCOR
3
, —NHSO
2
R
3
or —OSO
2
R
3
in which R
3
is substituted or unsubstituted aryl or substituted or unsubstituted alkyl;
(7) an aminium compound as defined in (6) wherein R
2
is independently hydrogen, hydroxyl, —NHCOR
3
, —NHSO
2
R
3
or —OSO
2
R
3
;
(8) an aminium compound as defined in (6) wherein R
2
is hydrogen or hydroxyl;
(9) an optical information recording medium comprising at least one aminium compound as defined in any one of (1) to (8) in a recording layer;
(10) an optical information recording medium as defined in (9) which further comprises a methine compound in the recording layer;
(11) an optical information recording medium as defined in
(10) wherein the methine compound is a cyanine dye; and
(12) an optical information recording medium as defined in
(11) wherein the aminium compound is used in an amount of 10 to 150 parts by weight per 100 parts by weight of the cyanine dye.
Best Mode for Carrying Out the Invention
An unsubstituted alkyl group represented by R
1
in the general formula (1) is specifically a C1-C12 alkyl group such as methyl, ethyl, propyl, isopropyl, 2-methylpropyl, n-butyl, t-butyl, pentyl, hexyl or dodecyl, preferably C2-C4 alkyl, more preferably n-butyl. Substituents in substituted alkyl groups include halogen, alkyloxy, alkyloxyalkyloxy, aryl and hydroxyl. Specifically, the substituted alkyl group is a C1-C9 substituted alkyl group such as hydroxymethyl, methoxyethyl, ethoxyethyl, butoxyethyl, phenylethyl, phenylpropyl, benzyl, tetrafluoropropyl, trifluoroethyl, methoxyethyloxyethyl, methoxypropyl, hydroxypropyl, furfuryl or acetyloxyethyl, preferably C2-C6 substituted alkyl.
A divalent organic anion represented by A
2−
is preferably an ion of an aromatic disulfonic acid having two sulfonic acid groups within its molecule, example of which includes an ion of naphthalenedisulfonic acid derivatives such as naphthalene-1,5-disulfonic acid, R acid, G acid, H acid, benzoyl H acid (a benzoyl group being attached to an amino group of H acid), p-chlorobenzoyl H acid, p-toluenesulfonyl H acid, chloro H acid (an amino group of H acid being replaced with a chlorine atom), chloroacetyl H acid, metanyl &ggr; acid, 6-sulfonaphthyl-&ggr; acid, C acid, &egr; acid, p-toluenesulfonyl R acid, naphthalene-1,6-disulfonic acid or 1-naphthol-4,8-disulfonic acid; carbonyl J acid, 4,4′-diaminostilbene-2,2′-disulfonic acid, di-J acid, naphthalic acid, naphthalene-2,3-dicarboxylic acid, diphenic acid, stilbene-4,4′-dicarboxylic acid, 6-sulfo-2-oxy-3-naphthoic acid, anthraquinone-1,8-disulfonic acid, 1,6-diaminoanthraquinone-2,7-disulfonic acid, 2-(4-sulfophenyl)-6-aminobenzotriazole-5-sulfonic acid, 6-(3-methyl-5-pyrazolonyl)-naphthalene-1,3-disulfonic acid, 1-naphthol-6-(4-amino-3-sulfo)anilino-3-sulfonic acid or the like. More preferable divalent organic anion is an ion of naphthalenedisulfonic acid. Even more preferable divalent organic anion is an ion of a compound represented by the aforementioned formula (2).
In the aforementioned formula (2), R
2
is independently hydrogen, halogen, lower alkyl, hydroxyl, alkylamino, amino, acetyl, —NHCOR
3
, —NHSO
2
R
3
or —OSO
2
R
3
in which R
3
is substituted or unsubstituted aryl or substituted or unsubstituted alkyl. The halogen atoms include fluorine, chlorine, bromine and iodine. Examples of the lower alkyl groups include C1-C4 alkyl as illustrated with respect to the unsubstituted alkyl group represented by R
1
. Example of the alkylamino group includes C1-C4 alkylamino. Examples of the substituted or unsubstituted aryl groups represented by R
3
include phenyl, toluyl, 4-chlorophenyl, naphthyl, nitrophenyl and butylphenyl. Examples of the substituted or unsubstituted alkyl groups include a C1-C8 alkyl group such as methyl, ethyl, propyl, butyl, pentyl, octyl, chloromethyl, chloroethyl, isopropyl, isobutyl, methoxyethyl or butoxyethyl. Preferably, the ion of the compound represented by the formula (2) is an ion of naphthalenedisulfonic acid having no substituent other than the sulfonyl groups or a hydroxyl group in addition to the sulfonyl groups such as naphthalene-1,5-disulfonic acid, naphthalene-1,6-disulfonic acid, or 1-naphthol-4,8-disulfonic acid.
Non-limiting examp
Kiyoyanagi Tadayuki
Onishi Masao
Barts Samuel
Nields & Lemack
Nippon Kayaku Kabushiki Kaisha
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